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View Full Version : Rifle Accuracy: Before/After Suppressor...


Stephen A. Camp
March 22, 2001, 09:11 AM
Hello. Just a note to advise on the most dramatic change in a rifle's "preference" of loads before and after addition of a (NFA-legal) suppressor. No doubt this is due to the altered bbl harmonics between the bbl before and after addition of the unit and possibly removing metal when reducing the diameter at the muzzle end for threading.

The rifle: Remington 700 in HS Precision stock with Shilen chrome-moly bbl. The bbl, a varmint heavy, but I don't know which contour, was originally 24" long. Unaltered, the gun's favorite load was Federal 55 gr BallisticTips, which it would regularly drop into 3/8" @ 100 yards. With the "can," this same group did about 4"! The suppressed rifle liked Hornady 53 gr HP and would drop them into about 1/2" at 100 yards.

However, with the suppressor on the 24" gun, it became unwieldy. The bbl was cut to 19" and rethreaded.

Now, none of the loads would group under 1 1/2" with the can attached! Some wouldn't stay within 7". No doubt the shortening of the heavy bbl acted to "stiffen" it.

Anyway, to make a long story short, THE load turned out to be Hornady's 40 gr V-Max! Groups in the 1/2" range now.

So, if and when you add a suppressor to a rifle, be ready to begin load development all over again. We all likely knew this to be true, but this was one of the most dramatic examples I've ever seen.


Best.

M16
March 22, 2001, 09:25 PM
Hmmm. I have a Gemtech TPRS with a bilock on my model 700 .308. The gun acutually groups slightly better with the suppressor. Although point of impact moves down about an inch and right about a half inch with the suppressor installled.

Stephen A. Camp
March 23, 2001, 04:04 AM
Hello. Yes, I do not doubt that you do. I've run into this before where the load groups better with the unit than without! This is mentioned only in that it's the most exaggerated example of it I've seen. Best.