breaking in new rifle barrel

[duane]

Just ordered a weatherby back country in 257 wby. Just wondering about fire lapping the barrel? Is it worth the effort? What about throat erosion? thanks

[versifier]

Welcome to Gunloads duane.

Shoot it and clean it first. Unless the bore is really rough, it will only lessen the lifespan of the barrel. Fire lapping is for giving shot out or corroded barrels some more useful life.

What about throat erosion? Do you handload? The hotter the loads you shoot, the sooner the throat will begin to erode. Another important factor is not to overheat the barrel. If you can't lay your hand over the chamber without it being uncomfortably hot, you need to stop shooting and let it cool. Overheating can warp the barrel and hasten the erosion process considerably. If you shoot milder loads and treat the barrel properly you should be able to shoot many thousands of rounds without problems. It is not unusual for one to go 10,000 rounds, but that sure isn't with factory ammo.

[chris112]

I've only tried breaking in one rifle since I found a decent set of directions on how to do it. Did it do any good? Ask me when I have put about another 5,000 rounds down the barrel, then I MIGHT be able to tell you if it did any good. I say might because it could be closer to 10,000 rounds before I really know. If it is about 10,000 rounds then the ammo used to break in would equal about 1/2 of 1% of the barrel life. Most barrels have a lot longer lifespan than a lot of people give them credit for.

[versifier]

Hi Chris, welcome to Gunloads.
Modern magnums, Weatherbys in particular, have notoriously short barrel lives. With the bigger ones, you are lucky to get 5000 rounds before the throat erosion has destroyed accuracy, and many will have a noticable effect by only 1000. Certainly an ordinary centerfire barrel if properly cared for could and should have a working life far in excess of 10,000 rounds, but the only rifle that I believe capable of 2 million rounds would have to be an extremely well cared for single shot or bolt action .22lr or something equally low pressure and innocuous that shot lead or lightly plated bullets. The action would likely fail long before that point and then I would not expect it to retain much of any accuracy by that point, even if the action were still functional.

[jlb300]

So is the firelapping worth it?. I understand all of the theories about hot loads erroding the throat and that lapping a barrel is actually polishing away the metal.
If the friction is decreased as a round glides down a barrel, wouldnt that "increase" the life of the barrel?
10,000 rounds is 500 boxes of factory ammo. Is that a real problem if you are hunting ?
At $30.00 @ box now adays (for factory 30-06)$15,000.00 is a lot to compare to a new barrel at an average purchase price of less than $300.00.
I think if you are just breaking in a new hunting rifle , then this is dependant on what you hunt also(ie varmints or venison) most of us would agree that a shooter usually fires more varmint rounds than deer rounds, shoot and clean the barrel often for the first 100 rounds. I find that you need to fire some rounds down range to get the barrel 'finished'. I know that todays tecnology has barrels comming from the factory better than they used tobut you have no way of knowing if the barrel on your action was the first one cut with the rifleing tool or nearer the end of the cutting life of the rifleing tool.
Does this make any sence to you? I think even though we have gun manufacturers using excellent materials and excellent tools and tecnology the barrel (to me) still needs "smoothed" up. Firelapping is supposed to speed up this process.
I have lapped barrels using cast bullets and valve grinding compound. This seems strange to some but I tell you it works and is much more cost efficient than buying a pre made lapping system ie"Tubbs" And I am not saying that is a bad thing to do. I have a friend who likes to use it but he has more means than myself and it works as good.
Versifier, I ope this dosent look like I am trying to step on any toes I respect your wisdom and would only offer this as MY HUMBLE OPINION.

[versifier]

No toes involved. If everyone agreed on everything life would be pretty dull.

Some people swear by it, most gunsmiths realize that it usually means a rebarreling job sooner rather than later. I have seen it do wonders for old milsurps that I wanted to shoot cast out of, but I am very skeptical of its utility in new barrels. Most good barrels today are button rifled, not cut, and the buttons are either pushed or pulled and swage the grooves into the metal without cutting it or leaving any rough edges (usually) and no tool marks. But cut rifled barrels are are still produced and they are a lot more rough inside because cutting tools actually remove metal and leave marks. Hand lapping can get to the toolmarks in the bottoms of the grooves and into the corners where most of the junk builds up, is more easily controlled, and likely to do a better job of polishing things IMO. Fire lapping has the most effect on the tops of the lands, the smoothest part even in a cut rifled barrel, where lapping is least necessary. Its main advantages are that it is quicker, easier, and less messy than the traditional method. For that, it is more likely to be used when it is not necessary and overused by someone who doesn't quite understand what happens and why. With an otherwise dead old barrel, though, there's nothing you can do that will make it worse and it often helps.

[jlb300]

I agree with the fact that the mess is reduced with the firelapping over the hand lapping. duane what are you doing about the 257 ? are you happy with the way it shoots out of the box or are you considering thte lapping yet? We would like to know.