Winchester m70 question. 220 swift twist rate

[john 800]

I am considering buying a pre 64 m70 my grandfather has. Does anyone know the twist rate they used back then? I am guessing its a 14 but wasn’t sure

 

[47WillysGuy]

I googled “220 swift barrel twist”and this is what I found and a lot more!
From ChuckHawks. Com


One caution applies when selecting bullets for a .220 rifle. The caliber's rifling twist rate was originally established at 1 turn in 14", due to the light bullets originally factory loaded. Rifles with this twist rate will normally not stabilize bullets heavier than 60 grains. One of the many excellent 55 grain varmint bullets is probably the best choice for .220 rifles with 1 in 14 rifling.

 

[Gary in MD]

Yea, almost surely a 14 twist

 

[FNSafari]

Nothing wrong with a 1-14 twist as stated above. Unless of course you are going to a PRC match and trying to shoot 80 grain bullets. But why would you want a 220 swift for that? Just a rhetorical question.

If its in great shape and the barrel has good life and its unmolested original factory its a reasonably valuable rifle.

 

[nakneker]

I wouldn’t worry about the 1-14 twist, I had a Pre-64 that shot 50-60 grain bullets well. I had a Winchester heavy varmint in 220 swift that shot those weights into itty bitty bug holes. For me, those are the “fun” weights in the mighty swift.

I never did check the twist rates on either though.

 

[snert]

When in doubt, shoot 50-55 grain Hornady or Sierra SP. Not only are they cheap, but they will surprise you in accuracy. For years this was my go to bullet in 22-250 and 220 Swift for accuracy. Only went to Vmax for a tad bit flatter at long distance, and I gave up a tad accuracy for it.

 

[Doug Casner]

Ive got two of them their 1 in 14. Mine like 50s or 55s with imr 4064. Doug

 

[freebird22/250]

I have a Mod. 70 Heavy Varmint in .220 Swift mine has a 1 in 14 twist.

 

[Pawnee Bill]

If memory serves me correctly, wasn't the original factory ammo loaded with 40 grain bullets and MV about 36 or 3800 fps?

 

[john 800]

Nothing wrong with a 1-14 twist as stated above. Unless of course you are going to a PRC match and trying to shoot 80 grain bullets. But why would you want a 220 swift for that? Just a rhetorical question.

If its in great shape and the barrel has good life and its unmolested original factory its a reasonably valuable rifle.

I was thinking a 14 would be borderline for 60s and 64s for coyotes. If the 14 is good for 60s that is all I am looking for

 

[john 800]

When in doubt, shoot 50-55 grain Hornady or Sierra SP. Not only are they cheap, but they will surprise you in accuracy. For years this was my go to bullet in 22-250 and 220 Swift for accuracy. Only went to Vmax for a tad bit flatter at long distance, and I gave up a tad accuracy for it.

I happen to have a bunch of those laying around too. Guess i gotta buy the rifle