Lil' Gun powder in a 357 Maximum?

[kingrj]

Kingrj: I think you are trying to compare the behavior of an ideal gas to something completely different; the production of a volume of gas by a chemical reaction - combustion. Just because similar weights of 2 different materials produce the same volume of gas during combustion does not mean that the heat of combustion is equal. As a matter of fact it would be rare that they were equal.

Whisler I agree with you...combustion gasses are not ideal gasses but if, as you mentioned, 2 different materials produce the same relative volume (number of moles) of gas the heat of combustion AND the temp of that gas does NOT have to be the same..Unless you generate the same pressure curve and velocity for a given barrel length and bullet. If the moles of gas produced is the same and the performance of the load is the same then the temperatures of the gasses generated HAVE to be pretty much the same. What am I missing? Is there a chemical engineer in the house? I am an electrical engineer so I don't really know diddly about the bonding energy of nitrocellulose and nitroglycerin but this is a very intersting problem.

[whisler]

I am a chemist. Admittedly an old retired chemist and my field of expertise was not fuel technology, but I still remember some of my chemistry.
The volume of gas produced does not indicate the number of moles because we are not talking about a homogeneous gas.(the term moles can apply to atoms or molecules or...)The volume of gas may be the same but the chemical composition of the gases themselves do not have to be the same and are dependent on the original composition of the material. We don't know the composition of the 2 materials in question or the differences in the gases produced.
And again I will state that the heat of combustion of the 2 different materials can be different and still produce the same volume of "gases" (not "gas" singular because it will not be homogeneous nor identical between the 2). If we were only heating up a gas to cause expansion, then an equal amount of expansion would imply an equal amount of heat applied to a given volume of the gas. But as I said we are not heating up an ideal gas but are generating a mixture of gases by combustion. Also we don't know how fast the peak pressure is generated which could also be a factor in the gun heating up.
I hope this helps.

[kingrj]

I am a chemist. Admittedly an old retired chemist and my field of expertise was not fuel technology, but I still remember some of my chemistry.
The volume of gas produced does not indicate the number of moles because we are not talking about a homogeneous gas.(the term moles can apply to atoms or molecules or...)The volume of gas may be the same but the chemical composition of the gases themselves do not have to be the same and are dependent on the original composition of the material. We don't know the composition of the 2 materials in question or the differences in the gases produced.
And again I will state that the heat of combustion of the 2 different materials can be different and still produce the same volume of "gases" (not "gas" singular because it will not be homogeneous nor identical between the 2). If we were only heating up a gas to cause expansion, then an equal amount of expansion would imply an equal amount of heat applied to a given volume of the gas. But as I said we are not heating up an ideal gas but are generating a mixture of gases by combustion. Also we don't know how fast the peak pressure is generated which could also be a factor in the gun heating up.
I hope this helps.

Thanks Whisler! As an EE I never took anything past chemistry 01 in college so I got a lot to learn! I also thought about the fact that even if you start with equal charge weights of Lil'gun and H110 and the Lil'gun charge does NOT burn as completely as the H110 then to produce the same pressures the Lil'gun charge HAS to burn hotter..I should have thought about that sooner before I shot my mouth off!

[Ramson222]

I have shot about a 1k rounds of 300 blackout loaded with 15grs of lilgun and a cast 155gr bullet. My 10.5 inch barrel still shoots into one ragged 1/2" hole at 50yrds when I use a 150gr Speer bullet. I dont wait much in between shot either.

[Newtire]

It is HOT burning, 12 shots from a .357 made the barrel so hot it could not be touched. The rest of mine will be for the 410. Freedom will not honor the warranty if you use it. It will erode steel.

Might come in handy to warm up a shelter in a survival situation then?👹🥴. Actually, found it to be pretty useful in .357 mag. in a Rossi rifle I have. I'll check out the hot barrel thing tomorrow but so far, haven't noticed it. I'll pay close attention and bring my thermometer to check it against some other powders.

[technojock]

Before I had my 77-.22 Hornet rebarreled, I found that it would get more than twice as hot from a 3 shot group with Lil'Gun as with 2400 or 4227. I traded off all the Lil'Gun I had and I won't consider buying more...

Tony

[Newtire]

Here's what I got using after firing 10 shots .45 colt 265 gr. cast P/C bullet 19.2 gr. Lil' Gun, out of my thin barreled .454 Casull Rossi carbine. Just ahead of the chamber area said 75 degrees F. At the muzzle it was 88 degrees F. Ruger gp100 .357, 12 shots of 17.5 gr. Lil' Gun and cast P/C160 gr. Barrel was just warm. Same thing with 16 gr. 296. Don't know what to say, that's what I got.

[AlaskaMike]

Here's what I got using after firing 10 shots .45 colt 265 gr. cast P/C bullet 19.2 gr. Lil' Gun, out of my thin barreled .454 Casull Rossi carbine. Just ahead of the chamber area said 75 degrees F. At the muzzle it was 88 degrees F. Ruger gp100 .357, 12 shots of 17.5 gr. Lil' Gun and cast P/C160 gr. Barrel was just warm. Same thing with 16 gr. 296. Don't know what to say, that's what I got.

Good to see this testing--thanks Newtire.

I'm one of those whose personal experience was that my .44 mag Rossi 92 carbine barrel heated up disurbingly, and I won't use Lil' Gun for anything.

However, your testing of your lot of Lil' Gun and 296 back to back, and showing no noticeable difference temperature-wise really makes me wonder if the formulation for Lil' Gun has changed at some point. My pound of Lil' Gun is probably over 15 years old now, and I'm assuming yours may be much newer than that.

Just one thought on what might explain the difference.

[Newtire]

Good to see this testing--thanks Newtire.

I'm one of those whose personal experience was that my .44 mag Rossi 92 carbine barrel heated up disurbingly, and I won't use Lil' Gun for anything.

However, your testing of your lot of Lil' Gun and 296 back to back, and showing no noticeable difference temperature-wise really makes me wonder if the formulation for Lil' Gun has changed at some point. My pound of Lil' Gun is probably over 15 years old now, and I'm assuming yours may be much newer than that.

Just one thought on what might explain the difference.

That may well be since the Lil' Gun I have is no older than 5 years.