69gr ss 223 out of a 16 in bbl w/ 1/9 twist

[atilliar]

Anyone been able to make this combo work? I'm using 4.5 grains of Trailboss... It's not stabilising the bullet.
The bullet I'm using is the 69 gr Sierra Match King
Shooting through a 16 inch 1/9

Trying to keep it subsonic... is this possible? would an increase/ decrease in powder load fix this? I'm not new to reloading, but I'm new to subsonics and never used such a heavy bullet out of a 223 before.

Any help would be awesome.

[Bendersquint]

Anyone been able to make this combo work? I'm using 4.5 grains of Trailboss... It's not stabilising the bullet.
The bullet I'm using is the 69 gr Sierra Match King
Shooting through a 16 inch 1/9

Trying to keep it subsonic... is this possible? would an increase/ decrease in powder load fix this? I'm not new to reloading, but I'm new to subsonics and never used such a heavy bullet out of a 223 before.

Any help would be awesome.

Not possible to keep it subsonic AND stabilize. Pick one and disregard the other.

You can play with it if you want(with no can on it of course) what is your chronograph saying?

[atilliar]

Why are they exclusive? I think I've heard of others doing it.. I'm not sure what barrel they had though... Are you sure I can't keep it from keyholing?

I unfortunately don't own a chrono

And of course I keep my can off.

[atilliar]

What would the heaviest bullet that I can sling out of a 1/9 twist 16" barrel be? That I can keep stable of course...

[oilfieldtrash76]

I have shot Hornady TAP 75 gr out of my M&P 16" 1 in 9. No keyholing at 100 yards. Bullet stabilization is also affected by velocity, a quick google search will turn up a lot of info and testing. Ive talked to some guys whos 1/9 twist barrells would not stabilize the heavier bullets but mine does fine.

[Wicked]

What would the heaviest bullet that I can sling out of a 1/9 twist 16" barrel be? That I can keep stable of course...

Use this: http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

Simply plug in your variables and see what you get. Look to achieve at least 1.5 or better.

You will not get that pill (69gr SMK) to stabilize in that barrel (1:9" twist) at anywhere close to sub velocities. I calculate stability at 1.19 using 1050fps. Not good enough.



p.s. you will need a chrono. Otherwise it's a wild-ass guess.