compressing powder?

[machinegunjohn]

I bought 500 , 240gr cast lswc from a friend, he doesnt know who cast them, I trimmed cases(44mag) to 1.275, loaded 18.5g 2400 and 19.5 grains 2400. I was concerned that the bullet was actually packing the powder in the case by the time it was seated to the cannalure with the 19.5 loads. Is this possible? If so, can the results be catastrophic? Dangerous?
Thanks

 

[flat top]

John; First off, I have never heard of a 500 grain bullet for a 44 Mag! 405 is the heaviest bullet that I know of. Weigh the bullet and see what the actual weight is. Secondly, I seriously doubt that a 500 grain bullet would even stabilize in the twists available for a 44 mag...the bullet would be WAY to long!!!! We have found that the 405 is about all that the cartridge and twists can handle. Some loads that I have used "are" compressed loads. You must consult your loading data and reveiw your reloading procedures to insure, that under no conditions, have any of the specs for your cartridge been exceeded, and that your charges are correct............by the way, where did you get loading data for a 500 grain bullet for the 44 Mag?

 

[Carnage_7]

I don't think he indicated it was a 500g bullet but that he got 500 bullets-quantity from his friend. It would help if you provided the actual grain of the lswc you got.

 

[flat top]

Thanks Carnage7...must have misread that...I hope!

 

[machinegunjohn]

sorry guys, quantity 500, weight 240 grains

 

[Skip Sackett]

I have an opinion!

A lot of you are saying "Like we didn't know that!"

At any rate, this is one reason we work up loads. Not all components/lots of powder are exactly the same. They are made by man and are subject to change, period.

It may be your batch of powder may be compressed in your .010" shorter case, it may be mine won't. I may be able to put enough powder in my case to cause a real catastrophic event. You may not be able to put that much powder in your case with the components you have.

Richard Lee says in his book that he saw some interesting things when it came to compressing powder. Remember this though, it was in bottlenecked rifle cartridges, not straight walled pistol cartridges.

Here is a way to check how much your compression is. Don't size a fired case. Fill it with the charge you want to use in your load. With the case this big, your bullet should slide inside without any pressure, do that. When you push it in by hand to the point you want to seat it at and release it, it should stay put. If not, try to get an idea on how much it comes back up. Call Alliant and ask them how much you can compress your load. Tell them your results from your test, ask them to comment on that.

Hope this helps!

 

[flat top]

John; Thanks! a 240 grain bullet should not be "compressing" 19.5 grains of 2400...depending of course on the base to crimp groove measurement of the bullet! With the 240's I have here, 19.5 grains of 2400 comes to the base of the bullet, but it is not a "compressed" load. Some bullets have a longer nose and shorter base (or vice versa) than others, and it just depends on the specific bullet you are using. If you are the least in doubt...start over again, insure that your powder "is" 2400, and recheck your charges by volumn and by weight, rezero your scale, weigh the bullet, and cover all the bases, etc. Safety First!!!

 

[oldRoger]

A compressed load in a relatively short pistol case is a far different thing one than one in a long bottleneck rifle case. I would be very nervous about it unless the published source clearly stated that the load was compressed given all the parameters of charge weight, case length & brand, and overall length.
+1 to smithcrazy I have a set of cases at hand which allow me to slip fit a bullet to see exactly how compressed or near compressed the load is.

 

[Alk8944]

For years the "standard" load in a .44 Magnum was the Lyman 429421 250 gr. +- over 22.0 gr. 2400. Literally millions of rounds so loaded have been shot in .44 Magnum revolvers with few, if any, catastrophic failures. This was before the SAAMI change in MAP* for the .44 Magnum from 45,000 CUP to 36,000 PSI, which are not equivalent figures.

Alliant still lists 20.0 behind the same bullet as maximum (based on the new pressure specification). Compared to your loads this is more powder and a heavier bullet. You have absolutely nothing to worry about.

FWIW, the reduced loads in recent loading manuals, compared to the older ones, are not a result of the burning rate of 2400 changing over the years as some claim, it is due to the change in SAAMI MAP specifications and the new pressure measuring methods now used.

*MAP-Maximum Average Pressure

 

[oldRoger]

The old loads of course as Alk8944 says, have been proven empirically to not destroy handguns. Advances in pressure/time mensuration techniques have allowed closer observations of interior ballistics but I hardly think that invalidates the empirical observations of millions of rounds fired.

Evidently when we changed from CUP to PSI, we made very little attempt to try to standardize the measurements so that the old numbers would be as much as possible equivalent to the new.
Not very surprising since a manufacturers group such as SAAMI is staffed with PR people, Lawyers, Lobbyists, and perhaps a few Scientists.

But let us not leave out the pervasive effect of our increasing litigious society, our increasingly wimpy corporate environment, consumer protection departments at the state and federal levels, etc and so forth.

The shorthand for this is: "blame it on the lawyers".

 

[mkk41]

The slower burning powders commonly used for magnum pistol loads , like 2400 , H-110/W-296 , AA#9 work best when slightly compressed. If fact , most data warns against reduced charges or 'loose' loading density.
However , ya can't just go by bullet weight , especially with cast bullets. Some designs have more 'shank' (distance from base to crimp groove or cannelure) than others. The Lyman 'Keith-style' has a relatively short shank with more weight/mass in the long nose , leaving more room in the case for more propellant. Loaded rounds are somewhat longer and may not fit some revolvers.
OTOH , an equal weight RCBS or Redding Saeco bullet of the same caliber and weight has more shank (less powder room) and a shorter nose. Cartridge OAL is a good bit shorter.