22-250AI 12 twist bullet problems

[CZ550]

Ok guys got a 22-250 AI with a benchmark 12 twist, it shoots the 40gr SBK and the 52SMK great but I would like to use a little heavier bullet. I have tried 53gr Vmax no good 1.5 groups @ 100, 55gr SBK no good either. Anyone else have trouble with these in a 12 twist.

How about 52gr Amax anyone the are a little bit shorter than the 53 and the 55SBK kinda thought they might work. Would really like to get a little better BC than what the 40gr has.

Thanks Corey

 

[KevinThomas]

Corey,

That's not a twist problem. A 1x12" will shoot any of the bullets you've mentioned here. In fact, they'll all work in a 1x14" as well. You have something else going on, probably related to just sub-par bullets in the ones that aren't shooting, or the load needs to be tweaked a bit. Every once in a while (okay, quite freqently in some cases) you run into certain components that just don't play well together.

It just needs a little more work, but I assure you, if the 52 HPBT is shooting, the others have the potential to shoot too.

 

[CZ550]

Kevin the holes in the paper dont look good, they dont appear to be flying well.

 

[Ackman]

Not necessarily twist rate. It just means that particular bullet/powder/charge weight combination doesn't work in your barrel.

 

[bozo699]

Corey,
Give us a little more info, like stock,action, scope, and bench set up. The 1:12 should stabilize up to a 64 grain varmint bullet according to bergers site, I shoot 55 grain bullets out of my 1:14's all the time. You have been shooting 40's out of it, at the speeds the AI can generate you may have copper and carbon issues, I think with a little more info someone will be able to help you sort this all out.
Wayne.

 

[bheadboy]

I can personally say the problem is not the12x1 twist, as i shoot a 13 and it will handle anything upto mid 60gr.

is you bbl really a 12?. check it as it may be mismarked, ,

also, you may be over pushing for velocity and with excessive pressure loosing accurcy,

check the crown, back off on seating depth, do not touch or jam

no way the smk will not shoot reasonably

if this does not work send the rifle to the bbl maker and ask him to check his work

Bob

 

[CZ550]

The rifle is a tikka 595 benchmark barrel chambered by them I bought it used off of the hide. I got 250 loaded rounds with 40gr SBKs with rifle. I bought some lapua brass from Sinclair when it went on sale. I started working on a load and fire forming and noticed that only the 40gr or 52 hpbt are the only bullets that shoot decent. The loaded ammo will shoot around .5 sometimes better. I tried some loads using 53 gr vmax with new brass and max load for varget for fire forming and shot about 4 inch group. I loaded some with 40gr SBK got a 1 inch group. Did the same with 52 SMK. The 55 SBK shot 2 shots about an inch apart and then threw one about 5 inches off. I am pretty sure the gun is not fouled up just shot 2 groups in the .5's.

However the 40 grainers are moly coated? Do moly and naked bullets get along in the same barrel?

 

[bozo699]

Corey,
No, some guns don't like to mix a molly fouled barrel with naked bullets and visa versa, however throwing one 5 inches out is ridiculous, you might check for loose screws or to long of action screw. I own several 22-250's and I don't think any of them would shoot a load out of a reloading manual for my twists over a inch and yours shouldn't either, your particular rifle is inherently accurate, if the barrel isn't shot out I would look for a mechanical problem, screws, bedding, ect,ect...
Wayne.

 

[CanusLatransSnpr]

Corey, get some Kroil and go after the molly in the barrel before you shoot any more naked bullets through it. From what I've read Kroil does a really great job of getting the molly out of a barrel. Well, Kroil and some good old fashioned elbow grease that is . Do that and tell us how the naked bullets shoot!

Mike

 

[CZ550]

I am sure it's not a scope or bedding problem the rifle will shoot a .5 group with 40 gr bullets as it is. I just talked to my buddy that had the same problem with his Mcgowen it shot light bullets good but would throw the 55's around 4 to 8 inch group. He was able to get one load that would shoot around 1.5?

 

[338Lapua]

100% its 1 in 12 twist, mine shoot 60 gr super accurately

 

[jonbearman]

It still sounds like a copper problem to me.I would use some sweets and see if the patches are pretty blue/green.You never leave sweets in a barrel over 15 minutes.It will wake you up because it has ammonia in it.