Definitely look for a carbon ring. But, I think the above is really your issue. Trashed brass (loading it hot), in my experience, starts expanding at the base too much and leads to clickers and other pressure signs. I'd test one piece of new brass and shoot it with your load until you get the same signs. Then, you'll know how long the brass will last.
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Increase in pressure?
- Thread starter Ucsdryder
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AnesthesiaMD
Well-Known Member
Do you shoot suppressed?? I don't remember reading that but could have missed it. If you do, my bet is carbon ring. And in my humble experience those are NOT removed with simple cleaning and patches. Patches can look spotless and still be a mess just past the chamber. I had the same thing happen to a 6.5x47 rifle that I shoot suppressed and it took JB bore paste and some work to get it cleaned of the ring…..and yes I have a nice borescope which is how I found out what was going on. It could also be a starting carbon ring combined with a stout load bc your charge weight is on the upper end of a 180 weight bullet in a 7 saum case. Let us know what you figure out.
QuietTexan
Well-Known Member
Copper fouling was my first gut reaction. Barrels are unique, and there doesn't seem to be any rhyme or reason to them. My most recent Mullerworks barrel copper fouled bad for some reason, breaking it in side by side with a Kreiger that picked up almost no copper and barely had any blue on the patches. Both overbore chambers shooting Berger bullets on the same schedule. The Mullerworks shot smaller out of the gate though even with the copper there.
FWIW I clean my suppressed barrels with VFG pellets, kroil, and JB paste, but haven't had carbon ring issues. Some of them go 100+ rounds without cleaning, one 6.5CM with several hundred with no problems. I guess I've never seen a carbon ring in person apparently, or if they're there then they come out with normal cleaning?
AnesthesiaMD
Well-Known Member
Using JB will take care of it/keep it from forming in the first place. When I first started shooting suppressed I was learning (and still am!) but my cleaning regimine consisted of passing a patch with a "cleaner" (boretech normally) and doing it until it was "clean". Then I realized that baked on carbon esp with a suppressor was incredibly hard to clean without using a light abrasive like JB or a solvent like ThorroClean (which is awesome by the way). I "thought" I was doing a good job until I started having the same issues as the OP. Took care of the ring and now clean similar to above on my suppressed rifles and don't have issues anymore.
QuietTexan
Well-Known Member
Fair enough, JB/Kroil is "normal" cleaning for me, maybe I should be less aggressive with cleaning in general. The rifle that went almost 400 shots without cleaning was a 6.5CM with H4350, and it was overall surprisingly clean when it finally opened up. Maybe that combo doesn't lend itself to ring formation, it's not overbore/a magnum like guys seem to have issues with. I thought it would be worse than it was because of the can and I was stepping on it hard with those loads.
RockyMtnUT
Well-Known Member
I just trashed some adg saum brass with exact results as OP. Ran new brass and backed down a couple +grains. lost some pockets at 3 firings
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RegionRat
Well-Known Member
Works the other way around, adding water slows it down and also affects the density which is a double whammy if you load by volume.
https://chronoplotter.com/2021/08/19/how-does-humidity-affect-powder/
I'm also thinking carbon ring given the symptoms you describe. The issue with hard carbon(ring or barrel slick) is that patches will(deceivingly) come out clean when using a typical cleaning process. The aid of a bronze brush and periodic JB Bore Paste will keep the hard carbon build-up in check. A velocity increase at 100-200 rounds on a new barrel is quite typical….A pressure increase isn't…. if carbon is kept in check. IMO…
Ucsdryder
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Does anybody have a picture of a carbon ring through a bore scope? Need to know what to look for.
I'll take a shot at it…along with throat erosion, copper fouling, and fired-cracking. (Not my photo, but a decent depiction)
Ucsdryder
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Reminds me of an ultra sound. I see nothing…tech sees a penis…
Not to be mean, but that bore scope is useless. If it's a Teslong, you need to install the tips and get it in focus by adjusting it in and out with the stopper.
I can tell you ran it from chamber to muzzle, but that is about it.
I can tell you ran it from chamber to muzzle, but that is about it.
GSSPatterning
Active Member
Something to consider. If starting with a fresh bottle/jug of powder, that powder has a particular amount of moisture in it. It weighs a certain amount of weight for a set volume. If that powder looses any moisture the the same weight as before now has more volume. If you're not capping your powder containers tightly or your leaving your powder in the powder hopper it is loosing moisture/weight and the volume of powder in your case is increasing. Return your powder to it's tightly capped container immediately after each loading session.
