View Full Version : cut a barrel with a chop saw??
01-14-2004, 09:30 PM
and how do i recrown it? sgn had a story on it not to long back, but it was one i didn't buy (figures)
01-15-2004, 06:35 PM
I assume that you want to shorten a barrel to be 16" with a muzzle brake of some type--in other words, you want to use the barrel after. You could use a chop saw, but I'd keep a flow of lubricant or water on it the whole time, to prevent heating of the barrel. You also want the minimum burring, especially on the inside (bore), and you want to be sure that it is cut as close to square as possible. I assume there is some reason you can't use a lathe--if you can, square up and finish the barrel with that. You could also rebate the barrel, cutting about .100 in for .050 - .100 around the bore.
There are hand crowning tools, I believe, but you can also use a round-headed brass screw chucked in a drill. Use valve grinding compound as the actual cutter. Keep the head of the screw lined up with the barrel so you're cutting perpendicular to the bore.I've also heard of it being done with a bullet and grinding compound, but I don't know the details.
01-16-2004, 01:15 PM
there is some great info over on the falfiles about using JB bore paste and a marble to make a nice new crown to a cut barrel. It can't get much easier than that.
01-16-2004, 01:40 PM
ok, thanks, i'll check out the sister site
01-16-2004, 08:40 PM
keeping any tool concentric with the bore axis is nigh on impossible without chucking it up in a lathe.
01-16-2004, 09:05 PM
over.the.years.i've.read.it.both.ways....its.criti cal.for.accuracy.and.its.not..i'll.play.it.safe.an d.take.it.to.'chine.shop..in.case.your.wondering,t he.space.bar.does'nt.work.on.in-laws.machine
01-17-2004, 08:06 AM
On a bolt rifle that you want .oo1 to matter, the crown is all important. On one of these a thousandth or 2 or 100 does not really matter. I have recrowned several FAL barrels using RCBS reamers with very good results, have never seen a loss of accuracy (yet). Remember these are not known for accuracy, they are known for reliability. You can crown it and get good results if you spend a little time. Concentric by hand is FINE, on an AK. I have actually gained accuracy results on a couple FALs after hand crowning.
01-17-2004, 09:29 PM
Can you chuck a barrel in a lathe without removing it from the receiver? Does having the sight and gas block on it cause a problem? (It seems like it should, but I don't know.) If you used a spire-point bullet of a larger calibre, so that your crown was deeper in the barrel, it would be protected. I know that in WWII, M1 Carbines with damaged muzzles were bored out 1" then crowned so the crowning was protected. Seems like a good idea, if the gasses flowing around the bullet after it passed the crown but was still in the barrel didn't disrupt the flight.
01-24-2004, 09:28 PM
i used a new blade in a hacksaw. i also used part of a pos tubing flaring tool to get a semi square cut, then finished with a file square against the tool, just like prepping tubing for a flare. will the square(flat) crown be a problem?
01-24-2004, 09:36 PM
Pack,how ya doin old buddy?Nice board here,my kind of place.
I asked a knowledgeable individual a while back about chucking a barreled reciever in a lathe and he said "nope" not unless the reciever was round or square and parallel with the barrel,that got me scratching my head about cutting and crowning my saiga,most of the smiths in this area have a "high fallutin`" attitude towards rifles that arent intended for taking game or issued by the U.S. armed forces,to heck with them,I can do it myself.
Dont get discouraged about this,you dont need a gunsmith to do a cut and crown job-unless of course you have a super accurate sniper rifle or the likes-I dove in head first and did it myself,simply because I couldnt find a local smith that wanted to work on a "killing machine".My rifle is just as accurate as when it was factory new(maybe even a little more so)I cut the barrel of my saiga to 13" and welded a 3" long hungarian muzzle brake to it for a legal 16"(yes I gave it an extra 1/4" just to be safe)
(it`s the rifle at the bottom)
I bought the SGN that had the article about cutting and crowning,good read,I learned alot.
Basically what the author said was.....
1. wrap a piece of tape around the barrel where you want to cut,use this as a guide when you hack-saw it.
2.use a machinists square to and a file to make sure the muzzle is square or perpendicular to the barrel(I cheated and I`ll go into detail later)
3.de-burr the crown with a carriage bolt and lapping compound.
Since I wanted my rifle to have the shortest legal length barrel,I couldnt use a machinist square,the gas block was in the way and prevented me from getting a good measurement,I used my lee .308 case trimmer to square the barrel.
The tool works very much like a real crowning tool from brownells but I didnt have to spend the $$ to get a new tool that I might use once every blue moon.
I chucked it in a big milwaukee hand drill and slowly cut the crown,it did quite a satisfactory job.
I then de-burred the muzzle with a carriage bolt and some lapping compound,you dont have to keep the bolt perfectly straigt,you can let it wobble around a bit,in fact I purposely made mine wobble around a bit to get all the burrs off,it really isn`t removing a noticeable amount of metal it`s just breaking the burr off the exit hole.When you think you`re done drag a Q-tip across the edge of the bore to see if it picks up any fibers,if it does polish it a bit more,if it does`nt,youre done.Hope this helps.
01-24-2004, 09:39 PM
Wow leper,you must have been writing the same time as I,any way the square bore will be fine,the only reason factories and gunsmiths recess the crown is to protect it from damage,now that you can re-crown your own rifle,just dont bang it on anything and if you do go fix it.
01-24-2004, 09:42 PM
01-25-2004, 07:15 PM
Bossman, good to hear from you. I've been telling people about your plywood laminate furniture. It looked good.
This sounds like the proper way to WECSOG an AK, a rifle made for WECSOGing if any were. And that Saiga looks good. I tried one of the Romanian side-folders (welded open, BATFE!) on one (16") I converted; it looked mean, and didn't shoot bad. I have a SA2000 with the AMD-65 brake and it looks mean, and throws out some gas. Maybe I ought to cut down my old Saiga 20" and get a brake like that for it.
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