.22-250 w/ heavy bullets

[ebd10]

I have a "walking varminter" that is quickly coming due for a new barrel. Since I already have the dies and brass, I was thinking of sticking with the .22-250, but I'd like to use heavier bullets. Any suggestions as to twist or load? The bullet I was looking at is the 77 grain SMK.

You guys are quickly becoming my "brain trust" for reloading.

 

[billmo]

The 1 - 9 may work but I think I would go with a 1 - 8 if I were going to lean to the heavy side with a new barrel. My experience with the tighter twist allows me to shoot the lighter bullets too. I hope this helps. Bill

 

[Preacher]

the 75 grain A-max is a stone cold killer, from small to large varmints.
It needs a 9 twist to run right, but a 1 in 8 sure wouldn't do it any harm..
Either one will still allow lighter weights to work well also......

 

[Dans40X]

Barrel the .22-250 with a 1:8" twist & push the 80-90gr VLD's to 3250fps with ease.
I've burned out a couple 1:8" twist Bbls chambered in .22-250.

The A-Max's pushed hard won't be to call 100% of the time.

 

[ackleyguy]

I currently have a Savage 12 LRPV 22-250 1-9...It is quite a machine. In this gun I shoot a 75 amax @3370 and its good to 1 k on pennsylvania groundhogs. That being said some years ago I bulit a .22-284 with a HART 1-8 twist finished at 29" TOO MUCH OF A GOOD THING! could get a bullet to 3700 out of it but most times they would not hold together. I know some guys are doing it with 22-6mm Imp and close velocity and it works ..but thats not been MY experience. First thing you need to look at is ROTATIONAL velocity, MVx720)
--------
Twist in inches
this equals rpm's
lets look at 75 amax @ 3350 1-9 twist=268,000rpm
increase the twist to 1-8 assume a 50Fsec reduction inF/sec for the twist increase and it yields 297,000 rpm...You are really starting to push the envelope for jacket failure if not surpassed it!There is some argument that barrel length has a effect on this as well, the theory being additional frictional heat being created as well as several nanaoseconds longer for thermal absorbtion due to the combustion of the powder...not sure if any of that has been proven. Long winded way of saying if your gonna shot 75 a maxs a 1-9 twist is all you need in a case which drives it in the 3200+ threshold.