I was loading up some Barnes 235gr tsx flat base for my 375 HH ruger #1. According to the barnes book, 748 is the most accurae load and can be charged up to 87.5 grains at a max length of 3.57 or so. Since I have no mag box I can seat the bullet whereever I want so long as it doesnt stick in the throat. I was using the ladder method and loading charges at .5gr intervals. I noticed that around 85.5 gr or so the seating felt a little differant and bullets did not seem to seat as deep, being about .003 or .004 further out. I know that some compressed loads are fine but I obviously want consistant seating with the final load.

Since I'm below max, should I: 1. adjust seater plug to seat to same depth and not worry about slight compression 2. adjust out slightly to avoid compression 3. assume 85 grains is max load until I can pressure test it 4. shut up and wait for one of you to tell me what to do next?

The cases are trimmed slightly shorter than book length, but powder charge is within book values. Not sure if you all will need further info to answer my question.

Hey Curtis, I realize WW-748 is a Ball Powder. Just wondering if you tried "easing" the Powder into the Case using the "Swirling Method". That is, slowly pouring the Powder into the Curved portion of the Powder Funnel so it "Swirls" into the Case. Also, a l-o-n-g Drop Tube helps get more Powder in.

If you tried all the above, then bumping the edge of the Case(with the Powder in it) against an electric toothbrush, razor, or Tumbler "might" get it to pack a bit denser. Then again, it might loosen it up, I've had it go either way.

That should give you a bit more room though.

Are you loading fired or new brass? There will be a considerable difference in powder capacity, with new brass holding a couple of grains less. This is particularly true with a long, tapered case like the H&H.

Slight compression of the powder is not a problem. Heavier compression can result in (1) deformation of the case so that it won't chamber, or (2) the bullet inching its way back out of the case. So long as the bullet does not engage the lands, you're fine to seat longer than "book" specs. Remember, however, that the monometal bullets are squirrelly and are recommended to be seated a few one-hundredths off of the lands.

quote:

Originally posted by Stonecreek:
Slight compression of the powder is not a problem.

M.L. McPherson, author of Metallic Cartridge Reloading, 3rd Edition said it is a problem.

quote:

Try to avoid powder charges that result in a slight compression of the as-dumped powder charge. Some slightly compressed charges might spontaneously settle, most likely from vibrations during transportation. If this happens to some of the loads, they will shoot to a different point of impact. The folks at Alliant have studied this effect in some detail and have found it to be significant. In moderately to highly compressed charges, the powder granules are pressed together so tightly that spontaneous settling can't occur.

Glean from this what you will.

I guess then that one needs to get the powder settled (like HC suggested) before you seat the bullet or traveled with the ammo.
I thought you weren't supposed to compress ball powder since it falls neatly into place. Not like the random hay stacks with the stick powder.
Stonecreek's comment about the 1X brass is sound.

quote:

Originally posted by wasbeeman:
I thought you weren't supposed to compress ball powder since it falls neatly into place. Not like the random hay stacks with the stick powder. .

This statement for the most part is true. The settling of fine ball powders is almost un noticeable.
A little side note. In my exuberence to compress ball powders I was successful in unseating the primers. roger

Curtis, there are several factors that can affect this.

Fired brass usually has aout 2% more case capacity then new brass. Another 2% variation can result in changing brands. HotCores method can make a bid difference when using ball powder, as much as 4%. I've managed to bulge a case or two. It's pretty hard to do, and you exert alot of effort while seating the bullets.

I used to use a compressed load of Lil'Gun in my hornet. I had a ram in my pres whith which I would compress the powder from half-way up the neck to the base of neck (long neck on a hornet). This formed a 'plug' of compressed powder under the boolit. I was paper cup seating with no neck tension and the bullets never moved - they couldn't move in as they sat on top of that powder plug. Removing a powder charge required digging the plug out then the rest would sort of flow out. That's the behaviour of Lil'Gun which may be quite different to other ball powders. (The compression did influence the ignition of the powder and seemed to reduce chamber pressure).

I'v enever compressed ball powders but routinely do so w/ stick powders, especially in smaller cases. A drop tube helps quite a bit, so does mild vibration of the case after filling.

All good advice. Also excellent that you noticed the OAL change with greater seating pressure from the powder compression. It is because the press linkages are under different stress and it will make a few thousanths of an inch different.

Normally I would adjust the seating die a little to seat to the same depth as the other bullets. An OAL change will result most times in a POI change.

However in your case since you are not limited by mag length, then you could pick the longer OAL and seat all loads to it even the ones that are not now compressed. If you have already seated the lower loads, then my advice would be to adjust your seater to compensate.

I have quite a number of "stick" IMR powder loads which I moderately compress and they work well.

But, I also ALWAYS compress AA 1680 ball powder when loading my Hornet, and I compress it substantially. I fill the case entirely full (15.0 grains in W-W brass), then seat a 40 gr. Sierra bullet on top of that.

It is the ONLY load in my Hornet which will reliably and regularly produce 1/2" 5-shot groups or better at 100 yards. Most other loads won't even produce 1.25" groups from my Martini Cadet.

quote:

Originally posted by onefunzr2:

quote:

Originally posted by Stonecreek:
Slight compression of the powder is not a problem.

M.L. McPherson, author of Metallic Cartridge Reloading, 3rd Edition said it is a problem.

quote:

Try to avoid powder charges that result in a slight compression of the as-dumped powder charge. Some slightly compressed charges might spontaneously settle, most likely from vibrations during transportation. If this happens to some of the loads, they will shoot to a different point of impact. The folks at Alliant have studied this effect in some detail and have found it to be significant. In moderately to highly compressed charges, the powder granules are pressed together so tightly that spontaneous settling can't occur.

Glean from this what you will.

I agree with Stonecreek....slight compression is not a problem!

Further moderate compression isn't a problem either..... and yes....large amounts of compression is not bad either.

If one goes beyond slight compression he might want to restart the load development with a magnum primer.

As long as one works up and don't bulge the case (or as Roger says) push out the primer he should not be afraid to compress powder.

Whether or not the gains from all this compression is worth the time and effort is another issue!

Very good gentlemen, and thanks for all the help. If I remember correctly, the Barnes book does list the max charge as 100+% load density, so I expected perhaps a little compression. I did try tapping the cases a little to settle the load and noticed that one of them settled well and the others didn't settle, one of them seemed to unsettle just as someone mentioned above! Perhaps in future loading, I will try doing some swirling etc to help in this matter.

In compression a 357 mag load onetime I did find that the case bulged and I had to pull a few bullets and resize. That was with H110. With these 375 HH loads, the tension on loading arm was not greatly differant, but noticeable (I try to pay close attention to such things) and seating was not "greatly" affected but I did't wish it to affect POI while working a load. I did have the rounds in the car while driving yesterday but ended up not getting to the range anyway, so perhaps there has been some settleing??? I think I will go and remeasure everything and perhaps re seat the last couple cartridges to the depth of the first several.

Thanks again for your comments.

Compressed loads are not good for accuracy period. If you are using stick powder it will break up the individual kernels changing the burn rate---you do the math. On ball powders a compressed load can push the bullet back up the neck over time causing all sorts of problems.