Piston or Gas

[razor]

Thinking about putting a piston sys. on my midlegth Grendel,are there any opinions out there???

[LRRPF52]

There are, but I would advise sticking with Direct Impingement, unless you are absolutely committed to an op-rod driven system for some reason. The DI system has proven to be more reliable for starters, and has less moving parts, and more inherent accuracy. The weight imbalance of almost every op-rod system is also a major turn-off for me. The AR is a great design in its original form, as long as quality parts are used, not vismod garbage that "looks like" the real deal, but cuts corners, especially on alloy materials, hardening processes, assembly procedures, and springs.

[stokesrj]

If you are a full auto enthusiast, then go with the op-rod, if you are more concerned about accuracy, weight and balance stick with direct impingement.
Bob

[rasp65]

A lot of people don't know this but the DI system has a piston it is also known as the bolt.

[LRRPF52]

A lot of people don't know this but the DI system has a piston it is also known as the bolt.

That is really the genius in the Stoner design, since it eliminated moving parts off the bore axis, and put the balance of the weapon in the center of the gun. I have yet to shoot an op-rod driven system that has the unusually low recoil impulse of the AR15, although I hear that the SCAR-L is very pleasant. The HK416 is a horrible beast to shoot, and feels nothing like an AR. The industry figures who have introduced some of the most popular op-rod systems in the past 10 years don't even use them in their courses, which screams volumes in my mind. (Magpul Masada, LAV & the 416)

The FNC has a considerable recoil impulse on SEMI, but is pretty much like a constant recoil system on AUTO. My main interest in AUTO on an assault rifle is a SEMI/2rd BURST/AUTO fire control group, with AUTO only used for break contact and rare scenarios. For CQB, 2rd BURST makes a ton of sense, and is great for Mozambique drills or continued shot placement to center with less trigger work.

[razor]

Thank's for the input you guys. Accuracy is what is all about.Ill stick with the gas sys. and save the money and weight.