Who's stretching it out with a 270 WSM?

[TannerGun]

Anyone care to comment on the temp stability of '22 vs. Magpro? Trying to decide which route to go...

[beretzs]

Couldn't really say. I do my load work in the Spring/Summer and shoot all year long. Haven't really noticed too much difference with RL22 or Magpro, in my case. I do notice that RL22 will climb in speed if shot quickly, due to chamber temps, but if allowed to cool, RL22 has been excellent as has Magpro.

[Truc]

Same here RE 22 and 150 bullets excellent velocity and accuracy and Reumbo for the 165 gr bullets

[beretzs]

Originally Posted by Truc

Same here RE 22 and 150 bullets excellent velocity and accuracy and Reumbo for the 165 gr bullets

I have heard great things about Retumbo/RL25 and the 140 AB's as well. Just haven't messed with it as RL22 works pretty well for me.

[longarm]

Can anybody tell me how fast I would have to get the .277 170 grain Bergers to stabilize in a 1 in 10 barrel? I am currently getting 3,420 fps with 140 grain Accubonds out of my 270 Dakota with 27 1/2 inch 1 in 10 barrel, so I could probably push the 170s at about 3,100. Also, I am thinking of a very heavy 28 inch barrel with 1 in 10 twist on a 270 WSM built on a long action or single shot bolt action to seat the projectiles way out, for varminting past 500 yards. I am aware that 1 in 10 twist is a bit slow.

[65WSM]

First we need to know the length of the Berger 170 gr bullets to use a formula to figure out the stability of the bullet. The Greenhill formula is the best known but RSI says they have a nore accurate one.

Second, what kind of powder are you using and what charge. It sounds like you have a real impressive load. Remember that 140 Accubonds have a higher BC than the Bergers.

For 170gr bullets I would expect that VV N-570 would be your highest velocity powder.

[bigngreen]

Originally Posted by longarm

Can anybody tell me how fast I would have to get the .277 170 grain Bergers to stabilize in a 1 in 10 barrel? I am currently getting 3,420 fps with 140 grain Accubonds out of my 270 Dakota with 27 1/2 inch 1 in 10 barrel, so I could probably push the 170s at about 3,100. Also, I am thinking of a very heavy 28 inch barrel with 1 in 10 twist on a 270 WSM built on a long action or single shot bolt action to seat the projectiles way out, for varminting past 500 yards. I am aware that 1 in 10 twist is a bit slow.

Punch your numbers into JBM stability calculator. JBM - Calculations - Stability

Your going to need to be 6000ft plus, I'm going to give them a try out of my WSM since the Matrix stabilize fine for me but bullet design makes a difference as well.