Hodgdon Lil Gun

[Teuthis]

Does someone have experience with this powder in 357 Magnum? It is new to me; and the pressure data I saw on the Hodgdon site for 158 grain jacketed bullets seems almost anomylous, in that the pressures are so much lower than surrounding powders for similar velocities.

Here is the excerpt from the site loading guide.


GR. HDY XTP Hodgdon Lil'Gun .357" 1.580" 16.0 1504 24,100 CUP 18.0 1577 25,800 CUP

I never load at max velocities but I do approach them at times. This data alsmost seems too good to be true.

[L_Killkenny]

I tried it last year. I didn't load max but close in a couple of loads. Worked fine but I didn't get the accuracy I get with Blue Dot.

[Prince55]

I've been wondering about it also and posted a question about it a
few days ago.
I've tried it in the .357 and got really good accuracy out of some
2,3, and 4 inch barrels with pretty hot loads.
It also gave Great performance in two .41 Magnum Ruger Blackhawks.
I couldn't believe how much lower the pressures listed were.
After you get to the .44 Magnum & .45 L. Colt loadings the pressure
seems to become about even with W 296.
Looks like it could be a Great powder in some handgun loadings.

[Stumper]

A number of people have praised li'l gun in carbines while complaining about it in their revolvers. My own experience suggests that high bullet pull is essential to get consistent high velocities in revolvers. If cases and crimps are TIGHT it gives amazing velocities at safe pressures. Are the pressures I'm getting the same as those published.... I dunno.

[SL1]

The Hodgdon pressure data for Lil’Gun in the .357 Magnum with the Hornady 158 grain XTP bullet has attracted a lot or attention and generated a lot of questions, but resulted in few answers.

I called Hodgdon’s some time ago, but only got statements like:
“Lil’gun powder has a pressure advantage over H-110 because it has 20 more years of powder technology development behind it.” And “The 18.0 grains filled the case, so we could not increase the charge to SAAMI max pressure to get even more velocity, because it is not good to compress spherical powders.”
From that, I could only take away the message that Lil’Gun should not be compressed. (I note that Accurate publishes compressed loads for ITS spherical powders, but I am not going to use that to argue that Lil’Gun can be safely compressed.)

Looking at other data in Hodgdon’s same manual, it appears that Lil’Gun loses its advantage over H-110 as the cases get wider and the bullets get heavier. That tends to suggest that Lil’Gun doesn’t completely ignite as fast as H-110 in that particular bullet and case combination, resulting in a lower and broader pressure curve.

Strangely, the QuickLOAD program does NOT show Lil’Gun behaving that way. That may well be due to the fact that the program ASSUMES that the powder is fully ignited. When making comparisons between QuickLOAD and Hodgdon’s data, it is important to recognize that the pressure data are in CUP, but QuickLOAD only works in PSI. However, the velocity data are for a 10” unvented test barrel rather than an actual revolver (like most manuals use for their velocity data), so Hodgdon’s velocities are unrealistic for revolvers, but easy to compare with QuickLOAD results, because QuickLOAD cannot simulate the barrel-to-cylinder gap.

I adjusted QuickLOAD to produce 100% filling of the powder space with the load shown for H-110 in the Hodgdon manual. This resulted in a velocity of 1583 fps with a pressure of 32,771 psi. Since the Hodgdon data gives a velocity of 1591 fps, I consider that to be in excellent agreement.

I then changed only the powder and charge weight to use 18.0 grains of Lil’gun. The QuickLOAD results were that this load IS compressed (111.2% of available capacity) and the velocity was 1820 fps with a pressure of 45,503 psi. MUCH HIGHER PRESSURE THAN THE MANUAL. To get a full case with no compression, I adjusted the Lil’Gun charge weight down to 16.2 grains, and got 1607 fps with a pressure of 30,706 psi. That looks close to Hodgdon’s “Start” charge of 16.0 grains, but still has more velocity and pressure than the Hodgdon data. So, I tried Hodgdon’s “start” data and QuickLOAD gave 1584 psi with 29,436 psi. Hodgdon’s data show the velocity as only 1504 fps for their start load, so there is still not good agreement.

I noticed that the “Propellant Solid Density” value in QuickLOAD was 1.570 grams per cubic centimeter, and that a typo from 1.75 grams per cubic centimeter would be what was required to make the 18.0 grain charge weight exactly fill the case. Since there are other typos in QuickLOAD, this MIGHT have something to do with ONE of the mismatches. But, it is more time consuming than I can do right now to change the powder file where the BULK density is accessible, and that doesn’t get recalculated when you change the solid density in the program, so I will leave that for another time. Changing the solid density alone did decrease pressure and velocity a lot, but not enough to get agreement with the data.

Another thing I tried was to match the Hodgdon Lil’Gun data for the 44 Magnum with the 240 grain Nosler JHP. The QuickLOAD results for Lil’Gun and H-110 were very comparable in velocity and pressure for the Hodgdon max charges. The slight differences between these two charges in the QuickLOAD results were similar to the slight differences between these two powders in the Hodgdon data. (But, the Hodgdon data gave higher velocities in addition to having the pressure unit incompatibility.)

So, I am still thinking that the .357 Magnum data with the 158 grain XTP bullet is an indication that Lil’Gun is igniting unusually slowly in that particular application. It concerns me that it might not ALWAYS ignite so slowly, and the result could be VERY high pressure.

There is a load that was NOT pressure tested in Handloader magazine using 19.0 grains of Lil’Gun with a SPEER 158 grain Gold Dot. It used 19.0 grains of powder and produced a surprisingly high velocity, 1493 fps from a 6” GP-100. For comparison, the same article listed the 16.6 grain max load of W-296 (supposedly identical to H-110) as producing a more normal 1329 fps from the same gun with the same bullet. The difference of 19.0 grains with the Speer bullet and 18.0 grains with the Hornady bullet seems consistent with the ratio of available powder space left by the two slightly different bullet shapes. But, the velocity seems way too high for a powder that is supposed to give similar velocities to H-110 with lower pressures. I suspect that the pressure was REALLY up there. QuickLOAD gives 55,098 psi with that load and only 30,698 with the H-110 load. It is difficult to compare velocities between a revolver and QuickLOAD, but the calculated velocity for Lil’Gun was much higher than for H-110.

So, I am suspecting that the load published in Handloader MIGHT be an example of Lil’Gun igniting faster than what is indicated by the Hodgdon data, producing MUCH higher velocity. The problem is that the Handloader load was not pressure tested. Can a GP-100 hold together with a load in the 55,000 psi range? I don’t know. Proof should be at least 130% of 35, 000 psi, which is 45,500 psi. But, I think the GP-100 was designed for the older 45,000 CUP SAAMI standard. So, proof should be at least 58,500 CUP. Everybody winces when you try to compare CUP to psi, so all I will say is that the fact that the GP-100 has not blown-up with the 19.0 grain charges of Lil’Gun should NOT make us rest easy.

In summary, that is why Lil’Gun scares me for use with 158 grain bullets in the .357 Magnum.

SL1

[Teuthis]

SL1, I agree with you. Lil Gun worries me too. I think I shall concur with L_Killkenny and stick with Blue Dot. I have used it for decades with complete satisfaction. I was thinking that some newer powders could offer more velocity with lower pressures. But there seems to be a comcomitant risk involved with those powders for unpredictable pressures at loadings perhaps between the benchmarks in the manuals.

And thanks for the comprehensive exposition on Lil Gun. It is much appreciated.

[SL1]

I talked to a ballistician at Hodgdon's this evening, and told him pretty much what I have written above.

His response was essentially that there really isn't any problem apparent in that information. He is thinking that the variation in cases, powder lots, and other variables in test guns and the Handloader gun can account for the differences. He doubts that the Speer GD bullet with 19.0 grains of Lil'Gun really hits 55,000 psi. But, he does think that it can be higher than the pressure gun data would indicate. He bascially thinks that the margins built into the testing of handloading data and the designs of firearms safely covers that level of variation.

I hope he is right.

Oh yeah, he did give me the bulk density of Lil'Gun as 0.950 gm/cc, the same as H-110. He did not have the solid density of Lil'gun.

He did not see any discrepency between 16.7 grains of H-110 and 18.0 grains of Lil'Gun filling DIFFERRENT .357 Magnum cases to ABOUT 100% loading density. He attributed the difference to different capacities of different case lots, different bulk densities of different powder lots, and slight differences in the degree to which the technicians approached 100% loading density in their test loads. But, the Hodgdon site still says not to compress spherical powders. SO, I guess it is up to us handloaders to know how much powder can fit into OUR specific cases and avoid exceeding that amount.

SL1

[amamnn]

I'm on my 3rd jug of lil gun; it works fine for me. I use it in .32 m HRM, .357 mag and .44 mag loads. I get all the accuracy I need from it, but I don't mind the recoil that would bother a lot of other people. Since I have started shooting at an indoor range I have noticed a lot less muzzle flash with LG than with faster powders. In the .357 and .44 mags I am loading near minimum for a light target load. In the .32 HRM I am loading near max for a 100 grain bullet.