pressure problem i can't figure out

[rockwind1]

i have a GAP extreme hunter in 6.5 saum (gap 4s) it gets pressure problems really quckly after a good cleaning. lately, within 3 or 4 rounds. the mv starts out normal, then goes up and by 3rd or 4th round, ejector marks, slight resistance lifting bolt.

the barrel is a bartlien 2b 24" with a harvester suppressor on it, approx 400-500 rds thru it although it had a radial gap brake on it for almost all of those rounds and had the same pressure problems (this has been over the last year or 2)

i've scoped it and haven't seen anything that jumps out.

although my reloads do the same thing, i have also tried 2 types of factory ammo, copper creek which uses hornady brass, 140 berger hybrids, and h1000. conservatively loaded at 3000 ish fps and well off the lands, like 40 thou.
the copper creek used to work just fine as far as pressure

the other factory ammo is prime. not conservativly loaded, it starts at 3150 ish and shows pressure right away

i loaded so many different combos for it trying to solve this problem i think it is something i am missing. has anyone had a similiar problem

i clean with wipe out patch out and the accelleratant, also use boretech products, eliminator, carbon removal, copper removal.

becoming frustrated

 

[MikeMcCasland]

Does this problem only occur after cleaning? If so, you're likely leaving some cleaning product in the chamber, and it'll do exactly what you describe.

You must remove all traces of cleaning solvents/moisture out of the chamber, or you're almost guaranteed to see pressure spikes until the chamber drys out.

 

[Brady W]

Hey Rockwind -

One of the first things I look into when I am seeing pressure problems that I know isn't the load (which we are not ruling out yet) is to check a couple of other things before I dive into a problem with the chamber/bolt/barrel, etc.

While you are not seeing extreme pressure signs - i.e. not piercing/popping primers - have you checked the head space on your brass? If you have the gauges, check a new round and a fired round. If the new round is longer than the fired round, there is a head space problem. The brass is getting sized down, even slightly, and can cause excessive pressure.

The next thing is to see if there is a carbon ring. That 6.5 SAUM is a pretty hot load, and hot rodding it can cause a build up of gunk and carbon at the mouth of the chamber. You should try scrubbing it out with some grey JB - only in the throat.

You can get some here: https://www.compasslake.com/index.p...ducts_id=295&zenid=mp8idbcl67uhscbn12g490p7u0

Is this the low node for your rifle? It is possible that this is too hot, especially when it is all fouled up?

If none of this is the problem, because I am sure that you know this stuff already, maybe we can do a little bit more digging. If you want, call us in the shop and one of us should be able to help.

Best of Luck! Brady @ Bartlein

 

[rockwind1]

Does this problem only occur after cleaning? If so, you're likely leaving some cleaning product in the chamber, and it'll do exactly what you describe.

You must remove all traces of cleaning solvents/moisture out of the chamber, or you're almost guaranteed to see pressure spikes until the chamber drys out.

i don't believe it only happens after cleaning. i am not a big cleaning guy i have only been cleaning it to see if it fixes the problem, which it seems to do for a short time. i have used jb past in the throat but my borescope shows the throat as clean. i don't see a carbon ring. where i do see a little bit of black stuff, and it isn't much, is right at the end of the neck (before it steps up to the throat)

when i first started loading for it with hornady brass, h1000, and berger 140 hybrids, i ran into a lot of problems, pressure too early and inconsistent results. i switched to norma brass and rl26 and all my pressure probs went away but i ran into a lot more temp insensitivity with the rl26,,,,at least i think it was temp insensitivity. i live in vegas and all my loads that had been at 3040 ish fps suddenly increased by 100 fps over 90 ish degrees. so i started with h1000 again and wasn't getting really good results. it has honestly been a shit show reloading for this gun and it's driving me crazy.. now even the old copper creek ammo is not working like it used to (i am not a fan of the CC ammo but at least it always worked)

i cleaned the heck out of it before trying the copper cr stuff again. i did put a suppressor on it which i hadn't had before.


as far as getting stuff out of the chamber, i feel i am pretty good about it, i even look with my borescope afterwards. i wrap a few 2" patches around a wire brush and put it on the end of a cleaning rod and go in there and run it all around and push it against the sides. it sure seems dry, any tips on improvements?

 

[rockwind1]

Hey Rockwind -

One of the first things I look into when I am seeing pressure problems that I know isn't the load (which we are not ruling out yet) is to check a couple of other things before I dive into a problem with the chamber/bolt/barrel, etc.

While you are not seeing extreme pressure signs - i.e. not piercing/popping primers - have you checked the head space on your brass? If you have the gauges, check a new round and a fired round. If the new round is longer than the fired round, there is a head space problem. The brass is getting sized down, even slightly, and can cause excessive pressure.

The next thing is to see if there is a carbon ring. That 6.5 SAUM is a pretty hot load, and hot rodding it can cause a build up of gunk and carbon at the mouth of the chamber. You should try scrubbing it out with some grey JB - only in the throat.

You can get some here: https://www.compasslake.com/index.p...ducts_id=295&zenid=mp8idbcl67uhscbn12g490p7u0

Is this the low node for your rifle? It is possible that this is too hot, especially when it is all fouled up?

If none of this is the problem, because I am sure that you know this stuff already, maybe we can do a little bit more digging. If you want, call us in the shop and one of us should be able to help.

Best of Luck! Brady @ Bartlein

as far as nodes,,,,, this is happening with factory ammo, if you consider copper creek to be factory. and it is pretty conservative as far as headspace, jump, and mv

the prime 6.5 saum ammo is already known for being a bit spicy. i shot 2 rds thru it and it had pressure for sure at 3160 fps ( i relooked at my notes) which is way to high for that rifle. my reloads were always around 3040-3060.

 

[Rsadams]

Carbon ring , your not completely getting out..?

 

[MikeMcCasland]

So it's shown excessive pressure signs since new, in all weather conditions, or did this start later in the barrels life?

 

[FeMan]

I'll cast a third vote for carbon ring. What powder are you using and how/how often have you been cleaning?

 

[rockwind1]

I'll cast a third vote for carbon ring. What powder are you using and how/how often have you been cleaning?

has anyone ever borescoped and seen the carbon ring? was wondering what it looked like. i started with h1000, then tried rl26 for a bit, then went back to h1000. the copper creek ammo uses h1000. i normally don't clean that much, 50 ish rounds maybe. but since i started having these probs, i have been cleaning a lot more, just to experiment.

 

[rockwind1]

So it's shown excessive pressure signs since new, in all weather conditions, or did this start later in the barrels life?

not since new, probably had 200 + rounds of copper creek ammo thru it before i started reloading. i started noticing it more as i did load developement, now i am noticing it even with the copper creek ammo that used to be fine.

 

[FeMan]

I have avoided the issue with thorough cleaning so have not had the displeasure of looking for the ring. Two buddies had rifles go down from it though with similar descriptions as yours. One was using RL16 and the other RL23. Both are Tactical/PRS shooters and neither was cleaning thoroughly. One of them got his barrel back after a week of solid cleaning. The other guy got ticked off and tossed the barrel. I shoot RL23 and clean after 150 rounds or so, but I clean super well and take a couple of days soaking to make sure the carbon is softened and then removed. That's why I asked "how" you clean.

 

[D-4297]

I've read all the posts here , and thought about this before deciding to comment on the situation . Two things I haven't heard mentioned here are ; Neck diameter , and Neck length . If this rifle has done this , regardless of the ammo , to one varying degree , or another , since new . It sounds like there isn't enough clearance for the neck to expand properly , to release the bullet . And a "short" neck-length , where the case-mouth is very close to the end of the neck bore can also cause similar issues . Not saying that is the problem here , but it may be worth pulling the barrel to check it with a good intra-mic for diameter , and also check the length of the neck bore .

 

[Lone Hunter]

Or do a chamber cast and check the dimensions.

 

[rockwind1]

Hey Rockwind -

One of the first things I look into when I am seeing pressure problems that I know isn't the load (which we are not ruling out yet) is to check a couple of other things before I dive into a problem with the chamber/bolt/barrel, etc.

While you are not seeing extreme pressure signs - i.e. not piercing/popping primers - have you checked the head space on your brass? If you have the gauges, check a new round and a fired round. If the new round is longer than the fired round, there is a head space problem. The brass is getting sized down, even slightly, and can cause excessive pressure.

The next thing is to see if there is a carbon ring. That 6.5 SAUM is a pretty hot load, and hot rodding it can cause a build up of gunk and carbon at the mouth of the chamber. You should try scrubbing it out with some grey JB - only in the throat.

You can get some here: https://www.compasslake.com/index.p...ducts_id=295&zenid=mp8idbcl67uhscbn12g490p7u0

Is this the low node for your rifle? It is possible that this is too hot, especially when it is all fouled up?

If none of this is the problem, because I am sure that you know this stuff already, maybe we can do a little bit more digging. If you want, call us in the shop and one of us should be able to help.

Best of Luck! Brady @ Bartlein

hi brady, i've reloaded before and have soooo many guages. wont' claim to be an expert but done enough to be pretty darn sure it is not the headspace. as far as the Prime Ammo, the fired case measures about .005-.006 longer than it was new. the cc ammo, same thing, it is longer.

other than the 2 rounds of prime ammo i tried in it, i have never hot rodded it, the 2 or 3 times i did load developement, i always stopped at first sign of pressure, never used a "node" that was close to the pressure thresh hold.

as far as this being a low node, i am actually getting these pressure signs with "factory" ammo, ie copper creek, that i have used in the past with no problems so i am not really on a "node".

i will try the jb paste though, can't hurt. i already have some. i also called you at work, left voicemail

 

[rockwind1]

I have avoided the issue with thorough cleaning so have not had the displeasure of looking for the ring. Two buddies had rifles go down from it though with similar descriptions as yours. One was using RL16 and the other RL23. Both are Tactical/PRS shooters and neither was cleaning thoroughly. One of them got his barrel back after a week of solid cleaning. The other guy got ticked off and tossed the barrel. I shoot RL23 and clean after 150 rounds or so, but I clean super well and take a couple of days soaking to make sure the carbon is softened and then removed. That's why I asked "how" you clean.

well, i have to admit, i don't soak it for a couple days. might try it. did your buddies ever visibly see the carbon ring with a bore scope before deciding that is what it was. sometimes it seems like the carbon ring is like the sasquatch of the shootin world

but i have long thought carbon ring for this problem, just kept thinking my cleaning would take care of it, only for it to pop up again.

 

[rockwind1]

I've read all the posts here , and thought about this before deciding to comment on the situation . Two things I haven't heard mentioned here are ; Neck diameter , and Neck length . If this rifle has done this , regardless of the ammo , to one varying degree , or another , since new . It sounds like there isn't enough clearance for the neck to expand properly , to release the bullet . And a "short" neck-length , where the case-mouth is very close to the end of the neck bore can also cause similar issues . Not saying that is the problem here , but it may be worth pulling the barrel to check it with a good intra-mic for diameter , and also check the length of the neck bore .

i like your thinkin. i tried a new load for this rifle with bertram brass, only to find out it is more designed for the no-neck turn chambers of .298. i will say bertram was super nice about it and let me return the brass, ( i wasn't into neck turning 400 cases at the time) i've since bought some adg brass which supposedly doesn't need neck turning for the tighter necked chambers like mine.

my neck is .2962 and the general consensus is that the hornady and norma brass don't need to be turned

i also have those sinclair tools to check neck length and i don't believe that is the issue after measuring, (you take a fired case, cut the neck back, stick this steel thing in it that is the same size as the od of the neck and then close the bolt, then measure to see exactly how deep the neck goes) then of course you know your trim length, i did that and it seem well within specs of the trim length recommend by gap, i am actually well under the trim length by .005.

as far as neck diameter, i have also looked into that by basically taking a fired round and seeing if a bullet will fit into it semi-snugly by hand and pull out, which it does. i've heard if it passes this test, it is probably fine. open to suggestions though

 

[Dusty Stevens]

That carbon at the end of the neck is missed by cleaning if you use a good boreguide. Maybe your factory ammo was longer, your reloads were shorter and let carbon build up, now your longer factory loads are getting pinched. Itll throw you off bad if this happens

 

[rockwind1]

That carbon at the end of the neck is missed by cleaning if you use a good boreguide. Maybe your factory ammo was longer, your reloads were shorter and let carbon build up, now your longer factory loads are getting pinched. Itll throw you off bad if this happens

thanks dusty!

 

[FeMan]

well, i have to admit, i don't soak it for a couple days. might try it. did your buddies ever visibly see the carbon ring with a bore scope before deciding that is what it was. sometimes it seems like the carbon ring is like the sasquatch of the shootin world

but i have long thought carbon ring for this problem, just kept thinking my cleaning would take care of it, only for it to pop up again.

I believe they did but am not sure. So no help there.

The one buddy who got his rifle cured of the problem had a 284 that shot 0.1 moa. It was (and now is again) a lazer! He used CLR, Bore Tech Carbon Remover, JB Bore Paste, many long soaks and lots of brushing. It took him the better part of a week but he got it restored and shooting lights-out again. It bugged him enough that he sold his RL23 and went back to H4831sc though.

 

[Rsadams]

Just look up carbon ring in the search function.... A very good cleaning isn't going to hurt anything....