model 70 winchester 22-250 bull barrel

[robs257]

trying to find out the barrel twist, the rifle was made in 1977 , want to reload some 63 gr. boat tails , i was told being an older model rifle the heavier grain bullet might not perform as well.

 

[JesseL]

Even if you find what the twist is, the only way to know for sure if your rifle likes the 63 gr bullets is to try them.

 

[robs257]

thanks for your input.

 

[Chawbaccer]

Lyman 46 setting right here says you have a 1 in 14.

 

[jlmurphy]

You can check the rifling rate by using a tight fitting patch on a jag, make a flag from tape on the rod, simply push/pull until the tape rotates once and measure how many inches the rod has traveled.