Supersonic .308 and barrel length

[jay6ird]

Can the .308 175smk make it to 1000 or 1200 yards with a 20" barrel on a bolt gun and still be supersonic or should a 24" barrel always be used? Thanks

 

[Flyingbullseye]

What's your velocity in the 20in barrel?

 

[jay6ird]

What's your velocity in the 20in barrel?

Well I do not know that answer yet. Maybe I should rephrase the question to- What muzzel velocity is needed for the .308 175smk to stay supersonic at 1000 yards and at 1200 yards..

Thanks again

 

[Huskydriver]

As fast as you can if your trying to stay super to 1200....

According to my calculator you need 2800-2850fps at Sea level

 

[Jcrios014]

I run a 24in with the 175gr Sierra TMK. It'll clock 2650 at the muzzle and I haven't hand issues getting out to 1000 yds.

 

[Huskydriver]

I run a 24in with the 175gr Sierra TMK. It'll clock 2650 at the muzzle and I haven't hand issues getting out to 1000 yds.

2650 will get you to 1k np and be super but not 1200

 

[Jcrios014]

2650 will get you to 1k np and be super but not 1200

Yep, according to sierra the tmk should stay around 1133 @1200 but unfortunately I'm limited to 1k so I can't verify if what the claim is true.

 

[db2000]

This is a Savage Ashbury 24” 1:10 running 44.4 gr RL15 at 2730 fps at DA 2194 ft.