subsonic 7mm-08 loads

[kodiakisland]

I will be adding a suppressor to my 7mm-08 soon and want to shoot the 162-168s subsonic. Anyone have a favorite load?

 

[kodiakisland]

Was hoping someone has experience with these loads. I am planning to start with 11gr Trail Boss with the 162s and 168s before I get a can and try to find a load that is stable around 1100fps. My rifle is a 9 twist but have never shot anything this slow, so have no idea if these bullets will stabilize at those speeds. If not I do have some 140gr Bergers that probably will.

 

[biffj]

I think you'll find the bullets won't stabilize in that twist at subsonic speeds. If you really want a sub shooter build one that will work right. You didn't get a 7mm-08 to plop bullets across the street. You have too much space in the case and bullets too light to do much good. Build or buy a 300 blackout and use the 7mil to pop a few off at 1000yds. The whole point of subsonics is to toss the heaviest chunk of lead you can at 1050fps so you have as much energy as you can get as quietly as possible. If you just want to shoot quiet buy a .22 and a cheap can. Now in reality you can shoot the hot stuff through the can too and it will surprise you how much quieter it is. Maybe not puff or pop but I shoot pretty much everything with a can anymore. Less recoil, less noise and still accurate whether sub or supersonic.
just my 2 cents of course
Frank

 

[myownman]

The guys at the range are doing it with there .308's with trail boss. I was going to do it with my 7-08.

 

[biffj]

Most of the guys doing it with 308 either have fast twist barrels or they're shooting light bullets and missing the whole point too. Trail boss is a pretty poor choice for accuracy too as most of them will likely tell you as well. I think the quiet thing is why most folks are shooting inappropriate bullets subsonic. However since everyone isn't trying to get max performance from their bullet with the lowest sound levels its up to you what you try. Everytime you drop bullet weight you lose energy since you're limiting the velocity to something under 1100fps. Shoot 100 different bullets at the same speed and the heaviest one wins on energy. This is one reason the 300 blackout type stuff has a lot of followers. Shooting 240gr 30 cal bullets subsonic gives you a lot more energy than shooting 125s out of a .308 so once again its all up to what you want. I think you may have to fiddle with your loads in the 7mm to come up with a subsonic load that works for you. Start a little high and work down. Unlike loading for the highest velocity you need to be careful of not having enough to get the bullet out the end of the barrel. Most of us have stuck one or more in our time playing with them. Start with a bullet that is on the light end to insure it will stabilize and as you get your powder charge close to 1100fps then bump up the bullet weight a little at time til you find the one that starts hitting a little sideways at 100yds. With heavier bullets your velocity will come down and stability will drop. There are some calculators that say they can figure twist rates for subsonics and probably they work for most but you will have to figure what really works for your rifle by testing. We had a Rem 700 in 300 blackout with a 1-7 twist and it won't stabilize 200gr bullets. Normally 1-7 will handle 240s with no issues.

Hope something there helps

Frank

 

[myownman]

Good info, thanks!

 

[shoot4fun]

A suppressor is a terrible thing to waste; and a baffle strike would put a frown on your face. I agree that the 1 in 9 twist will not be optimal for subs. On the other hand, I shoot my 7mm08 at full tilt with the can on and it does a nice job.
When I want to shoot subs I go 300BLK. My guns are a 1 in 7 Noveske and a 1 in 8 M&P15 upper. No problems stabilizing the 208 Amax at sub sonic velocities in either. Pretty good accuracy at the 200 yard line too.

 

[HodgdonExtreme]

I'd think a 7mm-08 would be a great application for seating bullets backwards for subsonic use.