I've allowed myself to get into a running discussion concerning the attributes between BP and smokeless and some of the hows and whys behind reloading for same.
So I would like to hear whether my take on some aspects is correct or flawed.

What they say- magnum primers should be used in loading BP because it is SLOW burning compared to smokeless and it needs the extra heat to make sure it goes off correctly.
What I say- Any primer will set off BP and it isn't slow burning. But it is inefficient and leaves a lot of residue. Magnum primers help burn that leftover residue and may give a bit of boost to the load. 
And after all, magnum primers were designed for modern magnum cartridges with slow burning SMOKELESS powders, not BP cartridges.

What they say- Smokeless powders burn faster than BP and that is why they generate more pressure and need heavier chambers than BP guns.
What I say- Smokeless generates more pressure by nature of it's chemical makeup, not just by it's burn rate alone.My impression is that smokeless can generate  3 times or more pressure as BP on a volume for volume basis.
So, am I close to being on target ??

BP is very easy to light, if you've ever shot a flintlock, you'll know that. The slightest sprark and it's gone. I shot slug guns for a few years (only straight black is allowed) and they all used SP primers. Slug gunners by nature are experimentors and the only primers that they would use, where 1 1/2 Remingtons (that was in the days that you could get ANY primer at your local store), Remington pistol are some of the weakest but, fully reliable primers you can get. I don't think that even today that cartridge rifles can beat the old slug gun scores at <220 yards.

Regarding volume for volume, I think you can get even higher pressures if your including pistol powder in that. Many of the ball powders have about the same density as BP (16 gr per cc) but, a powder like Titegroup, I think would go much higher than 3 - 1 using the same volume. I do think that 3 - 1 would work with H110/4227 types.

Frank

Those that are having powder pushed out the barrel may be because their:

1. Barrels are too short.
2. Packing too much powder in the case to burn in the barrel.
3. Using coarse powder which will not completely burn in the barrel.

I have switched to FFFg powder and I use R.P. 9 1/2M primers and I get excellent ignition; with only ash and smoke coming out of my barrel, and no burning embers in front of my bench.

With the fine powder and magnum primers I get complete combustion, and no unburned carbon causing fouling in my 30  inch barrels.

Primers are more about combustion, rather than ignition. And having unburned powder coming out of your barrel may be due to other factors.

By using finer BP I get increased velocities without adding additional powder that can contribute to increased fouling.

So I use the hottest and longest flash primers to ensure all of the powder is completely combusted to a fine ash before it exits the barrel.

craigster wrote on Mar 1^st, 2015 at 11:27pm:

Technically I must disagree. There is no supersonic Wave associated with BP combustion So it deflagrates Which is the most convoluted over used way of saying it burns by ordinary means

Technically I must disagree as well.

IMR's packaging:

DANGER EXTREMELY FLAMMABLE*

*Smokeless powder for small arms is not an explosive regulated by Federal Explosive Law, but may explode if misused.

craigster wrote on Mar 2^nd, 2015 at 1:01am:

It does not matter what is printed on the label of the IMR can or the loaf of wonder bread.

Black powder only requires a spark to get up to its full flame speed. Smokeless requires a secondary component to act as a detonator to get up to full flame speed.

That is the ONLY reason why there is different transport and storage regulations. They are both ordinary combustibles.

Black powder stinks.

And two stroke engines stink as well.
The question is how do they perform best.

Schuetzendave wrote on Mar 2^nd, 2015 at 8:50am:


If your two stroke stinks, your not usin' castor based oil in it