Just had 1 of my old 257's bore scoped & the gunsmith sail the back 1/2 of the barrel was great but the front 1/2 was smokey. He recommended that I either use a few tubbs bullets to fire lap it. I was wondering about having it lead lapped by another gunsmith. Do any of you have any experience in these methods?

tom,

I’m not a big fan of either unless everything else has failed, but I would suggest fire-lapping over lead lapping.

Fire lapping obviously traces the actual path of the bullet and doesn’t get into the areas of the throat that you don’t want lapped/altered. It’s pretty difficult to stay out of that area of the throat with a lead plug shoved down the bore.

Before I did either I would try some of the more aggressive cleaning procedures to see if that would take care of the problem first. Start small and work your way up has always been my philosophy.

quote:

Originally posted by tom ga hunter:
Just had 1 of my old 257's bore scoped & the gunsmith sail the back 1/2 of the barrel was great but the front 1/2 was smokey. He recommended that I either use a few tubbs bullets to fire lap it. I was wondering about having it lead lapped by another gunsmith. Do any of you have any experience in these methods?

Did he give you any indication as to why the back half is so much better than the front half? I agree with Rick, if an old barrel is going to be pulled back from the brink, provided a good agressive cleaning doesn't produce the desired results, then I would give it one last go using the fire lap method.

quote:

tom,

I’m not a big fan of either unless everything else has failed, but I would suggest fire-lapping over lead lapping.

Fire lapping obviously traces the actual path of the bullet and doesn’t get into the areas of the throat that you don’t want lapped/altered. It’s pretty difficult to stay out of that area of the throat with a lead plug shoved down the bore.

Before I did either I would try some of the more aggressive cleaning procedures to see if that would take care of the problem first. Start small and work your way up has always been my philosophy.

Rick 0311

As a simple IGNORANT rifleproducer i wonder why you thinks that a lead lap tuches the throatarea more than a firelaping.
In my little world a leadlap is (when relapping a chambered barrel)cast on a steelrod in the front of the barrel, and then added some lappingcompound then it is pulled forwards and backwards in the barrel, lapping both lands, growes, and side of the lands, removing fouling, burrs and old toolmarks. At least when done properly.
Firelapping is as far as i know a bullet impregnated with lappingcompound fired thru the barrel. As the bullet is larger than the borediameter it has to be forced into the lands, putting max grindingeffect on just the throat, where it is deformatet

I know you wasn't asking me, but myself, I was firelapping barrels back in 1980. I would charge the bore with regular "Clover" lapping compound, holding short of the throat area for that very specific reason, and firing a dozen specially assembled, low powered lead loads through the pre-charged bore. None of the compound made it in the throat during the firing. Anymore, I reserve the use of the lead lap, if at all, for new, unchambered barrels. New times call for new methods and firelapping, while not that new, can work wonders to "old" barrels. If done properly.

quote:

Originally posted by jørgen:

quote:

tom,

I’m not a big fan of either unless everything else has failed, but I would suggest fire-lapping over lead lapping.

Fire lapping obviously traces the actual path of the bullet and doesn’t get into the areas of the throat that you don’t want lapped/altered. It’s pretty difficult to stay out of that area of the throat with a lead plug shoved down the bore.

Before I did either I would try some of the more aggressive cleaning procedures to see if that would take care of the problem first. Start small and work your way up has always been my philosophy.

Rick 0311

As a simple IGNORANT rifleproducer i wonder why you thinks that a lead lap tuches the throatarea more than a firelaping.
In my little world a leadlap is (when relapping a chambered barrel)cast on a steelrod in the front of the barrel, and then added some lappingcompound then it is pulled forwards and backwards in the barrel, lapping both lands, growes, and side of the lands, removing fouling, burrs and old toolmarks. At least when done properly.
Firelapping is as far as i know a bullet impregnated with lappingcompound fired thru the barrel. As the bullet is larger than the borediameter it has to be forced into the lands, putting max grindingeffect on just the throat, where it is deformatet

I guess my views go to your own comment: “When done properly.†That‘s why I said that it was “pretty difficultâ€, not impossible, to do properly.

I was refering to the area where the chamber ends and the throat starts which a plug being pushed can touch but the bullet doesn’t when fired.

Just my opinion.

Malm,
How do you evenly charge the bore, did you make a squeegy? I would be afraid the compound would build up infront of the bullet on its travel and create a bore obstruction. Obviously it doesn't or you would't be successful with it.

When I fire lap I roll impregnate the bullets with Clover paste then wipe of the excess. I use pure lead or 20:1 alloy so that the bullet deforms very easily and gets into all areas of the rifling. I make 10 bullets of each grit, 220, 320, and 500. These are assemble into 5 "donor" cases with just enough Bullseye to get the bullet out the barrel. I shoot 5 clean, shoot 5 clean, working up through the 3 grit levels.

The last one I did was a 7mm Brazialian. It would pick up copper like a file and forget shooting lead bullets. It would take hours to get the bore clean, and accuracy was crap (3 moa). After fire lapping it cleans up with no problem and accuracy is around 3/4MOA with 135grGC lead out to 200 yards and 1 to 1.5 moa with jacketed bullets. Yes, the throat takes the initial hit , but it didn't appear to hurt anything on this rifle. I don't shoot it enough to worry about accelerated throat wear from the lap. But I did need better accuracy.

The first firelapping job I did was on a 10/22T. I was planning on tossing the barrel anyway (total garbage, the hammer forge marks were visable in the rifleing.) So figured why not see what firelapping does. The original barrel is still on the gun 6 years latter; the improvment was beyond dramatic, bordering on "miraculus". The bore picks up ZERO lead, and it cleans with three patches to a mirror shine. It shoots clean the same as dirty, and is just pain fun to shoot; it'll poke the spent primers out of a shotgun shells at 60 yards with boring ease. This is a gun that started as 2"+ POS at 50 yards.

I'm rambling, sorry.

tom ga hunter, I guess if you are planning on changing the barrel anyway, try firelapping, you have nothting to loose and the cost of a rebarreling to save. It has worked great for me, but I havn't done enough to be considered anything but a novice. Jorgen is absolutly correct, firelapping is more aggressive in the throat than anywhere else, but the use of dead soft lead bullets limits this somewhat. You also get the benifit of a constantly tapered choke of a few tenths (.xxxx") from breech to muzzle, there are arguments for accuracy both ways as to a dead straight bore or a choked bore, but the bottom line is it won't hurt anything in a gun that gets used for informal target shooting and hunting.
The Benchrest group and other high volume shooters tend not to like fire lapping because of the accelerated throat wear. Instead of getting 2000 accurate (remember we're talking benchrest accuracy) shots before rebarreling they might only get 1200-1500. And when these guys toss a barrel its still more accurate than any hunting barrel needs to be.

As said by rusty martin, there is no proof og a chocked barrel beeing more accurate than a completly cylindric one.
But here is a litle expirience with one barrel produced in 6,5x55. In the productionproces it was laped with a 8" long tenlap cast in the barrel, lappingcompound grit 220. It was lapped to a chok of 1/100mm.
It was tested as follows.

3rounds just for sighting in
3 times 5rounds group average center center 8mm at 100m ammo factoryloaded Lapua scenar.

For testingpurpose ft foulingtendence ther was fired totaly 2500 rounds over a period of 1 year with NO CLEANING at all, then the original accuracy test was repeated
Result average center center 11mm at 100m. same type ammo

Barrel handlapped lightly.
New testround as previus
result 9mm groups

this was repeated for each 1000 rounds and now the barrel has fired 5500 rounds and is capable of producing 12mm groups

quote:

Originally posted by Rusty Marlin:
Malm,
How do you evenly charge the bore, did you make a squeegy? I would be afraid the compound would build up infront of the bullet on its travel and create a bore obstruction. Obviously it doesn't or you would't be successful with it.

Obviously...

It isn't like you just push a glob of the stuff down the bore, you coat a patch and run it down the bore holding short of the throat and bring it back out. Simple. Not too complicated and no squeegy.

Then you assemble a dozen LOW powered loads using soft lead bullets, and send these down the bore. You can recharge the bore any time you feel it necessary during the process. You may have to recharge the bore twice during the process.

I'm not a proponent for firelapping in general. But as a last resort for an "old" or cheap barrel, it makes a hell, er, heck of a lot more sense than the time consuming hand lapping method. BTW, when the choice is mine, I install nothing but hand lapped barrels.

quote:

Originally posted by tom ga hunter:
Just had 1 of my old 257's bore scoped & the gunsmith sail the back 1/2 of the barrel was great but the front 1/2 was smokey. He recommended that I either use a few tubbs bullets to fire lap it. I was wondering about having it lead lapped by another gunsmith. Do any of you have any experience in these methods?

I've used the Tubbs system on a number of my rifle recently. It is easy and inexpensive ($27)to do, and does seem to help. Accuracy seems to have improved in all cases (for some rifles more than others), and copper fouling was definitely reduced for all rifles. Good product as near as my experience can tell, and dead simple to do...