[The Shrink]

Esteemed Board

I have long shot 23gr 2400 behind a 240 gr. bullet as my standard hot hunting load for the .44MAG. I'm shooting this in a Ruger SuperBlackhawk. I checked the load in the old Serria manual, they list 23.3 gr as a max load. OK so far, and it's worked for years.

I get the new Alliant Reloader's Guide, and lo and behold, 18.7 gr., 20.6 gr., and 21.5 gr. 2400 listed as MAX loads behind three different 240 gr. bullets. Same barrel, same cases, one different primer.

What gives here? Is this the normal variation given different conditions, the Sierra data being shot at sea level in dry conditions in the LA basin, who knows where the Alliant data was shot? But why the variation in the Alliant data, given the assumption it was shot under the same or very similar conditions? I can't imagine that three different bullet designs, all 240 gr. weight, would cause that much variation in MAX loads.

Also, why the low numbers compared to the old standard of 23 gr.? Is the new 2400 slightly hotter than the old 2400? Should I adjust my load now that I'm out of the old 2400 and will buy a new can?

 

[bfoster]

One factor:

If you weigh cases made say 35 years ago, and weigh current cases you'll likely find, on average, that today's cases are slightly heavier. The inside dimensions have been "beefed up" in the head area, in most brass for high performance cartridges. This reduces case capacity slightly, which in turn, requires dropping charges slightly if a given maximum pressure level is to be maintained. This is, IMO, a good idea, as it promotes longer case life, even if performance does suffer slightly.

Bob

 

[The Shrink]

Bob

I know that was true from the old balloon head cases, but didn't know it was true in the past 20 years. It still doesn't explain the variations in the Alliant data for 240 gr. bullets using 2400. I can't see an almost 4 gr. difference based on bullet design and primer for the MAX load.

Your argument, then, would be that as long as I am loading original cases I can continue to use the same load, but if I buy new cases I should drop down and work back up again, just as if in a new load?

 

[Flint]

44mag2400

The data I've used over the years usually put the max 2400 load with 240 grain lead bullets at about 23 gr, and the jacketed bullets 240 at 21 gr. Since law suits now run America, they might have lowered their max loads. They may also have changed the powder formulation.

 

[Joe Kool]

2400

The Shrink, 23 grs sounds like a fairly hot load. Most loading manauls list 22.2- 22.4 gr. as the maximum load. Sierra is the only manual that lists 23 grs.. I would only use 23 grs. with a Sierra bullet. I've always used 22.0 gr with Lyman #429244, cast of ww+2% tin and weigh 250 gr. This load is what I consider maximum. A year or two ago Alliant redesigned 2400. It's now supposed to be cleaner burning. I've read and friends told me, they had to back their loads off a 1/2 a grain with the new 2400. I still have some of the old unimproved 2400 so I haven't tried the new and improved yet. If you want to know why Alliant lists different charges with 240 gr bullets, why don't you call them? Most of the powder companies are more then happy to answear any questions you have. 8)

 

[bfoster]

Wayne,

Yes, I consistently recommend starting with about a 7% powder reduction when a new lot of any component is used. Exception: some loads using H110 or W296. Check the Hodgdon & Winchester manuals as appropriate. These powders have a high balance point and burn less than consistently at lower pressures.

Alliant is simply reporting the results of testing. Unfortunately, they don't fully report what components were used in the tests that they conducted. But with a twenty year span between results, it is not unreasonable to deduce that much has changed. The only load manual that contained specific data on pressure testing (component lot #'s and equipment used) was A-Square.

One other factor here is that the test procedures for handgun ammunition under SAAMI guidelines were changed, oh, about 6 or 7 years back. There was little effect on the low and middle end loads, but some "hotter" loads using medium to slow burning rate powders have tended to be cut. Why the change in procedure? The electronic pressure measuring systems have taught the industry engineers a lot about what goes on in the field of internal ballistics. While there is still much to learn, it had become clear that some loads were generating forces that were responsible for problems in some very popular handguns made by some "top shelf" manufacturers. Remember, the load manuals have to cover several arms for each cartridge, even when the loads are subdivided by classes. These loads may not be heavier than what is appropriate for the weakest arm in each class in the opinion of the ballistic engineer in charge.

Personally, were I shooting your Ruger SBH, and if I worked up my loads using 240 grain bullets with care to 23 grains of 2400, not noticing any pressure signs such as "sticky" ejection, I wouldn't anticipate mechanical troubles in my revolver. If the cases do eject less than freely, or if you see any other sign of excess pressure stop shooting, and back off your load. On the other hand, a prolonged and steady diet of such "hot" loads in a S&W M29 is a pretty sure invitation to mechanical troubles, despite the changes S&W implemented in '89.

One point to bear in mind: used in quantities beyond its working range for a particular load, a weight of powder/pressure graph for 2400 will show a very sharply rising curve. That is pressures increase very rapidly with the addition of very little more powder to a given load. SBH's have been blown up by floks that thought that they were immune to disaster.

Bob

 

[Tom W.]

I was using a load of 22 grains of 240 with the "old" powder, with a 240 gr. cast gas check bullet and it worked fine. The same load with the "new" powder got me sticky extraction. I backed off to 21 grains and all is well again.

 

[The Shrink]

Thank you, gentlemen. Bob in particular, I have been out of the loop for years, not reading shooting mags or buying new loading manuals. Most of whay you said was new information to me, and makes a lot of sense.

I got on RCBS's web site yesterday and noticed that they feature Alliant powders. I'll e-mail their experts with this question.

 

[Gregory]

I load 21.0 gr 2400 with a 250 Lyman cast SWC for my Ruger Redhawk, and the same powder charge under a 240 gr Hornady XTP out of my 14" TC Contender. Both loads have acceptable accurcy for me.
Greg

PS These loads seem to perform better with a CCI 350 primer instead of the WW primer.