240 gr RN-FP sized at .432 13-14 BHN @ 1440 fps when is gas-check needed??

[10mmShooter]

Hey Guys,

I'm currently running a .432 sized 240gr RNFP at 1440fps with only 16.2 grs of AA#9(actually a mild charge for the powder) in my 20 in Henry. Anyway ejected cases still drop in a .44 mag case gage...kinda impressive they don't even swell. No leading at all to report.

Question is since I'm at 1440 fps sized at .432 obviously plenty of room to go up in powder charge max is around 20+ grs of AA#9

My hardness is 13-14 BHN at 1440fps.... guessing I would need gas checks in the 1550-1600 fps+ neighborhood ??

Anyone running faster without checks?? I think the nice slow AA#9 is helping to not skid the bullets.

[rintinglen]

What I do in my Marlin may not translate to your Henry. I find I start getting leading at right about where you are now in my Marlin. My brothers Rossi can shoot the Lyman 429-667 a good two hundred feet faster. with minimal leading. This is one of those places where your milage can and will probably vary. You will find out when you put your foot on the accelerator.