How do you crown it?
A steel ball barring and a hammer?
How do you crown it?
A steel ball barring and a hammer?
A ball grinder mounted in an electric drill works fine. There are other methods.Originally Posted by 8mm RUM
Do a little research and Google search on barrel crowns. You will be quite surprised at your findings.
I used to have two books, Pistolsmithing by G Nonte and Gunsmithing by R Dunlap.
Both had many, many things that could be done with simple hand tools, including fitting a barrel to a rifle or pistol. They are worth what you will pay for them if you want to work on guns. Nonte's book, since it was written back before plastic guns, concentrated mostly on the 1911 and revolvers.
Dunlap's book was before the black gun so concentrated on the bolt guns, especially surplus, and the Garand. The many methods of cutting and crowning a barrel are in there. Also all the methods of bending/shaping/welding bolt handles for different looks or to clear scopes.
Crowning the barrel is not very difficult. And the type of crown is actually inconsequential. As bsekf mentioned, do some research on the barrel crown. Know why 11 degree was chosen as the consequential “Target Crown” used by everyone far & wide? Because it was more than 10 & less than 12! Seriously! There has been no definitive evidence of the 11 degree being chosen & used for any other reason except tradition! And since, there has been no proof that 11 degrees is any better than 19…or 17, or 14 for that matter! It really doesn’t matter how or to what degree the barrel is crowned, only that it IS crowned, so the escaping gas pressure can not hit the edge and deflect back into the cartridge.
Well, just to update the thread I had some better weather and took it to the range. Using target loads that I developed for a former heavy barrel in the same caliber, a 5 shot group at 100 yards was (I'm gonna go off of memory here) about 1.5".
So, I will call this a success!! I'm certain that if\when I would decide to fine tune a bullet\powder for this rifle I could get sub-MOA groupings. But, now that it's "done" the rifle is much easier to handle\shoulder than before.
And I would not be afraid to do this again. BTW, my "crowning" was done with a brass round head "bolt" that was screwed down on a short piece of all-thread. I used this brass bolt instead of a screw as I was concerned about a screw's "screwdriver cut" having an effect on the crown. I have no evidence that it would have a negative effect....it's just what I did and it worked out well.
If you try this...your on your own. (Liability disclaimer thing!)
IIRC, in Dunlap's book he mentioned using the slotted round head screw cut a bit better than a ball shaped lap. I don't think it really matters much as long as you keep the 'wobble' motion as you 'grind' it.
FWIW, a crown is not needed either. The crown is only there to protect the edge of the bore/rifling from being damaged, and, to remove any burrs from the rifling process.
Yup! Precisely what I was talking about. Some put too much emphasis on it being a specific way.
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