1:9 Twist 270?

[JFK]

I was recently gifted an older post 64’ push feed Winchester M70 in 270. It shoots ok, but it really doesn’t do it for me. I have another 270 and am setup to load for 270, so wanted to keep it a 270 for simplicity sake.

I don’t really need another rifle but since this one was given to me it has me thinking of rebarreling this one with 1:9 twist barrel, have the whole thing cerakoted and putting it into a new stock. My existing 270 is a factory barrel in the standard 1:10 twist. It shoots everything from 110gr to 150gr well. My thinking was to barrel this new rifle in 1:9 so I could shoot some of the longer bullets. The hammers require a faster twist for most of their bullets.

My main question is if I were to barrel it in 1:9 does this preclude me from shooting standard 130gr bullets? Loss of accuracy or speed? I’m not sure I’d want to be locked into only shooting the longer high bc bullets that require a faster twist if it meant I couldn’t shoot a standard length bullet from the rifle.

 

[kevin11mee]

It is quite tough to find stocks for model 70's, however, I have a pre-64 so maybe you will have better luck. For me, it was much cheaper to build off an R700. However, If it were me I'd twist it much faster - 1:8 or 1:7.5. It will allow you to shoot the heavier bullets and the longer non-leaded bullets like the Hammers. Also, I'd expect more high-BC .277 bullet options now that Browning is releasing their 6.8 Western. The 130's will still shoot great with a faster twist.

 

[EmperorMA]

Why would you want to shoot 130s if you could shoot 165-175s? You already have a 1:10" .270 for that.

BTW, I'd make it 1:8" or even faster, for sure.

 

[JFK]

I live in Ca and must shoot lead free when hunting here. For copper bullets, if it’s not leaving the muzzle at 3,000+ FPS I’m not interested in it. I’d probably continue to shoot the standard bullets the majority of the time. I guess my question should have been phrased that way. If I barrel it in 1:9, or even 1:8 would I be handicapping the rifle while shooting the lighter 130gr bullets?

 

[mcr-85]

I built a 1:9 270 WSM around the 165 matrix. I now shoot the Berger 170s and it shoots great. I'm at 5600 feet elevation and usually hunt higher than here though. If I did it over I'd do at least a 1:8 or 1:7.5 like mentioned above. A faster twist won't hurt you with the lighter bullets either, in my opinion.

 

[kevin11mee]

No. You’ll likely lose about 2 feet per second going from a 1:10 to a 1:7.5. Bring that model 70 to the 21st century and rebarrel with a 24” 1:7.5 twist and you can shoot all kinds of fantastic bullets.

 

[JFK]

Great. This is what I was hoping to hear.

 

[Goodhayman]

Why would you want to shoot 130s if you could shoot 165-175s? You already have a 1:10" .270 for that.

BTW, I'd make it 1:8" or even faster, for sure.

My Dad and I have shot 130gr 270 for years. Here is our reasoning for using the 130gr 270win combination.
The advantage is flatter trajectory maintaining a bullets path within an 8" kill zone out to 300 yards with the same point of aim (POA). Thus, theoretically, the 130gr bullet will kill more than a 165-175gr bullet, excluding game wearing bullet proof vests, if kill is defined as hitting a target within the 8" kill zone using the same POA. Simply put the 130gr bullet will be on target for a longer distance with the same POA.
Here is an article on this topic.

Jack O’Connor’s Formula For Shooting Game At Long Range

Outdoor Life’s legendary Shooting Editor Jack O’Connor’s simple system for shooting game at long range.

www.outdoorlife.com