optimal bullet weight for .308 subs in aw rifle

[dave338]

Looking for the optimal bullet weight for subsonic loads in .308 using a standard Aw rifle
This is specifically for use in a AW . Any favorite loads?
Was thinking
Barns 150 rrlp
Lapua 185 scenar
Sierra 175
Barns 150 tsx
This is what on the shelf
Cheers

 

[coldboremiracle]

Re: optimal bullet weight for .308 subs in aw rifle

Twist? a 10 I assume?

 

[bohem]

Re: optimal bullet weight for .308 subs in aw rifle

For an 11.25tw I'd use 180 RN or backwards loaded 190 SMK's

For a 10tw then 210 SMK or 220 RN's.

Always test for stability without any muzzle device attached (suppressor or brake) and look for round holes at 100 and if possible 200yd.

 

[dave338]

Re: optimal bullet weight for .308 subs in aw rifle

thanks
actually its not my gun , so not sure of the twist ,
its a AW about 2 years old ,
i thought it might be a 1-12?

just looked at the US web site for accuracy int it does say a 1-12"

 

[bohem]

Re: optimal bullet weight for .308 subs in aw rifle

Subsonic 180's will probably still work. The 150 FMJ's or a 150 FP lever action bullet are the next step if they don't.

 

[dave338]

Re: optimal bullet weight for .308 subs in aw rifle

I thought the 150 may work , I see its listed as loaded ammo by a couple of manufactures.
Will be trying them & 180 next week
Will be interesting to see if the barnes rrlp exppands at reduced fps
Will post results asap
Cheers

 

[kombayotch]

Re: optimal bullet weight for .308 subs in aw rifle

At this time of year a lot of combinations will stabilize that might not stabilize once it starts getting colder out. Also keep in mind that the speed of sound also drops when temperature does. So, loads that are subsonic now may not be when it gets colder out.

I would develop loads with both bullets and limit the velocity to 1040 fps. or even 1020 fps. if you plan to shoot them in the late fall/winter. If the 180 starts going sideways on you, then you'll already have the 150 load to fall back on...

 

[dave338]

Re: optimal bullet weight for .308 subs in aw rifle

We don't get the weather you guys have !
I got the impression the ammo is going to be used here and also somewhere a lot hotter.
Being cautious I was going to aim for 1000 fps @15c@100m alt
That I think should stay sub where ever used ?

 

[bohem]

Re: optimal bullet weight for .308 subs in aw rifle

Go slower, in the high 900's actually. The ammo gets a whole lot quieter (bullet noise reduction) when the bullets are in the high 9's vs. being over 1000fps.

Technically the bullet is going subsonic, but the flow expanding around the bullet as it moves through the air can break the speed of sound (critical flow).

 

[dave338]

Re: optimal bullet weight for .308 subs in aw rifle

ok will try the high 900fps,
just seen another bullet to try , nosler 150gr 30-30 combined tec plastic tip round nose also being black there would be no chance of it being mixed with regular ammo ?

 

[kombayotch]

Re: optimal bullet weight for .308 subs in aw rifle

Yeah, subs aren't like supersonic loads; you lose very little velocity over distances.

I would avoid the Lubalox coated rounds as they may affect the velocity and/or POI of non-coated rounds if you're switching back and forth.

 

[dave338]

Re: optimal bullet weight for .308 subs in aw rifle

not used any of the nosler coated bullets yet, but i think it says on the web site it does not coat the barrel like other coatings,
just going to get a good selection and head to the range next weekend see what happens?
the one good thing about the nosler is that it would stand out compared to other ammo