Pac-Nor Production Manager Casey Dichter says the Sunnen hone produces a consistency in bore diameter that is much superior to hand-lapping. The Sunnen machine has all but eliminated the standard pre-rifling lap. “You can really tell the difference between a bore that was honed before rifling and one that was [only] lapped”, notes Dichter.
Gun Barrel Honing System Hits Target for Pac-Nor Barreling
Manufacturing precision rifle barrels has always been something of an art that involves hand lapping of the bore surface twice, before and after the rifling profile is cut or swaged in by a rifling button. In fact, a bright, hand-lapped bore is considered one of the hallmarks of a precision rifle barrel, despite the inherent variations from manual work done by people who get bored and tired from the monotonous chore. Pac-Nor Barreling, Inc. set its sights on this issue more than a year ago and hit the X-ring with the newly developed Sunnen HTE honing machine. The machine has all but eliminated Pac-Nor’s pre-rifling lap, which is the more difficult and time-consuming of the two laps. Pac-Nor is also producing as many custom barrels as ever, but with a slightly smaller staff. “Our objectives with the hone were to build a better product with less labor, and the honing machine has exceeded my expectations,” said Pac-Nor Production Manager Casey Dichter. “The hone produces a consistency in bore diameter that is head and shoulders above lapping, within two to three millionths of an inch end-to-end when it’s really dialed in,” he said. “This, in turn, improves the consistency of the rifling process by minimizing variation in the depth of the grooves. We still finish lap after rifling, but it’s easier because we just polish off the fine crosshatch finish that may be left after honing and rifling.”
The Sunnen hone secures the barrel blank in a 3-jaw chuck, with honing oil pumped into one end while the tool works from the opposite end. Sunnen’s specialized Long Bore Tool uses metal-bond diamond or CBN superabrasives to quickly remove reamer marks, waviness, tight spots and other imperfections left by upstream processes.
Honing is an ideal replacement for hand lapping barrel blanks before rifling. It quickly removes reamer scratches and surface waviness without labor-intensive hand lapping. A typical 600-grit abrasive can produce a 6-10 microinch Ra (0.15 to 0.25 µm) finish in a reamed barrel blank. By producing a consistent bore diameter (±0.0001″ or less), parallelism, roundness and surface finish end to end, honing yields more consistent performance from rifling buttons and cutters, resulting in a constant groove depth. The ideal bore geometry reduces distortion of the bullet shape.
Pac-Nor’s barrel-making process starts with cutting and facing premium bar stock, followed by gun drilling, done by four Pratt & Whitney twin-spindle machines and an Eldorado CNC twin spindle. After reaming, the barrels are gauged for size. Depending on the condition of the reamer, 0.0004″ to 0.0007″ of material is left in the bore. This must be manually lapped out or honed out to final size for rifling. “Everyone who works here has done hand-lapping,” said Dichter. “It’s an unpleasant job, particularly if the reamer is starting to get dull. Lapping may take 10 to 45 minutes, depending on the caliber of the barrel. We tried to shorten this, but when chatter marks get ‘ironed’ into the surface by the rifling button, the finish lap is even longer and more difficult, so there is no advantage. With lapping, too, there is potential for variation, simply because it’s a manual process. Lapping can also be a production limiter and in our region we have a very small labor force to draw on when we want to grow.”
Pac-Nor cuts and faces premium bar stock, then gun drills on one of five twin-spindle machines, followed by reaming of the blanks. This rack of barrel blanks awaits completion.
The company had explored honing in the nineties, but re-visited the idea when Sunnen introduced its HTE honing machine in 2014. The HTE is a horizontal machine that can hone small-bore rifle barrels, with a diameter range of 0.150″ to 0.790” (4-20 mm), and lengths up to 60″ (1,524 mm). Designed specifically for long small bores, the machine features an extremely sensitive drive and tool feed system that provide maximum protection against tool overload/breakage. Tool specific force limits and run settings are stored in the touch-screen PC control, allowing the system to sense tight sections in the bore and correct them automatically.
Sunnen also developed a new Long-Bore Tool (LBT) designed to take on industry’s most difficult honing challenges in small bores of .17 caliber rifle barrels. The tool quickly remove reamer marks, waviness, tight spots and other imperfections left by upstream processes. The LBT utilizes metal-bond diamond or CBN super-abrasives for high productivity, long life and fast cycle times. Precision-machined of through-hardened tool steel, the LBT can produce bore accuracies of 0.000027″ (0.0006 mm) for diameter, roundness, and taper – from first part to last.
“We are currently honing about 80 percent of what we make and will do more as we acquire the tools in different calibers,” said Dichter. “Although there is a trade-off in cycle time and abrasive cost for additional honing, we are still able to run our reamers two to three times longer than when we lapped alone. With a hand lap, the time and effort increase when the reamer is getting dull.”
After honing, each barrel is inspected again before rifling with a pull-button. Pac-Nor makes its own Accu-Twist carbide rifling buttons and can provide different rifling styles, including polygonal, per the customer’s choice. A button is attached to a rod and the rod is pulled through the barrel. The company’s hydraulic rifling machine utilizes a CNC-machined twist bar with a helix angle that matches the twist rate requested by the customer. The final twist rate is confirmed afterward using a Barrel-Scan electro-optical twist measurement system.
The barrel is then stress-relieved in a tempering furnace, followed by contouring of the outer shape and final, finish lapping of the bore. “During the finish lap, you can really tell the difference between a bore that was honed before rifling and one that was lapped,” said Dichter. “You can easily sense any remaining tight or loose spots in the bore. The diameter uniformity and roundness of the honed bore are superb. The lap also feels different in a honed bore.”
In competitive shooting where winning scores may be separated by thousandths of an inch, a few millionths of an inch improvement in the uniformity of a Pac-Nor barrel may make a big difference for a skilled shooter. For more information, visit www.sunnen.com or contact:
Sunnen Products Company
Mr. Bob Davis
Global Communications Mgr.
Sunnen Products Company
Tel: 314-781-2100
bdavis [at] sunnen.com
About Pac-Nor Barreling Inc.
Pac-Nor Barreling is a true custom manufacturer catering to bolt-action rifle shooters. The company’s principle markets are law enforcement, military, competitive shooters and hunters. Started in 1984 by avid shooter and company President Chris Dichter, Pac-Nor is now in its second generation under his son, Casey. In addition to barrel manufacturing, the shop will install the barrel on a customer’s action, or add features such as muzzle brakes or fluting on bolts and barrels etc.
The shop runs two shifts per day. A day shift of ten people produces 30-40 custom barrels of different calibers in 416R stainless or chrome-moly steel. A night shift of three people produces one type of barrel — about 50 AR-15 barrels per day for a rifle OEM.
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The last half-inch or so of your barrel is absolutely critical. Any damage (or abnormal wear) near the crown will cause a significant drop-off in accuracy. Here are ways you can check the end of your barrel, using a common Q-Tip.
Use Q-Tip for Barrel Inspection To find out if you have a burr or damage to your crown, you can use an ordinary Q-tip cotton swab. Check the edges of the crown by pulling the Q-tip gently out past the edge of the crown. If you have a burr, it will “grab” the cotton and leave strands behind.
Larry Willis has another way to use a Q-Tip: “Here’s a neat trick that will surprise you with how well it works.” Just insert a Q-Tip into your barrel (like the picture below), and it will reflect enough light so that you can get a real good look at the last half inch of rifling and the crown of your barrel. In most cases you’ll find that this works much better than a flashlight. Larry tells us: “I’ve used this method about a jillion times. Q-Tips are handy to keep in your cleaning supplies anyway. This is a good way to judge approximately how well you are cleaning your barrel when you’re at the range. It’s also the best way to examine your barrel when you’re in the field.”
With barrels, one wonders “Can a little more length provide a meaningful velocity gain?” To answer that question, Rifleshooter.com performed an interesting test, cutting a .308 Win barrel from 28″ all the way down to 16.5″. The cuts were made in one-inch intervals with a rotary saw. At each cut length, velocity was measured with a Magnetospeed chronograph. To make the test even more interesting, four different types of .308 Win factory ammunition were chronographed at each barrel length.
Test Barrel Lost 22.7 FPS Per Inch (.308 Win Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. With a barrel reduction from 28″ to 16.5″, the average speed loss of the four types of .308 ammo was 261 fps total. That works out to an average loss of 22.7 fps per inch. This chart shows velocity changes for all four ammo varieties:
Summary of Findings: The average velocity loss per inch, for all four ammo types combined, was 22.7 FPS. By ammo type, the average loss per inch was: 24.6 (Win 147 FMJ), 22.8 (IMI 150 FMJ), 20.9 (Fed GMM 168gr), and 22.5 (Win 180PP).
Interestingly, these numbers jive pretty well with estimates found in reloading manuals. The testers observed: “The Berger Reloading manual says for the 308 Winchester, ‘muzzle velocity will increase (or decrease) by approximately 20 fps per inch from a standard 24″ barrel’.”
How the Test Was Done
The testers described their procedure as follows: “Ballistic data was gathered using a Magnetospeed barrel mounted ballistic chronograph. At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. Average velocity and standard deviation were logged for each round. Since we would be gathering data on 52 different barrel length and ammunition combinations and would not be crowning the barrel after each cut, we decided to eliminate gathering data on group sizes. Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. The barrel was cut off using a cold saw. The test protocol was repeated for the next length. Temperature was 47° F.”
CLICK HERE to Read the Rifleshooter.com Test. This includes detailed charts with inch-by-inch velocity numbers, multiple line charts, and complete data sets for each type of ammo. Rifleshooter.com also offers ballistics graphs showing trajectories with different barrel lengths. All in all, this was a very thorough test by the folks at RifleShooter.com.
Much Different Results with 6mmBR and a Longer Barrel
The results from Rifleshooter.com’s .308 barrel cut-down test are quite different than the results we recorded some years ago with a barrel chambered for the 6mmBR cartridge. When we cut our 6mmBR barrel down from 33″ to 28″, we only lost about 8 FPS per inch. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was 5″ longer than Rifleshooter.com’s .308 Win start length. Velocity loss can be more extreme with shorter barrel lengths (and bigger cartridges). Powder burn rates can also make a difference.
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Are you trying to decide what components to use for your next F-Class build, or are you looking to upgrade your current rig? Wonder what the “big dogs” in the sport have selected as their hardware? Here’s what United States F-Open team members are using. The most popular chambering is the .284 Winchester, followed by the 7mm Walker (a 40° .284 Winchester Improved). Kelbly and BAT actions are the most popular, and nearly all team members are using cut-rifled barrels. A wide variety of stocks are used, with PR&T holding a slight edge over second-place McMillan.
Criterion Barrels Inc. (CBI) has a policy of rewarding excellence. As a way of supporting top shooters, Criterion will provide a new, free barrel to any shooter who sets or ties a national record when using a Criterion product. To explain, you get a new Criterion barrel for free if you set (or tie) a national shooting record using a Criterion barrel on your rifle.
Criterion Barrels hopes to increase awareness of its free barrel for record sectors program. Over the last few years a number of F-Class and vintage military competitors have benefited from this program, receiving a complimentary barrel of their choice after setting a new national record in their shooting discipline. Past record breaking shooters have included David Mark Honeycutt (with a 300-yard F-Class score of 600-50X), Samantha Huhtala (four records set in 600-yard F-TR competition), and Victor Betzold (M1 Carbine with a score of 375-6X).
Criterion may, in the future, create a rewards program for winners of national, regional, and local rifle matches. Potential earned rewards by match winners could include equipment sponsorships, barrel discounts, and free apparel items.
Set a Record with a Criterion Barrel? Then Give Criterion a Call…
If you or someone you know has set a pending national record with a Criterion barrel, have the shooter contact Criterion Barrels. Send email to contact[at]criterionbarrels.com or call (262) 628-8749.
Once the shooter’s information is verified and the record is confirmed by the governing body of their appropriate shooting discipline, the order will be processed and shipped to the new record-holder.
About Criterion Barrels, Inc.: Criterion Barrels, Inc. was founded in 1999 as a division of Krieger Barrels, Inc. in response to demands of rifle builders and firearms manufacturers for quality match grade barrels at a lower cost. Our company is now completely independent from Krieger Barrels, featuring a separate facility, personnel, and ownership.
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The Lyman Borecam is an electro-optical borescope with a digital display. You can record “stills” on a SD card. This is one of the hottest products on the market right now — so hot that it has been sold out for weeks. But Grafs.com just got a shipment of Borecams (item LY04055), and the price is more than competitive. Right now Grafs has the Borecam in stock for $259.99 with free shipping (after a single $7.95 handling fee). That price is $40.00 less than some other online vendors are charging.
This is a good product. Guys who purchased the Lyman Borecam are very happy. If you don’t have one yet, now may be the time to “pull the trigger”. After this article goes live, we expect Grafs.com to sell out quickly. Graf’s inventory may be gone by end-of-day today.
Our British friend Vince Bottomley did an extensive review, giving the Lyman Borecam high praise. Vince says serious shooters should definitely acquire one of these tools: “In my opinion, this product is one of the very best to come along in recent years and I predict that the demand for these [Lyman Borecams] will be very heavy. I would advise you to place an order as quickly as possible if you want one.” Vince adds: “If I were to replace my [Hawkeye optical borescope] today with another Hawkeye, it would cost me well over £700 [$1015 USD]. Stick on a video adapter and we are looking at four figures. That’s what makes the new Lyman digital borescope so attractive — at around [$260.00 USD] including a monitor — it’s an absolute steal!”
The system really works. Many of our Forum members have the system and they say it functions very well and is “very easy to set up and use”. Here’s what an Optics Planet Borecam buyer wrote: “I have used Hawkeye borescopes and know their quality. The Lyman worked as advertised and is a great tool for checking for leading, cleanliness of bore, and bore wear. The compact size, ability to take pictures, and store them are a big plus.”
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At the IWA Trade Show in Germany a few years ago, a correspondent for The Firearm Blog interviewed Woody Woodall, who runs Lothar Walther’s USA operation. While many shooters assume that Walther hammer-forges most of its barrels like some other European barrel-makers, in fact Lothar Walther USA uses the button rifling technique for most of its US-made barrels.
In the video below, created for The Firearm Blog, Woodall explains that button rifling involves some extra steps to ensure a good result: “The extra work that goes into it is that you’ve got to make rifling, stress relieve it, and have it come out the right size. And it takes a lot of skill to do that. Lothar Walther invented button rifling in 1925, if a better way of making rifling came out, we’d be glad to go to it.”
Woodall explains that hammer forging is a good method for mass production, but it is costly to set up: “Hammer forging is relatively new, it came out in 1934, but did not come into prominence until the 1950s…. But the cost of [hammer forging] in the world today is getting above what the market will bear for barrels. [Hammer forging] is more complicated. As the hammers hit the barrel the barrel gets longer, but the hammers have to hit uniformly so the barrel [stays] straight. There’s a higher failure rate in that. There’s also some surface delamination that can occur, and some other issues. So if you’re hammer forging, you really have to pay attention to the details. So, it’s like button rifling, only ten times more complicated. It’s for super-high-volume production… The large companies tend to use the hammer forging, intermediate size companies tend to use the buttoning, and craft companies tend to use the cut rifling. All three [methods] can make an equally accurate barrel.”
This image shows a barrel in the process of hammer forging. Watch this operation starting at 1:15 in the video linked below.
You have probably heard the term “hammer-forged barrel”. But do you know how the cold hammer-forging process works? In this interesting video from Ruger, you can see the full barrel making process, including cold hammer-forging on a massive machine. Watch long rods of steel barrel material get cut to length, then drilled. After that Ruger uses CNC machines to contour the barrels before hammer forging.
Anyone with an interest in barrel-making should watch this video:
As the barrel is cold hammer-forged, a giant machine literally pounds the barrel from all sides around an internal carbide mandrel, which forms the rifling inside the bore. The actual hammer-forging is illustrated starting at 1:15 in this video. Through the process of cold-working the barrel around the mandrel, the barrel ends up with a longer length, a smaller outside diameter, and a higher hardness.
Before hammer forging, the barrels are deep-hole drilled, four at a time, with a bit that is slightly larger diameter than the caliber planned for the barrel.
Following the drilling, the barrel rod is placed in CNC machines to be turned down to the correct outside shape and size and both ends are trimmed.
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Editor: This article appears on the Criterion Barrels website. It provides good, conservative advice about barrel cleaning. Understand that cleaning methods may need to be adapted to fit the amount and type of fouling (and the particular barrel). In general, we do try to minimize brushing, and we follow the procedures Criterion recommends respecting the crown/muzzle. We have also had very good success using wet patches followed by Wipe-Out bore foam. Along with the practices outlined by Criterion below, you may want to try Wipe-Out foam. Just be sure to use a fitted cleaning rod bore guide, to keep foam out of the action recesses and trigger assembly.
What is the Best Way to Clean a Rifle Barrel?
We are asked this question quite frequently alongside requests for recommended break-in procedures. Improper barrel cleaning methods can damage or destroy a barrel, leading to diminished accuracy or even cause a catastrophic failure. When it comes to barrel maintenance, there are a number of useful techniques that we have not listed. Some techniques may work better with different barrel types. This series of recommendations is designed to incorporate a number of methods that the Criterion Barrels staff has used successfully both in the shop and on their personal rifles. Please feel free to to list your own recommendations in the below comments section.
We recommend the use of the following components during rifle cleaning:
• Cloth patches (sized for the appropriate caliber)
• Brass jag sized properly for your bore
• One-piece coated cleaning rod
• General bore cleaner/solvent (Example: Hoppes #9)
• Copper solvent of your choosing (Example: Sweets/KG 12)
• Fitted cleaning rod bore guide
• Plastic AP brush or toothbrush
• Q-Tips
• Plastic dental picks
• CLP or rust preventative type cleaner
There are a number of schools of thought relating to the frequency in which a barrel should be cleaned. At minimum we recommend cleaning a barrel after each shooting session to remove condensation, copper, and carbon build-up. Condensation is the greatest immediate threat, as it can cause the barrel to rust while the rifle sits in storage. Copper and carbon build-up may negatively impact future barrel performance, increasing the possibility of a failure in feed or function. Fouling should be removed whenever possible.
The below tips will help limit the wear of different parts of your barrel during routine maintenance, helping extend the life of the barrel and improving its performance.
The Crown
The crown is the portion of the barrel where the bullet loses contact with the lands and grooves and proceeds to exit the firearm. The area most critical to accuracy potential is the angle where the bullet last touches the bore of the barrel.
Avoid damage to this area by using a plastic toothbrush and CLP type cleaner to scrub the crown from the exterior of the barrel. Even the most minimal variation in wear to the crown will negatively impact barrel performance, so be careful to avoid nicking or wearing away this part of the barrel.
Reducing Cleaning Rod Wear to the Crown
When running a patch through the barrel, place the muzzle about a ¼” from a hard surface that runs flat at a perpendicular angle to the cleaning rod’s direction of travel, like a wall or the edge of a work bench (pictured). When the jag impacts the hard surface, retract the cleaning rod and remove the patch.
By withdrawing the jag prior to its exit from the barrel, you are limiting the possibility of the brass dragging upon the crown if the rod is at all bent or misaligned. The soft cloth patch will continue to serve as the point of contact between the jag and the barrel, minimizing potential wear.
If possible, insert the rod through the chamber, pushing it forward toward the muzzle. Some rifles, such as the M1 Garand or M14, will require you to insert the cleaning rod through the muzzle. In these situations the use of a cleaning rod guide is recommended to limit the friction placed upon the crown.
Avoid using cleaning rod segments for scraping carbon from the recessed muzzle of an AR-15 barrel. We used this trick in the Marine Corps to impress the armorers and NCO’s with the cleanliness of our muzzles, but it likely played a significant role in reducing the service life of the rifle barrel in question.
Use a Q-Tip soaked in solvent to remove any copper or carbon residue from the recessed muzzle of an AR-15 barrel. A little bit of remaining carbon on the face of the muzzle will not negatively affect bullet travel so long as the crown edge remains consistent around the circumference of the bore.
The Lands and Grooves
This portion of the barrel may experience reduced efficiency due to copper fouling and cleaning rod damage. If copper fouling takes place during the initial break-in of the rifle, make sure to check our barrel break-in article.
For regular maintenance we suggest using a single piece coated cleaning rod rather than the traditional segmented rod or bore snake. While segmented rods and bore snakes may be convenient for field use, the corners between the segments may bow out and catch on the lands, scraping along the length of the rifling. Residual grit and particles from expended cartridges may also get caught between segments, resulting in an abrasive surface working its way down the length of the barrel. Most bore snakes will remove significant amounts of carbon fouling, but may fall short in the removal residual carbon buildup and copper fouling during deep cleaning. Good rods can be sourced from multiple manufacturers, but we have found good results using both Pro-Shot and Dewey brand products.
General cleaning requires the use of patches rather than nylon or brass bore brushes. Brass brushes may be required when aggressive cleaning is required, but can lead to unnecessary wear on the barrel if used frequently. This is not due to the nature of the soft brushes themselves, but from the abrasive particles of grit that become embedded in the material that is being run repeatedly through the bore. We recommend the use of bore guides when cleaning from both the muzzle and breech. These bore guides will help serve to protect the crown and throat from cleaning rod damage.
If significant resistance develops while running the cleaning rod through the bore, no attempt should be made to force it in further. Back the rod out and inspect the barrel to determine the cause of the resistance. The jag may be pushing between a bore obstruction and the rifling, digging a divot into the barrel before pushing the obstruction back through the muzzle. One way to minimize the risk of a stuck rod is by utilizing a slightly smaller patch during the initial push.
The process of cleaning the length of the rifling is relatively straightforward:
1. Check to make sure the rifle is safely unloaded.
2. Carry out any necessary disassembly procedures prior to cleaning.
3. Remove bolt (if possible) and insert fitted cleaning rod bore guide in action.
4. Soak a patch in bore solvent (similar to Hoppes #9).
5. Center and affix the patch on the brass jag, inserting it into the chamber end of the barrel. A misaligned patch may cause the jag to damage the lands of the rifling, so make sure the patch is centered on the jag.
6. Run the patch the full length of the barrel, retracting it upon reaching the end of the muzzle.
7. Let the solvent sit for a minute.
8. Continue to run patches through the bore until carbon residue is minimized.
9. Run a dry patch through the bore to ensure carbon residue has been removed.
10. Soak a patch in copper solvent (Sweet’s or KG-12).
11. Run the patch through the bore, leaving it to sit for 3-5 minutes (do not let solvent sit for more than 15 minutes.*)
12. Repeat this process until no blue residue remains on the patches.
13. Run a patch of Hoppes #9 and a dry patch through the bore to neutralize the copper solvent.
14. Inspect the barrel prior to reassembling the rifle, verifying that no bore obstructions remain.
*Please note that some ammonia-based copper solvents may prove to be corrosive if left sitting in the barrel for an extended period of time. It is essential that these solvents be removed within 15 minutes to avoid ruining the bore.
The Chamber
Proper cleaning of the chamber is a critical component of a general cleaning procedure. Carbon rings can build up near the neck and throat of the chamber wall, leading to feeding malfunctions and pressure spikes inside the chamber.
The chamber can be the trickiest part of the barrel to effectively clean, due to its fluctuation in size and the awkward ergonomics often required to remove carbon residue. Numerous chamber specific devices have been created to address this problem, and while some should be avoided (steel chamber brushes), others can be used to great effect (cleaning stars and plastic dental picks). The simplest approach to cleaning a chamber is to apply solvent to a couple patches, and use the cleaning rod to spin the wadded up patches inside the confines of the chamber. This should aid in removing any excess carbon. A Q-Tip can be used to reach portions of the chamber unreached by patches.
The Barrel Exterior
While the condition of the crown, rifling, and chamber are essential to firearm performance, the finish of the exterior should also be cleaned after handling. Condensation, humidity, direct water contact, and salt residue from skin contact can cause rust or corrosion. An application of anti-corrosion products is recommended when placing a firearm into deep storage for an extended period of time. [Editor: AccurateShooter.com recommends Corrosion-X or Eezox, but other products work well too.]
Finding Cleaning Components
While most cleaning components can be found at your local gun shop, some specialty items may need to be sourced through online retailers such as Brownell’s. Criterion utilizes both Dewey and Pro-Shot brand cleaning components during our day-to-day operations.
Do you have any rifle cleaning tips or tricks not mentioned in the above article? We’d love to hear about them. You can post your comments below.
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Lyman’s digital BoreCam is one of the hottest rifle/gunsmithing accessories on the market right now. The product sells out quickly whenever a vendor gets a few in stock. Make no mistake, this is a good product that works well, and, at around $300.00, is it affordable for most shooters. The BoreCam provides vital information about your bore and chamber, and has the ability to save images to an SD card.
Our British friend Vince Bottomley recently obtained a Lyman BoreCam and put it through its paces. Vince came away very impressed. He says it is an easy-to-use and very capable bore inspection tool at a fraction of the cost of a high-end optical borescope (such as the Hawkeye). Vince says serious shooters should definitely acquire one of these tools: “In my opinion, this product is one of the very best to come along in recent years and I predict that the demand for these [Lyman BoreCams] will be very heavy. I would advise you to place an order as quickly as possible if you want one.”
Here are highlights from Vince’s review of the Lyman BoreCam: “If I were to replace my [Hawkeye optical borescope] today with another Hawkeye, it would cost me well over £700 – stick on a video adapter and we are looking at four figures. That’s what makes the new Lyman digital borescope so attractive – at around £250 including a monitor – it’s an absolute steal!
But £250 – with a video attachment and photo-capture facility – can this really be a useable borescope? Trust me it is! But what use is a borescope. Why do you need one? Well, whatever you shoot, the condition of your rifle’s bore is critical. And I’m not just talking about a bore that’s ‘shot-out’ – maybe you just aren’t cleaning it thoroughly. Or maybe some defect within the chamber or rifling is preventing your rifle delivering the kind of performance you expect. Even at £700, a borescope can be cost-effective – if it saves you the cost of just one new barrel.”
Vince explained how the BoreCam can quickly diagnose problems in a barrel: “A customer started to have difficulty chambering rounds in his 308 Target Rifle…. The borescope quickly revealed the problem – a hard ring of copper and carbon had built-up immediately in front of the chamber. When you use a bore-guide (and you always should do) it can sometimes ‘protect’ this first bit of the bore from the cleaning-brush. Although the rest of the bore was spotless, this tiny section was not. Once we knew where the problem was, it was simple matter to carefully clean it up.”
“A borescope will tell you if your cleaning regime is effective, or inspect for throat-erosion and the general condition of the rifling. In addition, it’s very useful to the gunsmith for inspecting newly-cut chambers – making sure they are free from scoring and other machining defects.” Vince also recommends using the BoreCam to inspect barrel crowns: “Tiny burrs can often be present on newly-cut crowns and even the minutest of damage to a crown… can play havoc with accuracy. For the serious shooter, you could say that a borescope is the equivalent of a doctor’s stethoscope.”
The Ugly Truth Revealed
Here are some inside-the-barrel photos Vince took with the Lyman BoreCam. Vince notes: “This barrel came out of the scrap-bin, but someone had actually been shooting this rifle before he finally gave up and came in for a new barrel. Shooting a barrel in this condition is really throwing good money down range! Buy a borescope and stop shooting long before your barrel gets into this state!”
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Here’s an interesting $75 product that can help you “tune” the cycling force of your AR-platform rifle. Wilson Combat offers an Adjustable Lo-Profile AR Gas Block for direct gas impingement AR-type rifles. Wilson Combat’s adjustable gas block replaces a standard AR gas block and allows you to tune your AR’s gas system for smoother cycling and enhanced reliability. Wilson Combat explains: “Adjusting your rifle’s gas port will lower or increase your bolt’s cyclic rate. This tailors your rifle’s performance to your unique needs.” When varmint hunting with an AR, we like a less-energetic ejection so the brass lands close to the gun (and doesn’t tag fellow shooters).
A simple adjustment of the hex screw at the front of the block modulates the gas volume allowing you to tune your rifle’s function to your favorite loads. This is very handy when shooting non-standard AR calibers, unusual hand-loads, or suppressed rifles. Adjustable Gas Block systems are sold as complete kits starting at $74.95. Wilson Combat offers two diameters (.750″, .937″) and three lengths (Carbine Length, Mid-Length, & Rifle Length), so you can select the right dimensions for your rifle configuration and barrel diameter. The blocks are Chromoly steel with a Melonited finish.
Package Includes:
Adjustable Gas Block (Melonite Finish)
Adjustment Set Screw (Installed)
Straight Gas Tube (Installed, Gas Tube Pin Installed)
12″-Long Allen Wrench to Adjust Inside Handguard
$74.95 MSRP
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Can you guess what your next barrel will weigh? In many competition disciplines, “making weight” is a serious concern when putting together a new match rifle. A Light Varmint short-range Benchrest rifle cannot exceed 10.5 pounds including scope. An F-TR rifle is limited to 18 pounds, 2 oz. (8.25 kg) with bipod.
One of the heaviest items on most rifles is the barrel. If your barrel comes in much heavier than expected, it can boost the overall weight of the gun significantly. Then you may have to resort to cutting the barrel, or worse yet, re-barreling, to make weight for your class. In some cases, you can remove material from the stock to save weight, but if that’s not practical, the barrel will need to go on a diet. (As a last resort, you can try fitting a lighter scope.)
Is there a reliable way to predict, in advance, how much a finished barrel will weigh? The answer is “yes”. PAC-NOR Barreling of Brookings, Oregon has created a handy, web-based Barrel Weight Calculator. Just log on to Pac-Nor’s website and the calculator is free to use. Pac-Nor’s Barrel Weight Calculator is pretty sophisticated, with separate data fields for Shank Diameter, Barrel Length, Bore Diameter — even length and number of flutes. Punch in your numbers, and the Barrel Weight Calculator then automatically generates the weight for 16 different “standard” contours.
Calculator Handles Custom Contours
What about custom contours? Well the Pac-Nor Barrel Weight Calculator can handle those as well. The program allows input of eight different dimensional measurements taken along the barrel’s finished length, from breech to muzzle. You can use this “custom contour” feature when calculating the weight of another manufacturer’s barrel that doesn’t match any of Pac-Nor’s “standard” contours.
To find out if you have a burr or damage to your crown, you can use an ordinary Q-tip cotton swab. Check the edges of the crown by pulling the Q-tip gently out past the edge of the crown. If you have a burr, it will “grab” the cotton and leave strands behind.
At the 
Can you guess what your next barrel will weigh? In many competition disciplines, “making weight” is a serious concern when putting together a new match rifle. A Light Varmint short-range Benchrest rifle cannot exceed 10.5 pounds including scope. An F-TR rifle is limited to 18 pounds, 2 oz. (8.25 kg) with bipod.
