This is really a Reloading forum question, but I know that a couple of you (at least) use Lil' Gun in your .221 Fireballs. I re-evaluated Lil' Gun and 40 grain V-Maxes and NBTs last night, and got some decent groups with the V-Maxes.

Anyway, it makes me wonder whether I should take my H4198 or H322/50 grain load, or the recently tested Lil' Gun/40 grain load on my upcoming prairie dog trip. The 50 grain load is even more accurate, but the Lil' Gun load shoots in the .6's (5 shot groups), which should be just fine for prairie dogs. While I'd rather have accuracy over speed, if I can get .6s AND shoot close to 3500fps, the choice is more difficult.

Here's the question:

With Lil' Gun, I get dirty necks and shoulders, and depending on primer, even a little on the main case body closest to the shoulder. Last night I only tested 16gr. Lil' Gun, but I seem to remember this happening when I started working up at 14gr. Normally, I would attribute this to a load that is not quite up to pressure, since the gases leak back from not fully expanding the neck in the chamber. I know that Lil' Gun does operate at lower pressures than some other powders in the Fireball, but with 16gr., I am starting to see the slightest evidence of primer cratering -- nothing bad, you might even see this type on factory ammo. The problem is, it shoots a hole (no pun intended) in the theory that this is due to low pressure.

Is it just because the powder burns so fast that it doesn't properly expand the case? Is this happening to anyone else?

VarmintGuy? I know you use Lil' Gun in your Fireball...help me out...please!

sounds more like a slightly larger than normal neck area in the chamber to me. I have used Lilgun in my .221 and if I recall (working from memory....and I have CRS)16.0 gr behind a 40 v-max I have no dirty cases necks or pressure signs of any kind. In my 16 1/2" barrel that gets me just under 3400 fps. But my chamber is a minimum spec Bullberry.
I have since switched to RL-7 (19.0 gr) behind the same bullet because it is every bit as accurate, slightly slower and I can use it in another chambering with excellent results.
Are you full length sizing or just the neck ? Reformed brass
or Rem. .221 ?
I just spent all last weekend shooting prairie dogs with mine using 40 v-maxs. Wicked wicked little cartridge !

New Remington brass, which could also be an issue because it hasn't been fireformed yet. Weird, though, because it only seems to do this with Lil' Gun -- not my other bullet/powder combos with the same new brass. I might need to try RL7 again, too...