shortening barrel length on semi auto rifle

[levi joseph]

I have a browning BAR 243 win that when I was a bail bondsman I tookin as payment for a bond.The rifle had been stored in a zipped up case in the attic of the clients parents home and was in real sad shape, all the metal was covered in a good coat of fine rust and was starting to pit some on the receiver. The wood finish was all but gone from going from hot to cold. needless to say The gun was in need of some severe  tender loving care, so I pulled the wood and refinished it and it looks real good, But the metal is a different story. I had a local  gunsmith to strip and re-blue but with the pits it doesn't look very good but the gun will make a real good shooter. So here is what I want to do. I have a 16 year old daughter who loves to deer hunt, and this gun has been promised to her. But she is a Peitie girl and the gun is two big for her to handle, the stock I can handle but will shortening the barrel affect the rifles reliability, and if not how much do you think I can remove. I am not really concerned about velocity loss as much as reliability and accuracy, we don't do very much shootin over 50 to 75 yards mostly hardwoods an rolling hills.

Thanks for your comments   

[Frank46]

Don't think you will experience any problems when cutting the bbl down. Little more noise, just make sure you have a good crown on the bbl. How long is the bbl before cutting and how much do you plan on taking off?.Frank

[gunnut69]

I wouldn't even cut the barrel down. The weight savings is nominal and little else is affected..other than balistics. The biggest drawback to the BAR is it's weight. I'd buy a cheaper laminated or wood erplacement and cut that down. The original stock could then be reenstalled when she outgrows it...usually not a very long time frame..  These are very fine weapons and easily classify as heirlooms..  If a general reduction is still desired i'd stay around 20 inches to maximise the rifles performance..

[oneoldsap]

   I have a friend that has a BAR in .300 Win. Mag . That he had the barrel shortened on to 20" . what he wanted was a .300WM Carbine . Well he got his Carbine but it's a Single Shot . Absolutely will not cycle no matter what , it's been to three different Smiths and is at the Smiths now . Browning told him that was a no no and they would be happy to replace the Barrel for a measly $600.00 .  Sell it and get something that will fit the girl , they're too freaking heavy anyway !

[gunnut69]

Your friends problem is likely short6 cycling caused by the change in the pressure/time duration of the gas pulse.  If short stroking is the problem, very very slowly opening the barrel port(s) will fix the problem.  Altering the barrel length is not just chopping off the tube.. Besides that's a poor way to lighten the rifle..  Also your friend should realize the velocity loss from the 300 Mags shortened tube will be proportionately great than a small cartridge..

[Nobade]

Don't open the port in the barrel. Install a bleed-off with a smaller hole in it. Those BAR rifles work kind of like a FAL. The hole in the barrel is really big, and they have a set screw looking arrangement with a hole in it that works as a bleed off. They came with different size holes depending on caliber. I think there are about five different sizes available, and you will likely want one of the smaller ones. The 300 win mag one is pretty big, and the 338 win mag one is fairly small for example. (The smaller bore holds pressure longer and higher than the bigger bore. I think the 30-06 and 7mm rem mag ones are the same. Anyhow, get a selection of them and find the smallest one. See if the gun will run. If not, you may need to make one with an even smaller hole.)

I have run into this problem before, usually somebody wants to add a muzzle brake and cut the barrel back so the overall length is the same. As you have discovered, a BAR is extremely sensitive to barrel length past the gas port. Usually if you cut even an inch off the barrel it won't work properly.

[gunnut69]

Nobade is absolutely correct.. I was going at fixing the problem from the wrong angle.. Comes from working from a faulty memory! The gas regulator is the part in question and the smaller the hole in it the higher longer the pressure pulse will be.