Spherical powder mystery

[Kachok]

OK I have been racking my brain over this one for some time and cannot dream up anything close to a rational answer. I load for 11 different cartridges I am not new to this but when loading for my 7mm-08 I was frustrated to no end because all of the powders that were supposed to work great for it shoot horribly with ever bullet and every charge. I had never given up on a rifle before but I was damn close. Well to make a very long story short I finally found two powders that did not just work well, they worked well across the board, like hitting a light switch all the sudden I went from groups that I am too embarrassed to share (when I could keep it on the paper) to drilling 1/2" groups and even a few lucky one hole groups and doing it in every bullet weight. The two powders that worked were H380 and Big Game they have one thing in common they both are very smooth spherical powders, now I don't recall anything in any manual about the texture of a powder making any difference in accuracy but the difference was so stark that is has me guessing, I know they are both close in burn rate but so are RL15 and 4350. Does anyone know why both spherical powders I tried could behave so differently then the extruded powders? Oh and before someone says anything about metering I was weighting every charge. I don't think it makes any difference with 4350ish burn rates but I was using standard CCI primers I don't normally use magnum primers until I hit RL22/H1000 burn rates which are way too slow for a 7mm-08.

 

[119er]

Intersting. Are you individually weighing charges or throwing them. It seems that the spherical powders would measure more consistently. In my 7mm-08 I've had good luck with both types. 39.5 RL-15 under a 150 SMK makes bug holes for me although the velocity is about 150fps below what I'd like. I was reading your other post about H380 and Big Game and will be giving them a try. Did you try Win 760? It is spherical or flattened ball. I think a while back I had a good load worked up with that and 154gr BTSP's.

I can't see how the propellant shape alone could make any difference, especially across other calibers and rifles. If throwing charges, check for bridging or incosistent drops. I'm as stumped as you are.

 

[Kachok]

Yes I weighed every charge, and I did try H414 (same thing as 760) but the flattened spherical powder did not have the magic like the super round/smooth powders, though it did shoot better then the 4350 in some weights,

 

[Fire_Moose]

From my reading, people seem to concur that spherical powders don't burn as well as extruded.

Magnum primers make sense to ignite spherical better but I'm not really sure.

Sent from my CZ85 Combat

 

[savanahsdad]

Yes I weighed every charge, and I did try H414 (same thing as 760) but the flattened spherical powder did not have the magic like the super round/smooth powders, though it did shoot better then the 4350 in some weights,

humm.... I use H414 in my 7mm-08 and have for years , I also use H380 in my 7mm-08 , 1/2 to 3/4 MOA with both, H414 for Sierra 140gr spitzer BT and H380 for 150 Sierra HPBT

 

[DanTheFarmer]

I've had my best luck with spherical powders too.

I've worked up some good loads for my 7mm-08 with BL-C(2), Hunter, and H414. I usually use standard primers but for the 130 Speer Hot-Cor and H414 the load recommends a magnum primer so I used them. I've got loads worked up for 120, 130, and 154 gr bullets.

I've finally gotten some good results with stick powders. IMR4064 with Sierra 140 Pro-Hunters and H4350 with Hornady IL 139 gr. Both of these had good results on one load on one trip to the range so will require verification. RL19 hasn't worked well for me at all and I was really trying the IMR4064 and H4350 to use them up because they had behaved so poorly.

Your observation is interesting. My results with stick powders have been many lousy accuracy with slow speed loads to finally discovering a couple of promising ones. With ball powders my results have ranged from a few fair accuracy and speed loads to many good ones.

I can't claim my results are rigorously scientific but they do seem to fall in line with yours.

Good luck and I'll keep everyone posted as to further results.

Dan

 

[243winxb]

. Another example of this is the 308 Winchester loaded with the ball powder. Here the pressure drops from a high of 64,800 psi to 62,700 psi, a change of 2,100 psi. The velocity drops from 2639 fps to 2637 fps, or only 2 fps.

See - "From The Lab" http://www.barnesbullets.com/resources/newsletters/september-2007-barnes-bullet-n/

 

[ADKWOODSMAN]

Had a friend drop by with his buddy and they were having problems with the 7mm-08. We did some handloading and testing and after a few trails they went away happy.

About 20 years back I purchased my first 7mm-08 and it took a few different loads to make it reach it potential. Now I am using 154 Hornady sp's with Winchester Western 748. Great combination. I also found good results with combined technology 140's and IMR 4895. These loads are for big Adirondack deer and bear. My two cents

 

[Lj1941]

Winchester 760 works fine business for me with 145 Speer SPBT as does Reloader 19. Both also work fine with 139 Hornardy and 140 Nosler BT. IMR 4350 ,IMR 4895 & IMR 4064 never really made it in my Remington 788 carbine.:banghead: