cast boolit suggestions - AR15 .300 fireball (whisper)

[todd987]

Just received my parts kit from model 1 sales.
.300 fireball, 1-8 twist, 16" barrel.
Looking for cast boolit and load suggestions.
Not looking for subsonic at this point just a good target and possibly hunting load.
Where I hunt max range would be 150 yrds.
Thanks

[Ben]

That fast twist may not be very cast bullet friendly ? ? ?
I've never shot a .30 cal. cast bullet in a 1 - 8 twist, you may need to get some other folk's opinion on this one.

Ben

[burr7870]

There are other people on this site that have experimented with this caliber. I believe it was Redneckdan that posted on this. This is my next project as well. I am also looking at the M1S upper.

I have brass, dies, trim die & mold just no rifle!!!

I plan on starting out with the lee 7.62x39 mold and 2400 powder.

Keep us posted.

[burr7870]

Has any one had any success or failures with the M1S upper & cast bullets? This is my next big project. I am interested in heavy cast subsonics & Moderate cast supersonics.

[redneckdan]

I've had excellent accuracy with both the lee 170gr flat nose gas check and 200gr HBC gas check, alloy is usually WDWW heat treated at 400deg for 1hr. Checks are important with the ar-15 platform for good accuracy. I have an oly arms barrel with the gas port in the carbine location. I started at 12 gr of H4227 and started getting reliable function at 13.2 gr, I run 14.0 grains for general shooting loads. No really problems with leading, lots of soft carbon fouling due to boolit lube. I clean after every outing...due to the ar-15 design, it ****s where it eats. I've tried H110, shoots nice but is a pain to use in the lee powder measure. About magazines, cast boolits have a more 'weight forward' profile in the ogive area versus jacketed bullets. This seems to cause tipping problems with GI 20rd mags, I got 5 c-products with anti-tip followers and have no problems. The root cause of the tipping problem is the fact that .308" part of the boolit rubs on the internal magazine should that is supose to go right in front of the shoulder on the 5.56 round, I took a GI 20rder and milled out the mag should....wasn't really worth the hassle.