IMR7828 SSC and 243

IMR 7828 SSC -243Win.

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Should work ok. The starting load of 42.5 gr listed for the 100gr bullet might be to light when used with the 85gr.? But should still get the bullet out of the barrel. Hodgdon lists maximum loads as "C" compressed with standard IMR 7828. With IMR 7828 SSC you should get enough pressure/powder in the case to expand the neck fully on firing.

IMR 7828 SSC -This magnum rifle powder has exactly the same burn rate as standard IMR 7828 and uses the same data. However, due to the super short kernels, metering is virtually as good as a spherical powder. This allows up to 4% more powder space in the case and in many loads yields more velocity than standard 7828. Such loads are marked with an asterisk in the data to show where standard 7828 will not fit.

Click to expand...

If the pressure is to low, this is the worst that can happen. The neck will not expand. IMO. [/URL][/IMG]

I can't imagine it would be dangerous. Probably isn't listed because even when you get to a compressed load it's not up to max efficient pressure yet for the light bullet.

I'm curious to hear your thoughts about the 7828 SSC. Just last night I shot the best groups I have ever shot out of my .270 WSM using the regular old 7828. I got about 3/4 lb of it for $5 from a friend who hated the way it metered and didn't like the performance in his 30-06. This was my first effort at trying it and sure enough it has to be the worst powder I have ever tried to meter in my Lyman 55 powder measure. I can live with inconsistent charge throws since I trickle everything up to weight anyway. But this stuff would bridge the drop tube 3-4 times with each throw. It meant constant tapping to get it down the tube. I was almost disappointed when I saw the outstanding groups it shot. I guess I'll put up with the lousy metering, maybe try to scoop it out next time. But if the SSC version actually shoots as well, maybe that's a better option to try once I use this up. But I have to say that I tried H-4831 SC once and it didn't shoot anything like the regular ole H-4831 so I'm leery about the short cut stuff.

I use IMR 7828 with 100 grain bullets with good success ... never tried it with lighter bullets... I usually use RL 19 for anything under 100 grains.... RL 17 data shows some really good numbers ... but I've never used it either.

Jimmy K

I have tried the 85 grn. barns TSX with IMR 7828 in both short and long configurations, It was over 1MOA, The 7828 is superb for 95 and 100 grn bullets but not so good with lighter weight pills, If you want a good metering powder try H4831 SC it does well in the 85grn TSX, but R-19 or IMR4350 works the best with the 85 grn TSX bullets in my .243's. But every gun has it's own like's and dislike's, good luck!

How long is the barrel? That has a bit to do with psi. Bullet crimp/neck tension also affects the load along with jamming the bullet into the lands.
Might have to go with a mag primer and 85% to get any velocity; shooting at dusk will let you know about how much powder is leaving unburnt.
My best accuracy load from a model 700 in 7STW and 150 & up bullets was with H7828, ditto for a model 700- 7RUM I was about to re-barrel...before I tried the H7828.
Just asking, but are you stuck with that H7828? HAVE to use it??
So many better powder choices- economically and performance wise.

Another question I have regarding the 7828 is whether most of you are using standard primers or magnum? As mentioned above, I shot the best groups ever out of my .270 WSM the other night. I had a 3 shot group of 0.6" and the 5 shot group with that powder weight was 0.9". So last night I decided to load up some more of that recipe, using a smaller powder weight change to confirm the sweet spot. I was double checking to make sure I was using the same cases and seating depths as before when I noticed I had written down that I had used CCI Large Rifle primers. I had that written down both in my logbook and on the label on the box. I couldn't believe I would have used standard primers for such a slow powder, but there it was. I had loaded those rounds 6 weeks ago and didn't shoot them until now. The only thing I can think of is that one of my manuals, the Speer lists that powder and bullet wt and they don't indicate a magnum primer.

By the way, I did solve my powder measure metering problems with this powder last night. As mentioned, when I used it before it was with my Lyman 55 measure and had an awful time with it bridging in the drop tube. Then I remembered playing around with my old retired Lee Perfect Powder Measure awhile back with the really long stick powders. I hadn't thrown any charges to measure them, I didn't even have it mounted to the table anymore. I just remembered that at least the sticks didn't bridge during the drop. I remounted the old Lee and dialed it in, hoping just to get within a couple grains of my target weight and then trickle it in. Hmmm... the dang thing not only didn't bridge, but it threw consistent weights to within 0.1 or 0.2 gr for 20 straight drops. Half the throws didn't even make me trickle any powder at all to get right on the money.

I can't remember now why I retired the old Lee Perfect Powder measure. I guess because the Lyman was considered a classier piece of equipment. Now they are both mounted on the table side by side.

I have used large rifle primers in my 7mm Rem Mag and have had great results. The large rifle primers will light a good sized load. I think the mag primers are just a little hotter in duration than the standard large rifle. I'm sure someone has the specs of each, but that said I know the mag primer is better for very cold conditions.

IMR 7828 does not need a magnum primer unless you're using large case round with over 70gr of the powder.
I really don't understand why you're having problems with your #55 measure dropping long grain powder, if you're using it properly. Consistent use of the knocker is the key to dropping repeatable charges, along with staggering the sliders properly.
The #55 Lyman is the most consistent measure that I have ever used in my nearly 50 years of reloading. It will throw all powders that I have +- .1gr.

There are much better powder choices than IMR 7828 in the 243 with medium weight bullets, that the OP was questioning.


NCsmitty