Re-Crowning Muzzles for Dummies

[The Mighty Beagle]

I was just wondering how to go about this as just a little while ago I damaged the muzzle of my Marlin 1894 .44 in a fall .:banghead: I don't yet know if the gun will shoot any differently, but suspect that the crown may need to be re-done.

Here's the problem - the only gunsmith around here is an incompetent jackass, who charges exorbitant rates I'm not willing to pay.

Is there a way to re-crown my rifle myself? I've done some minor smoothing and polishing before, but no real gunsmithing.

Thanks

 

[JoeHatley]

A ball bearing, valve lapping compound, and a drill press, will do a pretty fair job. You may want to check out www.brownells.com for some "proper" tools. They've got several, but if you only have one gun to do, it might be more cost effective to find a new smith.

Good Luck...

Joe

 

[HankL]

Shoot it first, not time to bang your head yet. If the crown needs more than lapping Joe has the right advise

find a new smith.

 

[The Mighty Beagle]

a ball bearing ... hmmm. I know someone with a drill press, but can this be done by hand?

 

[Jim K]

First, does the damage go in as far as the edge of the bore. That is the critical point. If that edge is OK, there is no problem except looks.

If the edge of the bore is damaged, the ball bearing trick might work, but I think I would find another gunsmith or buy the crowning tool from Brownell.

I wonder if there are any machine shops in your locality. If so, I would give them a call (don't just walk in with a gun) and see if they would be willing to tackle the job. Crowning is a simple operation, not even requiring barrel removal if they have a lathe with a decent size hollow spindle headstock. If they agree to do it, you remove the forearm, the magazine tube, and the butt stock (to keep the work more balanced).

Then just have them run a crown the same shape as the old one, or any shape you want. A straight cone or a target crown with just a countersunk center will do fine.

Jim

 

[C.R.Sam]

What Hank said....shoot it and see what is happening.

Then what Jim said, if it is not up to snuff.

Sam

 

[Mike Irwin]

Yes, it can be done by hand with a twist drill and large, round head brass screws.

I've done it a couple of times.

You'll need a stone to break the wire edge around the muzzle that forms from the lapping process, though.

 

[Jammer Six]

Twist drill? Ball bearings? Large brass screws?



Sometimes, I just can't seem to keep up...

The mind boggles.

How in the WORLD would you use all these things to crown a barrel?

"OK, I need a toothpick, a safety pin, two marbles, and a bandaid, and I'll get this sucker back on the road in twenty minutes."

 

[The Mighty Beagle]

Thanks so much everyone.

I'll be shooting the gun later today to see if there's any difference.

And yeah, the crown appears to have been affected, though we'll see if accuracy was harmed. Ironically, this was the best-shooting .44 rifle I've ever had, so it makes sense that I'd immediately break it upon acquiring it.

How much should a gunsmith charge for re-crowning it?

 

[HankL]

Jammer, Brass screws etc. along with a lapping compound, would be used to lap the existing crown if only minimal damage was done. I suppose given enough time and effort one could cut a new crown using this method.

If the damage is not so severe as to need to cut the barrel back a gunsmith would most likely charge $35.00 to $50.00 for a simple recrown. You will need to decide on how to refinish the area. IMHO small touch ups like those are exactly what cold blue was made for.

 

[Sunray]

Re-crowning involves machining the muzzle and takes a lathe. You can lap until the cows come home and diddly will have been done. If it's visibly dinged up talk to any machine shop. Preferrably one that has a shooter or two working there. At least they'll know what you're talking about even if their shop doesn't do firearms.

 

[The Mighty Beagle]

Well, I shot today and I don't think I'm going to do anything to the gun. I got several 1.5" to 3" 3 shot groups at around 100 paces with my 240 gr. reloads, though they weren't all this good. I almost thought for a minute that I had a serious problem while shooting the 300 gr. reloads for the first time - my Marlin DOES NOT like 300 grainers, I guess, literally shooting them all over the place.

How would a dinged-up crown shoot? Would it just be generally inaccurate, or would it shoot some good groups and then some horrible groups?

 

[Jim K]

A "badly dinged up" bore edge will raise hob with accuracy and I seriously doubt you would get 1.5" groups (at 100 yds) with such damage.

The problem is not only the marring of the bullet itself, which rather balances out, but that the damage allows gas to try to force itself past the bullet at the point of damage. That causes the bullet to tip as it exits the muzzle and the result in unpredictable.

Jim

 

[The Mighty Beagle]

Thanks Jim, that explanation is very enlightening.

Sounds like the rifle is fine and I just need to cold-blue the muzzle and practice with it a bit more to get more consistent groups.

It really is a wonderful gun.

 

[5pins]

For future reference this is a link on how to crown a barrel by hand.

http://riflestocks.tripod.com/targetcrown.html