BCG Weight & Dwell Time

[Kalakar]

Apologies if this topic has been covered before. I did my due diligence in searching but couldn’t find exactly what I’m looking for. Please point me in the right direction if I missed something.

Could someone school me on the relationship between bcg weight and dwell time? In theory, shouldn’t a lighter weight bcg require less dwell time?

For a specific example, let’s take a 15.5-16” barrel on rifle gas. Your dwell time is a bit lacking here. From my understanding, such a setup would require the port be opened up (.1ish?) to even begin to work unless you added additional backpressure to the equation.

Wouldn’t lightening the bcg alleviate this to an extent? Using say a 7.8oz bcg, could you technically reduce your port size to, say, .093ish? Let me know what you think. I’m sure I’m missing something. Thanks all in advance.

[markm]

Reducing BCG weight is never a good idea. It's really the buffer weight that can be adjusted. I've seen a 16" rifle gas set up that ran with the standard BCG and rifle Buffer with an opened up port. I forget the exact size. But getting the gas right is always better than messing with bolt/buffer mass. You want a certain amount of reciprocating weight for reliable feeding.

[titsonritz]

In the words of Jim Sullivan, "I know I've heard of people lightening the weight of the bolt carrier, that's crazy, you know."

6:20...

[MegademiC]

Dwell time
Spring force
Bcg/buffer weight
Port size

are the variables

[Kalakar]

Reducing BCG weight is never a good idea. It's really the buffer weight that can be adjusted. I've seen a 16" rifle gas set up that ran with the standard BCG and rifle Buffer with an opened up port. I forget the exact size. But getting the gas right is always better than messing with bolt/buffer mass. You want a certain amount of reciprocating weight for reliable feeding.

Not without adjusting the gas from what I’ve seen. Most combinations usually come with some sort of adjustable gas block or key. I’m willing to bet that port size was around .110 with a standard bcg. My question though is would you theoretically be able to cycle using a lighter carrier with little to no adjustment to the port size? Say like X PSI required to cycle Y mass, but if you reduced Y mass, should it also require less X PSI? Reliable feeding is a whole new challenge I’d imagine.

In the words of Jim Sullivan, "I know I've heard of people lightening the weight of the bolt carrier, that's crazy, you know."

6:20...

Crazy builds require crazy solutions. Those improvements were interesting to hear about.

[Kalakar]

Dwell time
Spring force
Bcg/buffer weight
Port size

are the variables

That’s about where I’m at currently. Full rifle dissipators eliminate all with the exception of Bcg/buffer weight and port size. If the port size were to remain somewhat consistent with rifle gas (.093ish?), your only option is then to adjust the carrier and buffer combo I’d imagine?

[prepare]

In the words of Jim Sullivan, "I know I've heard of people lightening the weight of the bolt carrier, that's crazy, you know."

6:20...

Does anyone know what changes Mr. Sullivan made besides increasing the weight of the BCG?

[Cagemonkey]

Does anyone know what changes Mr. Sullivan made besides increasing the weight of the BCG?

Check this out; https://www.m4carbine.net/showthread...vement-Program https://www.surefire.com/products/su...carrier-group/ https://defensereview.com/surefire-o...-better-weapon

[prepare]

https://defensereview.com/surefire-o...-better-weapon

Surefire already has their foot in the door with gov contracts. Wonder if DOD tested these and what the results were?

[sinister]

JP Rifles failures they blame on reloads.

https://www.jprifles.com/bulletin/pr...015_01_01.html
https://www.jprifles.com/bulletin/pr...016_02_01.html