17 June 2020, 06:01
The MazWatch Out With Reloder 50
I recently picked up some RE50, and found that Alliant's data for this powder is way too hot. Their published data for an M33 projectile is 255 grains, and this is the result that I got at 250. My lot of powder is probably a good bit faster than the lot the data was developed with.
The curve flat-topped, but the slopes indicate that the result was somewhere in the range of about 68k PSI, and the bolt had to be opened with a mallet. Brass showed no deformation and primer wasn't cratered or even flattened.
I needed a reminder to back off 10% before taking any data for granted! Luckily, no harm or foul here.
10 July 2020, 21:06
KennethIThat's interesting. So far with working up loads, I've used only Reloder 50. I was getting ejector marks and cratered primers 10-15 grains below their listed max with with a couple different bullets, although I didn't notice bolt lift being any harder than starting loads. Seems others haven't had any trouble hitting max loads though, maybe there is quite a bit of lot-to-lot variation? I have another lot of RE50 but haven't had a chance to try it yet. I have some 20N29 I'm going to be trying first.
How's the Pressure Trace with the 50? Did you have to fire any factory or calibration rounds to get it set up?
12 July 2020, 12:20
The Mazquote:
Originally posted by KennethI:
That's interesting. So far with working up loads, I've used only Reloder 50. I was getting ejector marks and cratered primers 10-15 grains below their listed max with with a couple different bullets, although I didn't notice bolt lift being any harder than starting loads. Seems others haven't had any trouble hitting max loads though, maybe there is quite a bit of lot-to-lot variation? I have another lot of RE50 but haven't had a chance to try it yet. I have some 20N29 I'm going to be trying first.
How's the Pressure Trace with the 50? Did you have to fire any factory or calibration rounds to get it set up?
I did fire other loads with it and it worked pretty well. Here's the result with some Federal XM33 rounds.
I consider the M33/XM33 to be the reference load in this caliber.
It is possible that the M8 projectiles used in the initial post are that much harder to engrave as to spike pressures, but I doubt that the result would be so dramatic. The copper jacket is just too thick for core hardness to have that much impact on the engraving forces.