Range Report What kind of accuracy to expect from Subsonics ?

[mgd45]

Over the past few weeks, I've been piddling around with making a good accurate subsonic load.....mainly for shits & giggles, but also when I finally get my suppressor, I wanted to already have a good load developed.

Before starting I did extensive research on the Snipers Hide Google search engine & read every thread with load data. My load is as follows:

Case: Federal
Bull: 180 grain round nose flat base bullet
Powd: Trailboss @ 11.0 grains = 1070 fps.
Prim: WLR, CCI-200, & FGMM
COAL: 2.660"

Rifle: Remington 700 PSS with 1/12 twist

So far the best grouping I can get is 1.5" at 100 yards....and I'm not sure if that is just a fluke because that was just one time & most of the groups have been around 3 inches. The holes in the paper are nice & round with no indication of instability. I am considering trying either a heavier bullet or even a boat tail designed bullet....but...

Am I expecting too much to get group sizes down to an inch or smaller....?

 

[ggarrett1911]

Re: What kind of accuracy to expect from Subsonics ?

I tried the 180 grain round nose bullets when I started loading subsonics for my Savage & found that mine seemed to like the 170 grain flat point bullets better...(10 rounds into a ragged hole while developing the load below at 50 yards) but a buddy's identical rifle likes the 180's so go figure. The 170's are a little "noisier" in flight but they hit harder than the 180's if you're hunting with them. Here's what I was shooting...

Federal case
170 Hornady FP
10.2 grains Trailboss
CCI 300 primers
2.530 OAL

You might experiment with seating depth a little, as my rifle seemed to be a lot more sensitive to seating depth with subsonic loads versus full power ammo. I also found that putting a very light crimp on the bullet when seating helped a lot with velocity consistency as well. That being said, YMMV.

Also not sure how heavy you'll be able to go with the 12 twist, my Savage is a 10 twist & I shoot the 208 AMAX as a subsonic load now & it stabilizes fine in my rifle & is very accurate.

Hope this helps!

 

[mgd45]

Re: What kind of accuracy to expect from Subsonics ?

Thanks. I'll experiment with the seating depth & maybe a different bullet...

 

[redbullitt]

Re: What kind of accuracy to expect from Subsonics ?

I have a 10 twist cut to about 19 inch.

I use the 180 round nose sierras, trail boss (1060ish fps),mag large rifle primer. I have been seating them to just over the crimp groove.

I get about 1 or 1.25 inch groups at 100. Sometimes better sometimes worse, but that is a pretty good average. It does what I need it to, so I havent tweaked it any more. There may be room for improvement.

Sub inch groups do happen for me with this combo, but they are not the norm. I think you could get something going better though. Try out the 150 and 170 grain flat noses. I have shot some of them, but not done a lot of tweaking. They seemed to work well.

 

[338LAPUASLAP]

Re: What kind of accuracy to expect from Subsonics ?

You should be able to achieve sub MOA by tweaking it, I have been able to get B416's to print in a quarter...