Shooters Forum banner

Anyone here Fire-Lap a .444?

1842 Views 11 Replies 5 Participants Last post by  johnacarver
My Hunting buddy and I have 60-70s vintage Marlin 444s/ss rifles and have refinished them both to perfect condition (with the addition of Kick-eez pads and mercury recoil reducers in the stocks - ouch...) Our final project is seeing about wringing all the accuracy out of these thumpers as possible. We have been experimenting with Hornady 265 and 300 grain bullets with only limited success. Marshall's articles on the .444 drew me to Beartooth and I have purchased all of the equipment to fire-lap our rifles. I'm in the process of reading his technical guide now. This book is a real 'forehead slapper' if you get my drift... Well more twice as much as the price he sells it for. I have a question about the loads to use for fire-lapping. I have some polyester batting and some bullseye powder laying around and want to use that for lapping loads. Can anyone tell me if they have used bullseye (or any other pistol powder) and how much powder was needed? Did you use batting in the case?
1 - 12 of 12 Posts

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.
See less See more
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.

See less See more
I am also going to lap my 444 but don't have any bulseye will unique work and if so where should I start 5 gr's or so?

how many lapping bullets come in a box?
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 :)
See less See more
Sorry, I forgot to add. Personally I'd stay away from the polyester batting. It is not needed to properly ignite the powder and may well get in the way of the lapping process. I never used it and never felt any need for it in the 444.

Best........ Bill

Thanks for the tip on cleaning. That would have saved me a lot of effort on certain guns!
I'm using Marshall's latest compound. Well, I think it's his latest - I just got it in the mail. When impregnating the bullets I'm unable to get the bullets to appear black with the stuff (like his book mentioned), just darker grey. I have six rounds loaded up with 3.5 grains of Bullseye, that sure is a small amount of powder... I also seated the bullets to sammi specs. You think I should seat them backwards? I was expecting some wadcutters but these are regular old bullets - real soft though, not alot of bearing surface. I'll go light them off and see if they work ok. Thanks for all the advice folks.
Hi, John:
I'd call it dark grey too. As long as the grit is embeeded in the lead, they're ready to go. 3.5 grains doesn't look like much, does it? The main thing is, if they make it out of the barrel they're going fast enough. Add a 100 fps to save sticking one in the barrel.

Always seat backwards, with the base of the bullet flush with the case mouth. Otherwise, if there is any exposed grit on the bullet, you will likely get some on the chamber walls and can scratch them.

For the rounds that you have already loaded, I would advise wiping them off carefully to minimize this.

The backwards bullet also takes up more airspace in the case and gives a better chance for the powder to burn more uniformnly.
Hi John,
Please let us know how it turns out for you.

By the way, there is no need or desire to scrimp on the lapping compound you work into the bullet. I like to have the compound filling most of the grease grooves. Though that does not replace the rolling of the bullet into the compound.

As was mentioned, before you shoot each lapping load, be sure to completely wipe any traces of the lapping compound off the loaded cartridge. If you are getting some resistance to loading the round, it's a good time to clean the chamber again (and again and again if you are lapping more rounds like in a revolver). The barrel too of course.

Best of luck to you........ Bill
Well believe it or not, it only took 2 grains of Bullseye. It was perfect, it sounded like a pop-gun and I could actually SEE the bullets flying downrange. I didn't use the batting and seated the bullets backwards - all the way in - flush with the case mouth after using a toothpick to smear a little more compound into the groves. Out of 50 rounds I had two get lodged in the bore right under the front sight. I cleaned every ten rounds. Before leaving the range I shot some full-house bear loads and already it's shooting tighter groups. Now I'll do some hand lapping and slug the bore again. Thanks for the tips everyone.
1 - 12 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.