Goofy Data?

[lizziedog1]

I have a Hodgdon Reloading Manual, not the text book, but the one made like a magazine. It is their most current. Anyway, I was looking at reloading recipes for the 32 S&W Long and the 32 H&R Magnum using Trail Boss.

I have some Hornady 90 grain lead semi-wadcutters in that caliber. Here is the data I found.

For the S&W case they List Trail Boss loads from 1.5 to 2.9 grains with velocities from 599 to 730 feet per second.

For the magnum the same powder goes from 2.4 to 2.8 grains of powder and a velocity of 751 to 785 feet per second.

The longs barrel length is 5.32" and for the magnum 5". Hardly enough to make a difference.

Does Trail Boss have some odd properties that explains this data? With the other powders listed the magnum is loaded with larger doses of the same powder for substanial velocity gains. So, what's up with this?

 

[jinxer3006]

The only "odd property" of Trail Boss that I know of is that you can NOT use it in compressed loads.

BUT, there should be more space available in the H&R mag than the S&W long, so I don't think that's the answer.

The SAAMI specs I have show the H&R mag to have a max pressure of 21000 CUP, but Hodgdon's website shows only 11300 CUP @ 2.8 gr.

I'm at a complete loss for an explanation for this one. Hopefully somebody else will have an answer.

 

[lizziedog1]

The velocities do not make sense either.

2.8 grains of trail Boss in the magnum case produces 785 feet per second.

You put 2.9 grains of the same powder, with the same bullet, in a smaller case and you get 730 feet per second. The barrel length of the long is even a tad longer.

I am no ballistics expert, but shouldn't the smaller case produce higher pressure, all else being equal? Then wouldn't higher pressure result in a higher velocity?

Something just dosen't add up here.

 

[ArchAngelCD]

There are many factors that will determine the velocity of a round.

As for oddities, yes, Trail Boss is a very odd powder. It was developed to be a "fluffy" powder that fills the case of old calibers that were originally Black Powder calibers without developing high pressures. I'm guessing the difference in revolvers is causing the velocity differences you are reading about. Trail Boss CAN NOT be overloaded or cause high pressures in any caliber unless you compress the load. You can't fit enough Trail Boss in any case that would cause it to go overpressure. (without compression)

 

[lizziedog1]

I am going to call Hodgdon as soon as they open. I'll report what they have to say.

Does anyone else here load their 32 H&R Magnum with lead bullets?

 

[MMCSRET]

I load 32 Mag with 94-95 grain cast bullets. I use 7.4 gr. of 2400 and shoot them in a 327 revolver. I'm still working up, so that is not my final data.