What is difference in IMR4831, H4831, H4831SC

[aggiejet]

We were searching for some new powder yesterday, based on recommendations from this forum for 25-06 loads. While we were in the store, we referenced a reloading manual (which we subsequently bought) for Sierra bullets, since we were reloading 117 gr Sierra game kings.

We initially were gonna try the IMR4831 and then noticed in our book there were recipes for H4831 and H4831SC. We really wanted to try the H4831SC because another customer at the powder shelf said it would be simpler to weigh. However, they were out of the "sc" and we settled on the IMR4831 because manual said it gave the best accuracy for the hunting bullet we had.

At the bench, I read somewhere in the manual that when using IMR4831 (and some other powder I can't recall) to weigh every charge, as this powder doesn't work well in a thrower, or something to that effect. I am new to reloading, and we weigh every charge anyway. Especially since we tend to load to 20-60 at a time for now, till we settle in on a load we like.

Besides a little powder education, I would like to get everyone’s opinion on powder throwers. I have a Pacific thrower that is about 30 years old. I am guessing here. My grandpa won this as part of complete reloading set, press and all and never used it and gave it to me in 1992. He had it for a while before that.

Generally, except for the long range shooters, is a thrower "close enough" and what style and brand do you like best? Does anybody have a favorite or recommended reloading manual? What is the difference in the powders referenced above?
Thanks,
Mark

 

[hovercat]

Only you can tell, and you have the equipment to do it. Throw 10+ charges and weigh what the variation is with your powder.
Next step is to decide if that variation is 'good enough' for your standards. Offhand shots at deer or reducing the groundhog population at 500 yards? Plinking or 500 yard match?

Please weigh everything when getting close to max. Personally I make a custom dipper when I have settled on a load, out of an empty case filed to proper volume and a bit of wire soldered on for a handle. But all my loads are low to mid range.

 

[Blue68f100]

The SC is a short cut. Meaning the extruded tubular/stick powder is not as long. These type of powders have never accurately dispensed, ±0.5 gr. The sticks are long enough it will hang the powder rotor as it rotates. So you can actually break the sticks.

I have always used the powder dispenser to get me close then dribble the balance while setting on the scales.

 

[Laphroaig]

Extruded powders with bigger grains, like IMR4831, do not do well in powder measures. The grains tend to get caught in the drum when you throw a charge and often require a violent force to shear the individual grain and throw the charge. The H4831SC, for short cut, has shorter grains to alleviate that problem. In my experience IMR4350 is another one that does not do well in a measure. I don't throw any powders bigger than IMR4895 for that reason.

As for close enough, that is a function of your measure and what your rifle likes. Personally, I think +/- 0.2 grains won't affect practical accuracy in most of my rifles. Your mileage might vary.

Laphroaig

 

[aggiejet]

<<I don't throw any powders bigger than IMR4895 for that reason.>>

This seems to imply that the the bigger the numbers the "bigger" the powder?
Am I reading that right? And why does IMR make a 4831 and Hodgen make a 4831? Are they the same powder, or do they have different properties because they are made by different manufacturers?

Thanks

 

[Lj1941]

IMR 4831 & H 4831 are entirely different powders and are NOT intechangable.

 

[KansasSasquatch]

<<I don't throw any powders bigger than IMR4895 for that reason.>>

This seems to imply that the the bigger the numbers the "bigger" the powder?
Am I reading that right? And why does IMR make a 4831 and Hodgen make a 4831? Are they the same powder, or do they have different properties because they are made by different manufacturers?

Thanks

No, the number doesn't have anything to do with grain size. Hodgdon actually packages both IMR and Hodgdon (and Winchester) powders, they don't make any of them. Hodgdon and IMR used to be completely seperately companies. IMR was making/selling powders while Hodgdon was packaging/labeling other powders. I believe Hodgdon used to "steal" IMR's numbers and put them on powders that were very similar. That's still pretty much the case. Hodgdon and IMR powders may have the same numbers, but they are usually a little different and data should NOT be used interchangeably.

 

[tightgroup tiger]

You can't assume that the higher the number the bigger the sticks.

And why does IMR make a 4831 and Hodgen make a 4831? Are they the same powder, or do they have different properties because they are made by different manufacturers?

The IMR powders are the original Dupont recipes that were imported from Canada, the IMR, Improved Military Rifle, designation was to differentiate those powders from the ones that were made in the US before that.

The H-Series of the same numbers were formulated by Hodgdon, not Dupont, and were a little different formula and the Short cut serious was the same formula as the H-serious but is a shorter length to be less temperature sensitive. The H-serious and the H-serious SC were a more recent development then the IMR serious which started in the early 1970s. None of these interchange directly and your load will have to be reworked with each of them. They are close but not close enough.
Just so you know there are also other powder companies that use the same number designation and they also don't use the same load data as the IMR or H versions of that number.

 

[Jim Watson]

I have a slightly different take on the history of these powders.

DuPont originated the IMR designation many years ago as the Improved Military Rifle powders replaced the MR series. Just that the Canadian manufacture took IMR as their company monicker.

Hodgdon got started in the powder business by selling WW II surplus powders.
They got established with 4895 and Ball C, but there were others in those bunkers, warehouses and railroad cars on sidings.

First sales of surplus DuPont manufactured IMR 4831 (20mm propellant, I believe) were as "4350 Data Powder". 4831 is slower burning than 4350 so you would not get in trouble using 4350 data, but you were not getting the velocity, either. So Hodgdon developed data for the powder on hand and commenced selling it as H4831. Time passed. Surplus stocks of 4831 ran out, so Hodgdon had a reasonable copy manufactured for them to load by the same data. I think their first source was ICI-Nobel in Scotland, now ADI-Thales in Australia. Burn rate of the copy was matched to the surplus.

In the fullness of time, DuPont realized that sales of 4831 were good for Hodgdon so they could be for DuPont, too. So they started selling IMR 4831 at retail instead of just to the Army and OEM manufacturers. Their load data was different and shooters soon found that there was a real difference in the rifles.

Hodgdon said DuPont had changed the specs. DuPont said it was the same as ever, just that Hodgdon's surplus was old and stale. Internet Experts say it was lot variation, Hodgdon's stuff was just a slower lot. Makes no practical difference, the new H4831 is copied after the surplus H4831 and is NOT the same as fresh IMR 4831.

H4831SC is "short cut" for easier volumetric measuring. They say it is "exactly the same" as H4831 otherwise. I think they had to fudge something, changing the granule size is one way of adjusting burn rate. Maybe a little more deterrent on the SC.

People these days demand close control of powder charge weight. If it is not within a tenth of a grain or two, they fear for their accuracy. This led to development of automated powder dispensers for 100% weighed charges. I use one myself.
Hatcher reported that one year the National Match .30-06 ammunition was loaded with a powder giving a 1.7 grain spread instead of one that metered within .6 grain. Scores were higher than ever. Of course the targets are smaller now.

 

[tightgroup tiger]

Jim, there nothing significantly different about your "take" on these powders except that you gave a much more detailed version of it.

Aggiejet, You also asked about our recommendations on measures for rifle powders. You may want to look at the Charge Master or the Hornady Auto Charge dispensers. They work really well for stick powders and are much faster than weighing every charge on a set of scales. I can't stand running stick powder through a hand crank measure.

 

[Aeisir]

The distinction that Mr. Watson alluded to is that IMR was developed at the Experimental Station in Wilmington, DE, and the nearby plant at Carney's Point on the Delaware river (powder development starting in the late 19th century). The Canadian plant in Valleyfield came on line after development and production of IMR powders matured about 70-80 years ago, if I remember correctly.

 

[savanahsdad]

Jim : post 9: nailed it , and yes DuPont 4831 started life as 20mm canon powder , and is a go to powder for 270win , H is a close copy , I now use H-4831sc (have an 8# keg) I read somewhere that the H-4831sc is less temp sensitive also, I used IMR4831 in the orange can for years , back when they still came in cans, in my gun and my Hornady powder thrower , I found that H-4831sc works better for me ,


Powder throwers . I have a friend that had a RCBS he didn't like it and got a Redding and loves it , I got a new Hornady thrower and was loading some 32rem's with RL-7 (stick) and he stopped by , and ask how I liked it , I said give it a try ....... he said he thinks its better that his Redding ? I think he needs to mount his Redding down better,, you will hear, Redding = best .. RCBS=best. Hornady=best, Sinclair ... ect... no mater witch one you go with they need to be mounted down rock solid , for the money I vote Hornady, they run about $80. and I'm getting +/- 0.20 with H4831sc , and RL-7 and better with ball powders , that's less than a 1/4 grain

for long stick stuff like IMR4831 I use a Lyman dps1200.

 

[CarJunkieLS1]

IMR 4831 is the ONLY powder that my .270 Winchester will ever see. As far as loading for your .25-06 you would do well with any powder that you listed. And as already mentioned the data for each powder is NOT interchangeable. And as far as measuring goes IMO weighing each individual charge is the best way to keep your loads as consistent as possible.