[Pancho Schade]

Hi all. I'm new to this forum (and forums generally) and don't know where to post this question. I have everything I need from Beartooth do lap my various guns, and have general instructions on how to load, but I haven't been able to dig up any load data. Range time is scare and expensive for me, so it would be great to have some ballpark figures to start with. Given the bullet seating, batting material, and everything else I have no idea where to start to get "airgun" speeds.

Here's what I have for lapping bullets:

150 grain .308 caliber for .30-30 cartriges
165 grain .38 caliber for .38 special cartridges (suspect there's no need to use .357 brass)

Powders I currently have on hand are:

Alliant Unique
Alliant Bullseye
IMR 4227
Hodgdon Clays
Hodgdon Universal
Hodgdon Titegroup
Western 5744

Thanks in advance!

 

[MikeG]

I just did a .30-30 with Bullseye, so can help you there. Just over 2 (two) grains was working for me BUT on top of the powder, I stuff the rest of the case full of polyester pillow stuffing (ie Dacron). So..... to be safe, you can up that charge to 2.5 grains.

It's been too long since I did a .357, but seems like between 1.5 and 2 grains of Bullseye. At the time I did not use any filler in the case but probably would if I had to do it again. Revolvers are tricky, because the b/c gap can drop pressure enough that what works in one gun will stick bullets in another.

Hope that helps.

 

[Davers]

I fire-lap most of my new rifles using hard-cast bullets. For example I use 20.0 GRS of SR-4759 powder & a 165 grain cast bullet (Plain based) in my .308's. I load-up 10 rounds, fire five rounds, wipe the bore after each shot. After the first five rounds I clean the bore, then proceed with the next five. This type lapping has worked for me. You can buy lapping (loaded) rounds for this but they are expensive.

 

[Pancho Schade]

Thanks you guys. I have a good idea where to start, but I'll break down and test some loads first before rolling all the soft bullets in lapping compound and loading them up in something that won't work. Sometimes there's no substitute for trial and error.

 

[unclenick]

Two comments. I think I would, indeed, use .357 cases, just to keep abrasive splatter from the edges of the bullet base from impinging on the chambers ahead of the throat. If you look at the muzzle or cylinder of a firelapped gun, you will see a certain amount of that happens. It doesn't hurt either one and probably wouldn't widen the chamber enough to matter, but why not leave the surface finish alone where it's not necessary to alter it?

I would not use very hard cast bullets if you have constrictions to remove from the bore or throats. The optimal cast bullet hardness for firelapping bullets is generally agreed to be around BHN 11. This would be wheel weights plus 2% tin or 16:1 lead:tin alloy. Softer bullets bump up after passing through a constriction under relatively light firing pressure, while harder bullets expand afterward by their own elasticity. As a result, either bullets too hard or too soft tend to polish the whole bore nicely, but are less efficient at removing constrictions because they tend to remove almost as much metal from the rest of the bore as well, thus making it wider than necessary by the end of the job.

I should note that the above assumes a bit more pressure than Mike's load's. From NECO's firelapping load data it would be more like 5 grains of Bullseye in the .30-30. There is one fellow on the Finish Gunwriter's site who describes a detonation in a .308 using lead bullets and 2.9 grains of N320 (which is in the burning rate range of Bullseye and Unique), so I think that Mike's wadding should not be treated as optional with his very small load in the .30-30. The pistol case's much smaller volume will be fine with it. Detonation, rare as it is, seems only to occur when a lot of extra empty space is available in the case.

 

[MikeG]

Let me note that I did stick a few bullets in the bore of the .30-30..... so, my loads are right on the cusp of not making it out of the barrel. In fact one of them ended up stuck about halfway out the muzzle .... just try to do that on purpose!

I would also add, and should have made it clear, that when I discuss stuffing the case full of polyester fill..... I mean, *really* cram as much in as possible. To the point the bullet is on the verge of getting pushed back out of the case by the filler. That is probably about the only hope for such light powder charges working.

On the plus side, I (quietly) shoot them into a large box full of rags, and avoid the trip to the range. Your situation may vary so take with a grain of salt...

Additional - once upon a time I did some lapping bullets with no stuffing, in a .30-06, and the powder charge was exactly 4 grains of Bullseye. That relationship of case volume to Bullseye is something I pretty well follow for rifles, although a bit more doesn't hurt, either. I have stuck bullets in a few rifles so be warned.....

Let us know how it goes.

 

[Pancho Schade]

Well this is just great! Thanks much for all the help, guys.

Recently returned to having guns after more than 30 years of having none, because my 16-year-old daughter took an interest in shooting. Three months later I have 9 guns and am hand-loading cast lead for all but the .22's, and finding that as shipped from the factory, these guns need some work.

Sure do appreciate the helpful advice from all of you.