Chopping and Crowning a Barrel

[bainter1212]

One good way to get a near square cut right off the bat is to use a good quality tubing cutter to deeply score the barrel where you want to cut it. Use the groove you just created as a guide for your hacksaw. This will make the outer diameter square, the rest can be squared with a file or crown cutter.

 

[LAGS]

@ bainter 1212
That is a good idea, but be carefull when using a tubing cutter on a Tapered Barrel.
The tubing cutter will have a tendancy to sit on an angle and follow the barrels taper.
It cuts a very nice spiral thread on your barrel if you don't use tape or something like that to shim up on one side of the cutter guide wheel.

Been there, Done That.

 

[KSCCHTrainer]

Witchhunter -- there is a famous video or illustrated article out there where a fellow took a good hunting rifle, shot base line groups with it, and then proceeded, step by step, the absolutely DESTROY the crown. At each step, he shot another set of groups with it.

There was virtually no change.

And I mean he DESTROYED the end of that barrel. He banged it, hacked it, cut it, did just about everything you could think of to it.

That gave me great solace when I hacksawed my Mosin Nagants (and I couldn't even cut straight). [Easier way to do it is with a chop saw, BTW] and then cut them square and flat with a Lee case trimmer shimmed up with McDonalds's straws to fit the bore....and then beveled just slightly with valve grinding compound in the gap of a big brass screw hand held in a 3/8" Black and Decker electric drill.

My groups got markedly better.

Give it a whirl!

Mosin 91/30 I used to have came from Gander Mountain when they were selling them @ $99.95 and I got to go through all they had and pick the one I wanted. I forgot to look at the muzzle end of the barrel and it was actually visibly oval shaped with stronger rifling on one side than on the other for about a half inch in. As it was, it shot 100 yard groups that looked more like a shotgun pattern.

Figured for 100 bucks I couldn't screw it up too bad so I cut the bad part off with a hacksaw (didn't even bother to square it up), took my Lee case trimmer with a .223 pilot to which I added some of that hard nylon water tubing used for refrigerator ice makers. That turned out to be a good fit to the bore and kept the cutter from wobbling. I chucked the trim cutter in my 3/8" battery drill and cut about a 1/16" deep, flat crown (if you care to call it that) on the barrel.

I carefully de-burred it with a large diameter countersink cutter to keep the angle as small as possible.

I have no idea whether or not it was getting rid of the part that had the uneven rifling, or the flat crown or simply psychological, but after that I was getting better than MOA groups at 100 yards using the Bulgarian heavy ball (180 grain bullets) and handloads with the 175 grain Sierra Match King bullets.

I do know that it was not difficult to square up the end of that barrel with the Lee case trimmer and it definitely did NOT destroy the barrel. I loaned my home made cutter to several other people who used it on 91/30 Mosins, M44 Mosins and even one Enfield 303 British that had a shot out muzzle with very satisfying results. Only a small sampling, so you be the judge and I will not respond to any flames -

Jim