Chambering a 270 Winchester barrel for 7x57mm Mauser. Can or should it be done?

[corbinace]

So, I have access to a takeoff 270 barrel for minimal cost. I own a 7x57 reamer. I am thinking of making a Handi stub barrel in 7x57 rimmed.

The 7mm calls for a .284-5 bullet.
The 270 calls for a .277.

Another thought is that I could use a cut down 270 size die, neck size, and load with the smaller bullet and call it a 270 Rigby.

One thought on the different nomenclature is that it would likely never be shot/blown up after I leave this earth as nobody would have the correct cartridges for it. I am making it rimmed, so a normal 7x57 would not chamber.

What are your thoughts?

[Loudenboomer]

It's a little unclear to me what the question is?? Just don't send .284 bullets down a .277 bore!

[country gent]

How are you going to get the 7mm pilot into the 270 barrel??????

[405grain]

1. The 270 cartridge is longer than a 7x57, so unless you set the barrel back the chamber won't clean up. 2. The pilot of any 7mm reamer is not going to fit into the bore of a 270 barrel. 3. A .284" diameter bullet is not going to swage down and pass through a .277" barrel without causing significant pressure (and possible damage) to the firearm.

It would be infinitely better and easier to get a 7mm barrel blank and chamber it in 7x57. Buying a barrel in a caliber that its incompatible with what you are trying to do is what is called "Spilling dollars to pick up nickles". Also, having a reamer is fine, but you also need to have at least a GO gauge so that you can set headspace, a reamer holder, plus a barrel vise and an action wrench.

[challenger_i]

CorbinAce: pm sent.

[Jedman]

I have something similar. I took a 270 Win sizing die and shortened it by the difference in length between a 270 and a 7 x 57 R and while it was in the lathe chuck I used a dremel grinder with a small sanding drum to grind the ID of the shortened die back to its original diameter. Then using 7 x 57 R brass I could size it with this shortened die and it would just change the neck diameter and shoulder angle to that of a 270 Win.
Then I turned a 270 take off barrel to fit inside a 20 ga. barrel as a thick liner and being it was pre chambered to 270 Win. all I needed to do is shorten the breech end of the barrel - grind the ID a few thousands and cut a rim recess .
Jedman

[porthos]

i think you better leave things alone. you seem to be missing the basics.

[challenger_i]

I would bet dollars to doughnuts the OP is asking questions of the Forum so-as he may GAIN knowledge? Seems a logical step to me.

[corbinace]

Good Afternoon Gentlemen,

Thank you for all of the replies and advice to go with my brainstorming.

I really did a poor job of articulating what I was thinking about in my OP. I woke up with the idea and was kind of rumbling it around while I took a shower and ate breakfast. I decided to pose the question just before leaving to work on another project and should have waited until later when I had properly thought it through.

That said, you all brought up some great points and filled in a lot of the blanks.

This would be a Handi stub project and cutting the old 270 chamber down enough to make a new proper chamber was in the mix.

I am liking what Jedman has done. Utilizing the forward portion of the 270 chamber as is and blowing out the 7x57 brass loaded with a .277 projectile to fill the chamber. That also helps mitigate someone down the road putting a normal 7x57 in there and firing it.

All in all, a few hurdles to leap over and maybe not the absolute best path to pursue.

Thank you one and all for wandering down this trail with me.

[corbinace]

i think you better leave things alone. you seem to be missing the basics.

Yours is a new post while I was typing my previous response.

A very astute observation, but incomplete, as I am missing way more than the basics. As Challenger i points out, I am here to learn and see if I can fill in some of the many voids in my knowledge.

This forum and its members have been instrumental in helping me down many unlit paths to get to the light at the end.

I am much happier having you see my shortcomings and lack of knowledge, than to have you think of me as a "know it all". If that day comes, I hope you will tell me that too.

Thank you for your input.

[Milky Duck]

chamber it in the 7mm imposter/.284 rimmed case use said same dies BUT install a .270 /true7mm sized expander ball......
you could make neck/freebore a fly**** skinnier BUT many of us have loaded and used .308 calibre projectiles in a .311 bore AKA the 7.62x39mm forsure your brass life is slightly less but thats 3 thou vs 7 thou so not huge difference.
Ive often wondered if a 7mmrem mag with .270 sized barrel would excell..... now we getting faster twist .277 barrels its a moot point somewhat.