AR BCG operating temperature

[jb7706]

I keep reading all the threads about the benefits of DGI vs. gas piston designs in ARs. One thing that always seems to come up is a cooler running BCG with a GP. I got to wondering just how hot a DGI carrier gets under a rapid fire string.

Let's assume a sustained rate of 120 rounds per minute for 2 minutes. Has anyone actually measured the temperature of the BCG under these or similar conditions? I know, I know it is HOT. I get that. I am very curious about a true temperature measurement.

Any takers?

[bwiese]

It's somewhat moot esp for ordinary folks like us.

The issues of suitability M4 for full continued fullauto usage are restricted to a very small group of operators (i.e, Delta/Seal etc) who were using them in things like 'break contact' hose-down maneuvers. The M16/M4 were never really MGs/SMGs and are really battle rifles/carbines.

120 rounds for 2 minutes is not a good thing for any ordinary AR user - that's awfully close to the 'cookoff' point for milspec ammo (which I think is around 130ish rounds fired sedately without long pauses) - and that has nothing to do with bolt/carrier temperatures but simple chamber overheating. Cooking off a round while bolt is not in battery is not a good thing especially to your face.

If you're firing at that rate without pause esp with nonmilspec ammo you should have some very good eye & face protection.

[jb7706]

Agreed, that is way too much too fast and teetering on the edge of safety/sanity. I really am just flat curious about the temperatures we would see at the bolt carrier at the ejection port. No real bearing on any practical purpose other than maybe knowing what to set my oven to bake in some Miltec-1.

[NiteQwill]

120 rounds in two minutes? sheesh. At that point, you're already losing in the battle. Better find more mags...

Miltec will stick just fine when applied on a dry, clean BCG and broken in with the next range trip. Don't worry about baking it in the oven.

[J_Rock]

You will NEVER have to worry about running the bolt so hot that it fails. Mostly because either the gas tube will melt or the barrel will burst long before the bolt fails from excessive heat.

Bolts usually break because they were either being used long past their service life or they were defective in the first place.