Recrown an old Mauser


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ldlfh7
August 16, 2013, 12:30 PM
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-tools-supplies/barrel-blanks-tools/barrel-chamfering-cutters/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.

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Sam1911
August 16, 2013, 12:39 PM
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...

ldlfh7
August 16, 2013, 12:51 PM
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?

Sam1911
August 16, 2013, 01:06 PM
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.

ldlfh7
August 16, 2013, 01:11 PM
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?

rcmodel
August 16, 2013, 01:31 PM
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

NCsmitty
August 16, 2013, 11:26 PM
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

dprice3844444
August 17, 2013, 01:03 AM
crown it anyway

ldlfh7
August 17, 2013, 05:21 PM
How does the recrown process work? Hook the crowning tool up to a drill and just drilling down?

BBBBill
August 17, 2013, 06:32 PM
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! ;)

4v50 Gary
August 17, 2013, 07:37 PM
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.

carbine85
August 18, 2013, 09:28 AM
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.

lathedog
August 19, 2013, 12:32 AM
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
August 19, 2013, 06:32 PM
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?

morcey2
August 19, 2013, 10:33 PM
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?
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

jstein650
August 19, 2013, 10:47 PM
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...

ldlfh7
August 20, 2013, 03:21 PM
Matt -

If you use the right caliber of mandrel for the case trimmer

Are you referring to the case length gauge tool?


http://www.midwayusa.com/product/257748/lee-case-length-gage-and-shellholder-8x57mm-mauser-8mm-mauser

morcey2
August 20, 2013, 03:23 PM
Matt -



Are you referring to the case length gauge tool?


http://www.midwayusa.com/product/257748/lee-case-length-gage-and-shellholder-8x57mm-mauser-8mm-mauser
Yes. For the crown on the 8mm, I used the 30-06 case length gauge tool in the trimmer.

ldlfh7
August 20, 2013, 03:35 PM
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?

ldlfh7
August 29, 2013, 11:17 AM
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.

colonelhogan44
August 29, 2013, 12:06 PM
Pictures or it never happened!
;)

ldlfh7
August 29, 2013, 12:10 PM
OK pictures to follow tonight when I get home. The blisters on my thumb sure say it happened lol

ldlfh7
August 29, 2013, 12:58 PM
http://i1364.photobucket.com/albums/r735/ldlfh7/20130829_105125_zpsc08d6465.jpg (http://s1364.photobucket.com/user/ldlfh7/media/20130829_105125_zpsc08d6465.jpg.html)

Here is a pic of the muzzle. Thoughts?

Disregard all of the blueing I have not done yet.

colonelhogan44
August 29, 2013, 01:10 PM
Looks great!

Sam1911
August 29, 2013, 01:18 PM
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.

ldlfh7
August 29, 2013, 01:24 PM
I will try to get a better pic up showing the rifling. I did cut about 1 inch off of the barrel to get to stronger rifling. The bore still needs a little cleaning and that should help you to see the rifling. Got done last night at 2 am so did not do a complete clean - There is still a lot of chalk residue in there from filing which is obscuring the riffling in this picture.

kwg020
September 2, 2013, 01:22 AM
SAM1911 said:
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 realize Sam just reported this. Under no circumstances would I counter bore. Take it to a gunsmith with a lathe and do it right. Brownells also sells some hand re-crowning tools that have been used successfully. kwg

Sam1911
September 2, 2013, 07:37 AM
Oh. Uh no. I don't think trying to counterbore the rifle on your own would work well. Maybe with piloted framers, but that's one I'd ask the smith to do.

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