Reloader 26/Short Barrels

[Mike Matteson]

It has nothing to do with individual cases and #lots of powder.
What it means is the powder burn rate is not CONSTANT across cartridges or even bore sizes.
Burn rate charts are a joke and not accurate in any way, they are a very rough guide as to what MAY be similar.
Anyway, this is well documented in many reloading manuals and powder sources.
For example, in straight wall cartridges, or those with minimal shoulder, such as H&H or 375 Weatherby, slow powders do not behave as they should, so a faster powder then behaves like a slow powder giving correct performance because the burn rate has changed due to the case shape. Example, H4350 replaces H4831 and gives far higher velocities in almost straight walled cases.

Cheers.

I see where you are coming from now. Thanks! I read about it sometimes. I didn't fully understand either. Learning and I will remember!

 

[AZ82New]

I am running Alpha SRP.in my 24", and Alpha LRP in my 20". I wanted to see if there was any difference between the SRP and LRP brass. So far, I haven't seen any difference in performance. We will see if the primer pockets stand up in the LRP as well as the SRP brass.

Yeah I was going to call bull on those velocity numbers (my 24 inch 6.5x284 runs 140's at your 20 inch velocities) but then I saw that you're using Alpha brass.

I'm running 212's out of a 20 inch 308 at 2,525 fps using Varget with srp 308 Alpha brass. Yeah, it's right on the edge of pressure but I've put 200 rounds down the tube on that load and never had an issue.

Alpha is just different stuff.

 

[AZ82New]

I would be interested to see velo in a 24" tube with that load, and the crazy thing is it also would probably be different in every 24" tube you sent one down. Love StaBall 6.5, I run it in a CM and 22-250 and it is lights out with both rifles.

I did dude, read the post further.

 

[lancetkenyon]

Yeah I was going to call bull on those velocity numbers (my 24 inch 6.5x284 runs 140's at your 20 inch velocities) but then I saw that you're using Alpha brass.

I'm running 212's out of a 20 inch 308 at 2,525 fps using Varget with srp 308 Alpha brass. Yeah, it's right on the edge of pressure but I've put 200 rounds down the tube on that load and never had an issue.

Alpha is just different stuff.

 

[AZ82New]

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Yep, I don't doubt you one bit.

Alpha is the best stuff you can buy. Period.

I have 600 pieces of 6.5 creedmoor I haven't built a light-ish weight hunting rifle for yet.