Very slow 8lb jug of H4831. What should I do?

[DCRYDER]

I recently acquired an English built Bat repeater with a 26” barrel chambered in 284 Shehane. Previous owner included about 20 loaded rounds loaded with 180 Hybrids and 56.9gr H4831sc. My LabRadar clocked these at 2850ish fps with zero pressure. I loaded a little ladder with same bullets and my 8lb jug of H4831 ranging from 56.7-57.6. My velocities were 2731-2777. This is WAY off. His 56.9gr load was 100fps faster than mine. I just shot one loaded with 58.5gr H4831 and it was only 2818fps still with ZERO pressure but quit a bit of soot on shoulder. Should I try this powder out some more or ditch it? Upper end of the ladder test printed 1/2” groups at 200yds. TIA

 

[rsmithsr50]

my 4831 never shot like sc never.
keep adding and testing

 

[Fred B.]

The 4831SC burns faster than 4831 because of the size (higher exposed surface).

 

[DCRYDER]

Think CCI 250’s would help speed it up and make it burn cleaner?

 

[Ned Ludd]

The two powders are not from the same Lot#. In fact, they're not even the same powder formulation (H4831 vs H4831sc). What did you expect? Try some H4831sc and see what happens.

 

[DCRYDER]

Same formulation, just cut differently for better metering.

 

[XTR]

I have seen lot to lot changes of 75 FPS with other H4### powders.

Keep adding more till you get a load you want, or it won’t fit, in which case try another powder.

 

[DCRYDER]

Thanks to everyone for their quick responses!!!

 

[johara1]

4831 has gotten so slow it near worthless, 4831SC. is the way to go ..... jim

 

[284winner]

Short Cut is your answer to that problem.

 

[DCRYDER]

That explains it being on sale for $150/8lb.

 

[rammac]

Same formulation, just cut differently for better metering.

Your evidence tends to make me believe that they are not the same, I would think that that was obvious.

 

[rammac]

The issue probably has something to do with bulk density (or load density, depending who you talk to).

 

[Falfan2017]

You got some sharp scissors? You could try trimming them into h4831sc

 

[Ned Ludd]

Same formulation, just cut differently for better metering.

It is chemically the same, but the formulation is different. Not trying to be obtuse, the term "formulation" has a pretty wide range of definitions and we are apparently not using the same one. As noted by Fred B., the smaller kernels of H4831sc provide significantly more surface area and could enhance the combustion rate, even though the two powders are chemically the same. Alternatively, I have also seen upwards of 75 fps differences between Lots of H4XXX powder as XTR mentioned, so it might just be Lot-to-Lot variance. In that event, increasing the charge weight might solve the low velocity problem, but only if you have sufficient case volume. I'd be cautious testing that theory at the very high end and test in small increments due to potential over-pressure issues. Let us know what you figure out. Good luck with it.

 

[rsmithsr50]

on paper, yes,
in real life..NO WAY
been there, tested, done that, have the test data,
just not true

Same formulation, just cut differently for better metering.

 

[FrankG]

A couple of thoughts/comments......

In my opinion your at max or beyond a normal max working load of 56+ grains. That 2700+FPS out of a 26” barrel is what I will call normal.

Just because you don’t see signs of over pressure doesn’t mean that your not over!

I wouldn’t keep adding/testing!

Just want you to be safe!

Later, Frank
Bartlein Barrels

 

[oldduc]

Should I try this powder out some more or ditch it? Upper end of the ladder test printed 1/2” groups at 200yds.

Not sure I see a problem. If it's shooting in the 2s with velocities in the 2700s, just shoot it!

 

[DCRYDER]

Those 1/2" groups were 3 shot groups.

I've shot a lot of short range benchrest over the last 12 years, so most of my experience is with fast burning powders, never saw this much variance with n133, H322, H4198, or Rl7.

At 58.5 gr H4831 @ 2818 fps there was NO bolt click, no swipe mark, rounded primers (CCI200) and zero cratering. With his loads of 56.9gr H4831sc at 2850-2875 same thing.

I may play with that powder a little more. Got a few pounds of H1000 and Rl23 to tinker with too.

I have a couple buddies with 28 Noslers to whoop up on at the informal 1,000 yd gong matches, just trying to squeak out all the edge I can.

Thanks all

 

[Fred B.]

If you really want to work out a load with your powders on hand, you might want to consider a pressure test first for each powder.
Maximum velocity should be what bullet likes and on the node.
Most times, higher node is not most accurate and forgiving.