Hot casses from an AR

[arnie19]

This question has been going around a lot lately .Why are cases coming out of and AR or other semi auto rifle so hot compared to a bolt gun even when you open the bolt gun and eject the shell as quick as possible after firing ?

[Merc1138]

This has been going around a lot lately? I rarely see it come up.

As much as you try, you will NEVER cycle a bolt action rifle as fast as a semi auto. It's not gonna happen. You might be able to do it even once per second, but when the cyclic rate of something like an AR is between 700 and 900 rounds per minute. Even with a semi auto rifle that can run at 600 rounds per minute, that's still 10 times faster than your 1 bolt manipulation per second.

Because the semi auto rifle can spit that case out at least 10 times faster than you can, that's far less time for the barrel(the chamber area) to absorb the heat from the case.

The faster you cycle your bolt action rifle, the warmer those cases will be(even before you actually get the barrel hot).

If for some reason your extractor fails and you end up having to manually pull the spent case out of the AR, it will be far cooler than if the AR had ejected it during it's normal cycle.

[Sabesimpson]

^^^ well said

[CK_32]

Just like Merc said, during the cycle of a AR literally just after the bullet leaves the barrel the case is already being pulled and tossed out. Also gas guns are operated by just that, gas so you have heat coming from both the neck and coming back through to cycle the bolt through the gas port. But that's minute compared to the heat the case already has. Again like merc said it's ejected literally immediately fresh from the oven (chamber).

https://m.youtube.com/watch?v=NHA2XGhjYXQ

[ar15barrels]

This question has been going around a lot lately .Why are cases coming out of and AR or other semi auto rifle so hot compared to a bolt gun even when you open the bolt gun and eject the shell as quick as possible after firing ?

Time.
In a semi-auto, the cases are extracted very quickly after they are fired.
In a bolt action, the cases stay in the chamber quite a bit longer.
During the time in the chamber AFTER firing, the barrel soaks up heat from the brass case which is QUITE hot from firing.
The longer the case spends in the barrel, the more heat that transfers into the barrel.