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Suppressors suppresor POI change?

TEAMSENDIT

Gunny Sergeant
Full Member
Minuteman
  • Sep 22, 2008
    2,947
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    whidbey island
    Well i just got my first 308 can a few weeks ago and have been testing it on my 6x47 lately and I have a few questions.

    First how much does your point of impact normally change from just barrel to barrel with suppresor. Mine is shooting exactly 1mil lower with suppressor attached at 100yds. i don't mind dialing it but it seems like alot.

    Second why does my first shot through the suppresor have a different point of impact than all the follow ups. mine impacts .2mil left and .2 mil low at 100yds after that it shoots into a nice little clover leaf. this is done with a warm barrel one that I have already fired a few rounds through so its not even my cold bore shot.

    thanks for your help if for some reason it matters I am shooting a gemtech hvt on a mak tube gun with a 26" medium palma fluted barrel and it is a thread on can not quick detach.
     
    Re: suppresor POI change?

    Think about your question...

    First off, what does your suppressor weigh ?

    Next look at how long your barrel is... 26", now think about putting the weigh of the suppressor on the end. It is the equavilent of pushing down on the barrel, so of course there is going to be a shift. if someone was pushing down on your unsuppressed barrel while you shot, you'd expect a change. That is what the weight is doing.

    Lastly there is difference because the internal composition of the can is changing slightly due to the addition of left over gasses. The cold can has nothing inside, the second shot is now full of gas, as well heat is included and may change the position due to the threads, and attachment point. Basically you want a can that will manage the gasses.

    This is why in my video I did a cold can shot and then the group to see if there was a shift or not.

    These are precision rifles, buying a can for one should not be based on sound suppression, but instead, weight, attachment, POI shift and first shot shift... nowhere in that is sound mentioned.

    Light is right, and this is why a shorter barrel on a tactical rifle is better, it minimizes a shift when you use something like a suppressor because it manages the weight bette than a 26" ever would.
     
    Re: suppresor POI change?

    I know there is normally a poi shift I was wondering if 1 mil is alot or standard? my suppresor weighs 25oz. Like i said before i don't mind the 1mil drop as long as it is repeatable which it seems to be. just wondering if people are having similar results.

    have you tested cans that don't have a first shot poi change, i didn't know if this is based on the baffle design or if this is normal. is their a certain brand of cans that has the least amount of first shot poi change.

    I understand that a short fat barrel would be better for change in poi. however I am not willing to give up the velocity in a caliber like the 6x47 that you would lose cutting it down to 20" or less.
     
    Re: suppresor POI change?

    Look at it this way, most of the titanium suppressors out there weigh half as much, they come in around 13oz, your 1 Mil is a product of the barrel length and suppressor weight. It is what it is and there is nothing you can do about it, it doesn't matter what other rifles experience, this is what your does.

    Go watch the suppressor video I just shot and posted yesterday. The answers are there. <span style="font-style: italic">(Gemtech vs Surefire or See the SH YouTube channel. )</span>

    Maybe we need a new category of "tactical rifle" one where people put velocity over practicality -- like a competition class with a matte finish. We just need to name this pain.

    Like Comptastic, or Tactition .
     
    Re: suppresor POI change?

    I don't think there is any particular standard on POI shift as every barrel is different. A 1 MIL change at 100; 3.6" would seem a lot but if it is predictable from off and on then you can anticipate the change and dial it in. I have a Gemtech HVT on my rifle using a QD and it is always 1 MOA up and .5 MOA right on all of my shots. I make the adjustment and move on.
     
    Re: suppresor POI change?

    The rifle isn't meant to be a "tactical rifle" it is meant to be a tactical competition rifle. it is built soley to shoot well from multiple positions, be repeatable, and readily available to take shots at steel at 1250yds and under. I am not in the military/le and won't be any day soon, however i do love the satisfaction of shooting steel at long distances and shooting in tactical matches it is a blast. Not all will agree with running a 26" barrel but luckily their are custom rifle builders out their are willing to build you whatever you want.

    I know that no to rifles are exactly the same or will act exactly the same just putting out a feeler to see if this is normal. You are right as long as it is repeatable i don't give a shit what it does I can dial for it, but if i can get a better can that i don't have to dial for.
     
    Re: suppresor POI change?

    I am just not sure getting a different can will change the issue; it will just have a different POI - not to mention but I consider Gemtech HVT to be a good suppressor (may be because I have one I could be tainted). I can suggest one thing - talk to Gemtech and see what they say. When I called them, numerous times, they were always very helpful.
     
    Re: suppresor POI change?

    I think 1MOA is pretty good. My POI shifts about 3MOA. Once I make adjustments on my scope it works perfectly, but there is a consistent 3MOA shift. Now that I know it is consistent, I simply make my adjustments before I take my first shot and it hits right on target from the first shot. For some reason, I do not see a shift from my first to subsequent shots.
     
    Re: suppresor POI change?

    he is 1 Mil, which is 3.6" as stated, not 1 MOA.

    Comptactilicious

    I have no problem ringing steel out to 1000 yards with an 18" 308, so I would suspect that 24" or even 22" 6X47 would work to 1250, I would have to run the numbers... it's not really any different needing X or Y Mils if both will get you there, I suspect you find the wind difference to be minimal and nothing but a thing. At 26" with an 8" suppressor you now have a 34" barrel, I am not sure what "tactical" competitions are you are competing in but it hardly sounds conductive to running and gunning.

    Either way, like was said, almost any can will shift on a barrel that long, I would recommend the SHARK as having the least and being very light. That is your best bet.
     
    Re: suppresor POI change?

    I installed my HVT on a new Wilson 10 twist barrel from a Win heavy varmint I rethreaded to a Rem 700, chambered it 6x47 and cut to 20". Haven't tested it alot for velocity and or repeatability but it shot super with 70TNT with or without the HVT. Was expermenting so didn't measure exact POI change but was around 1.5moa which for 24oz I thought pretty good.

    Surprise was screwing it onto my 18" Noveske 223 barrel. POI was 3" right and about 8" low!!!! But the Noveske 18" is a fairly light tube and hanging a 1.5# weight on the end is sure going to change something. Knew there would be a considerable change in POI but was hoping not that much!
     
    Re: suppresor POI change?

    <div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">he is 1 Mil, which is 3.6" as stated, not 1 MOA.

    Comptactilicious

    I have no problem ringing steel out to 1000 yards with an 18" 308, so I would suspect that 24" or even 22" 6X47 would work to 1250, I would have to run the numbers... it's not really any different needing X or Y Mils if both will get you there, I suspect you find the wind difference to be minimal and nothing but a thing. At 26" with an 8" suppressor you now have a 34" barrel, I am not sure what "tactical" competitions are you are competing in but it hardly sounds conductive to running and gunning.

    Either way, like was said, almost any can will shift on a barrel that long, I would recommend the SHARK as having the least and being very light. That is your best bet. </div></div>

    well I would say that 24" would probably be fine but shorter seems to shed velocity fairly quickly i have been told. i don't use the suppresor for matches. I don't find the barrel to be an issue for me but maybe thats because i am 6'5" tall so typically it isn't the rifle that has trouble getting comfortable it is my giant ass.

    I have considered a custom 6mm shark for awhile but the high price tag is hard to swallow. by the way i also have a 22" #7 308 barrel for the same rifle (switch barrel). I just prefer the ballistics of the 115dtac at 3000fps over the 308 when i have to shoot unknown distance stuff, it gives you alot more room for error in your ranging and wind reading. things that i need more practice in.