Chris Nichols with potential world record (1.297″ 4-Target Agg) Heavy Gun Targets!
Report by Bart Sauter, Bart’s Custom Bullets
Chris Nichols is one of the best 600-yard shooters in the game. This 2019 season he compiled one of the most impressive mid-range benchrest seasons ever. Check out the stats — Chris’s nine-match, Two-Gun Group Aggregate (Agg) for the year is 1.983″! That’s under two inches average at 600 for 72 record targets fired in competition. Many 600-yard shooters aspire to shoot a single, 4-target Agg that measures 1.983″, but doing that for 72 targets is amazing!
And of the nine matches Chris shot, he took SIX Overall Two-Gun wins — a 67% win ratio. And in the process Chris also shot what is possibly the smallest 4-target Heavy Gun Agg ever recorded — 1.297 inches. Hey readers — that Agg works out to 0.206 MOA average group size — well under quarter-MOA for four, 5-shot groups at 0.34 MILES (600 yards)!
Chris with 0.665″ group at 600 yards. This is the smallest HG group fired in the IBS in 2019.
The Equipment: 6mm Dasher Light Gun and Heavy Gun
Chris likes to run 1.550 stainless steel Bat “B” actions, Jewell triggers, Brux or Bartlein barrels. He prefers wooden stocks as he feels they produce a better resonance for Long Range rifles. Chris has his own stock design crafted by Johnny Byers. Imagine a Wheeler LRB stock front half mated with an McMillan ST 1000 rear section and you have Chris’ stock! It features a Wheeler-type, 4″-wide fore-end with an ST 1000 low-comb profile in the back. Both Light Gun and Heavy Gun sport Vortex 15-60x52mm Golden Eagle scopes mounted with Harrell’s double screw tall rings. Chris does NOT use either muzzle brake or tuner.
Here is Chris at his home range with his Light Gun (17 lbs. max).
Chris Nichols’s Heavy Gun is a true heavy coming in at around 42 pounds. It was responsible for the HG Agg of 1.297″ (potential new world record). His season-long aggregate with his Heavy Gun was 1.861″ for 36 targets! This rifle has similar components as his Light Gun, except the barreled action rides in a barrel block in a McMillan HBR 50 BMG stock.
Both rifles ride a top of a Sinclair competition rest with a Protector DR Flat Top rear bag. When Chris goes to HG gun he simply switches tops (made by Daniel Greenlaw) on his front rest to accommodate the larger forend. As Chris says ,” This keeps things simple and exactly the same. ” Just the way he likes it.
Reloading for the 6mm Dasher
Chris’s load choice for both LG and HG is Hodgdon Varget pushing 105gr Berger VLDs. He uses CCI 450 primers, seated with an old Lee hand primer. When it comes to reloading, Chris likes to keep things as simple as possible. “If people saw me reloading they’d probably laugh!” Chris revealed that he doesn’t anneal or clean his cases. He just sprays them down with Hornady One Shot Case Lube, resizes, then runs a brush down the necks, and cleans the primer pockets. The only cleaning his cases get is when he wipes the lube off of them. Chris WILL trim and chamfer as needed.
Chris says seating consistency is critical — he uses a K&M Arbor press with force dial indicator. I asked if there were certain numbers he looks for when seating. Chris replied, “I’m only concerned with consistency and not a certain number, 5 pounds or 60 pounds. It doesn’t matter as long as they are the same. I take what the brass gives me.”
Tuning the 6mm Dasher for Record-Setting Accuracy
I asked Chris what was special about his Dasher and how he kept it tuned and so competitive? His reply is something all shooters should pay careful attention to: “[Success] starts with having a good reamer, bullets and barrels. But more than that, it’s KNOWING your Cartridge, KNOWING your bullets, and KNOWING your barrels! I’ve shot it so much I just know what to do. I’m comfortable with it. I know how to get it to shoot and when it’s not, I have a pretty good idea how to get it back in tune. Once you know your equipment, then you can learn how to get the most out of it.”
Chris has a range at his house and he tunes at 300 yards. He looks for consistent, 300-yard 5-shot groups of 0.600″ or less! He wants to see nice round groups! Not groups with four in and one out or vertical strings. Chris starts by finding “touch” (to the lands) then he moves the bullets .002″ off the lands and begins tuning. Chris has found that usually somewhere around .008-.012″ off the lands is where his Berger 105gr VLDs shot best. I asked Chris what’s the biggest factor contributing to his success? He said, one big thing was that he can do his own work. That’s a huge advantage.
Look for Accuracy First, Velocity Second
Early on Chris had it in his mind that for a 6mm Dasher to shoot best he needed to achieve a certain velocity range — 2990 to 3030 FPS. The problem was he wasn’t paying attention to what the target was telling him. He’d get to the speed he was looking for but the accuracy wasn’t there. Once he started slowing the speeds down and giving the barrel what it wanted, then the accuracy came! Also with the slower speeds came better consistency.
Chris Nichols’s Tuning Tips for 6mm Dasher:
• Take consistency over speed.
• Only change one thing at a time and run it to the ground.
• Every barrel is a little different, so give it what it wants.
• Pay attention to what your target is telling you.
• Don’t be afraid to REDUCE your powder load.
Chris Nichols’s Advice for New Shooters
Chris says the best thing a new shooter can do is align themselves with knowledgeable people, and if they will talk, listen! Next, be ready to buy the best equipment or be ready to buy it twice. Chris also says: “Don’t cheap-out on sighters. Sighters need to be just as good as your record rounds.”
In the Beginning — Learning the 600-yard Benchrest Game
Chris’s shooting career began in 2012. His first win came in 2014. He was shooting beside guys like Sam Hall, Larry Isenhour, Mike Hanes, Jeff Godfrey James Coffey, and Chad Jenkins, who are very tough competition indeed. He said when he won he was ecstatic and he’ll never forget it! That first trophy had him feeling like he’d just won the Nationals! Chris shot a 6BR for the first two years of his career, before switching to the 6 Dasher. I asked him why he switched? He said, “guys were starting to shoot the Dasher and winning with it!”
I asked Chris if he had a mentor and he said, “not really”. He learned by watching the guys who consistently finished Top 5 at matches and occasionally asked them a question. Not two questions, just one! Chris didn’t want to push his luck by asking too much. Then Chris would take that information and test it and apply it to his own shooting. Chris says, “he learned mainly by the ‘school of hard-knocks’. The good thing about learning that way is it sticks with you!”
Chris Nichols 2019 600-Yard Win List and Statistics
How is a modern, metal-chassis rifle built? This very cool video from Masterpiece Arms answers that question. The nicely-edited video shows the creation of a Masterpiece Arms tactical rifle from start to finish. All aspects of the manufacturing process are illustrated: 3D CAD modeling, CNC milling of the chassis, barrel threading/contouring, chamber-reaming, barrel lapping, laser engraving, and stock coating. If you love to see machines at work, you will enjoy this video…
Kevin Muramatsu’s black rifle book, the Gun Digest Guide to Customizing Your AR-15, is a great resource for fans of AR-platform rifles. All the AR options you can imagine are covered: suppressors, premium barrels, adjustable stocks, free-float handguards, ergonomic grips, buffer systems, tactical lights and much more. Those planning an AR rifle build will find application-specific suggestions for 3-Gun, Service Rifle, High Power (Space Gun), Hunting, and Self-Defense use.
Firearms expert Muramatsu offers advice on choosing the right stock/barrel/optics configuration for your particular game. He also discusses the wide variety of options for slings, grips, magazines and other accessories. With over 520 photos, the book includes a large photo gallery of customized ARs, and includes bonus coverage of the FAL and other “tactical” firearms. The Gun Digest Guide to Customizing Your AR-15 is available from Amazon.com for $20.13, and a Kindle eBook version is offered for $14.99. The book is also sold by Barnes & Noble, and most other major booksellers.
In today’s economy, Free is good. Here’s a list of classic, older shooting books that can be downloaded for FREE from Google Books. This list includes many classic treatises on marksmanship that still have value for today’s competitive shooters. In addition, we’ve included illustrated firearm histories, such as Townsend Whelen’s fascinating book, The American Rifle, and The Gun and its Development (9th Ed.), by William Wellington Greener.
In the list below, the title link will take you to the Google Books page for each book. You can read the entire book online, or you can download it to your computer as a PDF file* and save it (or print it). You can also create your own Google Library and save the books there for access from any computer.
*To download a book, first click the title from the list above. Then, once you’re at the Google book site, look for the icon that looks like a gear in the upper right-hand corner. Click that and a pull-down menu will appear. Select “Download PDF” from the menu — this will bring up a security question to make sure you are a human. Respond to the security question correctly and your normal download prompt will appear. Choose a location to hold your new e-book, and click “save”.
What’s a “Frankengun”? Well it’s a one-of-a-kind rifle that has been pieced together from a variety of different parts and components. It might be a little bit Bolt Gun mixed with a little bit AR-15. Or it might feature some home-made components unlike anything you’ve seen before.
We’ve selected these four Frankengun rifles from a current thread in our Shooters’ Forum.
Frankengun #1 — The EXO (as in Exo-Skeleton)
Forum member jm850 calls this tube-framed wonder the EXO (as in “exo-skeleton”). He says: “This is a prototype I designed around a few core concepts that stick out to me on a traditional configuration. Eliminating stresses, lowering recoil moment, and improved barrel cooling. I’m really happy with it so far.”
The EXO is a very unique rifle. We’ve never seen anything like this since the late Shelley Davidson’s famous Tinkertoy Rifle, a brilliantly innovative 30BR that actually won matches. (Sadly Shelley has passed away). The Tinkertoy, shown below, was truely radical, but it worked ! Could this have been an inspiration for jrm850’s EXO rifle?
Frankengun #2 — Mossberg MVG in LSS Stock with BipodeXt
Forum member BallisticXLR has created something very weird to say the least. It started out as a basic, bone-stock Mossberg MVP Varmint in .223 Rem. Then the transformation began: “I replaced everything except the receiver. It now has an LSS stock, PSG-1 grip from DPMS, XLR butt stock, PT&G lug and barrel nut, Columbia River Arms 26″ barrel with Sonoran coral snake Cerakote, A2 flash hider, Timney and Jard triggers (depending on what I’m doing), and a USO B17 which is now a USO 3.8-22×44.” That long extension tube under the chassis is a BipodeXt from Accuracy Solutions.
Frankengun #3 — A Chassis Rig in 25 Creedmoor
This Frankengun belongs to Forum member Geraldgee. This “black and blue” rig features a mag-fed Kelbly Atlas action in a McCree’s Precision G10 Chassis. The barrel is a Bartlein Rem Varmint Contour, 1:7.5″-twist 4 Groove, chambered for the 25 Creedmoor. There are some interesting .25-Cal bullets coming on the market now. You can make the brass by expanding 6mm Creedmoor, or necking down 6.5 Creedmoor.
Frankengun #4 — MDT Chassis, Fore-end Whittled by Spook
Here’s a real collection of odds and ends, but Forum member Spook says it shoots well, and is a great example of “Left-over parts made useful again”. This mix-n-match Frankengun features a Remington M7 action with PT&G bolt. The barrel is a stainless Pac-Nor chambered in 6mm SLR. The barreled action is carried in an MDT Chassis with rear folding buttstock. Up front is something unusual, a Delrin fore-end that owner Spook “whittled in the mill”.
Frankengun #5 — 6.5×47 in Accuracy Int’l Stock
CLICK photo for full-screen version.
Forum member CT10Ring kicked off the Frankengun thread with this rifle. It’s actually not that shocking, but you rarely see a BAT action in an Accuracy International stock. The BAT VR action is mated to an AI Mag and set up in an AI folding stock. On top is an “old school” Nightforce Benchrest scope. The barrel is a very heavy Krieger chambered for the 6.5×47 Lapua. CT10Ring say the barrel alone weighs about 9 pounds, and the gun “shoots better than [he] can”.
Post Pictures of Your Frankenguns in our Forum
So do you have a favorite Frankengun resting in your gun safe? If you do, visit our Shooters’ Forum and post a description and some photos in the Frankengun thread.
by James Mock
After owning three different rifles with BAT actions, I have become a loyal fan of BAT Machine quality and customer service. Back in 2009, I traded my BAT/Scoville for the BAT/Leonard that I currently shoot. This rifle has a long history and Terry Leonard told me that “Old 87″ (as I have named it) was one of the earlier BATs that he stocked. He wrapped the stock in fiberglass and used 2-part epoxy back then. I must say that this rifle has held up remarkably well since it dates back to the 1990s. The action is a RB/LP/RE octagon Model B with .308 bolt-face.
Rifle Has Multiple Barrels for Multiple Disciplines
With this gun, I have shot several barrels of different calibers (.22 PPC, .22 PPC-short .095, 6mm PPC, 6XC, 6mm Dasher, .30BR, and will soon have a 6 BR-AI). It has been an exceptionally accurate rifle in several disciplines. In the hands of previous owners, it earned several Hall-of-Fame (HOF) points, and a “middle-of-the-pack” shooter (me) even received a HOF point with this rifle.
For most of its life, Old 87 served as a short range benchrest rifle, but I have used it for the last few years as a 600-yard rifle with the 6mm Dasher barrel. I was lucky enough to earn the Shooter of the Year award at the Prince Memorial Range in Louisiana for 2016.
After shooting my two Dasher barrels for last eight years, I have noticed a drop-off in accuracy at 600 yards. A decision had to be made — get a new barrel or sell the rifle and retire from competition. I will be 74 years old in six months and my competition days are limited due mainly to a chronic neck problem. After mulling over the decision to retire or not, I decided to give Old 87 one more year. Here is the story of how we upgraded the old war-horse.
Old 87 REBORN — Upgrading with New Components
I prefer cut-rifled barrels with four lands and grooves and have had success with .236 bore diameters and 1:8″ twist in long range rifles. I searched for barrels meeting those parameters and found a suitable BRUX at Bugholes.com (Southern Precision Rifles).
The 6BR-AI Option — Easy Fire Forming
I thought about having Billy Stevens chamber it for the Dasher, but decided to try something new. There seems to be a lot of interest in the 6BR-AI and I said, “Why not?” Well, I bought a shortened Dasher die from Harrell’s and will use my Wilson Dasher seating die. Bart Sauter was kind enough to let me use his reamer for chambering.
Fitting a New Roller-Type Cocking Piece on Older BAT Action
Since I was into the project this deep, I called Mike Ezell and ordered one of his Tungsten powder-dampened tuners. Since Old 87 had thousands of rounds since the firing pin spring has been replaced, I decided that it was probably needed. Well, I got to thinking (very dangerous) and asked Daryle Thom if it would be feasible to put a roller-type cocking piece and a new firing pin spring on such an old action.
The folks at BAT are very accommodating and they said that it would be no problem with such a conversion. While my bolt was in Idaho, the barrel with Ezell tuner arrived and I could not shoot it. However, my friend Jeff Turner loaned me his BAT bolt to see if it would work. Although the rifles differ in age by 15 or more years, the borrowed bolt worked perfectly in my rifle. This is a testimony to the great machine work performed at BAT Machine.
New Bolt Roller Tail-Piece Makes a Big Difference in Cocking Effort
With the borrowed bolt I managed to fire-form 50 rounds and get them ready for our 600-yard match on September 16. The folks at BAT quickly fixed my bolt by replacing the mainspring and ejector spring, polishing the ejector, and replacing the tail-piece with their roller type. Pictured below is this tail piece that makes a remarkable difference in the force needed to cock the action. It is amazing what this little wheel can do… even when placed in a 20+ year old action.
Working with the Ezell Barrel Tuner — Small Increments Work Best
Also, I would like to congratulate Mike Ezell on his new tuner which contains powdered Tungsten. It is easy to set up and Mike will help a buyer get maximum effectiveness from the unit. Just give him a call. Below is a picture of the tuner. I was lucky enough to have some time to “play” with it before the match.
Talking about the tuner, Mike writes: “Our new barrel tuners…
PDT stands for particle dampening technology. The science is there, we just applied it to a barrel tuner. The advantages are a wider tune window and more efficient control of barrel harmonics…in a tuner design that actually looks good.”
Mike advised me to set the tuner by turning it all the way into the shoulder and then come out to zero or the second time zero comes up if there is not at least half of a turn between the shoulder and the first zero. It is best to start with a proven load and adjust the tuner from that load. As unlikely as it seems, a rifle can go from a good tune to a very poor tune with only 5 marks (.005”) and vice versa.
Mike cautions those who use his tuner to NOT make adjustments which are too large. As a matter of fact, he recommends adjustments of .001 inch at a time. Ezell’s tuners are screwed onto the barrel with .900” by 32 threads per inch and has 32 marks on the circumference of the tuner. Therefore, each mark moves the tuner in or out by .001 inch. There are three set screws with Teflon tips which provide friction for the tuner on the threads. Do not tighten the screws so tight as they damage the fine threads.
If you want the smoothest bolt possible for your BAT, call or e-mail Daryle or Bruce Thom at BAT Machine and discuss your needs with them. I am sure glad that I did. If you want a state-of-the-Art tuner for your barrel, give Mike Ezell a call or visit his Ezell Custom Rifles Facebook Page.
— Good shooting, James Mock
Many hunters and precision rifle competitors use muzzle brakes because these ported devices reduce felt recoil significantly. That make s real difference getting back on target for quick follow-up shots. While many rifle owners appreciate the benefits of muzzle brakes, they may also neglect their brakes, allowing hard carbon and powder residue to build up. Not good. You should regularly clean your muzzle brake to remove fouling and carbon build-up.
As Mark Edgreen posted: “Carbon build up on the crown and in the brake is a recipe for poor accuracy.” And another gunsmith reported that customers complained about guns that “shot out way too early” but they only needed to have the brakes cleaned.
Gunsmith and PRS/NRL competitor Jim See recently reminded his Facebook Fans about the importance of cleaning muzzle brakes: “How many times do I have to say it? You need to maintain your rifles. Clean your muzzle brakes people!”. Jim, who runs Elite Accuracy LLC, notes that hard carbon build-up in brakes can definitely harm accuracy. Look at this example:
Muzzle Brake Cleaning Methods
There are various methods for cleaning a brake, we list a variety of techniques, but we would start with NON-corrosive ultrasound. You’ll want to remove the muzzle device before doing these tasks.
1. Use Ultrasonic Cleaning Machine with cleaning solution. This may be the most efficient method: “I place my brake in the ultrasonic cleaner. Shiney as new.” (Jim Moseley).
2. Spray with commercial Carb Cleaner and brush. Then apply anti-corrosion coating.
3. Soak in half hydrogen peroxide and half vinegar. Suggestion: “Let sit over night and carbon melts off. Brush remaining carbon off, rinse and put the brake back on.” Apply anti-corrosive before mounting.
4. Soak in 50/50 solution of water and white vinegar and brush. (Be sure to apply anti-corrosion coating, such as Eezox, after soaking).
5. Tumble in liquid solution with stainless pins. Comment: “Comes out slightly faded, but perfectly clean on stainless, non-painted brakes though.” Warning — extended tumbling could affect threads of screw-on brakes. Also, tumbling can possibly harm painted or Cerakote finishes.
Gunsmithing Tip: By fitting the muzzle brake so that the barrel crown is slightly forward, it is easier to wipe carbon fouling off the end of the barrel. See photo:
Brownells just made it easier to get product questions answered, and to find the items you want on the Brownells website at Brownells.com. Customers can now consult live with a Brownells Gun Guru Product Expert. In addition to giving product advice, the Gun Gurus can help customers with account issues, give information about previous orders, and handle most customer concerns.
Starting Monday, September 9, customers can click on the CHAT icon at the top of the website to be connected with a Gun Guru Product Expert.
Pop-Up Gun Guru Chat Window
There is also a floating chat button on the right side of the page (see photo at right). And, after 30 seconds or so a Gun Guru invitation window will pop up. NOTE: We found that if you click on the CHAT icon at the top of the page you must fill in your name and address. However, if you respond to the floating pop-up Chat Window you do NOT have to enter name and email. We think it’s easier to just use the pop-up window.
Gun Guru Product Expert Chat is available on Brownells.com Monday through Friday, 7:30 am until midnight (CT), and on weekends 8:00 am until 5:00 pm (CT).
When you start a chat, a chat window opens with a small photo of the Gun Guru. This person will be either a Brownells Gun Tech (an actual trained gunsmith) or a vetted firearms enthusiast who can offer advice on product categories for which they are most familiar.
“The mission of the Gun Guru Product Experts will be to help educate customers on products and give recommendations, so customers can make informed decisions,” said Ted Somers, Brownells Director of Customer Experience.
Telephone Customer Service is Still Available at 1-800-741-0015
While Brownells Gun Techs will participate in Gun Guru Product Expert chat online, customers with more technical questions can still call 1-800-741-0015 and ask to speak with a Brownells Gun Tech during regular business hours.
Trigger images from PrimaryArms.com, which sells all the triggers reviewed here: Geissele, Elftmann, Timney, and ALG Defense.
Are you thinking of upgrading the trigger system for your AR-platform rifle? There are dozens of options available, from $45 up to $300. Thankfully, Brownells has created video reviews of some of the more popular AR trigger options from Timney, Geissele, and ALG Defense. And we included a video review of the highly-regarded Elftmann Match Trigger. If you want the best solution for Service Rifle competition, you might favor the Geissele. For ease of installation, it’s hard to beat the Timney, a “drop-in” module. Like the Timney, the super-smooth Elftman is a drop-in module. At $249.00 it’s pricey, but it is one of the best AR triggers out there. If you’re on a tight budget, the best “bang for your buck” may be the “Perfected Mil-Spec” ALG which starts at around $45.00.
Multiple AR Triggers, including the Elftmann and Geissele, Are Reviewed in this Video
Though pricey ($249.00 at PrimaryArms.com), we really like the Elftmann AR trigger. It combines the best of both worlds — the precision and smoothness of the Geissele with the Timney’s ease of installation. This single stage trigger is user-adjustable from 2.75 to 4 pounds pull weight. It is offered with either straight or curved trigger blade. Primary Arms says: “The amazingly short take-up, glass-rod crisp break and [near-zero] over-travel can be compared to the finest custom 1911 triggers.”
Geissele Enhanced Two-Stage Trigger
Geissele makes a variety of quality AR trigger sets both single-stage and two-stage. Many High Power competitors like the two-stage Geissele trigger. This delivers a repeatable, controlled pull through the first stage with a very clean break in the second stage. The Super Dynamic Enhanced Trigger, shown above, features a distinctive, trigger blade. Reviewer Thomas Conroy says: “The flat surface is very easy to press against. Both stages are light and very distinct.”
Timney Drop-In Trigger Module
This trigger module is available for both the AR15 and the AR10 platform (see above video). Timney triggers are easy to install and come with multiple pin size and pull-weight options. Reviewer Thomas Conroy confirms that the single-stage Timney “breaks cleanly and crisply. This trigger is modular, meaning that the trigger, sear, hammer, and spring are all encased in a bright, shiny yellow aluminum housing.”
ALG Defense Trigger — Higher-Quality Basic AR Trigger
According to Thomas Conroy, ALG triggers “are the perfected version of the standard, non-adjustable mil-spec original trigger. They have the same geometry, but are made to higher quality standards, and come with … hardened and smoothed-out sear contact surface to eliminate all grittiness.” These are also offered in a nickle-boron coated version. Available for under $45.00, the ALG is a well-made, low-cost option for shooters who want a better factory-type trigger system.
For More Information about These Triggers
Learn more about Geissele, Timney and ALG triggers, plus two more AR trigger options (CMMG and Rock River Arms) in a Trigger Comparison Review by Thomas Conroy on Ammoland.com.
A couple seasons back, Bill did a fascinating barrel cut-down test on a .338 Lapua Magnum rifle. Bill, a skilled gunsmith who runs 782 Custom Gunworks, cut down the barrel from 30″ to 17″ in one-inch increments. During the cut-down process, Marr measured velocities at each barrel length, shooting four rounds after each cut. As you’d expect, there was a huge change in velocity from long to short. Speeds were measured at the muzzle with a Magnetospeed barrel-mounted chronograph.
If you’re looking for max velocity with the .338 LM, go long. With 250-grain Sierra MK bullets, the peak velocity Bill measured was 2942 FPS at the full, 30-inch length. This decreased pretty steadily down to 2547 GPS at the shortest 17″ length. That’s an average decrease of 30.4 FPS per inch from 30″ to 17″.
Bill also tested 300-grain Sierra MatchKings. This is interesting because Randy Wise ran 300-grain bullets (Berger Hybrids) in a 26″ factory barrel for his ELR record. Peak velocity was 2833 FPS at 30″, 2799 FPS at 26″, and 2492 FPS at the shortest 17″ length. Interestingly, velocity at 29″ was higher than at 30″ for the 300-grainers. Bill notes: “The 300 SMK load showed a slight increase from 30 to 29″. I’ve recorded this in other tests and it seems to be more common with a heavier load. I suspect it is primarily due to the small sample sizes being used along with the relative proximity of muzzle velocities in adjacent lengths.”
At each new (shorter) barrel length, velocity was measured with a MagnetoSpeed chronograph using two different loads, 250gr SMKs with H4831sc and 300gr SMKs with Retumbo. Four shots were fired at each length with each load, a total of 112 rounds.
Load #1: 250gr Sierra MK, Lapua brass, CCI #250 primer, H4831SC, OAL 3.720″.
Load #2: 300gr Sierra MK, Lapua brass, Win WLRM primer, Retumbo, OAL 3.720″.
.338 LM Barrel Cut-Down Test Results Summary
.338 Lapua Magnum with 250gr Sierra MatchKings
After shortening the barrel from 30″ to 17″, total velocity reduction for the 250-grainers was 395 FPS, an average loss of 30.4 FPS per 1″ cut. The amount of velocity loss per inch rose as the barrel got shorter, with the biggest speed reduction, a loss of 55 FPS, coming with the cut from 18″ to 17″.
Start Velocity: 2942 FPS | End Velocity: 2547 FPS | Average Loss Per Inch: 30.4 FPS