Yesterday's Weapons Forums

I've done quite a bit of experimenting with handloads for the 8x56R. Some of this was with cast bullet loads, and within that body of work, many of those were reduced loads. My concentration on reduced loads is the enjoyment of the light recoil that such loads produce.

One of the powders available for cast bullet and reduced charge centerfire rifle handloads is SR 4759. I've used it successfully for years with reduced loads. With properly calibrated charges of SR 4759, the shooter can obtain wonderful accuracy with very light recoil.

When handloading reduced charge loads, there's always the issue of excess case capacity. Reduced charges just do not fill the case up in the same manner that full charges usually do. The majority of propellants used in making reduced charge loads possess some degree of positional sensitivity in relation to the primer. The terms "primer up" and "primer down" indicate the position of the powder to the primer. The former means that the powder has congregated in the forward end of the cartridge case, away from the primer and behind the bullet. The latter means the propellant is concentrated over the primer in the rear of the case. Naturally, a rifle is seldom held in a perfectly vertical position at the time of firing, so an absolute of "powder up or down" is really a preponderance. For example, most of the powder could be in one end with a thin layer spread most of the way along the lowest horizontal interior side of the case.

The position of the powder inside a case with excess capacity has an effect on the burn of the powder. Within identical loads in the same caliber, I've noted variations of from 75 to 100 feet per second in muzzle velocity between loads having primer up and primer down. This kind of spread can increase group sizes on the target. Cases where the powder is spread along the entire length of the case will usually result in intermediate velocities.

Some cast bullet shooters who deal with instances of excess case capacity do so by using fillers to fill the empty space and physically hold the powder over the primer. Some of the materials used are kapok filler, dacron filler, or powdered fillers such as cream of wheat or granulated plastics made just for that purpose. I choose not to use any fillers. In my own opinion, the measurement and installation of fillers introduces another step or two in the process of handloading and therefore compounds the possibility of error to the point that the result may be no better (or worse) than if it hadn't been done in the first place. My reduced charge handloads are not used for field shooting anyway, only for target shooting. With this in mind, I try to minimize the problems of positional relationships between propellant and primer by establishing a routine where I raise the muzzle slightly before each shot.

The Austrian M95 aggravates the problem with powder position in reduced charge loads. With the straight-pull action, closing the bolt to battery position naturally tends to force the powder to the front of the case. There may be some bounce-back, but my guess is most of the powder remains forward in the absence of muzzle elevation after closing the bolt.

Today, I fired some 8x56R loads to the following recipe:

Graf case (new)
200 grain cast lead bullet with gas check (from Lee mold)
22.0 grains SR 4759
WW LR primer
Muzzle velocity with primer up: 1468 fps.
Muzzle velocity with primer down: 1565 fps.

It can be seen that the difference in muzzle velocity between the two strings of shots fired, one with primer up and the other with primer down, is nearly 100 fee per second.

Examine the four cases in the picture below:

[attachment=0]SANY1571.JPG[/attachment]

A black ring will be noted on each case about mid-way along the shoulder of same. The surface of the brass under this ring all around the circumference of the case is raised, forming a ringed dent. These cases were all from the batch of cartridges fired with the powder up toward the bullet in the forward end of the case. It appears that the initiation of the ignition of the powder occurred as a concentration in the shoulder area of the case, instead of being diffused around the entire inside of the case. Said another way, it seems that the reduced charge of powder blew up right behind the bullet instead of throughout the case. This certainly gives some credence to those handloading gun writers who have written over the years about ringed chambers resulted from certain kinds of reduced charge handloads.

My handloading experiments with 8x56R have shown me that the design of the cartridge case may make it more of a challenge to load using certain propellants in reduced charge applications.

Thanks for the heads up on this powder.
It is on my list of powders to experiment with for the 8x56R.
I have saved this info and when I get some of my other projects done, I'll test it out.
Since I have some of the plastic filler, I think I will use it in the tests.

In the meantime, I'll keep looking for some cast bullets larger than the .329 dia ones I have.

Dan

Not to say I am especially manly or anything, I like shooting non reduced loads. Especially when I have an Austrian Steyr that especially likes the load I came up with. Not being into casting, I use the 205 grain jacketed soft points available from Graf And Sons. Especially when they give C&R license holders a discount. My favorite load is one of those bullets and 48 grains of H4895.

I like IMR 4895 in the 8x56R, and it's interchangeable with H-4895. I've gotten good accuracy from it. I don't get up to 48.0 grains, rather I use loads of 42.0 grains @ 1932 fps. and 45.0 gr. @ 2054 fps. and around in that range.

I like the Hornady 205 gr. jacketed bullet; though it's pricey for bang-bang, boring-holes-in-paper-at-the-range shooting. For quite a while, I re-sized jacketed .338's down to .330 in a Lee sizing die. That's when I could find bargain-priced .338's. .338 is a hunter's bullet, and not much of a marksman's bullet and I used to be able to find these at discounted prices in gun shops and other places where they were slow sellers. Not any longer. I shoot cast GC bullets in the 8x56R in both reduced and near full-power loads, varying the propellant as appropriate. I don't like getting beat up by a rifle, so I tend to throttle back a little on my loads in most of mine. Some exceptions are loads for the M-1 Rifle which must be at certain levels with certain propellants to work properly; but with the gas feature of the action which bleeds off pressure to make it work, I never had a gripe with the recoil anyway. Another exception is IMR 4064 which (at least in my own experience) seems to give its best accuracy at near-maximum levels.

I loaded up a bunch with surplus RG4895.

Same recipe as IMR 4895.

I got some 150 grain jacketed spitzers from Buffalo Arms. But the only published recipe I can find for jacketed 150 grain bullets is right from the ones that came with the Lee Dies, and they seem EXTREMELY light. For instance, I us 49 grains of IMR4895 for a 205 grain jacketed bullet, but the Lee tables list a max load of 36 grains with this powder. It seems to me that is a much reduced load. Oh well, I guess the next range trip will tell.

And the boolits are the right diameter? Not .323?

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