I used to be a volume man, and certainly am for powder like Vihtavouri N140 etc., but recently went to trying H4831 and then H4831SC in my 270WCF. Loading 55.4 grains under a 140 grain Hornady Interlock to give 2850 fps.

But on trying the "short grain" version I have found that, and it's odd, H4831SC appears to meter LESS WELL in my RCBS Uniflow than H4831 with the normal "long grain"!

I used H4831 and got on fine with it. Then when my tub was empty I thought I'd try H4831SC as I believed that it would meter even better. Was I wrong?

Rarely did I get that "squeak" or "graunch" as I operated the Uniflow with "long grain" H4831, maybe twice or three times out of fifty operations but I get it seven to eight out of ten operations with "short grain" H4831SC.

Such that when my current tub is empty I will abandon the "SC" and either go back to regular "long grain" H4831 or simply revert to Vihtavouri N160 or try Re-22.

Have any others similar observations please?

Case volume should remain high on your list. Many shooters are finding that short cut powders such as 4831 and 7828 create about 4% less internal volume than their long cut counter parts. While burn rates are the same internal case volume and resulting pressures are different.

quote:

I used H4831 and got on fine with it. Then when my tub was empty I thought I'd try H4831SC as I believed that it would meter even better. Was I wrong?

Rarely did I get that "squeak" or "graunch" as I operated the Uniflow with "long grain" H4831, maybe twice or three times out of fifty operations but I get it seven to eight out of ten operations with "short grain" H4831SC.

How much did the different charge weights vary?
The "crunching" doesn`t mean much except the measure is cutting powder. The consistancy is the measure of how closely it throws the charge in weight, not how much powder is caught in the slides.
I`ve found the short cut powders to be at least as accurate, if not a bit more so then the std counter parts (H4350 & H4831). Other short grained powders like BenchMark, R22, ect also seem to be a bit better in reguard of keeping the thrown weights close then long grained powders.

Enfield-

What kind of powder measure are you using? One or two of the measures out there have tension adjustments which sometimes have to be adjusted differently for different size and shape of powder granules, to get their best performance. (One I have in mind is the Lee "Perfect" measure.....)

RCBS Uniflow that I have had for over twenty years. I also find that this powder is bridging. It concerns me that I have this shearing of the grains as, of course, it disrupts the regular and uniform operation of the powder charging process. You can't get a smooth "dump" or return back up. I've had a grain difference on a 55 grain loading. Never had a problem with Viht N140 etc or regular H4831 "long cut". Very odd!

Enfieldspares, I'd say your experience is very odd. I am using the same model RCBS measure as you, and having no problems at all with H4831SC. Definitely strange.
LLS

EnfieldSpares

As you probably know H4831SC is an Australian powder so we use plenty of it along with the short cuts 4350. They are called 2213 and 2209.

I have bridging or hanging up in the measure can be common with these powders. It might be that the granules being similar in length and diameter allows then to "collect" or "bunch up".

My experience has been that it varies quite a lot and so perhaps the weather/climate at the time is an issue.

Mike

Meters great in my Chargemaster 1500 !!!!

All powders meter well in my Lee Dippers!!!

I have also had problems with 4831sc. It does not appear to have any graphite coating on it. It hangs up constantly. I have cleaned and polished my RCBS powder measure and it did not help. The supplier said it came from Australia and they have no control on how it is made. I will weigh every charge until it is used up as I can't trust the charges it throws. I was lucky I caught what it was doing the first time I used it. Results would not have been good if I had fired some of the loads it threw, some of the cases were 1/2 to 3/4 full. Until one overflowed, I did not know the powder had been hanging up in the measure and throwing inconsistant loads. It did give exellent accuracy when I weighed the loads.

Thank you all for your input, especially the posts from SHORTSHOT and WBYPOWER. I think that I am going to go back to regular H4831 if I choose it again. The graphite coating, or lack of, seems to be the problem.