First shot POI shift

General silencer discussion. If you want to talk about a specific silenced rifle or pistol, it is best to do that in the rifle or pistol section for that brand.

All NFA laws apply.

Moderators: mpallett, renegade, bakerjw

Post Reply
Winky
New Member
Posts: 5
Joined: Wed Nov 28, 2018 10:44 am

First shot POI shift

Post by Winky » Wed Nov 28, 2018 10:54 am

New here, thanks in advance for your patience.
I am having my first shot ( while running a suppressor) POI hitting 1.5" high to the right, This is consistent. All other shots are grouping where I aim less than .75"...…… Is it that the can has oxygen in it, and the burn off causes the first shot to go wild? Im running a tuned up rem 700 - 308 tac 18" heavy barrel, the gun shoots great. Is there a "fix" for this?

thanks

quiettime
Silent But Deadly
Posts: 560
Joined: Sat Dec 13, 2014 10:11 pm
Location: N FLA

Re: First shot POI shift

Post by quiettime » Wed Nov 28, 2018 12:22 pm

Does it do this without the can?

Winky
New Member
Posts: 5
Joined: Wed Nov 28, 2018 10:44 am

Re: First shot POI shift

Post by Winky » Wed Nov 28, 2018 1:56 pm

No, only does this with the can on.

User avatar
1rflman
Member
Posts: 49
Joined: Wed Jan 20, 2016 2:27 pm
Location: Up North

Re: First shot POI shift

Post by 1rflman » Wed Nov 28, 2018 3:33 pm

I would suggest shooting your first and succeeding shots over a chronograph to determine if your first shot is being "boosted" by the oxygen burn in the can. This could cause the elevation deviation from the other shots.

Winky
New Member
Posts: 5
Joined: Wed Nov 28, 2018 10:44 am

Re: First shot POI shift

Post by Winky » Thu Nov 29, 2018 1:54 am

OK, I need to find someone who has one. I want to use this for deer hunting. My first shot is the important one. Trying to figure out how to deal with it. thanks, I will see if I can check it as you suggested and report back.
thanks again

#40Fan
Silent But Deadly
Posts: 150
Joined: Tue Nov 20, 2018 6:41 pm

Re: First shot POI shift

Post by #40Fan » Thu Nov 29, 2018 2:51 am

Winky wrote:OK, I need to find someone who has one. I want to use this for deer hunting. My first shot is the important one. Trying to figure out how to deal with it. thanks, I will see if I can check it as you suggested and report back.
thanks again
That is quite the POI difference. Mind sharing the silencer make and model or if an F1, how did you clip the baffles?

a_canadian
Silent But Deadly
Posts: 1105
Joined: Fri Oct 11, 2013 4:09 pm

Re: First shot POI shift

Post by a_canadian » Thu Nov 29, 2018 6:20 am

Winky wrote:I am having my first shot ( while running a suppressor) POI hitting 1.5" high to the right, This is consistent. All other shots are grouping where I aim less than .75"
Just for clarity, is this at 100 yards? Or what range?

And yeah, I'm wondering about asymmetrical clipping as well, a little, though really I'd expect POI shift to be consistent if this were the problem. Still, could be a good idea to modify the first and last baffles such that they offer symmetrical gas flow around the bullet, if they don't already.

SuthDet
Member
Posts: 26
Joined: Fri Nov 03, 2017 1:54 pm

Re: First shot POI shift

Post by SuthDet » Thu Nov 29, 2018 9:22 am

Is this a user serviceable suppressor?
Do you have any carbon leaking out? Either around the muzzle threads, or either end cap?

Winky
New Member
Posts: 5
Joined: Wed Nov 28, 2018 10:44 am

Re: First shot POI shift

Post by Winky » Thu Nov 29, 2018 12:02 pm

OK

1. I am shooting at 100 yards
2. it is an INNOVATIVE ARMS DECEPTION 7.62 EXOSKELETON up to 300 Win mag
3. it is not serviceable.
4. I do not notice any carbon leaking out.

quiettime
Silent But Deadly
Posts: 560
Joined: Sat Dec 13, 2014 10:11 pm
Location: N FLA

Re: First shot POI shift

Post by quiettime » Thu Nov 29, 2018 12:14 pm

Every commercial can I own has asymmetrical clips on all the baffles. I doubt that's an issue.

Have you tried multiple kinds of ammo?

ECCO Machine
Silent But Deadly
Posts: 534
Joined: Tue Nov 28, 2017 7:34 pm

Re: First shot POI shift

Post by ECCO Machine » Thu Nov 29, 2018 11:02 pm

Winky wrote: Is there a "fix" for this?
It's a monocore. They are what they are. Good for .22LR, not much else IMO.
FFL07/02SOT Gunsmith & Machinist

SuthDet
Member
Posts: 26
Joined: Fri Nov 03, 2017 1:54 pm

Re: First shot POI shift

Post by SuthDet » Thu Nov 29, 2018 11:41 pm

I'd contact the manufacturer. If that first round shift is a regular thing, that's unacceptable in my opinion.

Winky
New Member
Posts: 5
Joined: Wed Nov 28, 2018 10:44 am

Re: First shot POI shift

Post by Winky » Sat Dec 01, 2018 11:21 am

I did contact the manufacture...….. He said that doesn't happen. I disagreed, I have proof.

ECCO Machine
Silent But Deadly
Posts: 534
Joined: Tue Nov 28, 2017 7:34 pm

Re: First shot POI shift

Post by ECCO Machine » Sat Dec 01, 2018 11:49 am

Winky wrote:I did contact the manufacture...….. He said that doesn't happen. I disagreed, I have proof.
I wouldn't give up yet, but you may never get a resolution from the mfr.

If the tube walls are thick enough, the monocore could be cut out of it and the thing recored with a conical baffle stack. Better suppression and can probably trim some weight off that thing. Not gonna be super cheap with having to get mount & front cap done as well, but less than another suppressor + tax stamp.
FFL07/02SOT Gunsmith & Machinist

User avatar
doubloon
Silent But Deadly
Posts: 11901
Joined: Thu Jan 01, 2009 1:02 am
Location: Houston-ish

Re: First shot POI shift

Post by doubloon » Sat Dec 01, 2018 4:57 pm

Winky wrote:... tuned up rem 700 - 308 tac 18" ...
Don't rule out the cocentricity of the barrel threading and the stock fitment.
http://www.youtube.com/watch?v=BDtd2jNIwAU MUSAFAR!
http://www.youtube.com/watch?v=8CrOL-ydFMI This is Water DavidW
Complete Form 1s http://www.silencertalk.com/forum/viewtopic.php?f=10&t=79895

User avatar
1rflman
Member
Posts: 49
Joined: Wed Jan 20, 2016 2:27 pm
Location: Up North

Re: First shot POI shift

Post by 1rflman » Sun Dec 02, 2018 11:10 am

Winky wrote:New here, thanks in advance for your patience.
I am having my first shot ( while running a suppressor) POI hitting 1.5" high to the right, This is consistent. All other shots are grouping where I aim less than .75"...…… Is it that the can has oxygen in it, and the burn off causes the first shot to go wild? Im running a tuned up rem 700 - 308 tac 18" heavy barrel, the gun shoots great. Is there a "fix" for this?

thanks
With an 18" barrel, your powder may not be fully burnt in the bore, and will continue burning in the can with oxygen available. You could test with other ammo containing faster burn-rate powder, or the test below.

Here are some more ideas to try when testing for the cause of your POI shift:
- Don't clean the bore between shooting sessions
- Shoot 3 shots w/o the suppressor to establish the base POI
- Shoot 1 shot with the suppressor, wait a few minutes
- With the chamber empty and bolt open, blow through the bore to expel the gases
- Shoot another shot with the suppressor... same hold, trigger pull, etc.
- Repeat above 2 steps and check the results

Does it still have the 1.5" POI shift?

Post Reply