Cutting and recrowning barrels at home

[Dave Hoback]

Yeah, in the tool I’m going to machine, it will use Live Pilots. They fit in the bore under slight tension to keep the pilot from turning. The tool will turn on the pilot itself so it is as concentric with the bore as possible. Yes, the brass over time can deform. At which point I’ll re-machine the surface back to 11 degrees.

[charlie b]

The angle can be calculated given the velocity of the bullet and the base angles of the bullet (especially boat tails). Trouble is, it is only good for one bullet and one velocity and one powder load (gas density is a factor so change the amount of powder residue and the mass density changes a bit). 11deg may have come from some rocket engines, but, they are also setup for specific fuel and gas flows that are optimized for that use. At other than one condition the setup is not optimal. We worked with older design nozzles and had to compensate for issues when the flow was not as high as the design. Interesting work.

[mnbogboy2]

Brownells sells an 11° recrowning tool with pilots that works very good and makes excellent crowns. I like an 11° crown under a muzzle brake becausecarbon cleans off it much easier than recessed crowns. Also I shorten all my barrels with the saws all. I formerly used a hack saw and the filed them square with a bastard file. The brownells tool squares them up real nice when used with my battery powered hand drill. I also thread my own using a tat and threading die and appropriate die wrench. I have just finished cutting 6 barrels for a switch barrel "striker like" project I'm working on. The savage sporte r profile barrels do not need the ten on turned for 5/8-24 threads because they are small at the muzzle to begin with. I headspace the barrel and then time the brakes using jamnuts while the barrel is tight in the action. I have drilled and tapped the barrel nuts for 10-32 and 1/4-20 set screws. Once headspace I tighten the set screws and then remove the barrels and cut a divot in the breech threads for the set screw to set in. For now I will be using a rifle stock and not an actual striker stock. I would love to find a chassis to modify for the job.

[Fuj']

[QUOTE=bsekf;499141] Virgil King (Houston warehouse) said 21.75 is optimum barrel length.

Bill[/QUOTE

This length generally applies to short course rifles but not practical for
distance shooting in the target community, where fast twist, and high
BC bullets are used.

[Fuj']

Friend of mine was playing with a 14 degree on a 22/250.
The idea was to make the exit angle steeper so not to
erode the muzzle's edge. He used the same angle on the
220 Swift.

There's always a good discussion of exiting gases compared to
bullet bases whether it's flat, a boat tail and even a rebated
boat tail.

[wbm]

I agree that crowns are important but there are some interesting findings that suggest they may not be as important as many, including me, think. Precision Shooting Magazine did experiments much like the following and came up with some similar findings as well.

https://rifleshooter.com/2018/03/do-rifle-crowns-matter-does-a-crown-effect-accuracy/

[Newtosavage]

I agree that crowns are important but there are some interesting findings that suggest they may not be as important as many, including me, think. Precision Shooting Magazine did experiments much like the following and came up with some similar findings as well.

https://rifleshooter.com/2018/03/do-rifle-crowns-matter-does-a-crown-effect-accuracy/

I've seen that as well. Articles like that one are what gave me the confidence to try cutting and recrowning my first barrel, years ago. Turned out great and shot great so I did another. And then another. And now I don't even think twice about it. If I want a shorter barrel, I can have one, with a nice crown, in about 30 minutes without ever leaving home.

[Dave Hoback]

That was the point I was alluding to. Choosing the 11 degree crown which is universal, was pretty much pulled out of a hat. As wbm said it’s not quite what we think.

[geezerhood]

Been using a Manson crowning kit for years. Brought some real dogs back into the fold.

I know I would enjoy using the Manson crowning tool. No need for a lathe to get superb crowns by hand power. All that is needed to get near "Manson" smoothness with a bit more time spent, is some kind of a stop to eliminate chatter. Without a stop there is no way to stop the chatter. Manson solved that problem elegantly, but they were a lot more than I was comfortable spending even 20 years ago and are close to $400 for the basic tool once you pay shipping and tax.

Years ago when I had more time than money, I figured out a way to get a crowning tool/cutter meant for use in a lathe to work extremely well without the lathe. Two ways worked well for me.



Putting a stop in the bore such as a hardwood dowel or an aluminum rod. A threaded machine screw tapped into the rear end of the rod, bearing against the closed bolt, allows you to fine tune the final cut with no chatter.
If you have a drill press you can use the depth setting wheel for the stop. I would swing the drill press head so that it was over the edge of my work table, allowing me to have the barrel, crown up directly below the chuck with the barrel held by a vise.

I ended up using the drill press method the most since I didn't have to fiddle with different length stop rods. I probably cut a dozen or so superb crowns over the years with improved accuracy every time.

Obviously, be sure to clean out the chips frequently so as to not scratch the bore. With a fairly tight fitting, well lubricated floating pilot on the cutter, very little stuff got down inside the bore. I never scratched any bores. I tried to find the tool I bought decades ago but could not....It was pretty inexpensive, maybe $50? Bound to be more if you can find one today but still not close to the $400 / $600 for the Manson.

[Orezona]

Newtosavage,

Is this post based on your transaction in the Classifieds?

https://www.savageshooters.com/showthread.php?70119-New-unfired-takeoff-24-quot-barrel-6-5-Creedmoor-threaded-and-fluted-varmint-contour

[Newtosavage]

Newtosavage,

Is this post based on your transaction in the Classifieds?

https://www.savageshooters.com/showthread.php?70119-New-unfired-takeoff-24-quot-barrel-6-5-Creedmoor-threaded-and-fluted-varmint-contour

Odd question. I sold that barrel on FeeBay. Not sure what that has to do with crowning a barrel.

[Orezona]

Oh, my mistake.

[bsekf]

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