I have two mold number from Lyman #457406 500 gr + or-. & 457671 @ about 477 gr.

I have tried 4 or five different lead mixes. Have used 5744, 3031 & H4198. About 50% of shots are keyholed at 75 yds and even some at 25 yds.

Rifle is very accurate with any jacketed bullet of 350 to 500. Never tried heavier.

Any ideas or suggestion?

Slug the barrel and slug the throat, size as close to throat diameter as you can if your moulds cast large enough.Start with moderate velocity loads, get it to shoot with that first. As for alloy plain old air cooled wheel weights will work to 1800 or so with a medium speed powder like 4895. Whatever you do,start with a slug and get some measurements of groove , bore and throat, then see how large your molds are dropping. Sounds like classic undersized bullet syndrom.

As Swheeler said check the bore and throat diameters.
Do a check on cartridge length, relative to the magazine, will it feed and does the bullet engage the rifling when chambered.
Are you using the gas checks ?

Jim

quote:

Originally posted by arkypete:

Are you using the gas checks ?

Jim

Have laoded between 1600-1800 FPS. Using gas checks.

Bore is .457.

I haven't slugged the throat.

Sized .458. Will try unsized and see if that helps. Using NRA formula 50% Alox(discontinued #)/50% beeswax. Out of lube today except for the old black Lyman. More NRA formula on the way.

Thanks,

I have used 435 gr GCFPs and 500 gr GCRNs cast of wheel weights, lubed with Carnauba Red and sized 0.459" in my .458 AR propelled by 50 gr of AA5744. The rifle has a Douglas barrel. 435 gr mold was made by Ballisti-cast and the 500 gr mold made by Lee.

Rick Rose has used them in a .458 Lott using 3031 I think.

Neither of us have seen keyholing at all. I have seen groups as good as just over 1".

My guess would be that you are sizing them too small.

For what it's worth. When I started loading and casting for my 45-70 Siamese Mauser all I had available for lube was the Alox lube and Mirror Lube.
Both worked well.
Try sizing your bullets .459 or .460. You can skip sizing all together.

Jim

[QUOTE]Originally posted by arkypete:
For what it's worth. When I started loading and casting for my 45-70 Siamese Mauser all I had available for lube was the Alox lube and Mirror Lube.
Both worked well.
Try sizing your bullets .459 or .460. You can skip sizing all together.

Jim

I loaded some up today, unsized and hand lubed GC with H4198, 37 gr. Gas check, we'll see how they do. dropping from mold .458.5 to .459.

Thanks

Slow your loads down to about 1100 to 1300 using 4759,5744 or 4227.

Your SAAMI throat is really long so you need a bullet with a big nose.

Cast a your bullets between .460 and .462 and shoot as cast.

quote:

Originally posted by AfricanHunter:
[QUOTE]Originally posted by arkypete:
For what it's worth. When I started loading and casting for my 45-70 Siamese Mauser all I had available for lube was the Alox lube and Mirror Lube.
Both worked well.
Try sizing your bullets .459 or .460. You can skip sizing all together.

Jim

I loaded some up today, unsized and hand lubed GC with H4198, 37 gr. Gas check, we'll see how they do. dropping from mold .458.5 to .459.

Thanks

These unsized loads, seated out as far as I could and still feed, shot rather well, about 1 3/8 for 9 shots at 75 yds. No keyholed bullets, so progress.

Thanks

Sounds like you're making progress. Are you using a filler with that light load of 4198, if not I would consider it.

quote:

Sounds like you're making progress. Are you using a filler with that light load of 4198, if not I would consider it.

SWheeler has the right idea, using a filler. Many years ago Lyman was a bit loose in their tolerances and I got a .460 255 grain SWC mold. I experimented and found that 13 grains of Unique in my 45-70 cases with a 2 inch square of Klennex tamped down on the powder. I used a six inch long piece of wood dowel to tamp the tissue down with.
Most of the time the paper burned in the barrel.
Sounds good, you're making progress.

Jim

quote:

Originally posted by swheeler:
Sounds like you're making progress. Are you using a filler with that light load of 4198, if not I would consider it.

I used a 3/32nds thick cork wad over the powder.
I'll try some tissue or Dacron next.

I would stay away from a "wad" cork or otherwise, you don't want any airspace between the wad and bullet base. Get some dacron batting from a fabric store/dept I get mine from WalMart. Cut it into strips with scissors, you want enough dacron, fluffed up to completely fill the air space between the top of the powder all the way to base of bullet. One grain should be about right for your 4198 load, stretch /fluff it up, charge the case and use a small screw driver to put the dacron in, it will fill the space almost to the mouth of the case, let the bullet lightly compress the dacron when seated. The dacron will keep the powder back against the primer during ignition, it will also raise the pressure some so start working up your loads with the dacron until you find the best accuracy. The load you just got done shooting is still real mild, 1300ish I would guess.

swheeler is very correct about that cork. Please stop using that and instead use a Dacron wad that is not tamped down or packed into a wad. It is very important not to leave an airspace between the filler and the base of the bullet. This can compress the air and ring the chamber. Choose a large enough piece of Dacron that will with it's natural springiness feel the space between the powder and bullet base. Also if you have a load without any fillers and you decide to use a filler please adjust your load as your pressure will be higher with a filler.

Try a Styrofoam packing peanut roll with thumb and fingers to just fit put in case and use the boolit to push down. will expand and stay tight to the base of boolit Clint

I used florist foam bought at Wally World and cut it into ~1/8" thick squares with a miter saw. Took a square, set it atop the case and gently pushed. The case "cookie cut" a wad, and I pushed it down over the powder with a dowel.

The foam, 27 grains of AA5744 and my own version of Emmert lube on an unsized RCBS 45-500 cut holes at 100 yards out of a #3 Rolling Block in 45-70...

African Hunter

I did a bunch of research before I started loadinng for my doubles.

I found that in EVERY instance of a ringed chamber only a little dacron had been used.

When I load for my doubles and use dacron I make sure I use ENOUGH dacron to not only totally fill the space between the powder and the bullet but I make sure it is compressed between the bullet and the powder.

In my 450 No2 I MUST use a filler with ALL loads.

With full power loads and RL 15 powder I use 2 gr of dacron.

With my nitro for black loads, using IMR 4198, I use fifteen grains of dacron.

In my 450/400 3 1/4" with Nitro for Black lead bullet loads and IMR 4198, I use twelve grains of dacron.

I weigh the dacron in my electronic scale.

Just make sure the dacron is compressed.

It will be "spit" out the front of the barrel. it does not melt,burn, char or leave any residue in the case or barrel.

quote:

With my nitro for black loads, using IMR 4198, I use fifteen grains of dacron.

15 grains!! That's WAY too much dacron. You don't want a compacted compressed solid plug of dacron.

quote:

I found that in EVERY instance of a ringed chamber only a little dacron had been used.

450#2 I think you will find that "only a little dacron had been used" was a case of the LITTLE dacron had been pushed down and tamp on top of the powder as a wad, leaving a large air space between the top of the wad and base of the bullet. Enough dacron to fill the space between the powder and bullet base is all that is needed. I postede a picture of 4 grains dacron lightly fluffed beside a 50BMG round on another forum, more than enough for any sporting cartridge and a very reduced load of smokeless. I'll see if I still have the picture. I can't imagine that much dacron can do anything GOOD for accuracy.