Choosing powder...

[jjohnsonElknewbie]

Hey guys, dropped off barrel and dummy round for my 6.5x300WSM at the smith today. I've been running several simuations on Gordon's, and I've narrowed my initial load development powders to the following under a 147 ELDM at 3.094" COL and 24.3" barrel.

• IMR 7828 SSC
  • 68 grains max load
  • 3,178 MV
  • 95.8% load ratio with 100% burn rate
• H4831
  • 67.5 grains max load
  • 3,121 MV
  • 98.1% load ratio with 100% burn rate
• N565
  • 70.5 grains max load
  • 3,196 MV
  • 100.3% load ratio with 100% burn rate

Obviously these are max loads, and I would work up to them (hopefully). Given these choices, do you choose the N565 due to its superior case fill and velocity, or do you go with the IMR 7828 SSC since it's more efficient and just a hair slower? Or do you go with H4831 as a happy middle ground? I don't think a guy can really go wrong here, just looking for any feedback or experience.

Thank you in advance!

 

[TxLite]

Personally I’d choose the N565. It seems like it maximizes the use of the case. If it doesn’t like that I’d try the 4831.

7828 is not temperature stable so I wouldn’t roll with that one if you intend to shoot long range or in varying temps.

 

[Billogna]

I'm assuming these are powders you have on hand?? But if not have you run the numbers with RL23?

 

[jfk69]

I’d go with 565, second choice 4831. Unless you have it, 7828 is unobtanium anywhere. There might be other choices worth investigating too. Ramshot Grand, 560 and H1000 come immediately to mind if you have them. On hand or can get them.

 

[jjohnsonElknewbie]

I'm assuming these are powders you have on hand?? But if not have you run the numbers with RL23?

I don't have any of these in stock, I wanted to finish my research first. I have some H1000 on hand and thought it may be a possibility, but it's too slow. 102%+ fill to get close to these powders in terms of velocity.

I ran with RE-23, and at a 65 grain max, the case fill is only 95.8% with 3118 MV. Slightly slower than H4831, but could be a contender.

 

[jjohnsonElknewbie]

I’d go with 565, second choice 4831. Unless you have it, 7828 is unobtanium anywhere. There might be other choices worth investigating too. Ramshot Grand, 560 and H1000 come immediately to mind if you have them. On hand or can get them.

Ramshot Grand isn't in the Gordon's powder database unfortunately, but according to the burn rate chart, it's slower than H1000. N560 is very close the N565, but is faster burning with a 68 grain max and 96% fill rate for 3152 MV.

I also looked at Retumbo, and it's slower thatn Grand or H1000.

RE25 should be right on burn rate, but it's not in the Gordon's database.

 

[TaperPin]

I tend to avoid anything that is near 100% to avoid powder spilling out of the case neck while tapping to settle everything. I don’t mind compressed loads if needed, they are just more time consuming.

 

[SloppyJ]

I tend to avoid anything that is near 100% to avoid powder spilling out of the case neck while tapping to settle everything. I don’t mind compressed loads if needed, they are just more time consuming.

I believe that the 100% takes into account the bullet seated into the case so its not all the way to the neck. A way to check would be to adjust the OAL and see if the percentages changed.

Either way, some of the 223 loads I run with varget are pretty full. Put your thumb over the top and give it some love to settle it. If your wife has any vibratory uhhh... items, throw one of those on there! apparently a toothbrush works too but that's not as fun.

 

[WeiserBucks]

I have some H1000 on hand and thought it may be a possibility, but it's too slow.

Have you tried H1000, or loaded for a 6.5 WSM? Or just in the planning process?