first theres 2 kinds of leadin :
1- gas cuttin from a to small bullet , smeared mess from chamber to muzzle .
2- strippin , the bullet movin faster than the alloys ability to start it spinin if strippin is bad enuff gas cuttin is enevitable.
Pressure relates directly to speed& the "tuffer" or harder the bullet the harder you can push it & if it does`nt fit hardness won`t matter anyways & if it fits & is a decent alloy it`ll stand more pressure than ya think it will.
Last but not least the fire arm measurements.
Think of a funnel , ya gotta shoot lead into a funnel (larger to smaller ) not out of a funnel (smaller to larger)
& even .0005 can mean a bullet will or won`t shoot.
Now the gas check : it helps hold the gases back until the bullet is spinin plus if any strippin it keeps that pushed up into the voids ,to a point , then even a gas check fails but that`s in the upper pressure limits of most firearms .
& a point i almost forgot the check is clamped onto the bullet & as the check hits the riflein it helps spin also .
I hope this helps & I`m sure there`s different veiws & opinions & I hope someone chimes in !
