Good starring BHN for cast AR-15

[Wolfdog91]

For those who cast for the ar15 platform what have y'all found to be a good starting place as far a BHN goes ? I picked up some sketch pencils and tried testing some boolits I cast with wheel weight ingots I made and seems like there a 13-14 BHN and from my reading if I water drop them that can increase a couple so possibly a 16 after water dropping.
So since I have to run higher pressures to get the action to cycle would 16 BHN gas checked with powder coat be a good place to start or should I try somthing of a higher hardness ?
Thanks !

[DGV]

WW metal should be plenty hard enough for a AR-15. As you discovered water quenching them makes for some tough boolits. I am sure plenty of people will chime in with more. You could even use straight Lino if you have it.

[sigep1764]

I used COWW for the first few thousand boolits I cast for my AR's. Shot just fine with no leading. You should be good to go with water dropped COWW.

[mac1911]

For what is worth I ran COWWs water quenched for 1000 rounds with minimal leading.
Used that Lee bullet and tan H4895 until they just cycled. Accuracy for me was soso and I sold the mold to a friend as I wore out my cast in AR after those 1000 rnds. I used a Stag 1/9 carbine
It was fun running it as the Range experts all said it wont work, blow up , lead up ectect

[mehavey]

Gas-checked Lyman #2 (BH_15) is plenty hard for 2,500fps/mid-30 thousands psi/full-functioning.
See http://castboolits.gunloads.com/showthread.php?368459-223-cast-bullets-w-ar15&p=4472544&viewfull=1#post4472544

[fcvan]

I have 2 molds, the Lyman 225-415 which takes a check, and an NOE 225-62 RN designed for powder coating. I am getting 2250 fps with the NOE boolit through a Mini 14 and an AR 15. The AR I built with a 1 - 9" twist, and the Mini is 1 - 10". I have a single shot with a 1 - 12" 24" heavy barrel. Through that gun my loads run 2450 fps. I make my own gas checks but they are a PITA to make and seat due to size.

The powder coating toughens up the boolit which reduced the deformation through the feeding cycle. I probably have 10 pounds each of the Lyman and NOE boolits cast and coated. Next time I cast/coat I am going to water quench right out of the PC oven. I may also sweeten the alloy with some harder alloy. I really like shooting cast through the AR and the mini as it is cheaper and is devastating on tin cans.

[Boolseye]

I like to run them a little slow, 1800-2000 fps, just enough to cycle a carbine. 12-15 Bhn with a gas check is fine for this.
I will make sure they're a little harder if I'm pushing them above 2200 fps, at least 15 Bhn for those speeds.
I run the RCBS 55-225 (NOE clone).

[Conditor22]

quenched COWW (clip-on wheel weights) is overkill but an easy way to get harder boolits

I've had success with PC'd (powder coated), GC (gas checked) COWW

Lyman and RCBS call for linotype (19 - 21 BHN)