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historicfirearms
01-16-2014, 11:46 PM
I've got a revolver that I'd like to have the barrel shortened. I'm pretty good with tools and would like to try the job myself. Is it advise able to use a brass screw with lapping compound to do the crown? It doesn't seem like a very accurate way to do a crown. I know brownells sells the piloted cutters, but they are too expensive for how much I would use them.

RickinTN
01-17-2014, 12:07 AM
Many people do use a brass screw, and you're right they are fooling themselves. It is not a very accurate way. The Brownells tools are better but as you say quite expensive for one use. My advise is to go to your local steel bearing dealer and buy a single steel ball bearing two times or a liitle larger than bore size. No matter what position the ball bearing is in it will still make the same cut. I once epoxied a bearing into a 6" or so piece of barrel stub and could turn it between my hands for a little more speed. For facing the rest of the barrel square that is another story. This is where the Brownells tools are probably worth what they ask. I do have the Brownells facing tools and tapered brass lap, but the lap is only accurate if kept centered in the bore, which is almost impossible by hand.
Good Luck,
Rick

Whiterabbit
01-17-2014, 03:23 AM
you can rent a reamer, no?

I did a handi, but it was from a forum reamer over at greybeard. hacksaw and the piloted cutter. After the cutter I didn't need to polish the actual crown. As-reamed matched the pre-cut performance.

http://www.4-dproducts.com/displayitem.php?rowid=42&tname=tool

Wolfer
01-17-2014, 09:36 PM
After cutting off with a hacksaw and squaring up with a file I just used a carriage head bolt and valve grinding compound. While spinning in the cordless drill I wallered the drill around in a circle as per some instructions I'd got from somewhere. Don't remember where. I was a little skeptical but the rifle was very accurate when finished. I wouldent hesitate to do it again and certainly not on a pistol barrel. Woody

historicfirearms
01-18-2014, 10:29 AM
Thanks wolfer, I was looking for advice from someone that had actually tried that method.

sdcitizen
03-01-2014, 08:42 PM
I believe Surplusrifle.com has instructions to do what Wolfer did. I did that to a well worn Mosin-Nagant. Definitely helped the shooting.

country gent
03-01-2014, 09:03 PM
I have a brass lapp made up for lapping crowns. Its around 3/4" in dia with a stem on it to turn easily. I very seldome cut the barrel off any but will touch up the crowns occasionally. You can re square the barrel with a file and small machinist square working the square around the barrel. Then cut the crown. I normally only touch up with a light coat of yellow diamond lapping compound then a light finish with simichrome or flitz. Starting out medium valve grinding compound would cut much faster. I turn the laps by hand back and forth rotation about 1/2-3/4 turn each way and move stem in a figure 8 pattern. This keeps from cutting a ring or groove in the lap and also keeps the laps radious truer. It dosnt take alot to clean up a square muzzle with the crown.

mikeym1a
03-01-2014, 09:13 PM
Not trying to hijack a thread, but, some old guns with worn muzzles are counterbored to get back to semi-fresh rifling. How do they clean up that 'new' muzzle inside? Again, not trying to hijack, but, to me it seems related.

Wolfer
03-06-2014, 12:39 PM
I don't know how they did it but being a hillbilly I would turn a round head bolt down until it went in the counterbore. I'd just hit it enough to smooth it up.

I'd be prone to shooting it first. It may not need anything.

Whiterabbit
03-06-2014, 12:42 PM
Not trying to hijack a thread, but, some old guns with worn muzzles are counterbored to get back to semi-fresh rifling. How do they clean up that 'new' muzzle inside? Again, not trying to hijack, but, to me it seems related.

I was always taught to bring the cutter from the inside of the bore to the outside, so there is no burr on the inside to clean.

After this cut was made, I use a q-tip to drag radially out from my new crown and look for pulled fibers. No pulled fibers means its time to go shoot to test.

swheeler
03-06-2014, 12:53 PM
I've got a revolver that I'd like to have the barrel shortened. I'm pretty good with tools and would like to try the job myself. Is it advise able to use a brass screw with lapping compound to do the crown? It doesn't seem like a very accurate way to do a crown. I know brownells sells the piloted cutters, but they are too expensive for how much I would use them.

Just rent what you want, 11* or 90* comes with Thandle and pilot for cal, 22.00 with a deposit-http://4-dproducts.com/tools.php?group=

detox
03-06-2014, 01:06 PM
How will you reattach front site...just curious?

Hardcast416taylor
03-06-2014, 01:40 PM
I`m unsure of how the ball bearing procedure is done. Is a flat ground on the ball bearing to hold the grinding compound or is it left a round ball? Is the bearing affixed to a rod or T handle? I have a Mk 4 #1 Lee Enfield that was a "Bubba" gun when I got it. No sights on front of barrel so I`m wanting to cut barrel behind bayonet lugs and front sight then crown it.Robert

fouronesix
03-06-2014, 02:16 PM
I've got a revolver that I'd like to have the barrel shortened. I'm pretty good with tools and would like to try the job myself. Is it advise able to use a brass screw with lapping compound to do the crown? It doesn't seem like a very accurate way to do a crown. I know brownells sells the piloted cutters, but they are too expensive for how much I would use them.

If it's not a high dollar type handgun no reason not to try it. The biggest thing is getting a perfectly square parting cut to begin with (face perpendicular to the bore line). It is difficult if not impossible to get a perfectly perpendicular face using a hacksaw and file. If the face is not square to the bore line, then NO method of "easy" final crowning will correct it and may result in having to use a specialized crowning tool anyway. If the barrel is removable from the frame, is it possible to chuck it up in a drill or drill press so that the parting cut can be made while spinning the barrel? Cutting while spinning the barrel helps ensure the perpendicular face. If so, then using a fine grit circular cutoff wheel in a dremel or similar tool will minimize the bur formed inside the bore at the crown. Then to final crown, just use a steel or brass ball (as has been posted) with lapping compound to lightly dress the inside crown edge.

Otherwise, it's best done with the more specialized tools.

swheeler
03-06-2014, 02:18 PM
These are from Brownells(there's one missing-probably lent it out)20+ years ago these were 6-7.00 with a Type I98791


Personaly I'd spring for the 22.00 option from 4d, the guns gotta be worth 22.00;)

fouronesix
03-06-2014, 03:16 PM
Even if you put it in a vise, cut it off with a hacksaw, filed the face and did some kind of final crown, it would be hard to ruin the gun. If you cut the barrel to say 5" and fouled up the job and had to re-do it, you'd only lose, at most, another 1/8". The same would apply if you had to have a gunsmith re-do it. If worried about that then make the parting cut about 1/8" longer than the desired final length.

Whiterabbit
03-06-2014, 03:43 PM
while I agree 100% that it is a job for a lathe or piloted cutter (whether bought or rented) I have to agree with fouronesix. My buddy cut his Mosin without marking the barrel or any jig at all using a hacksaw. He then filed the muzzle profile flat with, at best, a carpenter's square. At worst, no square. Using an antique coarse file that had seen far better days in life. Brass screw with lapping compound for the crown. Then he put an NcStar 2x7 scout scope on it.

I told him it would never work and that he was gonna have to at least rent a piloted profile reamer to square everything up proper. The gun would never shoot.

He can shoot under an inch at 100 yards on a good day and has no problems hitting 2.5"x2.5" aluminum chunks at 100 yards. So much for shade tree bubbasmithing not being effective sometimes!

swheeler
03-06-2014, 05:31 PM
Or you could just lop it off with chop saw(or cutting torch) grind it square with bench grinder and crown it with your pocket knife:) a little chain yankin here

Whiterabbit
03-06-2014, 05:39 PM
why not? tolerance spec. Noone says we're shooting for accuracy here! :kidding:

swheeler
03-06-2014, 08:39 PM
He could send it to BR or LE for a quick dremel job:) yank

jonas302
03-06-2014, 09:57 PM
I did one exactly like Wolfer a bubbaed mauser with no rifling I cut back 6 inches trying to find a little better rifling cut with hacksaw filed strait crowned with a carriage bolt and valve grinding compound it shoots good and a lot better than it did before someday it will get a new barrel just couldn't right now

Lets not fool ourselfs f that just because a tool is sold it is automatically better or more accurate there was a time when craftsman built things with what they had and quality did not suffer

nanuk
04-14-2014, 11:34 PM
on another forum, a fellow did a comparison by damaging the crown on a rifle, a bit at a time....

read it Here! (http://www.longrangehunting.com/articles/rifle-crown-1.php)

an interesting experiment to dispell some myths.

doc1876
07-05-2014, 12:39 PM
109784

not to give swheeler too much credit, but that is almost what I did. No really, I used a hack saw, and cleaned it up with a file, and then "crowned" it with a counter sink and then polished it with lapping compound. It is what I wanted, and shoots clean. the trigger guard "adjustment" helps to keep it right where you want it in a front pocket, just don't try to spin it!