Maybe not new to you, but a mostly mysterious reloading recommendation to me:

In Accurate's 2001 Reloading Guide (p.39) and Handbook #1 I find as maximum load for .30/06 and 3100 Powder, 24"barrel, compressed loads:

59.0 grs for 150 grs bullet (2610 fps), 41,800 psi
59,0 grs for 168 grs bullet (2614 fps), 48,800
59,0 grs for 180 grs bullet (2611 fps), 53,300
59,0 grs for 190 grs bullet (2574 fps), 53,200
59,0 grs for 200 grs bullet (2561 fps), 58,900
59,0 grs for 220 grs bullet (2470 fps), 59,900.

As this data was published in earlier reloading guides also, nothing seems to be wrong or dangerous.

I am short of any explanation why a 50% increase in bullet weight needs NO reduction in maximum powder charge and why heavier bullets leave the barrel faster than lighter bullets.

Please, knowledgeable reloader and master of ballistics, enlighten me!

Thank you.

[ 10-17-2002, 20:34: Message edited by: waitaminit ]

wait -

What you're seeing here is that 59 grains of 3100 is a caseful in their particular test cases, and, aside from possibly the 180 grain and heavier loads, not that well suited for the caliber. Kind of like using 4350 in the 308; you COULD use it, but, it's not the best application. I don't have their book in front of me, but, I'd bet the pressures are WAY down for the light bullet loads, too.

Remember, it's their book, and they sell powder, so, if a powder works at all in a caliber (ie. no pressure spikes or weird velocity variations), they'll list it, in case you want to use it.

I actually tried the 59 grain/180 load, and, the velocity was down (around 2,580), but, the accuracy was really good. Very little velocity variation between highest and lowest, which, I'm certain, contributed to the excellent accuracy.

R-WEST

R-West, thank you for the explanation - I see, you know the tune.

I added some data from the AA-handbook #1 to my first posting.

Pressure develops exactly as you predicted.

The Sierra Manual starts mentioning AA3100 from 180 grs bullet weight onward, and their recommendations (26" barrel)are more the way we are used to:
max load for 180 grs bullets is 57.6 grs up to 52.5 grs for 220 grs bullet.

The low velocity variations you noticed will be the result of the compressed load: no chance for the powder to change location.

[ 10-17-2002, 20:53: Message edited by: waitaminit ]

wait -

I've found more than a few instances where a case full of slow (relatively speaking) powder, even when low velocities are produced, usually produces excellent accuracy. I'm sure it is as you noted, that the powder doesn't have a chance to move around.

One of the Nosler manuals (don't remember which one) listed 4350 with 180 grain bullets in the 308 Win. as producing excellent velocity and accuracy. Never having heard of using 4350 in the 308, naturally, I had to give it a try. I think they listed 52 grains in the manual, which I couldn't get in the case without standing on the press handle - major compressed load. They must have had a pretty fast lot of 4350, because my velocities weren't within 150 FPS of theirs, but, it put 5 shots under 1" with two different 180 grain bullets (Hdy. Spire and R-P Core-Lokt) from a 700 Mtn Rifle. Velocities were quite consistent, again.

I remember reading somewhere or the other of a guy trying a compressed load of Accurate 2700 in a 30-30. 2700 is in the general area of 4350, burning rate wise, so, normally would never be considered in a 30-30. He noted low velocity, very small groups, and SD under 10.

Without making a book out of this, I think the variations between individual rifles has to account for a lot, because, Nosler obviously got those results, or they wouldn't have printed them. Some of the loading manual makers use only SAAMI spec barrels/chambers, while other guys use regular old rifles they purchase just like you and I.

We never stop learning in this hobby, that's for sure.

R-WEST

Trying to produce super-compressed loads by pressure IMHO is, beg your pardon, not the smartest way: if you do not use a strong crimp, the bullet will be pushed out overnight and your OAL is gone.

Even better than an extra long drop tube any vibratorial device :-) will work.
I tried one of these cheap electric cleaners they sell for your specs and rings (where they do a poor job): amazing how much extruded powder fits in a case.
You may want to misuse your electric toothbrush or your shaver.

[ 10-18-2002, 01:22: Message edited by: waitaminit ]

At one time AA3100 was amazingly cheap. (Called MR3100 then and I think it was once under a buck a pound.) Many of us bought it in lots of 32 pounds and shot it in anything it would remotely work in.

I use my case vibrator to compress powder in cases. Set it up close to my powder measure, put a powder funnel on top of a case, dump the charge in, and touch the base of the case to the case vibrator.