Reloading Question

Bottom Gun

Can load data for H4831 powder be used for H4831SC powder? My charts show them having the same burn rate.

My Lyman manual (49th ed) shows .243 Win loads using H4831SC for bullets up to 70 gr but specifies H4831 for bullets 75 gr and heavier. Does anyone know why?

varian

in my 2017 basic reloading manual by Hodgdon in their powder description section it states "H4831SC ballistically this extreme extruded powder is the exact copy of H4831".

nononsense

I haven't used H4831 in several years since the advent of other powders which show better performance in multiple cartridges.

In your .243 Win. example, while you might believe the burn rate to be the same, the actual powder volume in the case does not all burn even in barrels up to 26" in length. In essence, H4831 is significantly too slow to use in the .243 Win. This is good for Hodgden because you use more powder yet achieve nothing more than wasting about 10% of every shot when the case is full. Pick a new powder for the .243...

The real difference should be obvious in that the labels state SC (short cut) which is shorter in length. This allows for more kernels to be added to get to a full case of powder. Empty the case then add the same weight of powder for H4831, you will overflow the case mouth since the kernels are longer, taking up more space.

Hodgden is addressing the burning energy released when ignited but they fail to recognize the difference in volume.

If you want powders to perform in the .243 Win. I suggest Re-16 and H-Hybrid 100V. 100V is is a cooler burning powder suited to the lighter bullets and Re-26 for the heavier bullets.

Best.

Bottom Gun

Thanks for the good info. It makes sense. I’ve had incomplete ignition before using slow powders, especially in handguns.

This .243 is a new cartridge for me. I’m in the learning stages of .243. I had to retire my .30 and .33 caliber rifles and move to .243 after my shoulder replacement.

I recently lucked out and found a nice 60 yr old .243 Sako on Gunbroker that turned out to be an excellent shooter. No surprise there, I’m a huge Sako fan.

I don’t have too many choices of rifle powder available at this time. I have H4831SC, H335, Win 748 and IMR4064. I’ve been getting sub-MOA accuracy with 85, 95 and 100 gr bullets with H4831SC and H335. It also shot well with IMR4350 but I have very little of it left.

I couldn’t get Varget powder to work well for me in .243 or .223. I was surprised by that since I hear it works so well for others.

So, I guess I’ll have to wait for a calm day to set up the chronograph to check some of these loads. If I’m getting incomplete ignition with H4831SC, hopefully the numbers will disclose it.

FYI, I sent an email to Hodgdon customer service asking my original question. If they reply, I’ll post it.

Thanks again for the good info and advice.

Bottom Gun

The chronograph is something I also use last and then it’s usually out of curiosity although it has alerted me to incomplete ignition in the past when I was developing a light bullet load for .357 Sig using slow powder.

When I’m developing a hunting load, I first test bullet performance. When I’m satisfied with the terminal performance, then I work on accuracy. Once I have an accurate load that performs, I’ll sometimes check my velocity estimates against the chronograph just to satisfy my curiosity. If I'm satisfied with the accuracy, I seldom bother checking velocity deviation.