Bhuij, I want to thank you for your efforts. I too began the search for a decent AR15 cast boolit load that could get the job done for me about 4 months ago. I think I have finally hit the nail on the head. I am a gunsmith by trade, and a bullet caster of almost 40 years, so I tend to try anything that seems to have merit. I cast and shoot about 30,000 rounds a year, so I think I might have forgotten more than most people know about the game. And forgetting stuff aint' always bad! Years before PC bullets came onto the scene, I was searching for the magic coatings that numerous bullet casters were coating their products with. I was trying desperately to cut my production times for making copious amounts of gun food for competition by not using traditional lubes in my star sizers. Finally, the PC info hit the web, and I was off to the races! The "forgetting" part comes from the fact that you can forget about most all of the traditional rules and things that you learned the old school way. The best phrase I ever read on a thread about PC'ing was "...PC changed EVERYTHING!". I agree. Back to the topic at hand... I started down the 223 path as many have with the Lee 55-225 6 cavity mold. I used safe low velocity loads working up to minimum loads that would reliably lock my M4 bolt open on the last round. I like to use surplus (cheap) gunpowder, and WCC844 is everywhere. I found that 20.0g of 844 behind the PC/GC Lee would cycle reliably in a 14.5 M4 piston variant. After my first 1k loads through the M4 (aka, 1K gas checks), it was still accurate enough to clang 10" steel 100% of the time at 100 yards with a zero magnification RDS, and there is ZERO leading of the barrel or the gas piston system. However, I found there was not enough "oomph" to reliably cycle some of my longer gas impingement systems with that load. So, back to the loading ladders.... I decided to run up a ladder of 1/2 grain incremental loads from the starting 20.0g, up to the suggested "book" loads 0f 25.0g suitable for 55g jacketed ammo. I figured that I would eventually find that spot where lead would eventually start to deposit in the bbl and bolt areas of the rifles. NOPE! Even at full loads the gun keeps hummin' like a jug! Additionally, at 24.5g I hit the sweet spot for one of my varmint AR rifles that grouped 5 round clusters into .92" and .96" groups. BTW, none of the loads went over 2.5 MOA at my 100 yard testing range. I'm done with ladders at this point! So, for those looking for the details, here ya' go: Use at your own discression with all the usual precautions of working up to this load:
FC cases, case mouths trimmed to length and inside neck chamfered to ease bullet insertion. WSR primers, 24.5g WCC844, COAL 2.13".
Boolit specs:
Lee cast 55-225 6 cavity gang mold. I use straight air cooled linotype (REAL lino with the headlines still readable on it!). At $3 a pound, its worth it to cast 15 pounds into 2000 52g slugs for $45. 1 light coat of HF red applied for 15 minutes in a dedicated HF vibratory tumbler. Toaster oven cured at 400 degrees for 20 minutes, then dumped and shaken to break up the clumps in an old wooden ammo crate before quickly cooling them down with a house fan. Hornady GC's seated and crimped in a Lee .225" push through sizing die (I used a .224 die the first 1K rounds) after PC'ing.
I know to those who are just starting out casting, this all seems like a lot of effort. But when you look at doing 2K or more at a single sitting, this effort is well worth the time and $ spent to squeeze the last cent out of your reloading dollars. Casting 2K takes about 2 hours. PC takes about 30 minutes. GC and sizing takes about 4 hours. TOTAL = 6.5 hours and +/- $100. The CG's are the most work really, and the most expensive part of the process, going anywhere from 2.4 cents (Midway USA, on sale last month), up to 4 cents apiece just for the copper cups from Hornady (I will use no others, as they are far superior in my experience). YMMV....