I will be using 180 to 210 grain cast bullets in a 300 Whisper 10" T/C. They will be subsonic. Do I need gas checks if I keep the fps below 1050? Will there be any advantage to using gas-checks even at this velocity? Accuracy? Reduced leading?

Thanks !

The ballistic environment you describe could be well-served with plain-based boolits. If you have a gas-check design, I suggest that you use gas checks with it. While others have reported good results using gas check designs w/o the checks, that has not happened for me. The base of a bullet is its steering end, and is the last part of the bullet to have contact with the muzzle/crown. EVERY bit of consistency possible should be present at the boolit's base.

Al,

Thanks. I was looking at a Leadheads 205 grain .309 boolit. It is available with or without the gas check and accordingly is designed for one. The cost differential isn't that much. I was just wondering overall if there were any advantages. I have read that the base is as, or more important than the front of the bullet in regard to accuracy. I have seen some UGLY gas check applications out there though that would lead me to believe if you don't need 'em, don't use 'em!

I would postulate though that Leadheads will provide quality work in regard to the gas check application.

Thanks again.

For a caster, the price of the gas check is a price hike that only makes sense if it makes a positive difference in a load. If a caster purchases a mold design with gas check shank, he/she should expect to purchase gas checks to maximize performance. The payoff is increased velocity potential--but increased velocity does not equate to enhanced accuracy--and can indeed degrade same. The velocity you indicate for the boolits is pretty non-critical, and some of my best loads run between 950-1100 FPS.

dino, if the bullet is designed for a gas check, use it. I tried shooting gas check boolits from a 30-30 without them and the boolits all went through the target sideways at 50 yds. With the checks on these boolits, I could hit a nickel at 100 yds. You would be fine with a plain base boolit in that caliber. Just decide which you want.