Recrown an old Mauser

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ldlfh7

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I am considering repairing the original crown on my Turk mauser in hopes of shrinking the groupings down a bit. I am shooting 4-6 inch groups at 100 yards as of now. Couple of questions:

1) Can I repair the crown or will I have to cut the barrel flush and make a new crown?? (Really would like to not cut the barrel down)

2) Thoughts on this tool from Brownells? (http://www.brownells.com/gunsmith-t...utters/79-muzzle-crowning-cutter-prod628.aspx)

3) I have also read of people using the Lee Chamfer tool to recrown but I am not sold on this method. Anyone tried it with good results? Tips??

I know my rifle is not worth much but I don't mind throwing a little money at it as it gets me some alone time from the wife and kids in the workshop.

I have never recrowned a barrel so any suggestions are greatly appreciated.
 
Whether the crown job will help or not depends a lot on what kind of damage you've got and how bad it is. Is this a nicked or dinged crown where there's an obvious screwed up spot? Or is this more of a deep erosion issue like from scrubbing the bore with segmented steel cleaning rods, from the front?

I've seen cutters (somewhere) that would restore the military-style rounded muzzle crown, but that 17 deg. cutter would do the same job, just look a little different. (Use the right sized pilot, of course.)

Some folks get fine results with a brass round-head bolt and some valve grinding compound...
 
Sam - It appears to be an erosion from scrubbing issue. The rifling in the barrel is strong and does not appear worn but the crown looks iffy. Is it worth recrowning?
 
I really couldn't guess from here. :) If the crown cutter will go deep enough to get back to clean rifling, it should.

A lot of military surplus rifles were counter-bored to solve the same problem. Drilled out oversized down an inch or so to create a new crown down inside the barrel.
 
I will try to post pictures tonight. Just out of curiosity, which is worse:

Nick or ding on the crown or erosion issues from cleaning from the bore?
 
Cleaning rod wear is worse because it goes too far inside the bore to clean it up without counter-boring the muzzle down past it.

What you probably have is the tops of the lands worn off inside as far as in inch or so, making the muzzle rifling over-size.

rc
 
What ammo are you achieving the 4-6" groups with? If it's some old surplus, could be the reason because usually under 4" is the exception, not the rule. If it's commercial stuff, then perhaps a fresh crown might help.
Those original Mauser sights do make it difficult to draw a good bead at 100yds.


NCsmitty
 
How does the recrown process work? Hook the crowning tool up to a drill and just drilling down?
 
Oh, HELL NO! a brass toilet screw is OK in a drill. Any of the crowning cutters are made to either be turned by hand or chucked in a lathe, depending on design.

Don't give me a heart attack like that! ;)
 
There's a decorative crown which requires you to grind a cutting bit and turn the barrel on the lathe and then there's the actual crown which needs that Browning crowning tool. I'd use the Browning tool.
 
If you have a lot muzzle wear the best thing is to shorten the barrel and crown. Counter boring is just a quick and cheap way to get down to good rifling. If the damage is just at the end of the muzzle it could be as simple as a brass screw and some grinding compound. A good file might be enough to get down to good rifling.
 
I concur with NCsmitty. Especially with the issue sights off a sandbag.

I would add that wear inside the muzzle is a problem if it is a burr or other deformity that damages the bullet, leading to inconsistent flight. A worn muzzle that does not damage the bullet will not necessarily open up a group. It will change point of impact, but there will be a consistent effect that is applied to every bullet.

I had a long conversation about this with several of the custom rifle builders at the last SHOT show. Many high end custom rifles have integral muzzle breaks where you cannot easily get down to the crown to properly deburr them, and yet they shoot very well. This led to follow-on questions about muzzle wear, and the various types of crowns, etc.
 
ldlfh7 said:
http://forums.gunboards.com/showthread.php?70890-Lee-Brass-trimmer-for-crowning-muzzle

Ok so I have been doing research and I came across this thread on another site. Anyone have any thoughts and or experience for this sort of hap-hazard method? Should I just suck it up and buy the right tools?
Click to expand...
I used that exact method on a mauser and it improved it immensely. If you use the right caliber of mandrel for the case trimmer with an aluminum shim, it isn't really that haphazard. It's not the same as using a proper crown tool, but it worked very well for me. I used a 30-06 mandrel and a shim around it from a pop can with a little oil. The rifling at the muzzle on it looks really good, but there were some serious dings around the crown. If this didn't help, I would have rebarreled the rifle.

I'd suggest getting the trimmer with the ball because it can be a lot of work and I got a good sized blister on my thumb. I tried hooking vice grips to it, but that felt like I wasn't cutting evenly.

Matt
 
My Enfield's muzzle looked like a blunderbuss - I cut off about 5/8" and did a do-it-yourself 'recrown' with a brass spherical bit and some lapping compound. It turned a 5" rifle into a sub 1 incher in one fell swoop. Obviously, may not be the best route for everyone, but my Enfield now shoots better than I can hold it.
YMMV, but my mileage has been very good indeed...
 
Matt -

I think I am understanding this method pretty well by now. Only question I have deals with the grinding/smoothing after the new crown is cut.

1) How do you ensure even edges around the crown?
2) Should I be concerned with an angle form the outside of the crown going
into the muzzle? Is flat OK?
3) What dremmel bit would you recommend for the final smoothing step?
 
I finally got the courage up to chop the barrel and recrown. The results were amazing. The muzzle looks identical to my Remington 700 270 now. All I used was a mill file, lee case trimmer, hacksaw, sand paper, and valve grinding compound. Just finished late last night but can't wait to get out and see how it shoots now. Thanks for all the suggestions and help - It surely saved me some good money and I learned a valuable skill in the process.
 
OK pictures to follow tonight when I get home. The blisters on my thumb sure say it happened lol
 
20130829_105125_zpsc08d6465.jpg

Here is a pic of the muzzle. Thoughts?

Disregard all of the blueing I have not done yet.
 
Can't see the rifling from the picture. As long as it is full-depth and symmetrical all around the muzzle, that should do fine.
 
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