Piston gun gas rings [Archive] - M4Carbine.net Forums

pbjb

08-03-13, 08:53

I currently have a Ruger SR556E and LWRC M6SL. The Ruger bolt has no gas rings and the LWRC bolt does.

Not sure why one does and the other doesn’t, both rifles work great.

Do gas rings make a different on piston rifles?
:confused:

Happy Shooting

az doug

08-03-13, 14:02

I cannot be certain, but I believe the LWRC is using the rings to hold the bolt in the unlocked position while the bolt strips a cartridge from the magazine. Without something to hold the bolt open, rings or a spring, the bolt will try to cam into the locked position. The early camming will cause excessive wear or worse, binding which can cause malfunctions.

The rings are not needed for the bolt to unlock, like a DI system.

Servo

08-03-13, 19:00

I cannot be certain, but I believe the LWRC is using the rings to hold the bolt in the unlocked position while the bolt strips a cartridge from the magazine. Without something to hold the bolt open, rings or a spring, the bolt will try to cam into the locked position. The early camming will cause excessive wear or worse, binding which can cause malfunctions.

The gas rings are not used to keep the bolt in the unlocked position while it strips a round from the magazine; The inside of the upper receiver does. The cam pin is not allowed to rotate in to the locked position until it reaches the cam pin hole.

As to why LWRC has gas rings on a bolt for a piston gun I have no clue.

az doug

08-04-13, 23:40

POF came out with the roller cam pin for their piston upper in an attempt at limiting the wear.

Please read post number 3 in the thread linked below:
https://www.m4carbine.net/showthread.php?t=101258

It appears most of the cam pin damage/wear in the receiver is caused by the unlocking of the bolt and camming too late rather than the bolt stripping the round and trying to cam too soon as I thought.

The spring on the bolt or leaving the gas rings on are an attempt at preventing this premature wear.

Vandal

08-05-13, 00:09

My PWS Mk114 Mod1 has no rings. Not sure why LWRC chose to put rings on their bolt, does it have the spring too?

az doug

08-05-13, 00:33

Manufacturers usually set the bolt up with either or. Your PWS uses a spring.

Vandal

08-05-13, 01:10

I am aware of that and it's the reason why I asked if the LWRC had the spring as well as having the rings, wanted to know more and maybe get some insight as to why they did that. I understand the purpose of the gas rings on my DI rifle, though, I see the gas rings on a piston gun as being useless when the spring is easier. My opinion only, YMMV.

az doug

08-05-13, 01:57

Vandal, sorry I didn't make it clear enough. A piston gun will have one or the other, a bolt spring or gas rings, from the factory.

Here is link to an LWRC operators manual in pdf format:

www.lwrci.com/support/forms/OPERATORS_MANUAL.pdf

If you scroll through it you will notice they only use rings, no spring.

If you read the other M4carbine thread I linked to in a previous post a person in post #3 explains the purpose of both, springs and rings.

The_War_Wagon

08-05-13, 05:29

My POF-415 didn't use rings, either. FWIW.

sinlessorrow

08-05-13, 08:12

Accordin to LWRC they use gas rings to hold the bolt open allowing for easier reassembly.

Vandal

08-05-13, 11:59

az doug, I was tracking on what you said originally and in the linked post. The purpose behind my post was that, the spring setup makes more sense in a piston platform, at least to me. Now if LWRC made a DI gun I can see where it would be reasonable to run a bolt with rings for ease of production such as the bolt on Colt's 6940P.

To the OPs original question, no I don't think it makes a difference. Just different ways of accomplishing the same task.

sinlessorrow

08-05-13, 12:23

az doug, I was tracking on what you said originally and in the linked post. The purpose behind my post was that, the spring setup makes more sense in a piston platform, at least to me. Now if LWRC made a DI gun I can see where it would be reasonable to run a bolt with rings for ease of production such as the bolt on Colt's 6940P.

To the OPs original question, no I don't think it makes a difference. Just different ways of accomplishing the same task.

All of LWRC's 5.56 bolts are just standard bolts. They cannot get a working ACB so they stick to standard bolts.