Lapping compound for fire lapping barrel?

[High Binder]

Does anyone know where to get dry lapping compound that could be tumble applied or rolled on to bullets, and what grits are best for a medium and final finish (400 final?). All I can find is wet (grease/water) formulas. Any other thoughts on any of this would be appreciated too.


(I know I can buy Tubbs, but I'm trying to do this on my own)

 

[427Cobra]

Re: Lapping compound for fire lapping barrel?

Why is the question?

 

[High Binder]

Re: Lapping compound for fire lapping barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427Cobra</div><div class="ubbcode-body">Why is the question?
</div></div>

For fire lapping a barrel that needs lapping.

 

[DocB]

Re: Lapping compound for fire lapping barrel?

High Binder,

NECO OS, the same folks who sell QuickLoad, sell a kit consisting of 200, 400, 800 and 1200 grits. I've generally found using patches and the paste grits work as well.

HTH,
DocB

 

[High Binder]

Re: Lapping compound for fire lapping barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DocB</div><div class="ubbcode-body">High Binder,

NECO OS, the same folks who sell QuickLoad, sell a kit consisting of 200, 400, 800 and 1200 grits. I've generally found using patches and the paste grits work as well.

HTH,
DocB </div></div>


DocB, thanks That does help a lot! Would you explain the patches part? Is that like patching your barrel with compound to in-effect pre-treat the entire ID? Is their kit dry or is all grease based? Instead of using the slugs do you think I could apply the lapping compound to a FMJ bullet with a tumbler (if it's dry) or is the steel plate good enough?

 

[DocB]

Re: Lapping compound for fire lapping barrel?

HB,

Q1. Yes, but you are not pre-treating. You are lapping the entire bore. The effect is more pronounced at the throat, but if you feel a tight spot in the bore, it can be removed.

Q2. All grease based.

Q3. The slugs are for checking the size (tightness) of the bore. Not for application of the lapping compound.

Q4. Not with a tumbler. The steel plate method works, but it is very slow and tedious to do a bunch of bullets. You also should consider throwing out the brass used for the bullets, unless you keep them sorted by grit for use in more than one rifle.

Caveat #1: Don't do any lapping by hand or by fire lapping on any barrel you aren't willing to throw out if you screw it up. Tubb sells ammo and kits for those who wish to follow a tried and true method.

Caveat #2: The #200 grit is only for very screwed up barrels. In 95% of the barrels I've done, it is not needed. Best results will be obtained starting with the #400 or #800.

Caveat #3: If you do this by hand, you better have action and lug cleaning tools. Any way you do it, it's better to have the bore and action too clean than not clean enough.

Caveat #4: Make sure ALL copper and carbon are out of the barrel before starting, and between changing grits. A ten stroke pass with JB compound, then a liquid bore cleaner helps the cleaning.

Caveat #5: DO NOT fire a round down the barrel with lapping compound in the barrel. Nothing good will happen. You perform any lapping at your own risk, and my directions here do not make me liable.

HTH,
DocB

 

[High Binder]

Re: Lapping compound for fire lapping barrel?

DocB, that's awesome! Thank you for all the info, I'm going to give it a go, and judging by the lack of responses I'm guessing it's a dying art so it seems like a good thing to learn.

Thanks again. I'll post back with results or how much I paid for a new barrel.

 

[mtrmn]

Re: Lapping compound for fire lapping barrel?

Everybody will think me an idiot, but I've done fire lapping using just clover valve grinding compound available at NAPA and industrial supply houses for years. I have fire-lapped I guess every barrel I have other than 22lr had NO ill results. They don't get nearly the amount of fouling as before, and I THINK some have improved in accuracy. Like my Winchester 94.

The WORST offenders were the barrels I got from Blackthorne in their AR parts kits. Looking down the barrel there were still burrs at the gas hole that sometimes half-blocked the bore. But they are all reasonable shooters now. I got to throw the BS flag on Blackthorne's claim of test-firing their uppers though. Everyone makes mistakes in life and that was one of mine, but I managed to get them reliable anyway.

Now if you are shooting a rifle that already has a custom barrel, or already shoots great groups without much fouling, or a magnum with only a limited number of rounds you can fire without burning out your barrel anyway, why take a chance with it?

 

[High Binder]

Re: Lapping compound for fire lapping barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mtrmn</div><div class="ubbcode-body">Everybody will think me an idiot, but I've done fire lapping using just clover valve grinding compound available at NAPA and industrial supply houses for years. I have fire-lapped I guess every barrel I have other than 22lr had NO ill results. They don't get nearly the amount of fouling as before, and I THINK some have improved in accuracy. Like my Winchester 94.

The WORST offenders were the barrels I got from Blackthorne in their AR parts kits. Looking down the barrel there were still burrs at the gas hole that sometimes half-blocked the bore. But they are all reasonable shooters now. I got to throw the BS flag on Blackthorne's claim of test-firing their uppers though. Everyone makes mistakes in life and that was one of mine, but I managed to get them reliable anyway. </div></div>

Not an idiot at all, in-fact I read a whole website devoted to using Clover lapping compound to fire lap a barrel (see below). How did you apply the Clover lapping compound to the bullets?

http://www.bellmtcs.com/FAQ/Fire_Lapping.htm
http://www.lasc.us/bellmFirelappingBarrels.htm