First Suppressor, First Impressions. And losing velocity?

[MarkTheFark]

After a 6-month wait, the ATF let me have my Thunderbeast Ultra 7 30-Cal. Some of my findings on POI shift, accuracy and velocity on my Tikka...



Accuracy and repeatability of zero after removing and reinstalling the suppressor are great. POI shift with and without the can is about 2.25-2.5"

What surprised me most was the velocity loss of about 10fps with the can. That's contrary to the slight increase that seems to be most common when shooting suppressed. Anyone else see velocity loss with a suppressor?

Small sample sizes here, but I have shot again since this video and had similar results.

 

[woodnut]

From my experience, your results are on par. I do , however, usually get better accuracy with the can. Knowing barrels are flexible, I bet the POI shift is caused by the wt. of the can as well as a change in harmonics.

 

[nikonNUT]

I'm still developing a load with my can on but I've seen about a 20FPS increase on my .338LM. I need to test it on my 6.5CM.

 

[AKironhead]

Great vid and great build! With my 24" proof I get about a 1" poi shift with an ultra 7 and gain an avg of 15fps with a 6.5 creedmoor. I have used an Ultra 7 on 6 different rifles and all have had varied impact shifts do to harmonics as woodnut stated but all of them had an increase in fps typically in the 10-20 fps range. A short barreled .260 rem however had an increase of 40 fps so may have more to do with barrel length and powder burn rate/charge weight. As long as the poi is repeatable you're good to go. Here is a vid where I shoot round robin style taking the Ultra 7 off every other round and correcting for the offset
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[MarkTheFark]

Great vid and great build! With my 24" proof I get about a 1" poi shift with an ultra 7 and gain an avg of 15fps with a 6.5 creedmoor. I have used an Ultra 7 on 6 different rifles and all have had varied impact shifts do to harmonics as woodnut stated but all of them had an increase in fps typically in the 10-20 fps range. A short barreled .260 rem however had an increase of 40 fps so may have more to do with barrel length and powder burn rate/charge weight. As long as the poi is repeatable you're good to go. Here is a vid where I shoot round robin style taking the Ultra 7 off every other round and correcting for the offset

Thanks for the info and video. I'll be running this Ultra 7 on a 20" 6.5 Creed as well, and am very interested to see the results for that rifle.

 

[Deleted member 103481]

Sounds right, I think most expect a slight velocity increase but it's overblown

 

[cohunt]

i have noticed that poi change is shooter dependent--which leads me to believe that it is partially contributed to how the individual shooter handles the recoil and recoil impulse.
I find that in every one of my rifles with every shooter with my suppressors the suppressor always shoot lower than un-suppressed --but the amount of vertical shift changes with each shooter--I mainly think this is attributed to the slight reduction in recoil, and the way it recoils an how the shooter handles that change in recoil
I agree that some of the poi shift is in the can itself, but I think some resides in the individual shooter also

 

[AKironhead]

i have noticed that poi change is shooter dependent--which leads me to believe that it is partially contributed to how the individual shooter handles the recoil and recoil impulse.

That's an interesting data point and makes a lot of sense. I'll have to test that out on a few folks.

 

[woodnut]

Hard to argue that point about poi change is sometimes the shooter. I still maintain though that the wt of the can and better harmonics contributes more to change in poi and accuracy. But still, a good point about each shooter. For instance, and not about cans, but I can zero my rifle perfectly and two shooters can get behind it and get a very different poi!