'06 to 270

[clodbuster]

Just catching up with the rest of the world and bought a .270.  it's in a  Remington model 760.  It shoots fine with 130 psp over H4831, what a surprise.  Now I'd like to make brass for it from 30-06 and noticed '06 is a little shorter around the shoulder.  What is a good way to push that out?   Seated way out over spud loads or what?

[Siskiyou]

First off congratulations on getting a 760 in 270 Winchester.  I have been loading selected 30 Cal. Military and commercial 30-06 brass for years.  I find that brass stretches a little faster in my M760 then in my bolt .270.  In my pre-case trimmer years this started to cause problems.  But the resized 30-06 brass have never been a problem.  I re-size it; chamfer the mouth, prime and load.  I got into this back in the 60’s when empty factory brass a little harder to get, and came in 20-round boxes. 

I have not noticed any negative effect on accuracy.  I believe the difference is .006, which might give you very slight amount of free-bore.  I rather doubt that this causes massive amounts of throat erosion. 

When my son received his .270 I loaded him up a couple hundred rounds in Mil. Cases.  It’s economical, works great, and improves functioning. 

I think the only time it would make a difference is if you were loading beyond maximum charges of H4831 and seating longer 150 or 160-grain bullets.  Because of the shorter neck the charge would be compressed.  When loading 130 grain bullets and below listed maximum charges you should not encounter a problem.

I am not aware of any issues with most U.S. manufactured commercial brass.  Care must be taken with military brass.  Some of it was loaded with mercury primers, which resulted in brittle brass.

Admittedly this is just my opinion and not the results of some university study. 
 

[Tom W.]

It works well, you'll just have a shortened .270 case. But PLEASE be sure to keep them separated from any '06 cases that you have, so you ( or some one else) doesn't look at the headstamp and try to chamber it in the wrong rifle.

[clodbuster]

Isn't there a headspace problem with a short case?  Shouldn't the shoulder be blown forward in a fireforming step?

[Tom W.]

Look at the diagrams of the two cases in your loading manual. The cases are almost identical. They headspace on the shoulder, not the case mouth.

[Siskiyou]

Normally when resizing from 30-06 to 270 a slight ridge appears at the base of the reduced neck.  The case is effectively fire formed and the ridge removed on first firing.  There is not a big difference between the old case and the newly formed case except the reduction in caliber.  I have not found a need to reduce the powder weight in the process after having developed the load.  In this case the shoulder is not blown out.