bore lapping?

[Strut64]

This question has been bugging me forever. I have JB bore paste (blue lable/non embedding) and use it when doing a serious deep cleaning. However there are other pastes out there. Example JB red lable and ISSO. Are they stronger? My understanding is that the blue lable is softer than steel and is only useful for removeing carbon or copper residue and wont alter the steel at all or improve the internal finish. Is there any occassion where you might want to use a stronger lapping compound to really alter the finish on the bore. For example Could you use a stonger lapping compound on a rough button rifled bore and polish it.

 

[308pirate]

If I need to polish a rough factory barrel I'll use Tubb's Final Finish. I've seen true lapping done at work and it take a lot of experience to develop the feel needed to do it right. I ain't got it.

With Final FInish I know the lapping is done uniformly because it's done by a "machine" (the abrasive bullet pushed down the bore by expanding gas).

 

[ken4570tc in WY]

This question has been bugging me forever. I have JB bore paste (blue lable/non embedding) and use it when doing a serious deep cleaning. However there are other pastes out there. Example JB red lable and ISSO. Are they stronger? My understanding is that the blue lable is softer than steel and is only useful for removeing carbon or copper residue and wont alter the steel at all or improve the internal finish. Is there any occassion where you might want to use a stronger lapping compound to really alter the finish on the bore. For example Could you use a stonger lapping compound on a rough button rifled bore and polish it.

Strut64,

Over the years I've hand lapped four barrels and improved accuracy on all of them. Each time I'd use a staggered stroke lap technique and work my way from a course compound to a fine compound and only push the patched jag out the last few inches at the muzzle on the last stroke. Be certain that you use a bore guide to protect the chamber and completely clean the barrel between grits. Shoot from a rest to verify improvement of accuracy. Don't keep going till your not gaining improvement. Watch for a diminishing improvement, stop, then run some Flitz polish and be sure to clean the daylights out of the barrel with non-chlorinated brake cleaner. Also, before the first lapping and after each round of firing clean all copper and carbon before repeating. If you leave any fowling in the barrel the lapping compound will tend not to polish down that area at the same rate as the clean areas and you could ruin the barrel. It's a lot of work, but what else is there to do on long cold dark winter nights. In the end the barrel will shoot better and clean easier. Don't try this on a new custom competition grade barrel it will void any warranty. The barrels I've don it to were all 'off the shelf, out of the box' fire arms.