Cold Bore Shots from Short Barrel

[ratrod54]

Some rifles need a couple of rounds after cleaning. Was your rifle cleaned before the shot? I won't eliminate shooter error, but that is for you to determine.
I'll give you an example. I shot a cow elk at 900 yds. A perfect shot died right away. A few weeks later, I completely missed on a moose at 300 yds. I went to the gun range. The rifle shoots 1/3 MOA at 300 yds. To this day, I have no explanation for how I missed that moose.

Yes sir, both we're cleaned a few months ago, but I have been at the range with both of them prior to my hunt. I had been working up a load for the 7-08 and had just shot 50 rounds trying to mess with my seating depth. So it was fouled. I changed the scope on the 308 and we zeroed and my son shot some since he hadn't for awhile. It was gtg as well.

 

[Mc Fraser]

Yes sir, both we're cleaned a few months ago, but I have been at the range with both of them prior to my hunt. I had been working up a load for the 7-08 and had just shot 50 rounds trying to mess with my seating depth. So it was fouled. I changed the scope on the 308 and we zeroed and my son shot some since he hadn't for awhile. It was gtg as well.

Weird. I definitely want to hear your thoughts after you're done with the investigation.

 

[skipglo]

I plan to go test it and see. No need to apologize for suggesting shooter error. It happens for sure and I'm not immune.

I do all my load work up at 200 and 300 yards and have found I don't get the fever when shooting at a cull buck. I am positive it wasn't unstable for the shot. I've shot from my BOG at the range and simulated the blind and shoot 3/4 MOA groups. Even a flinch wouldn't have been that drastic.

Both barrels were cleaned a short time ago, but fouled prior to the hunt.

I'm going to wait until it gets cold at home and take ammo from the fridge and see what happens at ambient temps with the rifle.

Why take it from the fridge? Leave it with the gun outside together....same temp then....apples with apples!

 

[ratrod54]

Why take it from the fridge? Leave it with the gun outside together....same temp then....apples with apples!

Agreed. Kind of a thinking out loud moment. I just need to make sure it's cold as well and not in my pocket or case.

 

[Chase723]

Pretty easy problem to figure out. Hang a target, either steel or paper, and shoot a group with a cold gun and your suppressor. Note the first round impact. Take it off and let it cool, put it on your sons gun and do the same. Put a muzzle brake on and repeat. Done.

 

[Window]

Point of impact with my rifles change

I 100% haven't excluded shooter error. I do not disagree that it's a possibility and contributing factor. That said, it's very hard to prove the state of mind at the time or my ability to shoot. I get that whole heartedly. I do not mean that to sound brazen at all. I fully expect people to draw the conclusion that it's shooter error. I am hoping though that someone has experienced something similar and can understand.

I went back to my original post and see that I didn't not mention both rifles were suppressed. I'm not sure why I left that out of my original post as I believe it is a contributing factor. (I cant seem to edit the original post to include).

18" Barrel had a TBAC Ultra7 suppressor on it and the 16.5" barrel had a TBAC 30BA suppressor on it.

Cold bore shots with a muzzle break have never been an issue. I have had some POI with a suppressor, but not extreme. That said, not had to deal with it from shorter barrels at all so this is why it's caught me off guard.

I would agree that without the suppressor, I would have a massive problem and would blame myself 100% for the cold bore miss. Down to my core, I think there is something else at play here though.

As for fooling, The 7-08 (18") had 50 rounds through it and the 308 (16.5") ha

 

[Window]

Sitting in a blind in 35 degree weather three weeks ago, I saw a buck I was ready to shoot. I do reload and the load has worked flawlessly. Shooting a 7-08 w/ 18" CF barrer built by Short Action Customs.

I Reload my ammo and have the utmost confidence in the load I've worked up. It has been a very accurate load to date.

I was preparing myself for a 230yd shot. First trigger pull, round is low. Put another round in and did not adjust anything. Second shot, aimed at the same place behind the shoulder and down he went. Never took another step. I questioned myself.

Fast forward to this weekend, my son set up in same blind shooting a 16.5" Barrel Savage PC10 308. Same exact thing. Low first, no adjustment then right on.

Curious, Does a cold chamber and a short length barrel (under 22") have more affect than a longer barrel? Has anyone ever just kept rounds in your pocket to keep them warmer with success and minimal POI shift?

POI shifts with suppressors on my rifles are 3 to 4 inches in vertical at 100 yds. At 200 plus, that would be catastrophic.

 

[Shane Lindsey]

I had zero shift with mine. First one, hopefully they all are like this.

 

[LaHunter]

Sitting in a blind in 35 degree weather three weeks ago, I saw a buck I was ready to shoot. I do reload and the load has worked flawlessly. Shooting a 7-08 w/ 18" CF barrer built by Short Action Customs.

I Reload my ammo and have the utmost confidence in the load I've worked up. It has been a very accurate load to date.

I was preparing myself for a 230yd shot. First trigger pull, round is low. Put another round in and did not adjust anything. Second shot, aimed at the same place behind the shoulder and down he went. Never took another step. I questioned myself.

Fast forward to this weekend, my son set up in same blind shooting a 16.5" Barrel Savage PC10 308. Same exact thing. Low first, no adjustment then right on.

Curious, Does a cold chamber and a short length barrel (under 22") have more affect than a longer barrel? Has anyone ever just kept rounds in your pocket to keep them warmer with success and minimal POI shift?

You should know, without a doubt, what your rifle does with a cold bore & a cold / clean bore. You should know if your rifle POI shifts in cold or hot temps. It is impossible for 'the internet' to diagnose your issue. It could be shooter error, it could be your scope has failed, it could be your rifle action screws are not torqued properly, it could be the bedding, etc, etc, etc. Sounds to me you need to get to know your rifle better.

 

[ratrod54]

Pretty easy problem to figure out. Hang a target, either steel or paper, and shoot a group with a cold gun and your suppressor. Note the first round impact. Take it off and let it cool, put it on your sons gun and do the same. Put a muzzle brake on and repeat. Done.

That's the plan, just has to get cold. I was hunting in Missouri in mid30's and I live in Dallas where it was 82 today, so I'll have to wait a bit.

Already have breaks on the rifles as the ultra 7 and 30BA cans screw on over a break.

 

[ratrod54]

You should know, without a doubt, what your rifle does with a cold bore & a cold / clean bore. You should know if your rifle POI shifts in cold or hot temps. It is impossible for 'the internet' to diagnose your issue. It could be shooter error, it could be your scope has failed, it could be your rifle action screws are not torqued properly, it could be the bedding, etc, etc, etc. Sounds to me you need to get to know your rifle better.

Thanks, I guess there's always one…

Scope is fine, action is bedded and torqued to spec. I know the POI shift on both rifles as well. I know what the groups look like with a clean bore and a group with a fouled barrel, granted I did all of that when it was warm outside. I didn't know it was a requirement to shoot in each and every condition. Never would have thought I could possibly have an issue with a shorter barrel vs a long.

Also don't need a diagnosis from the internet. Maybe feedback if someone had experienced it though would be good, which is what these forums are for.

The idea that someone has to regurgitate their life story to post a question about something that happened is laughable. I can bore you with all the details of this rifle since receiving it 8 months ago, but it's not necessary. If you feel I'm that ill prepared because I didn't prove my torque specs, bedding, scope condition, then so be it. Appreciate the insight.

 

[ratrod54]

POI shifts with suppressors on my rifles are 3 to 4 inches in vertical at 100 yds. At 200 plus, that would be catastrophic.

The savage my son hunts with was a 20" barrel originally and had 5 in of vertical shift. We cut it down to 16.5" and it went down some. Was concerned the shoulder was messed up when i first got it but It was repeatable and verticle. Spoke to Zak at TBAC and determined that it was good to go. That one was More than any other rifle I have. The SAC rifles I have have been around an inch.

I don't shoot or hunt without the suppressor so I don't worry about the shift without the suppressor.

 

[Window]

The savage my son hunts with was a 20" barrel originally and had 5 in of vertical shift. We cut it down to 16.5" and it went down some. Was concerned the shoulder was messed up when i first got it but It was repeatable and verticle. Spoke to Zak at TBAC and determined that it was good to go. That one was More than any other rifle I have. The SAC rifles I have have been around an inch.

I don't shoot or hunt without the suppressor so I don't worry about the shift without the suppressor.

I assumed so but wanted to throw it out there just in case. I hope you find your answer and please post when you do.

 

[Chase723]

That's the plan, just has to get cold. I was hunting in Missouri in mid30's and I live in Dallas where it was 82 today, so I'll have to wait a bit.

Already have breaks on the rifles as the ultra 7 and 30BA cans screw on over a break.

There was a thread similar to this on the Hide awhile ago. Similar to first round pop, the dynamic interaction of the gas composition and turbulence in the can on the first round is different than subsequent rounds and on some cans/can designs this will cause a POI change for the first round. TBAC cans are supposed to be pretty awesome, from both a precision and suppression standpoint…so for your sake, I hope that's not the case. lol. Mine are all Form 1s so I don't have any experience with other manufacturers and can't really weigh in on that otherwise.