2400 Burn rate changed?

[351 WINCHESTER]

My friend was reloading for one of my .351 winchesters. The data that we could find listed a max charge of 19grs. of 2400 behind a 180 gr. jacketed bullet. We found this data in an older book and it could have been 25 years old. He is always on the cautious side so he backed off to 18 or 18.5 grs.

When I shot I said, damm, I don't recall this gun kicking so hard. I let my oldest son shoot it and he said the same thing. It actually chipped a piece of the stock off too. I looked at the brass that we could find and found no evidence of flattened primers or backed out primers.

I told my friend about the recoil and we were scratching our heads. Somewhere in the back of my mind I remember someone telling me that the newer 2400 has a faster burn rate.

Can anyone confirm or deny this for me?

We also tried 4227 which worked well, but I'm kinda lerey of the 2400.

 

[cdrt]

I'm guessing you got that load from the 45th Lyman manual.

If you look in there, the load for the .44 Mag with a 240 grain jacketed bullet, maxes out at 22 grains of 2400. In the newer Speer book, their load for the .44 Mag with a 240 grain bullet maxes out at 17.7 grains of 2400.
The velocities are similar; 1300 fps vs 1271 fps.

Big difference in loads and one that may help explain the increased recoil.

 

[351 WINCHESTER]

I would have thought that the mfg. of 2400 powder or any other powder for that matter would have written in bold contrasting lettering something to this effect - "CAUTION THE BURN RATE FOR THIS POWDER IS APPX. 20% FASTER THAN EARLIER POWDERS". "PLEASE USE UP TO DATE LOADING DATA FOR THIS POWDER."

 

[GRIZ22]

Burn rates change and you would think that the manufacturers would let you know. The best way to keep track of this in my opinion is check the powder manufacturers websites (they don't say they changed the rate but you'll note different loads) or buy new manuals every couple of years.

 

[Geister]

2400 has gotten hotter in the last few decades.

In the defense of the manufacturers, they don't recommend anyone use that old of a load data book. You can find the load data on-line so I recommend at least doing that if you don't buy a newer book.

Speaking of 2400, does anyone know about what the current equivalency of the original .357 Magnum load is using current 2400 powder? Is it about 15.0 grains with a 158?

 

[Steve C]

I asked this question of an Alliant employee manning their booth at the NRA convention several years ago. He said that the burn rate of the powders haven't changed but the primers had become much hotter over the years and that had caused the reduction of recommended powder charges in their data.

Speer used to recommend a magnum primer with 2400 as did most other manuals. Their current #13 manual contains a statement that one should use only standard primers with 2400 as high pressure will result from using magnum primers.

 

[Geister]

Yeah, I recently tried a Magnum primer with 2400. I won't do it again. It catered the primer. I might do it again with a chronograph to see if there's any benefit at all but more than likely using a Magnum primer just raises the pressure without increasing the velocity by much.

 

[CMcDermott]

When Alliant bought out Hercules, the 2400 powder did acquire a slightly faster burn speed as a result of being manufactured by a new company. I don't think this was intended by Alliant, but it did happen. All of the old Keith 2400 loads (13.5 grains for hot 38 Special to 22 grains for 44 Magnum) need to be reduced by 1.5 to 2.0 grains for safety. 2400 tends to be used for magnum pistol cartridge loads, so magnum primers were used as the high for pistol cartridge pressure levels were thought to need the thicker primer cups to hold the pressure. But 2400 is very easy to ignite and you get a more consistent burn process if you use standard primers, so the change has been made over the last couple of decades to use standard primers instead of magnum primers.

The other force at work at reducing the pressure levels of all of the loads from those of 30-40 years ago is that there seems to have been a change from using an average maximum pressure level to using the single highest pressure level measured during testing as a limit. This reduces the pressure level of a given load one to two thousand psi on average, and for some powder/cartridge combinations five or six thousand psi. Look at some of the 357/41/44 Magnum Lil' Gun loads where the max average pressure reported is much lower than an equivalent H110 max average pressure given or the SAAMI max pressure allowed.

 

[Oohrah]

Have used these loads and one grain less in 45LC in Ruger and TC
Contender. Not the cleanest burn, but accurate in .357, 44, and
45 calibers. Anxious to try Lil Gun in my 22Hornet and some of the
above handgun cartridges.

 

[Chief 101]

351 WINCHESTER, I have an '07 Win and wouldn't mind reloading and shooting but you know the problems I would have. I do have the dies but cases and bullets are a minor problem aquiring. I know I can probably make cases out of .357 brass but what about the boolitz? Where do you find yours. I know Lyman used to make a mold for casting .352 diameter slugs for this thing, just seeing your "code name" brings back some interest in getting this gun in the field again. Chief aka Maxx Load