Anyone here Fire-Lap a .444?

John,

All I've used is Bullseye.

The amount you need is really dependent on the case capacity more than any other factor, from what I can tell.

The most I have used is 4 grains in the .30-06. If I get around to lapping my .458 or .338, I'll probably start with 5 grains and see how that does.

The least I have used in a rifle is 3 grains, in a .22-250 and also a .35 Rem.

Handguns I generally start around 2 / 2.5 grains for the .44 / .45 and down to a grain and a half for the .357, although sometimes that will stick a bullet. Revolvers are tricky because you lose a lot of pressure from the b/c gap. So it's a fine balance between sticking a bullet, and going too fast.

I never used filler in the past but have some to try now. Range results will have to wait till I get a little free time.

So.... without any fillter, I'd personally start with 3.5 grains in the .444, with the heaviest bullets you can find, seated backwards in the case and flush with the case mouth to take up as much airspace as possible. I won't swear this is ideal but it should get you started.

If you use the filler... dunno, maybe start a half grain lower.

There is some amount of experimentation required in all of this, I don't believe that there are ever hard and fast rules like you have for load data. If they stick in the bore, up your loads just a bit, if they lead too much cut them some.

I have also found that after a few lapping bullets go down the bore (or you've stuck a few and had to drive them back out), then it seems you actually don't need quite as much powder.

Hi, John:
I used 4 grains of Red Dot in a .30-06 and 3 grains in a .303. Red Dot and Bullseye are alike enough for this application. The case capacity of the .444 is about like the .303, but the bore's bigger, so Mike's 3.5 grains should be good.

I used unresized cases and the bullets were loose in them. Chambering them was a bit tricky and I had one slide back into a .30-06 case. I got it back in place, but there was powder stuck to the lapping compound and that one stuck in the barrel. I assume some of the powder didn't light. After that I used a 1" square of 1/4" thick polyester on the powder and didn't stick another bullet.

You should clean the barrel after 20 shots and slug it. If it looks good, break it in with jacketed bullets and see how it shoots before you lap any more. The first rule of lapping is "Don't fix it if it ain't broke." I may have goofed with the `06, because it was copper fouling badly after 20 lapping shots. I gave it another 20, and it was still fouling a bit after that. Marshall thought I should give it another 20, but I reasoned that it usually takes a 100 shots to really break in a barrel, and I'd only shot 40 jacketed rounds, I'd go to 100 before I did any more lapping. It only took another 20.

Bye
Jack

I have firelapped a bunch of handguns and rifles, including my 444 Marlin Outfitter. jack and Mike are right on the money with powders and amounts. I have also used a lot of Red Dot in firelapping.

I hope you are using Marshall's latest lapping compound. It cuts great with less leading the old LBT lapping compound I used previously. I have only recently learned to bristle brush the bore a lot more than typically recommended. With revolvers, I brush any lead out every 6 shots. Next time I firelapp a rifle, I'll brush out the lead every 2 or 3 shots at the most. I was amazed how much faster the firelapping went. By the way, this does not mean I saw much lead in the barrels. It must be that the thin flashings of lead are very hard to see in a barrel (especially near the breach) and when there is even the thinnest coating of lead in the barrel, firelapping takes so much longer.

So have fun. Remember that it's a lot harder to put metal back on than to remove it. If I were to firelapp my 444 again, I would bristle brush the bore between each shot and only firelapp 10 round before retesting for accuracy and leading.
Just my 2 cents worth.

Best.......... Bill