Proof/suppressor problem?

[STLSteve86]

Have tenacity action, 22” proof sendero chambered in .308 (10 twist) that is dropping shot to shot with a TBAC 30-p1. Stock is a AG composite. Suppressor is fine and shoots great with other rifles. Target was duplicated back to back weekends from a cold bore. Shooting different factory loads with the same results. When the suppressor is off it will shoot 1/2” with 168 Berger hybrids from federal. Has anyone else seen this?

 

[ALShooter]

Action screws are to spec?

I have a 24” proof sendero 308 1:10 and don’t experience anything but a half mil shift down with a heavy spec war.

 

[STLSteve86]

Yes I even separated the action from the stock to check free float or anything else that could cause bad accuracy. Re-torque the action screws alternating back-and-forth 5 inch pounds at a time to 55 inch pounds The action was bedded when it was built.

 

[drglock]

I run a TBAC Ultra 9 with my Switchlug and 20” and 22” Proof CF barrels and have zero problems. I’d be checking stuff like action screws, scope screws and making sure your suppressor isn’t coming loose while shooting .

 

[STLSteve86]

Tried my Nightforce ATACR and a Nikon both with same results. Direct thread can and I check it often. I don’t shoot strings or more than 3 rounds in a minute.

here is another target with some more Berger’s. I shot the group on the right with the can on then while still hot took it off and put two on the black target to confirm it’s not me.

what the heck?

 

[Supersubes]

Is this a profit barrel, or a custom job?

My experience is like the other posters, no issues. May want to call Proof and get them in the loop.

 

[b6graham]

Can changes the node. Not uncommon. But that seems a little more than normal

 

[nn8734]

Any pressure signs on the brass when shooting suppressed?

edit: you shoot any other ammo through it w/the can on? If so, similar results or different?

I know with my cans and rifles, if the load is too hot, the gun will send shots low and to the right relative to the normal POI.

 

[BigTex]

Is the barrel still floated with the can on?

 

[b6graham]

Is the barrel still floated with the can on?

That's a good one actually

 

[WeiserBucks]

I use a 9" can on my Proof CF 7 RM , it has a huge POI shift with the suppressor mounted but accuracy is not affected at all .

 

[STLSteve86]

Still free float

poi isn’t consistent. Cold bore or warm moves lower with each shot.

no prefit. It was a custom build from a well known smith and is going to do some testing with it.

no pressure signs with the can on.

targets were shot at 100 yards

 

[nn8734]

Interesting case...problem seems to be related to the presence of the suppressor (not saying the suppressor itself is the problem, just it’s presence on the rifle).

Did this just start happening last weekend or was it always an issue?

Edited: just reread OP and multiple factory loads were shot with the same results.

You can rule out pressure as a potential issue by using a micrometer or dial caliper to measure the thickness of some unfired cases just above the extractor grove then measure your fired cases when the suppressor was on...if you see more then .002 expansion, you have an over pressure condition but ejector/extractor marks and primer cratering wouldn’t be visible yet...I dont start to see that stuff until the brass is expanding .003+

 

[AIAW]

Like a few others said, it’s most likely timing differently with the can attached. Rather common. If you don’t reload, best thing you can do is try different ammo brands to shift you into a different node. If you reload, then back to the drawing board with load development.

 

[STLSteve86]

Suppressed shots have been stringing down since the beginning. Never had a round come back up like I’ve seen on a semi-auto.

This is a brand new build that has maybe 50 rounds through it. Shot 1 and cleaned 1 first 10 times. I know break in doesn’t really do much different than if I hadn’t but I do it anyways.

no pressure signs from any loads. Can on or off. I did shoot some 175 smk hand loads I had from another gun but it didn’t like those. It will shoot most factory ammo .75 or better. The 150g cheap stuff I used during break in where almost 1”. 165 trophy noslers were not much better until I got into the 168 ammo.

 

[RTH1800]

Wow, new build. Scope, ring and can issues.
darn...

 

[STLSteve86]

Wow, new build. Scope, ring and can issues.
darn...

like my dad always says just rub some money in it and it will go away.

Rings are cheap and ordered some this morning. I’m sure the scope is ok just disappointed in myself but that’s what I get for burning it and at both ends working 76 hrs a week and trying to still have fun.

can shoots great in all my other guns. I have a 16” sps .308 factory that’s in a m40 stock that will shoot .80 with the can all day.

used the can on a trued 300 mag with a 24” proof and shoot great too with factory HSM ammo.

I hope it’s just a streak of bad luck that will get resolved. If it ends up getting another barrel I don’t know if I will take another chance with a proof.

 

[Aftermath]

I think I'd leave the can off and put about 200 rounds through the bore, cleaning etc appropriately. Then try the can again. 50 rounds is not that many downrange yet. I'm interested because I have 2 rifles currently being built with Proof barrels and a third with a Hells Canyon Armory carbon barrel. You might give Mike at Hells Canyon Armory a call and pick his brain.

 

[drglock]

Mine is mostly for hunting and I don’t go out and just shoot groups very often but do shoot steel at distance and have never had a problem with mine , even when the suppressor and barrel get so hot I have to stop because of the mirage coming off the barrel. This is 4 at 100yds shot with a 22” Proof CF in 6.5 Creedmoor and TBAC Ultra 9.

 

[SonicBurlap]

Time to give PROOF Research a call. Have heard of only one case of a new PROOF Research barrel having issues but they sure made it right for the guy. Their number: 1 (406) 756 9290

 

[STLSteve86]

Rifle has been sent back to the smith for them to test on. On a better note I took out my stock rem 700 16” and shot it to rule out me and the suppressor. Still using factory ammo. Same bipod and bags and the same cheap Nikon scope. First target was win 150g power points. Not ideal for a 10 twist. 4 shots after sight in. Second target is federal 168 smk 3 shots.

 

[6brshooter]

I have an AI Proof Prefit that does the same thing. I need to contact Proof and see about sending it back

Steel or carbon?

 

[STLSteve86]

I have an AI Proof Prefit that does the same thing. I need to contact Proof and see about sending it back

Can you post up some targets?

 

[STLSteve86]

I would be interested to see them.

I haven't kept any photos. I've been meaning to put it through a series of repeatable tests so I can document it in order to send it back to Proof. I've just been busy with other projects and work

 

[STLSteve86]

is there post of proofs delaminating? The goal of this gun was to keep weight as low as possible. Ya I could of went with a shorter barrel and a titanium action but this is what I ended up with. I hope it’s just a fluke and they see the same results as I have found.

I got cold feet and changed a current build to a steel barrel from a proof.

I have 6 proof barrels right now.

None of them do anything weird like that at all.

I have shot out 8 more proof barrels and none of them did strange shit either. Not much of a sample size I admit.

I suspect that either the gun is having a problem related to having a pound of weight at the end of the barrel (like walking in the bedding maybe)...Or the node changes badly on you...

Or maybe this is what proof barrels do if they delaminate. The extra weight causing movement.

 

[Snuby642]

Is the can a direct mount?
I had to work on an adapter just the other day to get one to lock up good.

Some barrels I have are harmonic sensitive to a can, some not much at all.
Some shot best with the can on no matter the load.

Have a 6.5g gasser that goes spastic if it even sees a can. Lol, wip.

 

[Snuby642]

@rubenskie
No the op, I changed up my post sory for any confusion its late.

We had to lapp in an AAC mount and it works fine now.
The can worked elseware we just missed it.

I saw adapter mount models on tbac and did not see it mentioned.

Evidently common on AAC mounts.

 

[STLSteve86]

This is a direct thread. 419 did some more testing with a ultra 338 with good results. They sent the gun back and it doesn’t look like they did anything to it but shot it and cleaned it. I haven’t had time to shoot it yet. Here is a picture of 419’s testing. I don’t understand why it took them 5 months to this kind of testing.

 

[Snuby642]

Well direct thread cuts down possibilities and also makes it more critical in any fix.

The aac mounts can be lapped on the mating cone (bearing surface) of the mount and any mistakes are on a replaceable mount.

The can is moving so not seated compleatly.

I would measure thread distsnce (length) on rifles it works on and compare. I would look at thread relief at shoulder and the shoulder on the barrel.

At times carbon buildup / removal was the culprit for me.

If it's hitting a thread relief or too long a competent gunsmith can take care of that.

Just some things I have ran into on our cans.

 

[STLSteve86]

This is a brand new rifle they built. You would think area419 wouldn’t have this problem. Craig at 419 says it could be me and that the rifle is too light. Lol. My groups don’t look that bad at 800 yards

 

[Huskydriver]

I have a carbon proof axmc prefit that can't hit the broad side of a barn if I use any of my heavy cans on it. Without the cans, the proof groups okay. Those cans on my other steel barrels absolutely hammer.

Put a lightweight can on the proof, it groups okay

I really think the carbon barrels are way more sensitive to weight on the muzzle

 

[STLSteve86]

I have a carbon proof axmc prefit that can't hit the broad side of a barn if I use any of my heavy cans on it. Without the cans, the proof groups okay. Those cans on my other steel barrels absolutely hammer.

Put a lightweight can on the proof, it groups okay

I really think the carbon barrels are way more sensitive to weight on the muzzle

this is what’s happening! Area419 produced the latest groups I posted a few weeks ago. I couldn’t believe it. I have only had groups that tight with the can off. I have a feeling I’m going to produce the same results I shot last time. My groups with the 30-p1 will drop 1/4” each shot at 100 yards. I havent gone further than 5 shots at a time so I do not know how far down it will impact.

 

[Huskydriver]

this is what’s happening! Area419 produced the latest groups I posted a few weeks ago. I couldn’t believe it. I have only had groups that tight with the can off. I have a feeling I’m going to produce the same results I shot last time. My groups with the 30-p1 will drop 1/4” each shot at 100 yards. I havent gone further than 5 shots at a time so I do not know how far down it will impact.

Yea with a titanium can I can get repeatable sub moa .8ish groups np...

If I put my saker ASR on there it's a full 16 mil shift left and 1 mil down but hey it's repeatable lol!

 

[hlee]

I had terrible precision with my RPR and thunder chicken. Yes, this is a steel barrel and a different can- bare with me. I found that hand tight, the suppressor would slowly try to walk off the end of the barrel. Torquing the can to 25 ft-lbs cured the slow loosening of the suppressor, and the rifle is as accurate with the can as it is without- though with a 0.7 mil shift down...

 

[Iznthesky]

My first reply here....but this is just one minor check that will cost nothing.
take a couple of good High Def photos of the threads and SHOULDER of the muzzle.
one of my rifles was accurate, however with the suppressor attached...the impact was unreasonably shifted.
Several gunsmiths could not diagnose the culprit.
Good High Def photos of the threads and shoulder revealed the threading job was straight and true.....but the shoulder was not perfectly square. It was minor...almost unnoticeable, especially with the thread protector installed, but when the suppressor was tightened,
it caused a shift in impact.
The barrel was removed and the shoulder was squared. The threads and crown were not touched. They only took about 1/100th to square it...but the results were no shift in impact with or without the suppressor.

 

[kingzero]

^^^^^ Holy balls, that's terrible.

 

[BigTex]

Maybe it's just the photo but that is far from "almost unnoticeable". That is Busch League shit. I'd be finding me another gunsmith ASAP.

 

[Iznthesky]

My eyes aren’t as good as they used to be....and I was Taken by surprise with the impact shift. My first contact was to the suppressor manufacture. It was the suppressor maker that gave me list to check that led me to closely examine and HI-Definition Photos of the factory muzzle and the internals of the can. Sure enough....they were correct. I had shot this rifle quite a bit before tightening up a can on it.....and I never thought twice about the threads or the shoulder....until the excessive impact shift. A lazy barrel maker pulled the cutter away from the barrel before the Shoulder was completely cut square. As a simple exam..... I thought I would pass it on. It might help someone.

 

[JeffLebowski]

You’re keeping the barrel cold, not heating it up? Otherwise, I’d agree on checking the shoulder and threads.

 

[STLSteve86]

You’re keeping the barrel cold, not heating it up? Otherwise, I’d agree on checking the shoulder and threads.

yep, always stays cool

 

[STLSteve86]

I took the gun out again this time shooting the first 5 rounds unsuppressed clean cold bore. Using 175G black hills ammo, first round was low right the rest of the groups was me but stayed together.

the 30-p1 went on for the next 13 rounds. Using a bipod and a rear bag took my time and watched what I had seen before. Shots starting walking down as if I was dialing for it. This time on the drop it looks as if it were pausing every other round. Here we go again! Another 5 months this gun would sit at area419 if I sent it back just to hear it shoots fine.

with the chamber open my wife and I went down range for a closer look. No more than a few minutes. Proceeded to shoot for a second group on the left side of the target. I settled in and let one go. Already I could see 1” low of aim. So the next 6 rounds that where left in the box I loaded the bipod and continued to shoot. Still With a low Poi i was able to produce two 3 shot groups close to each other. Best I've seen this pos shoot to date. Now I’m baffled how after 3 rounds the group shifted and produced another 3 rounds. I’m starting to guess that’s why area419 sent photos of 3 shot groups and not 5.

so now is this a bedding or AG stock issue? I don’t want to go on a wild goose chase so I will swap stock and go shoot again soon.

 

[BigTex]

No offense intended, but have you had someone else shoot the rifle? If shooter error can be ruled out, it could be a bedding issue, but you have horizontal stringing sometimes and vertical stringing other times. Is your parallax adjusted correctly? How does it shoot at distance?

 

[STLSteve86]

No offense intended, but have you had someone else shoot the rifle? If shooter error can be ruled out, it could be a bedding issue, but you have horizontal stringing sometimes and vertical stringing other times. Is your parallax adjusted correctly? How does it shoot at distance?

none taken. I’m trying to get my dad to shoot it as well as a friend that is a great shooter. My range close to my house only has 200 yard range. I’ve ruled out the scopes. Nikon, atacr, Vx5-hd. Just had to throw in the Nikon for the heck of it. I’m hoping it’s just the stock. The same suppressor produced amazing results in my gap hospitaller with zero poi shift. little shift in A factory rem 700 gun but still a great shooter for $600

 

[mkelly]

It's it possible the threaded muzzle is out of spec, not concentric?

 

[STLSteve86]

It's it possible the threaded muzzle is out of spec, not concentric?

it could be but I can’t check it. I have looked at the shoulder too for squareness. you would think This wouldn’t be an issue unless someone new was on the mill that day.

 

[Iznthesky]

Iam impressed....Stl-Steve is doing a very comprehensive diagnosis on this issue and we will all benefit from his journey to discovering what gremlin is affecting the accuracy of his rifle.
Iam with Steve on this one.... I think he is chasing the correct ghost on this one....the Stock....or rather how the stock is contacting the action / barrel.
good luck Steve....keep us posted

 

[Torchy]

Iam impressed....Stl-Steve is doing a very comprehensive diagnosis on this issue and we will all benefit from his journey to discovering what gremlin is affecting the accuracy of his rifle.
Iam with Steve on this one.... I think he is chasing the correct ghost on this one....the Stock....or rather how the stock is contacting the action / barrel.
good luck Steve....keep us posted

I have a pretty good amount of experience in these situations. I think your correct.

I'll add that if your stock is very close to the barrel (tight barrel channel) and you are using a very heavy can, it could be hitting the stock. I can almost guarantee it.

Thanks OP and keep us posted.

 

[STLSteve86]

Turns out I don’t have another chassis that will fit a proof sendero. So after talking to a local smith and weighing the $85hr shop rate and me knowing they may not try what I would do or they don’t have a chassis on hand that would fit that sendero contour I decided to call proof again.

I got lucky and got the same gal I talked to the first time or maybe that’s just who handles the calls about possible issues. They where happy to email me a RMA. It’s now on its way to Montana for Proof to see if they can duplicate my issues.

I hope it’s as simple as a stock and I will leave it with proof if they can put it in a manners for me. At this point I have reason to believe it’s the stock or the barrel. I have proven the can on a few rifles so that’s out. I have shot a friends 300 win mag in this same model stock from AG with a 24” sendero proof with awesome results. Built on a 700 action and I used this same suppressor. That 300 is what stemmed this whole project and the fact that 419 could do a 6 week turnaround.

i have already made up my mind if this problem I’m having doesn’t exist for proof. This rifle will be sold and I will start over. I have bigger problems like trying to find a place to hunt this year so I can stay safe and away from people lol.

I let y’all know what proof says when I know. Cheers

 

[STLSteve86]

Here is 2 pictures of the AG stock

 

[STLSteve86]

My gun went to proof for testing. I will say that their contact with me is how customer service is suppose to work. I even offered to pay for shipping but they sent me a shipping label and foot the bill both ways. Long story short they shot it in their indoor facility with a omega suppressor. Both groups were impressive to say the least with factory ammo. They used fgmm 168g.

so now I guess I need to try some other suppressors to see if I can get it to group. It obviously doesn’t like this 30-p1. if I am unsuccessful this gun will have to go up for sale or re barrel it with a steel barrel.

I will reach out to some friends that have 30 cal cans and see what happens when I shoot it.