Subsonic .308 loads, suppressed

[machinehead1]

I am using a Remington 700 SPS 20 inch barrel.
I am using Sellier/ Bellot factory sub sonic loads.
All of my shots are keyholeing, do I need a different barrel twist?

Thanks for info on this.

 

[illinoisburt]

Need a little more info. What is bullet weight? What is current twist?

 

[taliv]

almost definitely

 

[wally]

Be thankful you aren't having baffle strikes.

 

[dubbleA]

I would not shoot any more of those in your rifle with a suppressor attached, bad things could happen.

It's always a good idea to shoot several subs through your weapon before shooting with a can to check for a stable bullet regardless of what twist you choose.

 

[MCMXI]

The only S&B subsonic ammunition I could find uses a 200gr bullet. I find it odd that S&B doesn't list any subsonic .308 Win on their US or CZ websites but a bunch of online stores offer it. Regardless, if you run some numbers using the Miller bullet stability calculator you'll find that a 1:12 twist won't stabilize a 200gr (1.410" long) .308 bullet at 1,050 fps. A 1:10 twist gives the velocity corrected SG value as 1.54 which indicates that the bullet will be gyroscopically stable.

 

[chaser_2332]

take the suppresser off and shoot paper at about 5-10 yards, always check this before shooting with your can on. 8 twist would have been a better for your application.

 

[machinehead1]

I have a lot to learn about this site,
I could not find my orig. thread, I will get better.
I do not know twist, I will find out.
Thanks to everyone for your help.

 

[zerobarrier]

I have a lot to learn about this site,
I could not find my orig. thread, I will get better.

Once in the thread look towards the top and right of page. You will see "Thread tools" Click on it to get a drop down menu then select "subscribe to this thread" choose your notification type, I always use no email. Then when you sign on once you go to "user option" on the top left of page, you will see all you subscribed threads with any new posts. Never lose one again.

If it came with a factory threaded barrel then it should have a 1:10 twist, if it is the one without the threaded barrel from the factory then it should be 1:12 twist which is not fast enough to stabilize the subs. Need 1:10.