Cutting and recrowning barrels at home

[Newtosavage]

I'm curious how many of you cut and recrown your own barrels at home.

I've been doing this for about 6 years now and darned if every barrel I've chopped and recrowned by hand didn't shoot better afterwards. Not sure if it's a better crown than the factory crown, or the shorter barrel is just stiffer. Either way, I quit worrying about it years ago.

All my barrels are lightweight hunters in the 20-21" range. That's just where they balance the best for me I guess.

I followed the method described by Larry Potterfield for cutting and recrowning a barrel, and finish with a brass screw and valve grinding compound followed by abrasive toothpaste and 1000 grit wet/dry sandpaper. They come out looking and shooting great.

https://www.youtube.com/watch?v=b43odFm0mrI

Here are the results from my latest barrel, after chopping my .284 Win X-Caliber down to 21" and recrowning

[Phreddie30.06]

All I am capable of is cleaning guns after my wife gets them dirty. Ask her! That looks like it works out pretty good for you.

Sent from my SM-G991U using Tapatalk

[Underdog]

Very nice work you've done there, and I have several rifles I'd like to shorten a bit. I never really gave it a try though, but I believe it is something I could accomplish once I got past the first cut. I have an old Axis with a damaged trigger and sear that is unable to fire anymore, I guess that would be the perfect practice rifle to hone my skills on.

[Newtosavage]

Here's one I did recently on a .308 Savage barrel. Prolly shoulda kept that barrel.

[Newtosavage]

The key is the use a clean, new brass flat head screw and some good valve grinding compound like this

[PhilC]

Can't argue with successful results. Nice work!

[NF1E]

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

[charlie b]

Yep. As long as the cut is square it is a pretty simple job. I like to 'crown' them as little as possible. Since I don't take them to the field I don't have to worry about nicking the muzzle.

[Dave Hoback]

I’m actually machining a piloted crowning tool. My son put another AR pistol together & chopped a barrel he had. So now Dad has to fix it, LOL!

I was just gonna do what I used to with AKs I built in ‘05, but decided machining a piloted 11 degree crowning tool would be fun.

[pdshooter2]

the key is the use a clean, new brass flat head screw and some good valve grinding compound like this

flat head screw ??

[Blue Avenger]

I always thought it was a Brass, straight slot, Round head screw recommended
.

[Dave Hoback]

Yes, it’s Round head brass bolts. Brass Carriage bolts work great as they have no slot. Just a perfect round head.

[Newtosavage]

I always thought it was a Brass, straight slot, Round head screw recommended
.

Yes, that's what I meant.

[Fuj']

I indicate the bore in my lathe and cut. Most are 11 degree.

Sometimes when you think your barrel is going south, a re- crown
can bring it back for a few hundred rounds. I will cut 1/2" off the
barrel first.

[Dave Hoback]

Yup’er.. that’s the way to do it. Unfortunately, I no longer have use of a lathe, and no room for a proper unit. But those who do, that’s the right way!


BTW: Just a little piece of info.. Anyone know where 11 degrees came from? You can’t find the answer. No one knows. It was just seemingly “chosen from a hat”, and it caught on. Truth is, you could cut it at 12, 13, probably 15 or 20 degrees & not see a discernible difference. Just taught that was interesting. 11 wasn’t chosen based on scientific testing with modern machinery. Someone just decided on it.

[Blue Avenger]

11 degrees was picked as that was supposed to be the angle that gas exited the bore when the bullet cleared the bore.

[bsekf]

OK, so you use a brass carriage bolt chucked in a drill press with the barrel held perpendicular. Liberal application of valve grinding compound. Seems like the brass bolt head would form to the muzzle/bore rather than the muzzle/bore forming to the bolt head? Why not use a carbide deburring tool rather than a brass carriage bolt? I agree the angle of the muzzle is not as important as being square and sure wouldn't want anything turning in the bore to screw up the last few inches of the rifling.

We agree that it is impossible to bore and rifle a barrel perfectly straight (tools drift), so I figure by cutting it, removes some of the drift. Virgil King (Houston warehouse) said 21.75 is optimum barrel length.

Bill

[Newtosavage]

Chucked in a hand-held drill and you rotate the drill itself as you form the crown. This keeps the brass from forming to the bore and gives you a nice uniform crown. The valve grinding paste does the work.

I also don't want anything turning inside the bore. However, it's my impression that the dedicated crown cutting tools have a bushing that goes in the bore so there is no turning against the lands/grooves inside the bore. Someone correct me if I have that wrong.

And I can't disagree with Virgil's recommendation. I'm liking my 21" .284 Win barrel quite a bit.

If you can get your barrel weight down to 2 lbs. 5 oz., then a standard Savage short action and factory stock (non-accustock) will give you a 6 lb. 2 oz. rifle. Topped with Talley rings and a 13 oz. scope, that puts my rifle right at 7 lbs. exactly, which is my upper limit for my hunting rifles.

[pdshooter2]

OK, so you use a brass carriage bolt chucked in a drill press with the barrel held perpendicular. Liberal application of valve grinding compound. Seems like the brass bolt head would form to the muzzle/bore rather than the muzzle/bore forming to the bolt head? Why not use a carbide deburring tool rather than a brass carriage bolt? I agree the angle of the muzzle is not as important as being square and sure wouldn't want anything turning in the bore to screw up the last few inches of the rifling.

We agree that it is impossible to bore and rifle a barrel perfectly straight (tools drift), so I figure by cutting it, removes some of the drift. Virgil King (Houston warehouse) said 21.75 is optimum barrel length.

Bill

IN CONTEXT for a purpose built BENCHREST RIFLE...noting to do with a field or hunting rifle.

the 11 DEGREES MENTIONED comes from the exit nozzle of an rocket engine

[pdshooter2]

you guys keep this up you will put real gunsmiths out of a job.
i own a manson crown tool kit. it is acceptable for rifles where a lathe is not practical.
all else go in a lathe, dialed in as close to 0.0000 as possible ,high speed, cut inside to out with very sharp carbide at 45*.
typically 2x the height of the lands.

[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.