What does "gas check" mean on 45-70 ammo?

[sea trout]

Howdy fine folks!
On HSM ammo for 45-70 it says on the box bear ammo and it says gas check.
What does gas check mean?
Thanks

 

[bullethead]

It is a copper base that snaps over the base of lead bullets to help reduce the amount of lead build up in a barrel. Basically, depending up the hardness of lead, the faster it is driven down a bore the more of it that smears off.

 

[sea trout]

Thanks!
That sounds confusin.... I'm not smart on this stuff for sure.
So the hardcast lead leaves a lead deposit in the rifleing grooves and the copper base cleans it as it passes behind the lead projectile?

 

[pacecars]

It also keeps the base from deforming. Gas check bullets can be pushed faster than plain lead bullets

 

[rmp]

High pressure hot gas from smokeless powder will deform softer lead and try to cut around the sides of the bullet. Called gas cutting by many. Think of the hot gas trying to find a way out of the muzzle by any means necessary. Soft lead and/or a poor bullet to groove fit gives it a chance to “cut” or go around and likewise deposit lead. A gas check clips on to protect the base and form a seal for the hot gas to push against.


I hope that reads alright. Long day

 

[Buck70]

High pressure hot gas from smokeless powder will deform softer lead and try to cut around the sides of the bullet. Called gas cutting by many. Think of the hot gas trying to find a way out of the muzzle by any means necessary. Soft lead and/or a poor bullet to groove fit gives it a chance to “cut” or go around and likewise deposit lead. A gas check clips on to protect the base and form a seal for the hot gas to push against.


I hope that reads alright. Long day

Understand it perfectly.

 

[Dub]

Sorta like making sure ya add cheese to anything that is loaded with jalapeños…..

 

[sea trout]

Thanks y'all that's makin sense even to me!
Y'all are always awesome!

 

[Stevie Ray]

Sorta like making sure ya add cheese to anything that is loaded with jalapeños…..

Haha!

Yea, this and the fact that they just make a run of the mill cast bullet look very businesslike ... and cool.