Twist rate on 12BVSS 223 varmint rifle ?

[Hammer]

Does anyone recall the rifling twist rate on the Savage 12BVSS varmint rifles in 223 Rem ?

It's keyholing with some 55 grain bullets.

[DiRTY DOG]

1:9 twist originally. In 2012 it was offered in 1:7 just for that year.

You can call Savage with your SN# and ask.

https://www.savageshooters.com/content.php?305-Savage-223-Remington-Twist-Rate-History

[NF1E]

I was thinking the problem should be something other than twist rate. Faster twist should not destabilize light bullets.

[charlie b]

I agree. The 1-12 twist was designed around 55gn bullets. Are they factory loads or reloads using surplus bullets?

[pdog06]

I agree too. Should be a 9 or 12 twist, but even if it was the 7 twist it should still shoot 55’s..
how many rounds down the barrel? And have you tried different 55’s or just one bullet type?

[Hammer]

have tried

Hornady flatbase
Hornady boattail
Sierra flatbase
Sierra boattail
etc...

The vast, vast majority fly true. But sometimes some will keyhole.

[NF1E]

First think I would try would be a re-crown and if that doesn't work pop on a new barrel. I just put a .223 26" Criterion SS Varmint profile on one of mine. Whatta Hobby!

[LDSILLS]

heres the latest from savage for a 12BVSS in .223. It shows a 1-9 twist

https://www.savagearms.com/content?p...ummary&s=19139

[sharpshooter]

Sounds like hard carbon fouling to me. How many prairie dog towns have you wiped with that stick?

[South Prairie jim]

Sounds like hard carbon fouling to me. How many prairie dog towns have you wiped with that stick?

I’d like to understand that line of thought, could you expand on that please?
thanks
jim

[finebead]

I have a 12bvss varmint rifle in .223, 1 in 9 twist. I used to post here years ago, back for a bit.

[DiRTY DOG]

I’d like to understand that line of thought, could you expand on that please?
thanks
jim

Google :carbon ring

Basically, a hard ring of carbon forms in the throat that must be cleaned/maintained. It acts like a constricting ring that the bullet must squeeze through. It can deform the bullet or cause pressure spikes.

[NF1E]

Have heard of that with rimfire, but with centerfire I always worried about throat erosion and never considered carbon ring. Always something new to explore. Whatta Hobby!

[243LPR]

A brass brush and a drill will get that out quick.

[South Prairie jim]

Google :carbon ring

Basically, a hard ring of carbon forms in the throat that must be cleaned/maintained. It acts like a constricting ring that the bullet must squeeze through. It can deform the bullet or cause pressure spikes.

Wow, that must be one hell of a carbon ring as they form just ahead of the case mouth and well inside the bullets ogive, j would certainly expect resistance while chambering a round if its were that severe. I suppose that may cause the key hole effect reported by the OP , IDK for sure leading to the question.
Thanks
jim

[pdog06]

Fred might’ve been referring to hard carbon buildup in the rifling. It can be really tough to get rid of it once it is there, and without a bore scope you’ll never know it’s there.

For a carbon ring the best way I’ve found to remove it or keep it away is to buy a chamber rod. Put a 1-2 caliber oversize brush on it and and clean just the neck/throat area by turning clockwise in and out for 30-40 turns. Can use a rod chucked in a drill as well but manually is more controllable.

[sharpshooter]

Hard carbon fouling is not a "ring", it is a long trail of hard carbon deposits in the bore that has been building on itself. Typically hard carbon fouling occurs when the rifle is shot repeatedly in hot conditions,(i.e., in a prairie dog town once a person loses his good sense) and in overbore cartridges.
The carbon builds to a point that it constricts the bore and causes pressure spike and /or destabilization and even bullet termination before it hits the air.
The best way to eliminate the fouling is to scrub with a brush(actually 2 or 3) using GM top engine cleaner or the equivalent. When patched out, the patches will be BROWN...not black. Finish up with some JB bore paste.

If it still won't stabilize bullets......it's cuz that barrel is shot out.

[South Prairie jim]

Hard carbon fouling is not a "ring", it is a long trail of hard carbon deposits in the bore that has been building on itself. Typically hard carbon fouling occurs when the rifle is shot repeatedly in hot conditions,(i.e., in a prairie dog town once a person loses his good sense) and in overbore cartridges.
The carbon builds to a point that it constricts the bore and causes pressure spike and /or destabilization and even bullet termination before it hits the air.
The best way to eliminate the fouling is to scrub with a brush(actually 2 or 3) using GM top engine cleaner or the equivalent. When patched out, the patches will be BROWN...not black. Finish up with some JB bore paste.

If it still won't stabilize bullets......it's cuz that barrel is shot out.

Thank you Sir,
that makes perfect sense to me.
Jim