Cutting a barrel - send it to someone with a lathe or use a hacksaw?

[user 34300]

The beauty of the lathe is making an optimal crown. I use a sickle shaped cutter. The inner most part of the crown is a shallow angle and the outer most is rounded over. That means the rifleing lands are removed gradually over about 0.1". Then the taper increases leaving room to start the patch ball, then it rounds over. It is not grossly funneled (coned) like some do. It only takes a few thousands removed to make a good crown. Only the minimal is removed. It is also dead nuts concentric with the bore. The last step is to polish it to the 600 grit level. A smooth surface is very important.

If you have sharp edges where one angle changes to another, it makes loading more difficult. A simple one angle crown will have the same problem. A crown that is done free hand will be hit or miss on accuracy and point of impact.

 

[Eutycus]

It's obvious that this topic is referring to rifle barrels. I recently saw a picture of a snub nosed 1851 Navy and am considering the idea for concealed carry. I really hate the idea of taking a hacksaw to my barrel. Are extra or shortened barrels available or is it cheaper just to whack off a length of mine? It's an ASM. I doubt crownng would be too have much of on effect on accuracy because afterall this would be a snubby.

 

[Phil Coffins]

Hand work doesn’t necessarily mean a hack job. These two muzzles although different are both good. On the left is by hand with a modest crown and on the right is machine cut. The right may be a fine job but I dont know who did it. It shows a gradual radius, that is more then I care for. The left one loads easy and is very accurate. It is my main rifle and I have never needed a short starter yet win match’s regularly.
A single angle crown of any degree would be my last choice for a muzzleloader.
IMG_0421 by Oliver Sudden, on Flickr

 

[Okie Hog]

Over the years i've cut and crowned a a couple dozen muzzleloader rifle barrels. The barrel is cut with a hacksaw in a homemade miter box made of steel. Learned that 65 years ago from a serious old time gunsmith. The crown is done using a round ball bearing with a drill shank welded on. The grit is valve grinding compound.

 

[Flintandsteel]

If it’s a straight sided barrel, (not swamped), the hacksaw, and square method will work just fine. If the muzzle is square, and a smooth crown, it will shoot to its potential.

 

[gkterry]

It's obvious that this topic is referring to rifle barrels. I recently saw a picture of a snub nosed 1851 Navy and am considering the idea for concealed carry. I really hate the idea of taking a hacksaw to my barrel. Are extra or shortened barrels available or is it cheaper just to whack off a length of mine? It's an ASM. I doubt crownng would be too have much of on effect on accuracy because afterall this would be a snubby.

If you check out the website of the gun manufacture, they will have different barrel lengths available in the parts section of the website. At least I know Pietta and Uberti do. You may want to check the Traditions firearms website also.

 

[pooch156]

I cut the barrel off due to damage to the muzzle. You guessed it, I dropped it. Drat! Luckily I have a stationary metal cutting bandsaw along with a disc grinder. So, I cut it off, made sure that it was dead square with a mill file & several grits of wet/dry emery paper. Then I polished the face. Must go out & purchase a Dremel #971 grinding stone. No, I won't use it in the Dremel. I have a hand held, hnd operating drill made by Stanley for that. I'll use several grits of wet/dry paper on the face of the stone. 220, 320, 500 & 2000. Without the input of all you people on the forum, I wouldn't have tried it. Thanks!

 

[Sam squanch]

I’d learn to do it yourself. The local gunsmiths here have a 6 month waiting period , they are so busy. No machine shop will touch anything gun related,for fear of being sued or arrested. May be different where you are at.

 

[Vaino]

I use different size ball bearings that have flats for clamping a Vise Grips along w/ lapping compound. The ball bearing is rotated and not too long after a really nice chamfer is achieved. My .45 squirrel LR has a chamfer made by a ball bearing and head shoots squirrels regularly. ....Fred

 

[Artificer]

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

Well, I guess someone has to be the stick in the mud on that article.

First of all, I give the author full credit for using the Gold Medal Match Load and nothing else. That's just about the most accurate ammo made.

In a bolt action rifle in .300 win mag, the groups such a rifle should shoot at 100 yards is actually under 1/2 inch and that's for a 10 round group, not a four or five round group. So even the best group of five rounds at .575" though good, is not that hot.

Also, I'm not sure if the author knows this, but as you cut a rifle barrel back, you would see variations because of the different harmonics in the barrel at different lengths. You will wind up with at least one and maybe two "sweet spots" as you cut it back where it shoots the best groups at the sweet spots.

We used to "touch up the crown" of a barrel shot on THE Marine Corps rifle team every 400 rounds to get the very best accuracy out of the barrel. We did that with a piloted 12 flute carbide cutter. (Many folks would call this a Muzzle Chamfering Tool.) The erosion from only 400 rounds at the Muzzle is nothing compared to how the barrel was hack sawed.

I made pilots for my 12 flute, carbide cutter for many ML calibers. When a muzzle face is uniform and the chamfer is as well, it is going to shoot better. Of course the same thing can be done on a lathe.

Gus

 

[SDSmlf]

Here is my method to smooth out or polish a muzzle crown once it has been cut square to the bore that I have posted before. Really minimizes if not completely eliminating patches being damaged at the muzzle when loading.

A lot of folks like to use their thumb and a bit of sandpaper on bore crowns, but I take it a little further, just for the sake of consistency, at least in my opinion.

I use a series of ball bearings, from about one and half times the bore diameter, to right around bore diameter, and use sandpaper of different grits from 120/180 up to 320 or finer (I take it up to 1000 grit for a mirror finish). A couple of turns of muzzle over each ball bearing with progressively finer sandpaper over them gives a smooth barrel crown to bore transition

Basic idea is to hold the sandpaper over the ball bearing (you can place ball on the floor and hold paper with your feet, maybe on a pad or thin carpet if you don’t have a lathe to chuck up the barrel in) and rotate the barrel bore on the bearing with the sandpaper on it. Easy to keep barrel square with the floor. I’ll start with the larger diameter bearing and roughest grit paper and end with a smaller ball bearing near bore diameter, repeating with progressively finer grit sandpaper. I stop when I have a slight chamfer on bore and rifling lands that is highly polished.

I use Dykem (or a Sharpie) to mark the inside the bore so I can easily see when I starting to clean up everything without going too far. Note the 60° chamfer in the photograph was cut on a lathe, I just use the ball bearings to break sharpe edges and polish.

Just note with either method. If your barrel is already finished, you are going to remove finish from the face of the bore if you don’t protect it. I’ve used ‘masking’ tape with a hole punched through it (use a wad punch), but only on other people’s gun’s, not worrying about it on mine.