Casting a barrel lap

[Jim Flinchbaugh]

I posted this in the "barrel" section of the gunsmithing area but got no responses, so I'll ask here.
I've read around here on casting a lead lap in the barrel for lapping.
Can some one give a simple idea of how to contain and pour the lead without making a mess, and approx how long the lap should be? What would be a good plug to contain the lead in the barrel?
I assume I can just use care with my ladle to pour?

Jim

[Harter66]

Jim,
There are several in the stickies as I recall at least 1 has very detailed instructions.

Sorry I can't be more help.

[OuchHot!]

I have used an undersized bore brush as the structure/core. A leather washer above it will char but keep most of the lead on the lap and not drooling down the barrel. Sometimes I cut the brush down so it is only 1-1.5" long....I like to be able to push the lap partly out during the process and wack it to uspet it to tighten the fit. I guess maybe 1.75" long??? been awhile but that is how I recall doing it. For revolvers, the lengths are more like half that above.

[725]

I've never cast a bore lap, but have used boolits to accomplish the same thing. Loverin type work well with the lapping compound put in the lube grooves. Push it back and forth or just load it in a mild load and shoot it.

[Jim Flinchbaugh]

Jim,
There are several in the stickies as I recall at least 1 has very detailed instructions.

Sorry I can't be more help.

I found several references to it, which is what got my wheels turning, but i did not find the detailed one you mentioned. Got a link or an idea for search criteria?
I'll keep looking in the mean time

I thought about using boolit, my question is, to remove the thread pinch on a Redhawk, it wont get to the groove diameter, only the bore diameter,
Maybe that wont matter as much?

[OuchHot!]

I have done this only once on a revolver (to remove thread pinch on a sbh). I know that quite a few people report firelapping as effective on thread pinch but I was worried that I would increase the throat size so I lapped. If you use a bullet to lap, you can pull it part way into the forcing cone and set a piece of steel against it and wack the steel to upset the bullet and get it to scrub the groove.

[Harter66]

Try this 1. I just kinda dumb lucked into it .

http://castboolits.gunloads.com/show...light=bore+lap

[Jim Flinchbaugh]

Bookmarked- thank you very much!

[runfiverun]

airc the article in handloader years back showed a lap 3" long in a rifle bbl and about 1-1'2" in a revolver.
they pushed it about half the way out the bbl and added the lapping compound.
they also advised oiling the bbl. and to not push the lap out of the bbl more than a half inch after the initial adding of the compound.

[Wolfer]

I cut all of the whiskers but the last few off a bore brush. Then put a patch on the end and pushed it into the muzzle until only the threads were sticking out. Wraped a rag around the barrel and very carefully ladled lead into the barrel. Don't let the lead come all the way to the top of the barrel. Screw a rod on it, slide it about halfway out and smear on your compound. It's very easy to feel the tight spots and work mostly on them. When the lap gets too loose stick it back in the melt then pour you another.
Repeat until there are no more restrictions. Good luck!

[Mk42gunner]

Jim,

I lapped a .50 cal muzzleloader barrel that my Uncle had let rust. It had about six to eight inches of rust/ nastiness that you could feel with a tight patch midway down the barrel.

I used several patches about two inches into the barrel to block the lead. You definitly want a smaller caliber brush, the lead will solidify before it works its way through one that is even close to bore size, I think I ended up using a cut down thirty cal brush, with the lap about two inches long.

It has been about 17 years, but I think I used 600 grit lapping compound (it was what I had on hand). The rifle turned out okay, but I don't think it shoots quite as well as it did when new.

Robert

[WilNsc]

Is there a recommended grit size to finish with?

[stubshaft]

I have an old NECO lapping kit and after using 1200 grit I finish with Flitz.