Suppressors 3.5" POI shift with an AAC Cyclone?

[TOPO-sniper]

Re: 3.5" POI shift with an AAC Cyclone?

It doesn't escape me bro, I just dislike the idea of a "precision" tool producing non-precision results. But that’s just me, if you don’t mind having to compensate for your suppressor’s lack of precision by dickin with the windage on the scope, that’s your prerogative.

I also posted here about it because I do not completely understand the non-vertical POI change. Is it just barrel harmonics? Why? The way it was rifled, the way the blank was made? Suppressor? Baffles not concentric to the bore or parallel to each other? Is it delta pressure in the chambers that minutely affect the bullets flight? Shock reflections from the bullet on interior parts of the can causing some disturbance?

Thats why it was posted on this forum, we had questions. I do not beleive "there is little rhyme or reason", if it is different it can be characterized. Some of us just happen to be curious about that.

 

[HPLLC]

Re: 3.5" POI shift with an AAC Cyclone?

Tukka that is a big batch of silencers for one day!

Topo- clear the weapon and put a piece of white paper against the bolt, look through the muzzle of the can and check alignment visually. The human eye can probably distinguish more than .005" out of true. It will probably take more than .005" to make a difference of more than 1MOA.

 

[Tuukka]

Re: 3.5" POI shift with an AAC Cyclone?

POI shift will happen, it is just a matter of ensuring it is as little as possible and repeatable, by verifying the suppressor bodies are correctly aligned.

We believe that anything over 4-5 MOA shift at 100 meters is not really acceptable. Usually with our bolt action rifle and assault rifle suppressors, the shift is 0-3 MOA.

HPLLC, to give you an example, two employees can manufacture 100 centrefire suppressors in two days ( that includes the initial machining of the castings and also the finishing )

 

[Conqueror]

Re: 3.5" POI shift with an AAC Cyclone?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TOPO-sniper</div><div class="ubbcode-body">It doesn't escape me bro, I just dislike the idea of a "precision" tool producing non-precision results. But that’s just me, if you don’t mind having to compensate for your suppressor’s lack of precision by dickin with the windage on the scope, that’s your prerogative. </div></div>
By your first sentence, I think it DOES escape you. Just because a suppressor produces POI shift does not mean there is a lack of precision anywhere in your setup. You can have a high-end rifle made by the best smith, with flawless class 3A muzzle threads and flawless class 3B threads in the silencer, a silencer with zero runout, etc., and you still might see significant shift. If the groups are still tight, then the setup is precise (google the difference between accuracy and precision). Repeatability is what determines precision.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I also posted here about it because I do not completely understand the non-vertical POI change. Is it just barrel harmonics? Why? The way it was rifled, the way the blank was made? Suppressor? Baffles not concentric to the bore or parallel to each other? Is it delta pressure in the chambers that minutely affect the bullets flight? Shock reflections from the bullet on interior parts of the can causing some disturbance?</div></div>
Every factor you just listed plays a part. And none of those can be altered when you have a given rifle and a given silencer unless you're gonna rebarrel the thing or start machining bits off your can to try and change the POI. And even then, if you are successful, you only have a silencer that produces no shift on THAT rifle. Screw it on your buddy's gun and it will have shift. This is why I always laugh when I see someone recommend a Surefire silencer because they "have the lowest POI shift." Their light weight will minimize weight-based shift, but there is absolutely no way to predict that a brand of silencer will have less shift on a given rifle, because of the factors above (and many more).

 

[chainring]

Re: 3.5" POI shift with an AAC Cyclone?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Conqueror</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TOPO-sniper</div><div class="ubbcode-body">It doesn't escape me bro, I just dislike the idea of a "precision" tool producing non-precision results. But that&#146;s just me, if you don&#146;t mind having to compensate for your suppressor&#146;s lack of precision by dickin with the windage on the scope, that&#146;s your prerogative. </div></div>
By your first sentence, I think it DOES escape you. Just because a suppressor produces POI shift does not mean there is a lack of precision anywhere in your setup. You can have a high-end rifle made by the best smith, with flawless class 3A muzzle threads and flawless class 3B threads in the silencer, a silencer with zero runout, etc., and you still might see significant shift. If the groups are still tight, then the setup is precise (google the difference between accuracy and precision). Repeatability is what determines precision.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I also posted here about it because I do not completely understand the non-vertical POI change. Is it just barrel harmonics? Why? The way it was rifled, the way the blank was made? Suppressor? Baffles not concentric to the bore or parallel to each other? Is it delta pressure in the chambers that minutely affect the bullets flight? Shock reflections from the bullet on interior parts of the can causing some disturbance?</div></div>
Every factor you just listed plays a part. And none of those can be altered when you have a given rifle and a given silencer unless you're gonna rebarrel the thing or start machining bits off your can to try and change the POI. And even then, if you are successful, you only have a silencer that produces no shift on THAT rifle. Screw it on your buddy's gun and it will have shift. This is why I always laugh when I see someone recommend a Surefire silencer because they "have the lowest POI shift." Their light weight will minimize weight-based shift, but there is absolutely no way to predict that a brand of silencer will have less shift on a given rifle, because of the factors above (and many more).</div></div>


All this. Well said, as usual.

 

[TOPO-sniper]

Re: 3.5" POI shift with an AAC Cyclone?

Conqueror, you’re entitled to your opinion buddy. I respectively disagree that my acceptable performance of a weapon system has to necessarily coincide with your standard. My background, education and personal preference dictates what is reasonable to me. But thank you for your input.

 

[fastford]

Re: 3.5" POI shift with an AAC Cyclone?

come up to Waco sometime, and i will try yours compared to mine!

 

[patches]

Re: 3.5" POI shift with an AAC Cyclone?

Well, it looks like my shift is repeatable. I guess I'm not going to worry about it for now.

Just a heads up for those guys that are wanting to use the Cor-Bon subsonic .308 ammo plan on about a 12 inch downward shift due to the slower moving round. I did some testing with the SRS and 12" seems to be a reliable number.

 

[HPLLC]

Re: 3.5" POI shift with an AAC Cyclone?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tuukka</div><div class="ubbcode-body">POI shift will happen, it is just a matter of ensuring it is as little as possible and repeatable, by verifying the suppressor bodies are correctly aligned.

We believe that anything over 4-5 MOA shift at 100 meters is not really acceptable. Usually with our bolt action rifle and assault rifle suppressors, the shift is 0-3 MOA.

HPLLC, to give you an example, two employees can manufacture 100 centrefire suppressors in two days ( that includes the initial machining of the castings and also the finishing )


</div></div>

That is pretty damn good volume and speed. You guys probably have the fastest volume manufacturing in the world by that measure.

 

[Conqueror]

Re: 3.5" POI shift with an AAC Cyclone?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TOPO-sniper</div><div class="ubbcode-body">Conqueror, you’re entitled to your opinion buddy. I respectively disagree that my acceptable performance of a weapon system has to necessarily coincide with your standard. My background, education and personal preference dictates what is reasonable to me. But thank you for your input. </div></div>
I didn't imply that my standards override yours. But I am right that there is no way to predict POI shift on a given rifle unless you send the entire setup to the silencer manufacturer and have them build a can specifically tailored to your rifle. You live in a fantasy world if you think you can buy a production silencer and have the manufacturer guarantee that there will not be POI shift, standards be damned.

 

[j-huskey]

Re: 3.5" POI shift with an AAC Cyclone?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: patches</div><div class="ubbcode-body">Well, it looks like my shift is repeatable. I guess I'm not going to worry about it for now.

Just a heads up for those guys that are wanting to use the Cor-Bon subsonic .308 ammo plan on about a 12 inch downward shift due to the slower moving round. I did some testing with the SRS and 12" seems to be a reliable number. </div></div>

Mine drops 19".....

 

[patches]

Re: 3.5" POI shift with an AAC Cyclone?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jhuskey</div><div class="ubbcode-body">

Mine drops 19"..... </div></div>

Holy frick on a stick 19"....? What length barrel and muzzle velocity are you getting out of the subsonic cor-bon?

 

[j-huskey]

Re: 3.5" POI shift with an AAC Cyclone?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: patches</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jhuskey</div><div class="ubbcode-body">

Mine drops 19"..... </div></div>

Holy frick on a stick 19"....? What length barrel and muzzle velocity are you getting out of the subsonic cor-bon? </div></div>

22" 10 twist and 1005 fps, off my 100 yard supersonic zero from FGM 168 running 2675 average. 19 minutes different between the two.