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What's up with this?

Same powder, same bullet and same chamber (6mmBR) in different barrels but one has pressure signs earlier than the other? Varget is the powder and loading for 80gr Berger flat base bullets jumping .012 and both barrels are Criterion. One shoots awesome at 33.0 grs but the other barrel has tight bolt lift at 32.6 grs and on half of the loads at 32.4 I get the "click" at the top. Possible that Criterion changed or used a different reamer? The new barrel does not shoot as good as my older one.
 
I’m guessing a different reamer.have you measured fired cases from each barrel?...I’m betting there not the same at all. Also take your bore scope and make sure your case neck on a chambered empty case isn’t to long.
Wayne
 
Same powder, same bullet and same chamber (6mmBR) in different barrels but one has pressure signs earlier than the other? Varget is the powder and loading for 80gr Berger flat base bullets jumping .012 and both barrels are Criterion. One shoots awesome at 33.0 grs but the other barrel has tight bolt lift at 32.6 grs and on half of the loads at 32.4 I get the "click" at the top. Possible that Criterion changed or used a different reamer? The new barrel does not shoot as good as my older one.
I dated twin sisters once, long ago. They looked the same but had completely different personalities!
 
I’m guessing a different reamer.have you measured fired cases from each barrel?...I’m betting there not the same at all. Also take your bore scope and make sure your case neck on a chambered empty case isn’t to long.
Wayne
I have a few 6mmBR's and I try to set up the barrels headspace to be able to use brass from one in another and I have been able to pull that off with all but one rifle that has a "tight" chamber. I have to use a different die on that gun. Another reason Savage is nice, I can easily set headspace in my garage. Sometimes it takes a few tries though to get them the same.
 
Had a 6BR Savage barrel that would show pressure signs with moderate even light beginning loads. I didn't have a bore camera at the time, but suspected it was a "tight, rough" bore. Went to a slower powder, VVN160, and was able to get the MV I wanted with no pressure signs.
As to Criterion barrels. You didn't mention how much older the old one is, however I just got one that has yet to shoot < 1 MOA. I've tried different loads and bullets. Very disappointed.
 
Barrels/chambers are like fingerprints and snowflakes...no two are ever exactly the same, even if cut with the same reamer. You might consider determining water volume of a few cases fired in each rifle. It's a fairly simple and minimally painful experiment. If there is a significant difference in the way the chambers were cut, that might reveal it.
 
Had a 6BR Savage barrel that would show pressure signs with moderate even light beginning loads. I didn't have a bore camera at the time, but suspected it was a "tight, rough" bore. Went to a slower powder, VVN160, and was able to get the MV I wanted with no pressure signs.
As to Criterion barrels. You didn't mention how much older the old one is, however I just got one that has yet to shoot < 1 MOA. I've tried different loads and bullets. Very disappointed.
had the same problem with a .308 Win from Criterion a few years back. I tried several different bullets and three or four different powders and could never get sub MOA performance even at 100 yards. At James of Northlands suggestion I contacted Criterion they paid for shipping back. They said they could not find anything wrong but they replaced the barrel anyway. The barrel they returned must have received extra TLC becasue it broke in faster than any barrel I have ever owned and was a tack driver for close to 4K rounds with a couple of different powders and 155.5 Bergers, 168 SMKs, and 175 SMKs.. When It started to lose accuracy I had a buddy set it back, shortened it and tapered in a sporter profile and used it in a hunting rifle build for the son in law.

You may want to call Criterion and talk to them, they are great people to deal with
 
I married a twin, and wife's twin sister lives next door. :rolleyes:
I married a twin, he sister thankfully lives far away. As my wife is the younger, the older likes to tell her what to do. Forty seven years later and it still happens. She (the older) believes salad dressing is a waste of money. That is just the tip of the iceberg. Her in her husband are cheap, not poor, can remember more than one occasion where broke down on the way to holiday gatherings. You have not lived until you make a road trip on the interstate at 55 when every one else's is growing 80. What was the topic.
 
I married a twin, he sister thankfully lives far away. As my wife is the younger, the older likes to tell her what to do. Forty seven years later and it still happens. She (the older) believes salad dressing is a waste of money. That is just the tip of the iceberg. Her in her husband are cheap, not poor, can remember more than one occasion where broke down on the way to holiday gatherings. You have not lived until you make a road trip on the interstate at 55 when every one else's is growing 80. What was the topic.
lmao
 
Two probable reasons: In the absence of one chamber but deeper, resulting in noticeably longer shoulder to base length - I'd attribute it to a tighter barrel diameter on one versus the other. I have ordered "twin" barrels from the same manufacturer many times, cut on same reamer by same guy - and within .003" base-to-shoulder lengths. None of the "twins" ever had velocity within 40 FPS with the same load. In one case - the difference was almost 150 fps. These were all "premium" barrels from the "best" manufacturers. I'd say normal if you are running a load right up at the top. One will hit the wall before the other every time.
 

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