IMR 7828 vs IMR 7828 ssc

[grizzly340]

I was testing  my 340 wby. Last summer with the 250 gr. Nosler Partitions 5 rounds loaded with 87 5 grs. Of RL 25 velocity. Of 2816 vs 5 rounds loaded with 86 grs. Of IMR 7828 ssc. Velocity of 2965 I have loaded 86 grs of just IMR 7828 many times. But when I used the ssc My cases were sticking and the 3rd round was stuck.  And that was all for the test.
From what I read the burn rate is the same. And that should not have happened.
Anybody else notice hotter loads when using ssc powder ?

[JWDynamics]

I'm pretty sure I've used both IMR 7828 variants in my 7mm Rem Mag. Using the same charge in weight I observed no differences.

[Grouchy]

Does temp come into the picture?

[grizzly340]

I wondered about that Kevin it was Mid August when the case stuck. I normally write down the temp. But didn't that day. I also normally shoot on cool days. But I remember zonie saying you should mix it up so you know what you got at different Temps. I will pull the last 2 bullets and re weight the charge and make sure it is 86 grs.

[Dino82520]

I don't have a 340 but I do shoot 7828 in my .300 Wby. I now use 7827SSC since it seems to flow better through my Lyman Gen 6. The smaller grains also flow better through the funnel when charging cases. I haven't noticed any difference in velocities or pressure signs.

[kmoore]

 I load/loaded the older 7828 in .338 RUM and had ran out several years ago. When switched to 7828SSC I used the same loads in the 338 and have not had a problem. I have loaded bullets in the 185gr, 210 and 250.
In 7mm wby, I have only used 7828SSC. Without going into which loading books and charges. I was firing bullets in 150 and 160 gr. I had loaded/fired about a hundred plus before firing in outside temps near 110-115f. the first 2 rounds had hard extraction. The third round cracked the stock and blew the floor plate open. I spend a lot of time trying to figure out why. The load was under max in the book I used but over another. The brass had been reloaded about 6 times. It split just above the belt. It was an overpressure load but why? wore out brass, outside air too hot, chamber to hot? I backed off the charge and no other problems since.         

[grizzly340]

Same Here Kmoore
I have been all through my 340 targets. Have shot 86 grains many times.  Up to 55°
But I don't think I want to try it again any warmer than that. I have targets that say my velocity is at 2938 with 85 grains . That's fast enough. In fact very close to Weatherby factory loads.
I think I will try that load in the summer to make sure it works and call it good.

[kmoore]

And don't do like I did. I know better but I did it. Round one that day had hard bolt opening. I did not look over the case/primer. 2nd round a minute or so later same problem. I should have just stopped shooting all together. But no, I fired again. I felt lucky I only needed a new stock.   

[grizzly340]

Me too. I was just luckier than you. Only had a stuck case. I'm going to stick with 85 grs of 7828ssc but I have a hole box loaded with 86 grs of std 7828 I will keep shooting those unless they show any sign of pressure.

[PARA45]

I've only used 7828 ssc on my 300 Weatherby, and what I got was very consistent velocity.  I didn't push too far at all; I stopped when I was getting 1/2-3/4" groups. 

[Grouchy]

I had to look. I have used both in 270 and 300WBY. I saw no difference, but my temps typically only swing 25 degrees from hot to hotter.    86 right now! 

[zoniezonie]

If you are working up loads at or near maximum,  IMO it's best to load and test in the summer time when it's hot out, that way when hunting in winter temps you shouldn't be over charged VS the other way around i.e load and test in the dead of winter or very cold conditions and then run into over pressure loads come summer or hot weather,  probably a little more important for me living in Arizona in hot weather.  Always use published/tested load data from manufacturers and correctly work up loads.  When I started we didn't have short cut powders so my test loads were based on regular powders normally it was H-4831 and IMR-7828 of the powders that later introduced the short cut versions.  I do think there is a difference between the short cut's and regular powders when you are at max loads. I have stuck bolts  with both types.  Keep things simple and after you find a good load stick with it.  reloading 101 if you change ANY components even seating depths back your powder charges off appropriately just to be safe.  Use brass  and the ammo you re-loaded  specific to each gun you have in the same caliber, more so with high pressure cartridges including pistol calibers.  To be honest I rarely buy short cut powders if I can help it, but in todays climate beggers can't be choosers and buy what you can find that's suitable.  Accuracy to me is far more important than shear velocities.  I try to pick powders based on highest published velocities with lowest pressures and start from there and if that doesn't pan out try a different powder or bullets.  I'm not sold on any one type of powder,   stick vs ball vs flake ,  single or double based.  one of my favorite powders is a ball powder TAC in AR's with Wolf primers dead nuts accurate .  Good luck finding Wolf primers today. 

[grizzly340]

I'm glad you brought that up before Zonie.
And that's why I was shooting in August.  I doubt I will ever use that rifle in summer Temps. But you never know. Last year for my son's bear hunt in Sept. It was over 70 ° every day in Northern MI

[grizzly340]

I did a 3 shot test today in 50° MI February weather. 85 grs. 7828 ssc vs 86 grs. 7828 with 250 gr. Partitions.  The 85 grs of ssc were 40 fps faster than the 86 grs. Of 7828
7828ssc was 2895 avg.
7828 was 2855 avg.
So that proves it to me 7828 ssc is Faster/Hotter
Note : that load Kicks.

[Grouchy]

No pressure signs?