Suppressors P O I change when i install my can

[tjonh2001]

i am wondering if others are haveing problems when then install there suppressor and zero there rifle. then i remove it and the first time i was 1.75 moa higher and .25moa right. a few days later i went and installed the suppressor again and now my drop differance was 2.75 moa and 1moa wind. a couple days later i went and checked it again and it was different again.

just wondering if this is normal as i hunt with it and there are times that i dont want it on, but i dont want to have to go rezero the rifle.

any thoughts?

 

[RayDog]

Re: P O I change when i install my can

Look through the barrel with the can on and make sure things are straight and you aren't getting baffle stikes. Look for copper on the exit hole

 

[tjonh2001]

Re: P O I change when i install my can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RayDog</div><div class="ubbcode-body">Look through the barrel with the can on and make sure things are straight and you aren't getting baffle stikes. Look for copper on the exit hole </div></div>

no baffle strikes this was threaded by one of the best and i have checked it multipl;e times i even pulled the can apart and inspected. no hits.

 

[ORD]

Re: P O I change when i install my can

Some degree of POI shift is expected with many suppressors...the key is getting a good, consistent shift so that all you have to do is dial in your scope for both suppressed and non-suppressed fire.

What kind of mounting system does your can use (i.e. - direct thread onto the barrel, QD setup, etc.)? A difference like that could be something as simple a torque differences with a thread-on can or with a QD setup, it could be a lose QD adapter or inconsistent lock up.

 

[tjonh2001]

Re: P O I change when i install my can

thats what i am trying to find is how much of poi i have with or without the can. lattly i have just been leaving one can on a rifle and then i dont have to worry about the poi change. the problem is that i am carrying 2 guns when going after coyotes. would like to take one and be able to adjust the rifle scope (sb pmII) instead.

this is a shark can.so its a direct mount to my barrel threads. installed by a quality gunsmith. when i install it i turn it and lightly snug the suppressor on.

 

[Jeff in TX]

Re: P O I change when i install my can

I'm having the exact same issues and it’s been extremely frustrating. My can switches between two rifles, my AR-10 and my Tikka T3 lite. The one issue we’ve discovered were my threads on both the AR and Tikka we’re over cut (not sure of the correct term), but it didn’t allow the suppressor to fit flush against the barrel. When I screwed the suppressor on it left an extremely small gap between the barrel and suppressor. My can designer undercut the threads so the suppressor now fits flush against the barrels. Also was not getting any baffle strikes.

I’m hoping like heck this alleviates the POI shift problems as we haven’t shot it yet to verify. The thought of having to re-sight my rifle(s) in every time I take the suppressor on and off will drive me nuts and make me really question my investment in a suppressor. My buddy can remove his can and reinstall it and never see a shift in POI. Any thoughts or insight from anyone who has experienced this would be greatly appreciated!

 

[BOLTRIPPER]

Re: P O I change when i install my can

savvy what the can has to "shoulder" up to.....if there is a gap,,,,then the can must snug up to a shoulder to expect consistent poa/poi

this goes for any lose end caps or adapters....threads not kissed with a bottom tap or a die to chase threads WILL lead to frustration,,, and possible baffle strike.

stuff like this helps so one do not lock up your toys
http://i48.photobucket.com/albums/f236/BOLTRIPPER/MVC-016S-5.jpg

 

[tjonh2001]

Re: P O I change when i install my can

anti cease is a must.. my suppressor is shouldered on the rifle. im hopeing someone else has an awnswer.

 

[biffj]

Re: P O I change when i install my can

You might try using a torque wrench to install the can a few times and check to see if the poi changes at different torques. Its not unheard of for different torque to change the poi but its also not usually a big problem.
Make a line on the can and barrel with a sharpie and see if you are getting the can in the same spot each time.....thats another way (roundabout) to check torque. Knights Armament recommends rotating their Mk23 can on its nielsen device to find the poi closest to centered without the can. This is because the can will change poi based on rotational location.
Anti-seize is a good idea but be careful not to overdo. Too much can make it possible to either over or under torque the can. Many types will build up and you don't want anything between the can and shoulder as that is your index.

Some rifles are more affected by the can than others so its not always a simple thing.

good luck
Frank

 

[737shark]

Re: P O I change when i install my can

TJ

You pms are full. This is not normal. Contact me I have more questions

It could be a few things.
214-394-3529

Thanks

David

 

[737shark]

Re: P O I change when i install my can

Jeff in Tx

I don't think your can is mine but if the threads on the different rifles are not the same carbon build up may prevent the can from going back to the same place

1. The length to the shoulder may be different I see this many times on 22 cans

2. The od of the threads may be different, it should always shoulder in the same place

 

[737shark]

Re: P O I change when i install my can

Plus .50 to the shoulder on threads is not enough

.625 minimum

I prefer .750

 

[Jeff in TX]

Re: P O I change when i install my can

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 737SHARK</div><div class="ubbcode-body">Plus .50 to the shoulder on threads is not enough

.625 minimum

I prefer .750 </div></div>

David,

Many thanks for the reply. When I get back from my business trip I'll check the length of the threads.

 

[737shark]

Re: P O I change when i install my can

I spoke with tjohn today it's an abs barrel..he's going to make sure it's tight and check it sounds like his threads are good.. I dont know about abs carbon barrels