5R mil-spec

cohunter1 · #1 12-02-2012, 12:06 AM

A question for those more knowledgeable about ballistics than I. Does the 1 in 10 twist in these barrels stabilizes a 180 gr bullet, or do they prefer a heavier weight bullet? I am thinking of one, and have lots of 180's for 300 win mag.
Thanks for any input.

Aim Small Hit Small

tomt · #2 12-02-2012, 07:34 AM

This might help:
JBM - Calculations - Stability

I have the 5R in .308 Win, Betsy is her name.

cohunter1 · #3 12-02-2012, 11:24 AM

That is an awesome link. Very helpful info. That's why I love this forum, somebody always has an answer. Thanks again TomT

Aim Small Hit Small

twoftagl · #4 12-04-2012, 06:44 AM

308 or 300wm? and where are you in CO?

tomt · #5 12-04-2012, 07:35 PM

The 5R 300 win mag has a 1-10 twist, the 5R 308 win has a 1-11.25 twist.

cohunter1 · #6 12-04-2012, 08:04 PM

I am in Pagosa Springs waiting for it to turn into winter, but I am looking for a new 300 win mag in a 5R. I already have a 308 that shoots 1/4 moa if I can get my head in the same place every time.Was wondering if a 180 gr would stabilize in a faster twist, and apparently it will, so I am on the hunt for a 5R mil spec.

Aim Small Hit Small

twoftagl · #7 12-05-2012, 07:11 AM

I'll be moving to CO Springs here in January, and have a 5r in 300wm. I'm assuming your 308 is a 5r? and you're looking for a 5r in 300wm?

I believe the twist in your 308 is kinda non-standard (11 1/4 if I remember correctly) so it can handle the 168 and 180 slugs, but don't have the specs in front of me. With the 300/5r you'll have a 1 in 10 and no problems stabilizing up to and past 210, and I believe even 230.

I'm currently trying to work up a load in my 300wm 5r, didn't have much success with a newer powder, Magpro (but fantastic velicities) so I'm going with one of the standbys for caliber: H4831sc. That should get me going for next season with all summer to practice.

From what I've seen so far, I can't get mine to shoot decidedly better than a moa, but it consistently shoots right at with the cheapest factory ammo out there. Sometimes a tad more, sometimes a tad less. I'm hoping a good load workup can bring it consistently under, so I can push my max out a little further.

I just wish it was as much of a tack driver as the 308 5r's.

Good luck and keep us posted!

Chris