Crown Opinions or Advice

ssapach

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Before I get all out of control, I'm just curious what everyone thinks of this crowning job. I have a few more rifles I'd like to touch up, but thought it might be nice to get some opinions before I get out of hand and do a bunch wrong.

This is the final outcome (or so I think) on a .303 Brit. The outer edge has a very gradual radius to is, I just ground a piece of tool steel for a quick run on the lathe to do that. Mostly just to eliminate the sharp, squared edge. The bore is a 45 deg cut I made using a Brownells kit.

So, good or bad?

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Good to hear, thanks everyone!

Nice job. Just ordered my Manson Military crown kit for my SKS. Hopefully my results will be just as nice.

It took me a few tries to find out what worked well with my tools. I was getting a lot of chatter marks at first, then I switched to a heavier cutting oil. It helped, but didn't totally eliminate the marks. The final result was after chucking the barrel into the lathe and turning it on real low speed, then doing the crown cutting in one quick shot with lots of pressure on the cutting tool.
 
Luckily the Manson kit has carbide inserts arranged in a manner so as to eliminate chatter. fact or fiction? We will find out when it gets here. Apparently lubrication is not necessary.
 
It looks good, nothing to say about it.

The set-up in the late is really important, any looseness and you will get chatter. The size of the machine has to do with it too. Sharp HSS tools and good cutting oils should be all you need.

Good job
GST
 
There was a time when I was really anal about the crown on a muzzle. Now, not so much unless I am working on a match barrel. I read an article about crowning muzzles by PO Ackley many moons ago that came as a revelation to me. If you ever talked to or met Parker he was passionate about firearms, how they functioned and what caused them to operate reliably or malfunction when it came to feeding, accuracy or component breakage. He ran a very successful gunsmithing and firearms sale outlet in Utah. He wrote a few books and articles as well and was a hands on honest type of guy. I liked him a lot.

Anyway he did a series of tests on a few different cartridge chamberings, using new barrels but cutting them back to determine average velocity loss. While doing so he wasn't being overly careful with the crowns because they were only going to be needed for ten rounds of velocity testing and only needed to be accurate enough to cut the screens out to 25 yards.

This is what he found out by chance, rather than purpose. He found that unless a muzzle was burred or dented at the juncture of the crown and bore that accuracy was only minimally effected by crowns that weren't cut square to the axis of the bore. He even went so far as to cut 30-60 degree muzzle angles to verify this in his own mind and found that it really didn't make a lot of difference unless the angles were extended past a certain point that seemed to have more to do with the caliber than with any other thing.

Obstructions, even tiny ones, are the culprits of inaccuracy rather than crowns is what he deduced. Of course, true to bore axis crowns don't hurt anything either and at long range or even certain types of precision shooting there is a good chance they could effect the outcome but for most intents and purposes ???????????????????.

OP, the other comments made here are bang on IMHO. I like your crown because it protects the juncture of the muzzle and bore effectively from damage such as that found on rifles whose users insist on jamming their muzzles into the floors of their vehicles. Nice job.

By the way, I use a Supertanium 1 in countersink with 9 flutes, held in the tail stock quill. It is very sharp and cuts a smooth true and even edge, without burrs of any sort.
 
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