Gas checks?

[Anvil]

I'm looking for some bullet moulds in 45-70 and 44 mag. The gas checked bullets look better and I've read up on gas cutting but are they necessary for 150 yard shooting? I'll probably never aim my guide gun or SBH out farther than 150 at the extreme. Do I need a gas check on my bullets?

[CZ93X62]

Need? In 45-70, it is really an "option".

The determining factor for gas check/no gas check is the load's pressure. This assumes a bullet well-fitted to the throat and grooves. A loose bullet won't shoot well, but will lead your barrel comprehensively. If a bullet fits well, you can get away with a lot more pressure than the bullet's Brinell Hardness rating would indicate.

The general rule in rifles is that at ~1400 FPS--or, more properly, at the pressures that create that kind of velocity--a gas check starts becoming a good idea. 1873-level 45-70 loads (405 grainers @ 1300 FPS) need no gas check if the bullet fits well. Same story in the 32-20 with 115 grain bullets at 1200 FPS. Ya want to run the bullet at 1500-1600 FPS, go gas check.

Kind of an over-simplified answer to a rather complex issue, but I don't want your eyes to glaze over.