Does anyone have any suggestions for loading cast bullets using reduced loads (2000 fps or less)in a 300 Win Mag? I would like to give this a shot. I will give me some cheap practice ammo. I realize accuracy probably will not be great using reduced loads in a large case. If you have done this in a similar case I'd love to hear what kind of results you got. I dont want to buy the bullets etc if I cant get it to shoot 2.5" groups at 100 yards.

Ken Waters gives one cast bullet load for the 300 WM. The bullet is Lyman's #308334GC with 24.5 gr. of IMR-4198 Estimated velocity was 1750 FPS.
Looking at the mold #, his was an early Lyman as mine is marked #311334. Bullet is roughly 187 gr. nominally, but cast closer to 190 gr. in wheelweights. I can't say just how good the bullet shoots as I bought my mold just two days ago and only ran a few yesterday to see how it casts.
Looking at lyman's web site, I find no mention of that bullet, so it is probably another good bullet that Lyman no longer makes, even on special order. My suggestion would be to try either the RCBC #30-180-FN (190 gr. in wheel weights) or the Lyman #311291 (180 gr. in wheel weights).
The .300 Win. and Wby. mags are very dificult to get to shoot light loads well. Waters mentioned no filler, but I believe I'd use about a one grain tuft of kapok or dacron to hold the powder close to the primer. Hope it works for you.
Paul B.

How do you use the filler material? I'm assuming you put the powder in the bottom of the case, and put the dacron etc.. on top of it. Do you get any build up of this material in the barrel? The fiber must melt and it has to go somewhere.

elkhntr,

I second Paul, especially as to the kapok or Dacron tuft over the powder.

FWIW, the Lyman Cast Handbook lists the 311291 with:

Red Dot 16.0 gr @1640 to 19.0 gr @1790

Unique 18.0 gr @1705 to 22.0 gr @1910

SR-4759 30.5 gr @2075 to 40.0 gr @2472

748 45.0 gr @2176 to 60.0 gr @2729

H4895 40.5 gr @2157 to 56.0 gr @2748

IMR4064 42.0 gr @2073 to 60.0 gr @2810

Intrestingly, they show the most likely to be accurate as the 311467 with 30 gr SR-4759 @2025.

Many of the old Lyman moulds show up on eBay, along with some RCBS now and then.

Good luck and happy shooting!

elkhntr,

Be advised, you don't want to use a solid filler in a bottleneck case! Just noticed what I said below and thought I'd better get that in first.

It's not really a "filler" as it doesn't fill the case solid like corn meal would. You just push it in with a pencil, etc., over the powder and push it the rest of the way down with the bullet.

There shouldn't be any problem, but if you are really concerned about the Dacron melting, use the kapok. An old life jacket should provide many years of material.

I tried loading a 300 winmag and the only bullet that I could get to shoot worth hoot was the short 311316, a 115 grain gas check. The short neck of the case really limits what bullets you can use in it. Best I got was about 5 inches at 100 with Unique loads.
Short neck makes using longer bullets extend past the neck shoulder junction- at least in my rifle.

good luck,
graycg

Don't have a 300 Win Mag, but I think you're going to run into the same problem I have with cast boolits in the 7 Mag - very short neck and very big boiler room. Not to say that you won't find a load that will work, you'll just have to fiddle around with it. As it turns out, I did find one good load with a 175 gr boolit and 3031, but it shoots well only with Dacron. sundog

btw, be sure to get ALL the copper out of the bore before shooting cast, don't mix cast and jacketed in a shooting session, and make sure you clean good again before shooting jacketed.

To answer the question of dacron melting. I have not had any problem with this in the .308 Win. or 30-06. I shoot hundreds of rounds in .308 Win. with the one grain tuft of dacron with no apparent problem.
However, I have heard that melted dacron builds up on the inside of the shoulder which could be a problem if you switched from l the light cast bullet load to a full power load back and forth. me? I keep my cast load brass separate from my full power brass, end of problem.
Getting a magnum cartridge to shoot decent groups with cast is no easy task. Still, the chalenge to get a good cast bullet load can not only be fun, but a serious learning experience as well.
Paul B.

Elkh, All of the advice you received is sound, but let me add my $ .02. First, you can avoid a filler of any kind if you use a powder that is designed for reduced loads, e.g., Accurate Arms' XMP 5744. Second, how well cast bullets perform has everything to do with how well they fit the throat and bore of your rifle (This can be a matter of .001".); how well they're cast (as close to perfect as can be); how fast they're driven (1,750 fps is good); how accurate your rifle is; and how good a shot you are. Third, I shoot an "as issued" K-31 Swiss, which has a very short neck (The cartridge is a cross between a .30-06 and 8 x 57mm Mauser as far as reloading is concerned.) and a shallow throat, yet I have no trouble achieving 2 m.o.a. or better with CB's seated well below the neck-shoulder junction. Lastly, CB design is another factor in achieving accuracy and to that end permit me to recommend Lyman's #311644. It is longer & heavier than #311291 and is tapered (by design) to fit the standard (and sometimes not so standard, e.g., K-31) .308" throat. If I include Sundog's rifle, several .308Wins., my '06 and K-31, you have a nice array of rifles which handle it astonishingly well. It's worth a look. ...Maven

We're only a few months from having our .30 caliber bullet available, which will lend itself quite nicely to the question at hand.

We're casting our cores, using a 11% antinomy mix, and then copper plating the entire bullet.

The 300g .375 has just been tested, and running at a touch over 2500fps, printed into 4" at 400 m off the bench.
Shooting off the knees, with a 4X power scope, managed 30mm at 100 m.
The 400g .375 is virtually complete, and we expect the same accuracy.

Anybody interested in more info,( .458 and .416 ) feel free to send me a PM.

regards