How low can you go with Pyrodex?

[tacotime]

Old Army with bad tool marks in the bore all the way up like a washboard. Really poor. Anyway, thought about fire-lapping the bore. Heard it was not very effective because the slug couldn't be slowed down to proper lapping velocity (very low speed).

But I thought you could load down a pistol with Pyrodex to very slow speed? Is there a Kaboom risk with, say, 5 to 10 grains of Pyrodex, felt wad, farina, compressed, round ball?

How low can one go with Pyrodex? Is 777 any different?

Thanks.

[oldracer]

When you say "old Army", if that is a rifle, can you pull the breech plug? If so run several soft lead bullets through the barrel like you were slugging it. The drill and tap holes in the bases that fit a cleaning rod. Put the bullet on the rod, then take a bore mop and run some of that old Cloverleaf valve lapping compound down the bore. The slowly work the bullet through the bore while keeping the lapping compound from drying out. After several bullets worth, scrub out the bore and inspect. Repeat if necessary until smooth and free of tool marks. I did this on an Italian Sharps that had terrible marks and they all went away after about 15 passes.

If the gun is a pistol then it is even easier, just pull the cylinder out and lap.

The bore dimensions did not change at all.

[tacotime]

Ruger Old Army revolver...

I guess that makes sense, for an ultra slow lapping slug, just pushed by hand.

Still curious about reduced charges with Pyrodex though...

[Nobade]

Sure, load it as light as you want. The powder is right against the base of the nipples so it'll light off even with extremely small charges. You will want to use farina to allow everything to be compressed.

-Nobade

[newton]

Here is an article I came across the other day. It actually is counter what you are thinking, but makes sense nonetheless.

http://www.beartoothbullets.com/tech_notes/archive_tech_notes.htm/48

[fouronesix]

Shoot at a paper target at fairly close range so you can account for each ball getting out the muzzle. Take a short brass rod and mallet to the range in case one doesn't make it all the way out.

[tacotime]

Good article. Details what there is to gain from the process. I don't see why the principals and effects wouldn't be the same on a cap and ball revolver, especially if there is no significant risk of a Kaboom with the lower charges. This gun has a super-rough bore and some bore restrictions also.

[Hellgate]

I'm not sure how you can imbed the abrasive into a round ball. Better to use the LEE conical for a projectile as it won't get the bearing surface sheared off when rammed into the chamber. Otherwise you may want to put lapping compound onto the top of the seated ball and shoot up into the air (if safe to do) before it flows out. I'd use a small charge like 10 grains, cream of wheat filler and then seat the ball. Do one chamber at a time so all the lapping is not done by the same chamber.

[fouronesix]

especially if there is no significant risk of a Kaboom with the lower charges. This gun has a super-rough bore and some bore restrictions also.

With either Pyrodex or real black powder there is no risk of kaboom with light charges as long as the ball is seated to make contact with the powder and if the gun is in otherwise good structural condition. I think the only concern with a suer light charge is sticking a ball in the bore then shooting another one on top of it. Likely that wouldn't cause a kaboom other than maybe dog knotting the barrel at the point of obstruction. That's the reason for taking a brass rod and mallet to the range-- just in case.

To imbed the compound on a round ball- use two flat metal plates. Smear some compound on one plate and roll the ball around between the two. Given your description of the bore condition, I don't know how many shots will be required to smooth the bore?? Clean the bore between shots and clean the cylinder once all are shot. Just keep shooting and checking. It may take quite a few repetitions to show any real or observable results. You may end up with a fairly smooth bore, some pits that will never go away and very worn down lands.

[Rattus58]

Old Army with bad tool marks in the bore all the way up like a washboard. Really poor. Anyway, thought about fire-lapping the bore. Heard it was not very effective because the slug couldn't be slowed down to proper lapping velocity (very low speed).

But I thought you could load down a pistol with Pyrodex to very slow speed? Is there a Kaboom risk with, say, 5 to 10 grains of Pyrodex, felt wad, farina, compressed, round ball?

How low can one go with Pyrodex? Is 777 any different?

Thanks.I've actually fire lapped several guns and I'm not convinced that the process does any better than hand lapping with the exception of it being more consistent probably. As far as velocity goes, I don't know that you need to slow anything down do you? I mean the bullet is going to spin only so many times per inch whether at 800 or 8000 feet per second right? The idea of more power might obturate the bullet better at a more conventional load too. In any event, if you need more lapping, shoot another bullet... :)

Much Aloha.. 8-)

[tacotime]

10 grains clears the barrel easily. Those with lapping experience call for the lowest velocity that will clear the barrel. Not sure why it helps. It was suggested to lightly swab the bore with compound. I want to leave the chambers alone as much as possible. They say the stainless is very tough. Probably the bore is bad enough at the muzzle to need a counter-sunk recrowning in about a half inch, if that it possible...