What difference does powder brand make, really? Look here...

[Ian]

Take a look at these QuickLOAD predictions for .38 Special, with three different powders, with charge weights adjusted to achieve similar PEAK pressures, at around 80% of maximum allowable peak pressure.

Note that on one particular relative burn rate chart, Bullseye is listed as #10 and Clays occupies the #31 slot, while Titegroup sits at #26. Does that jive with this? I think not.


Less than 98% of the Bullseye burned in a 5" barrel, and it has a muzzle pressure of 3710 psi.

Clays is all done in the first inch, with only 1988 psi muzzle pressure. Bet it will be quieter!


Now Titegroup is all burned in around 2.3", with a muzzle pressure of 2637 psi.

Interesting, and this explains to me why Bullseye has always been loud and dirty in a .38 revolver.

Also note that Pmax is reached in less than half an inch of bullet travel, while the base band of the bullet is still in the cylinder throat.

 

[Brad]

Burn rate charts are very relative. All depends on the exact load to see where powders are relative to each other.
I would definitely say Clays reaches peak pressure faster than Bullseye. It is very fast, far more so than Bullseye. I have used a fair bit in 45 ACP but never pushed it very hard, not a good powder for that.

Interesting to see how Titegroup compares.

 

[Ian]

I noticed a similar trend with Unique and Universal in both .45 ACP and .45 Colt. With the ACP Alliant powder would still be burning at the end of a 16" barrel, while the virtual Hodgdon equivalent was done in four inches if loaded to same peak pressure. The Unique made a lot more velocity per grain, as one might intuit. This explains, if nothing else, the common perception that Universal is much "cleaner burning" than Unique in similar applications.

In the interest of getting the most out of my silencers, I've been paying special attention to powder burn percentages and muzzle pressure when selecting powder for load development. If I had bought QL years ago it would have saved me many hundreds of dollars in components, range fees, etc.

 

[freebullet]

Mmmmm, loves some titegroup.

Quickload sure seems like a handy program. I've been putting off buying it because, I have no time & dislike computers immensely.

 

[RicinYakima]

Ian,

Interesting. What difference does it make if you use a heavier bullet? Such as the Lyman 358430 195 grain? Does it change the relationship for your suppressors?

Ric

 

[Ian]

Heavier bullet only burned .6% more of the Bullseye at same pressure (14,560psi), so it did make a difference in the right direction, but a small one. For the same 5" barrel, peak pressure had to be pushed to around 22,000 psi before 100% burn was achieved, regardless of bullet mass.

 

[RicinYakima]

Amazing! Lyman lists 3.3 grains at 15,000+ psi. You would think that 4.8 grains would be more from quickload.

 

[Ian]

Bullseye is very strange in the QL program. I keep finding that it calls for a lot more of it than any of the loading manuals for similar velocities and pressures. Even .45 Colt shows a lot more BE than the manuals would advise, even Speer #11 which seems to put their max charge weights comparatively very high with Alliant pistol/shotgun powders.

 

[KHornet]

Believe I will stay with the manuals for load recommendations. The publishers have a lot more time
and money than me to test. That's just me however, and I don't load max loads anyhow.

 

[Rick]

Yep, same here and not to mention trained ballisticians. I don't have QL because I have seen so much from that program that is real eyebrow raisers. It absolutely is not gospel on any loads, it may be an additional source of info to have a look at but in the end I'll stick with proven safe and tested load info. I've done a lot of wildcat loading and working up loads for which there is no published data, perhaps QL could be something to look at there. Cautiously.
/

 

[Ian]

QL is not intended as a replacement for published, pressure-tested load data, never said it was. However, it can show you some interesting trends with powders and what happens when you change this or that, and is certainly a very useful tool.

For example, take the 80% max load with Clays above, and seat the bullet just .050" deeper, and it goes over pressure. How may times have people taken a Lee bullet for which there is no published data and used data for a "similar" bullet that maybe is set a little deeper, or has a little more or less bearing surface, and unknowingly gone +P?

That said, I've been amazed repeatedly by how close the predictions come to real-life muzzle velocities. The only thing that I've found to throw it off are gas systems and revolver cylinder gaps. If you have a locked breech and no leaks in the barrel, the data comes very close. If you know what you're doing, and I don't, you can change the values of bullet engraving force and a host of other things to make the predictions even more accurate. What it CANNOT predict is how well a given load will actually shoot.

 

[RicinYakima]

Right on, Ian. It is a very useful tool, but like all others, you have to know what it can and can't do. One gentleman sent me QL data he generated for the .30 Johnson wildcat, that was amazingly accurate with 3 powders. But not so much with another one that was double based, as it seemed to not follow the programs with varying seating depths of different weight bullets.

 

[quicksylver]

Yes...QL is an interesting tool...I personally wouldn't use it to develop a load...but rather to investigate the "WHY"..why something does or doesn't work well..or has some particular characteristic..

Like all tools it is a part of a whole..the whole being a Tool Box...

I am still of the old school...I read the target..it tells me pretty much what I need to know..as to what a particular bullet , powder or combination is doing...IN A PARTICULAR GUN...

Too many times I have seen things work that should not according to all engineering evidence and things that should, don't.....

Most of the time I prefer to just try something...it seems quicker...

Playing with QL seems like it would be a lot of fun....I prefer to spend my time shooting....casting or prepping cases..

Don't get me wrong ...I really appreciate the fact that there are people out there who "Just have to know WHY".....

Me ...I just want to know WHAT works..

Now back to my concentrating on sight picture , breathing and trigger control.....

BTW...thanks for the info Ian....two thumbs up!!..

Dan

 

[Pistolero]

I won an 8 lb jug of Clays a while back and so far only use it in std .38 Spl plinking loads. 3 gr of
Clays under a 158 commercial SWC is good for friends who want to just try it out. Seems like no point
in worrying about great hand cast bullets and super loads when most of them are beginners and will
not be able to detect any difference. About 16-17,000 loads left in the jug at that rate.

I looked at using Clays for .45 ACP, which I shoot the most of pistols, and did not like the ultra fast and
peaky nature that is clear from reading the loading books. You cannot make std full power with a 230 gr
bullet with Clays and stay inside SAAMI pressure limits. OK with 185 and 200. It does burn very cleanly,
if the cases were tumbled and shiny inside before, they are fairly shiny inside after shooting, not true
with BE or TG.

I need to buy some BE, have been out for years after decades of using it, replaced it with TG for .45 ACP.
I need to see if BE does better for match loads than TG does, seems like I got some better loads way back
when - but then again, my eyes were better then, too.

Bill