BAR 30-06

[acearch72]

I just got a new BAR 30-06.  I posted some questions about its accuracy on another forum, but I wanted to put some questions here on the gunsmithing forum.

OK, here's the issue.  I have tired both 180 gr and 165 gr bullets.  The 165 gr seems to perform a little better, but I get curious results from both.

It seems the 1st and 2nd shots are consistantly about 1/2" or less.  Then it opens up to about 2" to 4", random locations.  They seem like flyers.  If I shoot another group 10 minutes later, the same thing happens.  This would seem to be a hot barrel issue, but the barrel does not seem hot so I don't think its that, but don't know.

I checked with the gunsmith at the shop where I bought the gun, and he said that he had another one in there now doing exactly the same thing, but he didn't have a clue.  He says that there are no screws that he knew of that could get loose.  nothing visible either.

Anybody here heard of a similar problem, or got any suggestions??

[gunnut69]

It's fairly easy to find out if heating is the problem...just wait 5-6 mins between each shot.  This time should allow the barrel to cool to a uniform degree between the shots.  I have not worked with the latest version of the BAR but sounds as if the barrel is getting hot (doesn't have to burn your hand) and is growing.  The barrel will actually get longer as it heats.  This combined with the taper on the barrel touching something can apply pressure which can cause the barrel to warp (or simply viberate a bit differently).  Very small changes in barrel harmonics (vibrations) can cause groups to open and as the pressure changes the variations can cause wildly vaiable grouping.  Try some slow fire groups see if that helps..  Unfortunately it is also possible the barrel was not properly stress relieved when it was made.  Barrels build up a lot of stress in the steel as they are being manufactured.  Normally these are removed after the barrel is complete and sometimes during the manufacturing process.  If not done the normal heat built up by the firing process can cause the barrel to warp.  This will be a very small amount but can do disastrous things to accurracy.  If your problem does not occur when firing the rifle slowly and the weapon is new, I would consider sending it back to Browning..  I've excellant luck with their service department..  good luck from the gunnut69

[W. Tell]

I cain't say for sure, but this is most probably a forend problem! Does anything rub against it (action parts). Bedding could be a solution.

The barrel deal is not it, they are cold hammer forged. Your barrel is OK!

I don't like and have little experience with semi's. But I know there is also som'ting called "firstshot syndrome". Pistolshooters complain about this I've heard: When the action operates under manual force, the locking is a little different, than it is when it is operated by recoil/gas...but you should find a better gunsmith than the one you got it from! If he sells you a gun he'd better know how it works!

[gunnut69]

Any barrel can have stress...  Hammer rifled barrels by their nature are some of the most stressed of all..  Look at the manufacturing method.  They insert a rod with the image of the bore(or bore and chamber) into a thick walled tube of steel about 12-16 inches long.  This is then run thru a rotary hammer that literally hammers that short heavy tube down around the mandrel.  It gets longer as it is hammered and the stresses are immense!!  Hopefully they then stress relieve the barrel before it is completed.  The least stressed barrels are those which are cut rifled and even they have some manufacturing stresses.  Barrels change dimensions as they heat.  They get longer and if the barrel is not perfectly concentrict with the bore, they can warp...   Also when we hang things on barrels, like the gas system of an autoloader, that can affect their heat induced motion.  And by the way, 'first shot syndrom' does occasionally happen.  It is less likely in an auto rifle but it means that the first shot fired usually lands outside the group, not the 3rd and 4th.   Try firing groups slowly 5-6 minutes between shots.  If the groups are consistant, you have a heat affected group problem.  It may be caused by a barrel warping or simply growing and either touching something or being distorted by pressure from the mechanism hanging on it.  Never assume that because a reputable manufacturer made a barrel that it cannot have a problem..  I've found that the good makers just have fewer problems than the rest and handle them better.  There is no such thing as perfection in a modern production rifle!!  The BAR is a really great rifle, probably the best of the autoloaders, but they do have problems.  Test to determine the problem, then either fix it or let Browning have a chance to correct their error..

[W. Tell]

Sure I'm with you gunnut69! All you said sounds allright!  :grin:

Any barrel can have stress in it more or less, as you said, or shall we say they all do. Cut barrels have the least. Another manufactureing method, used more than cutting, is buttonrifled barrels, this method is VERY dependent on the quality of each bach or lot of steel than coldhammering is. Only Savage, of all of the largest makers, makes cutbarrels these days. I still think we can be quite sure his barrel is ok. It's not the first thing to look for att least...

I'm with you, it's probably a heat problem- some part is rubbing the forend-be it barrel or gas operating parts...bedding is probably a solution. The damn thing IS gonna warp by heat no matter what, they all do!