Home Forums Hunting & Shooting General Big Game Fire-forming 280IMP brass from 270 brass?

I have a 280IMP(50 degree shoulder)that I purchased here on the CF and was thinking about full-length sizing some once-fired 270 brass into 280 and then fire-forming into the improved 280. Would this be OK? First time dealing with a wild-cat. Do not have any specs on COAL either? Any suggestions? Thanks!

No reason it would not work except that some fool might try and cram one in a 270 or 270 IMP and blow his head off.

Why not just but some 280 ammo and fireform it in the rifle ?

You don't have a 280 RCBS (30 degree) or 280 AI, (40 degree) doesn't sound like a Gibbs or Hawk design. 50 degree shoulder is an invite to feeding issues.

Have you done a chamber cast ? (as, if the shoulder has been moved forward, like Gibbs, firing factory 280 in it could cause bad things to happen.)

Any idea who made it?

I have used once fired 270 brass necked up to 280 and fire formed into 280AI. Works just fine. MTG

With the slightly more forward shoulder and reduced body taper, you wouldn't be able to chamber the .280 Imp cartridge in a .270 chamber and close the bolt--no matter what headstamp is on the brass you use to fire form with.

Obviously you've never seen a 270 Gibbs.

It was built by Thomas Ambler of "The Gun Room" in Wisconsin.

JawnHenry, I have 100 polished once-fired 270 empties sitting around so I thought I might put them to good use.

A .270 Gibbs would not chamber, even if it did, it wouldn't "blow his head off". The .270 bullet would rattle down the barrel and pressures would be extremely low.

For example, I mixed up some .264 Win mag loads in with my 7mm mag loads. I was shooting my 7mm mag at the time at long range prairie dogs. I was missing by several YARDS and couldn't hit a house at 400 yards. I scratched my head wondering what was going on. I finally realized that I was shooting the .264 Win mag loads through the 7mm mag. The smaller bullets were rattling down the pipe and tumbling once they exited the barrel.

A smaller bullet being shot through a larger bore isn't going to cause catastrophic issues, unless the case is WAY undersize and doesn't seal the chamber.

Using .270 brass would work fine in the improved chamber. The only issue I can see is the length of the neck. .270 neck length is quite a bit longer than the .280 neck. You wouldn't want the mouth of the case pinching the bullet on ignition. I have seen this happen and it does cause extremely high pressure. If the resized rounds easily fit in the chamber, you are good to go to fire form. I'm still confused as to why anyone would make a 50 degree shoulder. Flinch

a few pics:

Where the HELL did you mention a .270 Gibbs in your previous post?