Home Forums Hunting & Shooting Ask The Gunwriters Can I re chamber a 7x57AI to 280 Rem.?

Or is this not going to work.

Yes, but why ja wann do that. They should be pretty much equal.

Ehh. Im not sure I want to mess with the whole fire-forming cases and trying to find load data Haven't decided yet

Don't think so . . .

The 7x57 AI is shown as 0.455" diameter at a distance of 1.800" from the case head. The 280 Rem is 0.447" at this same location. It won't clean up w/o setting the barrel back.

Holy ssheeite. Just use 7x57 data + 5%, or whatever your case capacity increase is. It ain't that hard.

You cannot ream a 7x57 chamber to .280. Problem is, the chamber neck is smaller on the .280. There will be a residual neck left in the chamber from the original 7x57 chamber. Problem with shoulder could be another issue as was mentioned. If so, simply go to a .280 AI instead.

Fireforming an issue? If the chamber was properly cut, you simply insert a standard 7x57 loaded round and fire.

I load up 100 .280 cases at a time, then go hunt/shoot with them and I have firefromed .280 AI cases for the next time.

Why don't you rebarrel to a .270 PooBah (.270x57) its the greatest cartridge evah. Ingwe should be along soon to tell you all about it...

Actually you can, but your absolutely right on the neck.
I have a .280 reamed from a 7x57.
The smith turned one thread off in an attempt to not get that "residual" left. As it is there is approx 1/8" of that oversize neck upon fireing. It hasn't been an issue, I simply only neck size as far as the residual.

I still can't figure how people get any amount of accuracy from a cartridge(7x57) with that amount of slop in the neck dia....well at least I couldn't, that ream job tightened my group sizes in my rifle by 3" or so.

My main concern is lack of finding any reloading data for the AI chambering.

i'm a novice reloader and the "work up to x velocities doesnt work for me be ause I dont own a chrony. The price on this rifle was just to good not to pass up


If anyone has any load data I would be greatly apreciative

Not in my shop. No two step necks allowed. You could ream the neck larger, but as you pointed out, why induced the extra slop.

Easy thing to do is simply work up to book max for the std 7x57. If it is safe in the std 7x57 it will be more so in the AI.

I think muskegman gave you good advice. Most 7x57 max loads are still low pressure loads for modern actions.

pm sent

Update: Located the previous owners load notes and reloading dies for the rifle and probably some brass for it too.

I've taken a lot of animals with an HVA Husky 7X57 AI I got years ago for peanuts from my friend, the pawnbroker. He had it in the store for a year without a bite. I got it for $200.00 OTD with an older Leupold 3-9X40 in Redfield mounts. It's one of the most accurate rifles I own.

Fire forming is as easy as shooting factory ammo out of it. Loading data is all over the place and is listed in several of the bullet manufacturers' manuals. As stated above, a 5% increase above standard 7X57 data is pretty much rule-of-thumb.

I don't see any advantage of re-chambering it if you're re-loading.

The price of a chrony is less than a good chamber job...

I believe that z1r hit it on the head. One thought: You may have to set the barrel back unless you want to have double diameter neck though even with the 280 AI.

JOC wrote this years ago about re chambering 7x57's to 280 Rem...he also said, nevertheless that some guys did it and seemed to get away with it.

Personally I would want it done "right". Otherwise what is the point.

Hmmm...

Now, that's funny...

DF

I'd just stick with it as-is. Whatever hassle / cost is involved with working up loads in the AI chamber will be less than the hassle / cost of rechambering.

If that's not the case for you, then you screwed up when you bought it - probably need to suffer a bit to drive the lesson home. A good price isn't always a good deal.

7x57AI sounds pretty cool to me, though. I think ya done good.

Tom

I used to have a neck reamer just for when I re-chambered a 7x57 to 280. One ended up with a larger neck than SAMMI specs called for but it didn't appear to do any harm.
You cannot re-chamber a 7x57 AI to the standard 280 but you can rechamber to 280 AI. Still, the neck diameter may have to be addressed. This is, of course, dependent upon the neck diameter of the 7x57 AI chamber which might be tighter than the standard 7x57 chamber since the AI is often chambered to tighter specs. By the way, if I was going to have an AI, the 7x57 would be on the short list for sure. GD