At the IWA Trade Show in Germany earlier this year, 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.”
Smart shooters know the importance of using a quality cleaning rod bore guide when cleaning barrels. The rod guide helps center the rod in the bore, preventing uneven wear on the rifling. Good bore guides also seal off the chamber to prevent solvents and gunk from flowing back into the bolt raceway and trigger housing. While most bore guides are “better than nothing”, the best designs are custom-sized to the chamber and also have a very tight clearance around the rod shaft. This prevents the rod from bowing and from dragging on the critical throat area of your rifle. We use Lucas Rod Guides for many of our rifles. The Lucas two-part design, with a caliber-specific insert, provides a tight fit for the rod.
T.K. Nollan’s Barrel Saver System
While many readers may have seen or used Lucas Rod Guides, T.K. Nollan makes another very high-quality cleaning rod guide that is favored by top benchrest shooters such as Tony Boyer, Dwight Scott, and Dick Wright. If, like many short-range Benchresters, you do a lot of barrel brushing, it may be worth investing in the $135.00 Barrel Saver.
T.K. Nollan’s patent-pending Barrel Saver is a precision-machined system designed to provide maximum protection during barrel cleaning. The Barrel Saver features a double O-ring “fail-safe” seal, and a stainless steel outer tube with straightness held to within .001″. To help ensure optimal alignment, a bushing, custom-sized for your action, precisely centers the outer tube in your action. Models are offered for Hall, Stolle, Grizzly, Farley, Remington, RFD, Nesika Bay, Borden, BAT, Viper and similar 2-lug actions.
Each Nollan Barrel Saver comes with two (2) metal guide tubes, one for brushes and the other for jags. As you can see in the slide show below, these brush/jag tubes run INSIDE the larger diameter guide which slides into the action and chamber. This “tube-within-tube” design, combined with the 0-ring for the chamber, ensures that the cleaning rod stays precisely centered, even if you brush fairly aggressively. While we strongly advocate bore-brushing only in the outward direction, we know some shooters prefer to brush back and forth. If you are a “back and forth” cleaner, you NEED a product like the T.K. Nollan Barrel Saver.
T.K. Nollan Barrel Savers start at $135.00 plus $9.00 shipping for PPC-type chamberings. Custom sizes cost $150.00 plus $9.00 shipping. Each Barrel Saver kit comes complete with two Rod Guide Tubes and spare O-rings. For more info, visit the Barrel Saver website, or contact T.K. Nollan at this address:
TK Tool Co. – Precision Benchrest Tools
tknemail [at] gmail.com
401 South Cimarron St.
Catoosa, OK 74015
(918) 633-2966 (Call before 9:00 PM CST)
Selection from BARNES BULLETS’ Tips, Tools, and Techniques by Ty Herring, Barnes Consumer Service
The purpose of this month’s Tip from Barnes is to make you aware of valid pressure signs in most centerfire rifle cartridges so you can keep yourself out of hot water. Following the Barnes Manual should do exactly that. Below are photos of cartridges that definitely had too much pressure. Fortunately [they] were fired in controlled circumstances and no one was injured. But this shows what can happen if you are not careful….
High-Tech Pressure Testing Equipment
At Barnes Bullets, we use some of the best equipment when we develop load data for you. Ours is state-of-the-art with a specialized “conformal” pressure system. This set-up uses a high-tech SAAMI-spec pressure barrel with a hole bored into the chamber area and a piezoelectric transducer is installed. As the pressure peaks under firing, the gauge that is specially calibrated reads the pressure and sends a signal to the control box where a technician can see the results.
For many years hand loaders have used the old fashioned trial and error method, hoping that by adding another grain of powder you don’t blow yourself up. Certain “guidelines” have been the standard — such as when the primer gets flat, or when the bolt locks up — you should stop and reduce the charge. These methods have worked for many, but some of them are more myth than reality. I’d like to go over some of these common pressure signs to help you avoid the pitfalls.
Pressure Signs That May Be Unreliable or Deceptive
When I first started hand loading centerfire rifle cartridges, I was told that when the primer flattens I should back the load down. This is one of those semi-myths. Some primers will flatten under high pressure and others will not. I’ve had some Remington primers that have blown right out of the case without ever showing any sign of flattening and on the other hand I’ve had Winchester primers that flatten with only a starting charge. I believe this to be a function of the thickness and hardness of the primer cup. The other myth that seems common is primer “cratering”. Cratering of the primer can be caused by a hot load. But it can also be a result of a slightly large firing pin hole in the bolt or a firing pin that is a bit too long or excessive headspace. Split or cracked cases are another area where it’s assumed that high pressure is the cause. Again this is only myth. Although it can be a result of high pressure — split or cracked cases are more likely caused due to a flaw in the case, improper head space or just simply from being sized and fired repetitively.
[Editor’s Note: Flattened Primers, Primer Cratering, and Cracked Cases CAN DEFINITELY BE CAUSED by excessive pressure. Accordingly, you SHOULD be careful when you see any of these conditions. If you see very flat primers or deep cratering be alerted that you may have exceeded safe pressures. Ty Herring simply makes the point that these telltale pressure signs may sometimes occur even when pressure levels are “normal” or moderate — due to the presence of other problems. Hence these indicators may be misleading. Nonetheless — all these signs (flattened primers, cratered primers, split cases) CAN be valid warnings. If you see these conditions, exercise caution because you may, in fact, have excessively hot loads.]
Valid Pressure Signs You Should Understand
So what are valid pressure signs? I’d say the most common and repeatable pressure sign that one can visually see is the “ejector groove mark”. It shows itself on the bottom of the case [between the edge of the rim and] the primer. It is caused when the pressures within the chamber force the case against the bolt face. On most bolt faces there is a round spring loaded ejector pin. On others there is a rectangular groove to eject the spent round. Under very high pressure the brass case will flow into this groove thereby causing the “ejector groove mark”. If and when you see this mark, it is a sure sign of high pressure. Some of the new high pressure cartridges such as the WSMs are made to run at these higher pressures and some factory loads will manifest the ejector groove mark even though they are within their pressure specification.
Older-Generation Cartridges
Some cartridges have very low maximum pressure ratings such as the 45-70, 30-30, 416 Rigby along with many others that will never show an ejector groove mark. Or should I say, they should never show one. By the time you reach that high of pressure in one of these rifles, it is likely the gun will be in pieces and the bolt may become part of you.
Sticky Bolt Lift and Difficult Extraction
Another common and very real high pressure sign is heavy or sticky bolt lift or extraction. This is caused due to the brass flowing and swelling in the chamber under tremendous pressure. However heavy bolt lift is not always a sign of high pressure. It may be caused by a variety of other issues. Knowing your gun and how it usually extracts a cartridge will be a clue as to whether or not you are actually getting high pressure.
This article appears courtesy Barnes Bullets. The article originally appear in the June 2011 Barnes Bullet-N Newsletter. Story tip from Edlongrange.
As posted in the Calguns.net a while back, there was a nasty out-of-battery firing incident involving a BOHICA Arms .510 DTC AR15 upper. The cause of the out-of-battery firing is not certain but it appears that the ammo was not sized properly and the firing pin may have been stuck in the extended position. As a result, the round went off before the bolt was closed with the lugs seated. In the process, the bolt handle broke off, as the bolt retracted violently, actually ending up outside the bolt raceway.
The shooter was badly injured, with multiple broken bones and ligament damage to his left hand and tissue damage to his right hand. The shooter was holding the rifle with his left hand near the front of the chamber where a gas vent was located. Gas and shrapnel existed the vent hole causing the severe injuries to the left hand.
From range reports, it appears that the shooter had been struggling to chamber previous rounds, and was having trouble closing the bolt. After talking with one of the rangemasters, a poster on AR15.com reported: “The guy was using new reloads that weren’t exactly fitting well into his chamber. [The shooter] was slamming the bolt handle with his palm trying to get the cases to lock in. The guy was also slamming the bolt forward full force from the rearmost position back and forth trying to ram the cases into chamber in an attempt to squeeze the rounds in so the bolt could close. Finally, on one of the attempts … the possibly stuck firing pin rams into the primer and explodes the round when he slams the bolt forward (zero lug engagement hence the KB) and shooter puts himself into a world of hurt.”
Lessons Learned — Don’t Try to Force Oversize Ammo into a Chamber
By all reports, the shooter’s ammo wasn’t fitting his chamber properly. In an effort to force the ammo into the chamber, he worked the bolt with excessive force. That MAY have caused the firing pin to extend or the hammer to fall without the trigger being pulled. One theory is that the trigger system may have been modified, allowing the hammer to fall from the force of slamming the bolt forward. Others have speculated that the firing pin may have failed to retract because the bolt handle was over-torqued — a safety issue listed in the BOHICA manual.
Whatever caused the out-of-battery firing, it appears that improperly-sized ammo (or a poorly-cut chamber) was the root cause of the problems. If you go to a range and find your bolt does not close easily over the ammo — STOP SHOOTING — don’t try to force the issue. Disaster may result. To paraphrase Johnnie Cochran: “If the ammo doesn’t fit, it’s time to quit”.
Photos by Wildcard, originally posted on Calguns.net.
Shooters who convert factory actions to run 6BRs, 6PPCs or other high-pressure cartridges should consider having the firing pin bushed. These modern cartridges like to run at high pressures. When running stout loads, you can get cratering caused by primer flow around the firing pin hole in the bolt face. The reason is a little complicated, but basically the larger the hole, the less hydraulic pressure is required to crater the primer. A limited amount of cratering is normally not a big issue, but you can reduce the problem significantly by having a smith fit a bushing in the firing pin hole. In addition to reduced cratering, bushing the firing pin often produces more consistent ignition.
This is a highly recommended procedure that our editors have had done to their own rifles. Greg Tannel (Gre-Tan Rifles) is an expert at this procedure, and his turnaround time is fast — usually 2-3 days (shop time). Current price for a bushing job, which includes turning the firing pin to .062″, is $82.00 including USPS Priority Mail return shipping.
If you have a factory rifle, a bushed firing pin is the way to go if you are shooting the high-pressure cartridges such as 6PPC, 6BR, 6-6.5×47 and 6.5×47. This is one of the most cost-effective and beneficial upgrades you can do to your factory rifle. For more info on the Firing Pin Bushing process, visit GreTanRifles.com, or email greg [at] gretanrifles.com. (After clicking the link for GreTanRifles.com, Click on “Services” > “Shop Services” > “Bolt Work”, and you’ll see a listing for “Bush Firing Pin Hole & Turn Pin”. Select “View Details”.)
Firing Pin Hole Bushing by Greg Tannel
Work Done: Bush firing pin hole and turn pin.
Functions: Fixes your cratering and piercing problems.
Price: $75.00 + $7.00 return shipping Total Price: $82.00
Actions for which Bushing is Offered: Remington, Winchester, Savage, Sako, Kimber, Cooper, Nesika, Stiller, Bat, Kelbly, Lawton, Surgeon, Borden, Wichita, Hall, CZ, Ruger, Mauser, Howa, Weatherby, Dakota, Pacific Tool, Phoenix, RPA Quadlite, and Defiant bolt action rifle or pistol. Note: There may be extra tooling charges for case-hardened style bolts (Mauser, CZ, and similar) .
Actions for which Bushing is NOT Available: ARs, Accuracy International, Desert Tactical Arms, Big Horn, Rim fires, Falling block, Break open, Lever, Pump rifles.
How to send your bolt in to be bushed:
You can send your bolt snail mail, priority mail, UPS, Fed-Ex. What ever you prefer. Please include your name, phone number, and return shipping address. Turn around is normally 1 to 3 days shop time (plus shipping time). We usually do them the day that we get them in. Total cost is $82.00 for one bolt or $157.00 for two (this includes return shipping, priority mail.) Three or more will be sent back to you UPS and we will have to calculate extra shipping. We can overnight them at your expense. Check, money order, or credit card is fine with us.
RCBS Chargemaster 1500 Electronic Powder Dispensers are normally quite accurate. However, build-up of static electricity can cause some issues, such as kernels of powder clumping together. Nat Lambert found that reducing static charges can “cure” the clumping problem: “Discharge the static in your machine and you won’t have those clumps. Either use static wipes inside and out on your machine or use a Zerostat. It will make a huge diference. Walmart has the anti-static wipes in the computer section.”
Forum member J. Cummings reports: “My Chargemaster drifted due to static electricity after a thunderstorm. I contacted RCBS. They told me to turn it off, wipe it down with an anti-static cloth then try it. That was more than six months ago. It has worked fine ever since.” Forum member Harvey concurs: “As long as I use the static dryer sheets my Chargemaster VERY RARELY will drift. [If it drifts now] it’s usually me breathing hard or moving things like seating bullets or bumping the bench with my knees. I had problems until I used the sheets and ran pieces thru the tube on a pipe cleaner.”
Others have found that they can reduce the clumping problem by prepping the inside of the dispensing tube, by removing burrs and rough spots. Milanuk has a very simple solution: “Stick a one-inch piece of drinking straw in the discharge tube; tape it in place. Clumping problem solved.” Below is a commercial anti-static cloth. You can also use the “anti-cling” fabric pieces used with clothes dryers.
Butch Lambert, who distributes the Elliott “Aussie” BRT wind flags, gave us some expert advice on wind flags. Butch writes: “Chatting with the top shooters in our sport about flags gave me some surprising insights. You do not want your flags balanced. The weight should be biased to the vane side. That will help take the twitch out of your flags. It will take the windshield wiper effect out. The Aussie propellers are used for velocity reading only at very low wind velocity. They are mainly to let you see a pickup or a let up. The sailcloth tails are attached with a clip that does not allow the tail to twist and it also holds the shape of the flag in a V so that it doesn’t flop in the wind. Daisy wheels slow response of the vane, puts a shake in your wind flag, and hides the vane on any tailwind.” If you have more questions about wind flags, contact Butch at ShadeTree Engineering.
A while back, Forum member Andy (aka GrayMist) did an interesting test, with five (5) different types of .243 Winchester Brass. He collected Federal, Lapua, Remington, and two different lots of Winchester-brand brass. Then he selected ten (10) cases at random from each brand and measured their weights. To ascertain case capacity, three (3) cases from each brand/lot that were closest to the average weight for that brand/lot were selected. The results were surprising: there was less than one (1) grain capacity difference between all the cases, even with a 14.7 grain maximum difference in case weight!
Measuring Procedures
The cases were sized in a Redding body die then primed with a spent primer. All were weighed before and after filling them with distilled water. The capacity shown is an average of all three (3) cases from that lot and represents grains of water. Note, I tested two lots of Winchester brass. Lot A was purchased in 1999. Lot B was from factory .243 ammo. There is a rather large disparity in case weight between the two lots.
Brand
Federal
Lapua
Remington
Winchester A
Winchester B
Capacity
53.9
54.4
53.7
54.8
54.8
Aver. Weight
173.28
173.13
165.34
158.58
166.44
SD¹
0.46
0.39
0.17
0.58
0.42
Range²
1.70
1.10
0.40
1.80
1.40
% of Avg.³
0.98%
0.64%
0.24%
1.14%
0.84%
1) Standard Deviation in grains.
2) Range is the difference in weight between the heaviest and lightest cases in the test.
3) Case range weight divided by the average weight.
What the Numbers Mean … And Some Speculations
Andy observes: “It certainly seems there is a huge difference in case weight between Winchester lot A and any other brand of 243 tested. What is also surprising is that there was less than one (1) grain capacity difference between all the cases, even with a 14.7 grain difference in case weight!
Should one be wary of trying the same loads that were initially tested in the light weight Winchester brass even though the capacity difference is small? I have had some interesting results with one brand brass that I cannot pass on yet, except to say I sent that company a sample of the lot I have been using. The Remington brass weight range was very low. These were taken from a box of once-fired factory ammo. I will have to acquire some more and measure it.”
Results of Larger Lapua Sample
In a previous session Andy weighed all 100 Lapua cases he had on hand. His measurements showed a total variation of 2.1 grains, with the weight range being 172.5 to 174.6 grains. That is a 1.2 percent spread. The most that came in at the same weight were 11 cases at 173.5 grains.
Here’s a word to the wise — not all full-length sizing dies are properly dimensioned to carry out the important task of “bumping” shoulders back on fired cases. With some dies the task may simply be impossible (without die or shell-holder modification). In fact, you may find that your attempt to bump the shoulder may actually INCREASE the dimension from base of case to shoulder datum!
We recently had some four-times fired 6mmBR Lapua brass. Using a Harrell’s collar that indexes off the shoulder, we measured the length from base of case to top of collar at 1.570″ (with primer removed). We noticed a little more resistance to bolt closure compared to fresh brass, so we decided to bump the shoulders back two thousandths. As a point of reference, we measured the same dimension (base of case to top of Harrell’s collar, primer out) as 1.5675″ on once-fired Lapua 6mmBR brass.
This Can’t Be Right …
To bump our shoulders we had an RCBS Gold Medal bushing full-length sizing die. Per the manufacturer’s instructions, we started with the die backed off 1/2 turn from contact with the shell-holder with the press ram at full height. We lubed and sized one case and then measured it. The shoulder had not moved. OK, no problem, we screwed the die down to contact the shell-holder (at full ram height) and tried again. This time the measured dimension was actually longer by a couple thousandths. The brass which measured (with collar) 01.570″ before sizing now measured 01.572″ — we were going in the wrong direction!
“Bumped” Shoulder Stretched .003″
Frustrated, we screwed the RCBS die in 1/8th turn past touching to allow “cam-over” which is necessary with some presses to actually push the shoulder back. We sized the case again, and this time the dimension had grown another .001″, to a total length of 1.573″! Wondering if there was something wrong with our calipers, we took the full-length sized brass (which previously had chambered just fine) to our 6BR rifle and tried to chamber it. Sure enough, the headspace had been lengthened by .003″ and the brass would not chamber at all.
Die Was Too Long Inside to Bump Shoulders Properly
What was going on? Here’s the explanation: the interior cavity of the die was too long so the shoulder surface inside the die was never actually making contact with the shoulder of the brass — and the die could not be screwed down any further. As the RCBS die, which was fairly tight in the bottom half, reduced the diameter of the brass, the case actually grew in length. While the brass was sized at the bottom it grew upwards because the “shoulder” section on the inside of the die was too high. As we “squeezed” the brass at the bottom it simply flowed upwards, increasing headspace.
With this RCBS die, in its current configuration, there was no way we could bump the shoulder back, even by .001″. The die would likely function effectively if we ground a few thousandths off the bottom, but we don’t think a die user should be obliged to make such a modification.
Lesson Learned: If your full-length die can’t bump your brass even when it is screwed down all the way (to cam-over if necessary), then you need a different die or you need to modify your die. As proof of this, we took out my trusty Redding 6mmBR full-length sizing die. This was set up (from experience), one-half turn off contact with the shell-holder. In that position, the Redding die easily bumped the shoulder of a fired case .002″ with no trouble whatsoever. We started at 1.570″ and ended up 1.568″ — right where we wanted to be. The task that couldn’t be done with the RCBS Gold Medal FL Die was accomplished easily with the Redding die. After lubing the case, we simply raised the ram to full height, and this moved the shoulder back .002″ as measured with the Harrell’s collar positioned on the shoulder.
You can purchase a Teflon stock tape kit from Sinclair Int’l for $14.95. This has four 5″x5″ segments, enough for two rifles. But if you have a large collection of rifles, you’ll save big bucks by buying directly from a bulk tape supplier. C.S. Hyde Company, CSHyde.com, (800) 461-4161, sells 6″-wide, flexible Teflon-coated and UHMW tapes that work great, with either rubber, silicone, or acrylic adhesives. The price works out to about $1 per rifle.
MiKe Ratigan recommends the “Skived” (blade sliced) PTFE Teflon .005″ tape with silicone adhesive, item 15-5S. This is very low-friction and highly conformable, so it bends easily around your stock contours. You’ll need to call for custom 5″ or 6″ widths, and expect to pay about $40 for a 5-yard-long (180″) roll.
A less expensive option is the UHMW (ultra-high molecular weight) Polyethylene Tape with High Stick Acrylic Adhesive, item 19-5A. C.S. Hyde explains: “UHMW Polyethylene provides a nonstick, low-friction surface similar to PTFE tape but with much higher abrasion and puncture resistance. It is ideal for anywhere high-pressure sliding contact occurs.” The price is just $32.34, for a 6″-wide by 5 yard-long roll, enough for 36 rifles! Compare that to spending $12.50 for four 5″x5″ pieces. On Benchrest.com, AbinTX reported that C.S. Hyde “sent [him] samples of various thickness to try out before ordering. They will price a roll for you depending on how wide and how long you want. It’s not very expensive and you can tailor the amount to your needs.”
At the IWA Trade Show in Germany earlier this year, 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.
High-Tech Pressure Testing Equipment
Firing Pin Hole Bushing by Greg Tannel
RCBS Chargemaster 1500 Electronic Powder Dispensers are normally quite accurate. However, build-up of static electricity can cause some issues, such as kernels of powder clumping together. Nat Lambert found that reducing static charges can “cure” the clumping problem: “Discharge the static in your machine and you won’t have those clumps. Either use static wipes inside and out on your machine or use a Zerostat. It will make a huge diference. Walmart has the anti-static wipes in the computer section.” 
What the Numbers Mean
We recently had some four-times fired 6mmBR Lapua brass. Using a Harrell’s collar that indexes off the shoulder, we measured the length from base of case to top of collar at 1.570″ (with primer removed). We noticed a little more resistance to bolt closure compared to fresh brass, so we decided to bump the shoulders back two thousandths. As a point of reference, we measured the same dimension (base of case to top of Harrell’s collar, primer out) as 1.5675″ on once-fired Lapua 6mmBR brass.
This Can’t Be Right …
Die Was Too Long Inside to Bump Shoulders Properly
