- Thread starter Mjnelson
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Can you provide more information? Cartridge, load, barrel length and twist rate?
How many rounds on barrel?
Even at 2450 in a 7.5 twist, I got perfectly round holes. I'd say you have something else going on there - especially if that caliper measurement is right. What do other 6mm bullets measure on your calipers?
....how many instances of occurrence and is any muzzle device in use?
There is another post here on a bad run of 112 mb. Based on what you said I would say that is a possibility. I ran them in an 8 twist without issue and your data sounds good, should not be doing that.
Berger 109’s measure at .2435
It’s happening at about 1 every 5-10 rounds.
I was hoping there was a bad batch going around and I didn’t some how dick up my barrel.
Tested without my brake with the same results. Crown looks good.
Yeah, did not consider muzzle device. I have seen baffel strikes before. And what lot are those? Wonder if it is same lot being reported as having issues.
...I didn't catch that .240 measurement earlier, sounds like you are going to have to go thru your inventory to look for undersized bullets if its happening that frequently...
I've been running that same lot number in my Dasher with a 7.7 twist (might be 7.5?) at 6300 feet. I've been chasing my tail a little bit with unexplained flyers. I've not seen keyholes, though. I have 1500 more of a different lot that I've not opened yet. I've got loads ready to test. I'm going to push them faster and seat deeper and see if I find something better.
It’s starting to look like there’s a bad lot out there. On the 6gt forum someone identified a possible culprit. The gas ring is oversized and inconsistent. I found this to be true on my lot as well. I have reached out to other members that have reported problems ranging from flyers to keyholes and exploding bullets. I won’t be surprised at all if they share this lot as well.
Measured 10 of each at the pressure ring using a Mitutoyo micrometer. I know it's a small sample size. I was thinking the ten thousandth was outside of my measuring margin of error until I did the second lot and it was more consistent.
Lot #7276476-5
.24325
.24325
.24325
.24335
.24325
.24310
.24325
.24300
.24320
.24330
Lot #7276476-7
.24360
.24350
.24350
.24360
.24350
.24355
.24360
.24355
.24350
.24350
Lot #7276476-5
.24325
.24325
.24325
.24335
.24325
.24310
.24325
.24300
.24320
.24330
Lot #7276476-7
.24360
.24350
.24350
.24360
.24350
.24355
.24360
.24355
.24350
.24350
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This makes three of us at least with this lot and problems with it. I emailed Barns about it and I’d encourage anyone else too with problems with this lot. I’ll update with their response. Maybe if we are lucky we can get replacements, but who knows.
Well I'm glad I'm not the only one with a problem with them. I had gone through about 2k through my dasher and 6creed no problems. I switched to a new lot and new 6 creed barrel and couldn't get them to shoot. Like laughably bad groups. So I switched to another 6 creed barrel and then back to my dasher barrel. Nothing would work.
Got hold of Dtacs and the creed shot 1/2 moa with little work. I've got two 500 packs that I don't trust at all now after seeing this.
Got hold of Dtacs and the creed shot 1/2 moa with little work. I've got two 500 packs that I don't trust at all now after seeing this.
Attachments
I'm getting inconsistent accuracy with the 112gr, which I suspect is due to the pressure ring being significantly larger than the shank diameter. Theory is this the pressure ring at around or nearly 0.244" is sizing the necks enough when passing through to make neck grip on the bullet really light and variable. Seating these bullets, I get normal-ish resistance until the pressure ring passes below the sized portion of the case neck then resistance drops off precipitously. I can also push deeper seated bullets (ogive still well above case neck) in to the case by hand, even though measuring neck tension with calipers suggests I should have 2-2.5 thou.
I'll try to measure the shank diameter and pressure ring diameter on a sample tonight and post them up.
I'll try to measure the shank diameter and pressure ring diameter on a sample tonight and post them up.
Fuck, I just switched to these but haven’t loaded any up other than the 100 I tried out
Don't laugh, this is an honest question. Is there some sort of tool that pushes a bullet through and sizes the outside? They exist for cast lead bullets, but I've not heard of them for jacketed bullets. It would seem that if we can point bullets we could just as easily uniform the outside dimensions.
I once had some 109s my barrel didn't like and I asked Berger about the "pressure ring" on this particular lot of bullets I was using. They said a pressure ring is the result of the manufacturing process and not a design feature, at least not in Berger bullets. He said it was very difficult to control as well.
I once had some 109s my barrel didn't like and I asked Berger about the "pressure ring" on this particular lot of bullets I was using. They said a pressure ring is the result of the manufacturing process and not a design feature, at least not in Berger bullets. He said it was very difficult to control as well.
...yes, I've used a Lee bullet sizer to resize some Hornady VMAX 123gn AK bullets to .308 for use in my 300BLK back in the last supply shortage, they are one of my more accurate bullets. I lubed them up with my alcohol/lanolin mix and they went thru like butter. I had tested them "as is" and "resized", they had to be seated at different depths due to the "touch point" of the ogives and pressure was reached faster on the "as is" bullets. I did not encounter any "spring-back" when checked months later...
Link to a representative image of unit I used... https://www.titanreloading.com/prod...reloading-equipment/lee-lube-and-sizing-kits/
I assume the AK bullets are boat tail? How did you push them through the sizer? It seems like they would need a pusher that matched the boat tail shape?
If you are talking to me I can't say with any authority. From what I picked up talking to Bob at Berger is that a "pressure ring" can occur due to the different materials and machinery used.I.E. tolerances. It wasn't designed in, but would just happen. It sounded, and I'm reading between the lines, that when it happened it wasn't a big deal until it got beyond their acceptable amount. Once that happened they stop producing them and changed something in the process to get the pressure ring down to what they considered acceptable or removed completely.
...no, they were flat base bullets. Back then Hornady had a couple of bullets for them, FMJ, SP, Vmax, SST and the "Zombie" (which was essentially a Vmax/SST with neon green tip). The nominal diameter was .310 so resizing took them down .020, I would imagine same could be done with the 112 Burners you have. The ram the bullets sit on is flat so even a boat-tail could be used. The ogive actually helps to center the bullet and it should only affect the oversized area you identified, not the full bullet body...
...for me the approximate cost of $20 dollars was a minimal amount that I could walk away from if it didn't work out, but I could also just use it for my pistol reloading, especially since my ancient Star lube/sizer for .45ACP was lost in a moving shuffle...
I imagine it's worth a shot. I wouldn't think that I'd actually be resizing the bullet, just touching up the pressure ring area. I don't think that would be enough to deform the boat tail or separate the lead from the jacket? That would likely be disastrous at 300,000 RPM.
...really only one way to find out
...and I'd do it with a bare muzzle, not brake or suppressor attached.. Finally got around to measuring some 112gr from batch # 7276476-4. The first measurement is near the center of the cylindrical bearing surface of the shank, and the second is at the pressure ring on the same bullet.
Shank _____ Pressure ring
0.2431 _____ 0.2441
0.2430 _____ 0.2439
0.2432 _____ 0.2439
0.2432 _____ 0.2438
0.2431 _____ 0.2440
0.2431 _____ 0.2439
0.2431 _____ 0.2439
Seems like a sizeable bulge, I've only looked at some 108gr ELDs, and some 105gr MBs for comparison, but they don't show anywhere near the delta between these measurements that the 112gr do.
Shank _____ Pressure ring
0.2431 _____ 0.2441
0.2430 _____ 0.2439
0.2432 _____ 0.2439
0.2432 _____ 0.2438
0.2431 _____ 0.2440
0.2431 _____ 0.2439
0.2431 _____ 0.2439
Seems like a sizeable bulge, I've only looked at some 108gr ELDs, and some 105gr MBs for comparison, but they don't show anywhere near the delta between these measurements that the 112gr do.
Thanks for making me paranoid. 
Lot # 7276476-8
Shank - - - Pressure ring
0.2435" - - - .2440" (x10, SD = 0 over the 10 I measured...)
I've shot ~2000 of these and still have ~500 more of this same lot and they have been great for me. I just got 2000 more all from the same (but different) lot, but I haven't seen anything (besides this thread) to get into them and start measuring them...
EDIT: @Gtscotty I haven't experienced/felt anything wonky while seating bullets, and my bullets stay put ...but I anneal every firing/loading with an AMP, FL size followed by a mandrel, and am pretty OCD with my brass prep in my quest for consistent neck tension... not sure if any of that is different from how you do it.
Lot # 7276476-8
Shank - - - Pressure ring
0.2435" - - - .2440" (x10, SD = 0 over the 10 I measured...)
I've shot ~2000 of these and still have ~500 more of this same lot and they have been great for me. I just got 2000 more all from the same (but different) lot, but I haven't seen anything (besides this thread) to get into them and start measuring them...
EDIT: @Gtscotty I haven't experienced/felt anything wonky while seating bullets, and my bullets stay put ...but I anneal every firing/loading with an AMP, FL size followed by a mandrel, and am pretty OCD with my brass prep in my quest for consistent neck tension... not sure if any of that is different from how you do it.
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I've shot enough of these to feel sorry for the guys having issues with them, all while I'm buying more of them.
Thanks for making me paranoid.
Lot # 7276476-8
Shank - - - Pressure ring
0.2435" - - - .2440" (x10, SD = 0 over the 10 I measured...)
I've shot ~2000 of these and still have ~500 more of this same lot and they have been great for me. I just got 2000 more all from the same (but different) lot, but I haven't seen anything (besides this thread) to get into them and start measuring them...
EDIT: @Gtscotty I haven't experienced/felt anything wonky while seating bullets, and my bullets stay put ...but I anneal every firing/loading with an AMP, FL size followed by a mandrel, and am pretty OCD with my brass prep in my quest for consistent neck tension... not sure if any of that is different from how you do it.
I'm annealing every time as well, I am just using FL collet dies instead of a mandrel. How much neck tension are you using?
~.002 -.0025" (.268" bushing, followed by .241" mandrel)
Strange, if anything I'd think I'd be worse off than you because I'm running necked-up 22-250 Rem brass with shorter than normal necks..?
Lapua doesn't make LRP 6CM brass, so I made it myself (I just ran the mandrel through them, loaded and shot them... and FYI/FWIW they shoot great even while fire-forming). After 4 firings they're still only scratching SAAMI minimum now at ~1.90-1.88" (haven't trimmed them, and may never have to).
I'm also jumping a bunch (~.100" off the lands, CBTO is 2.145" using the Hornady comparator), so I'm seating the pressure ring past the neck/shoulder junction.
When you say "FL collet dies" do you mean a FL die followed by a Lee collet die..? and, If so, is the collet die's mandrel stock/standard at .242"..?
Just spitballing here: but there might be a chance that the extra .001 thou of neck tension I'm using (if you're using a .242" mandrel) is the difference... or, and this is a super long shot: I've heard some say using a Lee collet die after a FL die can be a little weird here and there since, done that way, one is effectively/literally sizing the shoulder/neck twice in a row, which some say isn't the best, since it's introducing a tiny bit of work hardening and undoing the slightest bit of what you just made right during annealing, and possibly introduces slight concentricity errors... but that's kind of wading deep enough out into the weeds to drown.
Yeah, 6GT and 6CM are different, but I think it's weird that I'm not seeing the same issues if the pressure ring is "oversizing" the necks during seating...
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Sorry, brain fart, I meant to type "FL bushing dies" not collet dies, RCBS Matchmaster to be specific. I'm not doing double sizing or anything like that, just size with the bushing die, clean the necks, charge and seat.~.002 -.0025" (.268" bushing, followed by .241" mandrel)
Strange, if anything I'd think I'd be worse off than you because I'm running necked-up 22-250 Rem brass with shorter than normal necks..?
Lapua doesn't make LRP 6CM brass, so I made it myself (I just ran the mandrel through them, loaded and shot them... and FYI/FWIW they shoot great even while fire-forming). After 4 firings they're still only scratching SAAMI minimum now at ~1.90-1.88" (haven't trimmed them, and may never have to).
I'm also jumping a bunch (~.100" off the lands, CBTO is 2.145" using the Hornady comparator), so I'm seating the pressure ring past the neck/shoulder junction.
When you say "FL collet dies" do you mean a FL die followed by a Lee collet die..? and, If so, is the collet die's mandrel stock/standard at .242"..?
Just spitballing here: but there might be a chance that the extra .001 thou of neck tension I'm using (if you're using a .242" mandrel) is the difference... or, and this is a super long shot: I've heard some say using a Lee collet die after a FL die can be a little weird here and there since, done that way, one is effectively/literally sizing the shoulder/neck twice in a row, which some say isn't the best, since it's introducing a tiny bit of work hardening and undoing the slightest bit of what you just made right during annealing, and possibly introduces slight concentricity errors... but that's kind of wading deep enough out into the weeds to drown.
Yeah, 6GT and 6CM are different, but I think it's weird that I'm not seeing the same issues if the pressure ring is "oversizing" the necks during seating...
View attachment 7735422
Ok, cool, got it.
Then weird, IDK? Maybe try a mandrel (or a Lee collet die - which some do swear by and sort of does the same thing)? Definitely odd.
...Honestly (and besides the potential Match Burner issue), in the pursuit of getting more consistent neck tension, I'd be a terrible human if I didn't recommend a mandrel to anyone not already using one, cut my SD's in half and I'd never go back to just the FL bushing die alone. Yeah, adds a step, but so worth it IMO.
Just curious what your jump is? Was thinking if you’re very close to the lands that maybe the effect of stretching the neck may be less? That is if the pressure ring is possibly causing a tension problem as mentioned in an earlier post?Thanks for making me paranoid.
Lot # 7276476-8
Shank - - - Pressure ring
0.2435" - - - .2440" (x10, SD = 0 over the 10 I measured...)
I've shot ~2000 of these and still have ~500 more of this same lot and they have been great for me. I just got 2000 more all from the same (but different) lot, but I haven't seen anything (besides this thread) to get into them and start measuring them...
EDIT: @Gtscotty I haven't experienced/felt anything wonky while seating bullets, and my bullets stay put ...but I anneal every firing/loading with an AMP, FL size followed by a mandrel, and am pretty OCD with my brass prep in my quest for consistent neck tension... not sure if any of that is different from how you do it.
I'm ~.100" off, piss drunk on the bullet-jump kool-aid, nowhere near the lands.
Granted, I only measured 10 bullets, but with mine it was only .0005" difference between bearing surface (shank) at .2435" and pressure ring at .2440"... and even with annealed-every-time brass there is still a hint of spring-back, maybe just enough, IDK? No issues.
Maybe the big jump does the same?
IDK, I haven't had any issues... but I did measure a couple Hornady 108gr ELD-M's and they were .243" at the bearing surface (shank) and the same .243" at their pressure ring, so there is a chance the Match Burners (with their fatter pressure ring) are indeed messing with some guys I guess...
That said, I'm a little OCD when it comes to bullet seating and want it to be as smooth and as consistent as I can make it and I think that probably helps.
I'm probably a little more crazy when it comes to brass prep than most (and of course, less crazy than others); I've spent a lot of time and $$$ trying just about every which way to clean brass for precision rifle... including: 3 different types of ultrasonic cleaners (up to and including the most powerful smaller commercial-type available), different soap/Lemishine combinations, a bunch of testing between wet and dry tumbling with a bunch of different types of media, and about 10+ different ways of wet tumbling (with pins, no pins, a small amount of pins, a lot of pins, a little water, lots of water, different numbers of tennis balls in the tumbler with the water, and just about everything in between)...
The main 2 reasons I've tried all that crap is:
#1 - Repeatability - decided since I can't control the brass being the same amount of dirty every load cycle, I might as well control it all being the same amount of clean every time.
#2 - Eliminating peened case mouths - yeah, wet tumbling works awesome, but wet tumbling without fucking up case mouths is much harder to figure out.
In the interests of seeing if there's anything special that I'm doing that might be helping, here's my whole brass prep regime I've settled on (for now):
(After firing, all my cases get annealed on an AMP, Aztec mode since all my brass is from the same lot.)
1. Deprime/decap
2. Wet tumble in rotary tumbler - 100 cases, 7L tumbler with 5lbs of SS pins and enough Pelican cut-up foam wedges to take up most of the tumbler volume before filling it all the way up with water and then adding a 1-2 second pour of Armor All Wash & Wax and 1/2 a 9mm case full of Lemishine - usually 30-45mins, never more than 1 hour.
My 2 "secret ingredients" are: the Armor All Wash & Wax is absolutely essential to me - it leaves a thin layer of wax behind on the cases and inside the necks post rinse that helps with sizing and later when I get to seating bullets. After trying the tennis ball thing, I decided it was a good idea to take up the volume of the tumbler so cases couldn't bounce around so freely, but the tennis balls were too heavy handed and actually seemed to agitate a small percentage of cases even more aggressively than usual... IDK how I thought of it, but I had some extra Pelican foam kicking around so I cut up a few pieces and put it in the tumbler and it worked pretty damn awesome... through experimentation I've now arrived at cutting up the foam into little wedges like girls use to apply makeup, it takes up the volume in the tumbler and keeps the cases from crashing into each other so hard, but the smaller wedge shapes seem to let the brass migrate around better (I'm still sort of playing with this, but it definitely helps big time).
3. Dry brass in brass dryer (food dehydrator type) 2-4 hours (depending on how cold my garage/outside is).
4. Lube with spray-on lanolin/alcohol case lube and swirling the cases around in a bucket (not aggressively, because I'm still trying to baby the case mouths).
5. FL size with a bushing die -0.003" under loaded round neck OD (for me that's a .268" bushing, my loaded neck OD is .271"), expander/decapping stem removed. (I use an LE Wilson die with a TiNi Redding bushing)
6. Mandrel die with .241" mandrel (TiNi Sinclair turning mandrel).
7. Dry tumble in vibratory tumbler and 20-40 grit corn cob blast media for 1 hour.
This removes the lube, but it is gentle enough where it leaves most of the Armor All wax behind on the inside of the necks, and the special 20-40 grit media is important because picking corn cob kernels out of 99% of the flash holes fucking sucks. I don't just do this too remove lube, the corn cob does put off some dust, not nearly as much as walnut media, but enough to where the dust does really seem to help at bullet seating... and I've also found that the usual/normal coarser grit corn cob media like Lyman and most others sell (that gets caught in all the flash holes) actually produces more/better dust than the finer 20-40 grit stuff so I still use some of the coarser stuff later...
8. Trim for consistency (or just if necessary), once my brass is all above 1.9" I'll be trimming every cycle so they're all uniform (I recommend one get a good trim tool so it doesn't suck and goes fast).
9. Inside neck chamfer (VLD type), always, ...but I only lightly deburr the outside of the necks if it's new brass and/or freshly trimmed.
For the chamfer I don't get too aggressive, I want the brass to either be silent or "whistle" on the cutting tool, I'm not trying to remove more material than I have to.
10. Prime
11. Powder
12. Bullet seating - I dip the base of the bullets in the coarse corn cob media just to grab a little extra dust to help with seating. It's the same sort of thing as guys do with graphite dry lube, but it's not as messy or heavy handed (I feel like the graphite is actually too slippery and masks if anything else is going on with the seating pressures). I'm actually still playing around with this step as I also like using a q-tip with a little lanolin/alcohol lube on it in the necks before seating too, just not totally sold on which method I prefer because they both work well...
- As an aside, after listing out all those steps, it's pretty funny that in another thread on the forum the other day, someone was giving me shit saying I'm lazy and don't put enough effort into my reloaded rounds and/or load development because I disagreed with them about OCW/ladder test nonsense.... if they only knew.
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I’ve only shot a little over 500 through my 6bra and haven’t had any troubles with a 1:7 barrel. I’m running them very slow and jumping FAR. Only reason I’m moving on is because at mag length I can’t get anywhere near the lands with my freebore.
I had 5 blow up at the last match I shot them in...I went back to D-Tac's the following weekend with no problems. 6XC @ 2820, 7 twist
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What lot number? Did you contact barnes about the issue? I'm curious how barnes will deal with the situation.
I just bought 500 before I saw this thread. Turns out mine are the same lot as what was shown except mine are -10 not -9 if that makes a difference. I still have about 150 of my original lot. I measured the new lot which were .243 for the mid bearing surface and from .2435 to 2.44 at the pressure ring. My original lot (7225641-1) were all .242 with no pressure ring that I could measure. And they shot as good as DTACs
I will be VERY interested to see what Barnes says about these. I would think that like Sierra and Berger that they would shoot each lot for accuracy at a distance and it would have shown up in their testing but... I guess something could get by. It would be interesting if other people with this lot don't see an issue. I figure in January I am going to build up maybe 25 and give them a test but the longest range I have to test on is 100Y.
David
I will be VERY interested to see what Barnes says about these. I would think that like Sierra and Berger that they would shoot each lot for accuracy at a distance and it would have shown up in their testing but... I guess something could get by. It would be interesting if other people with this lot don't see an issue. I figure in January I am going to build up maybe 25 and give them a test but the longest range I have to test on is 100Y.
David
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