TNW $250 gas piston conversion (got it today)

[Dave_M]

Let me start out by saying that I am an DGI disciple--I do not think that a gas piston makes the rifle any more reliable than it already is since 99.99% of malfunctions are tied to the magazines and extractor--something a gas piston conversion does not affect at all. Despite my opinion, $250 was too small of a price to pay to play with a piston. Actually, $250 is a misnomer as I purchased a new carrier for this project. The real price is around $310 or so after taxes.

Okay, so I finally received my gas piston kit today. I installed it in one of my M4's.

Initial impressions:

The instructions are terrible. The images are too small and the directions not specific enough. Since this conversion requires a gas key replacement I purchased a stripped bolt carrier instead of mucking up one of my LMT carriers.

http://img.photobucket.com/albums/v11/DavePAL84/projects/GP7.jpg

First, I completely stripped the rifle (pulled off the quad rail and took the optics off)
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP4.jpg

I knocked out the roll pin for the gas tube and pulled out the gas tube. Since this rifle hasn't been shot a whole lot it came out easily
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP2.jpg

I field stripped the old bolt carrier and removed the gas rings
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP10.jpg

Then I installed the new gas key onto the stripped carrier and staked it into place. The front screw is longer than the usual front screw for some reason.

I replaced the gas tube with a short tube and roll pin (new, longer pin was included)
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP3.jpg

Assembled piston and spring
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP1.jpg

Here is a pic of the new cylinder block assembly
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP8.jpg
The cylinder block fits onto the gas tube and the piston fits into the rear end of the cylinder block.

Since the barrel is an M4 profile, I had to use the included shims. Unfortunately, the shims were too large. I had to spend some time with a dremel tool before I got them to fit. I'd like the parts to be too large rather than too small but this was more work than I expected. Since the gas block itself was not replaced (which would keep cost down) I think that shims were necessary.

After some dremel work, here is the whole thing together
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP9.jpg

I checked for fit with the quad rail--no go, I had to use the handguards that came with the conversion
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP5.jpg

Because I was unable to use my quad rail, the EOtech had to be moved back so I could not longer have the EOtech, magnifier, and BUIS on the rifle at the same time. I opted to remove the rear BUIS to keep the magnifier. All together:
http://img.photobucket.com/albums/v11/DavePAL84/projects/GP0.jpg

I'm taking it to the range either tomorrow or Friday. There is no regulator on the piston so I am concerned that Wolf will not cycle--only a test will tell.

If everything goes well with the test, I'll completely clean the rifle and document the wear over the course of 1k rounds without cleaning to see what kind of damage carrier tilt causes (if any). Very few rounds have been fired through the test rifle so any additional unusual wear will be easy to see.

[Seth Harness]

Looking forward to your wear report. Especially the tilt issue.

[decodeddiesel]

Especially the tilt issue.

This. Plus I really wish these piston conversion kit "engineers" would get a clue and make a product which will work with the popular rail systems (ie LaRue, DD, Vltor) :mad:

[30 cal slut]

interesting. it's nice that you don't have to knock the front sight out like you do with other more expensive kits (that can be a real PITA).

look forward to hearing your range report.

[Dave_M]

Just got back from the range. I fired Wolf and some M193 through it. I fired a little over 250 rounds. No problems. Handguards got pretty hot have a couple of mag dumps (I wish I had a vert grip on this thing). Accuracy was fine, saw no real difference (it is a carbine afterall). I'm going to strip it all down and clean it to begin the 1k test tonight.

[ABNAK]

Just got back from the range. I fired Wolf and some M193 through it. I fired a little over 250 rounds. No problems. Handguards got pretty hot have a couple of mag dumps (I wish I had a vert grip on this thing). Accuracy was fine, saw no real difference (it is a carbine afterall). I'm going to strip it all down and clean it to begin the 1k test tonight.

[Col. Klink voice on] Verrry interrresting [Col. Klink voice off]



Glad it worked out for you. One of the advantages of this particular system (as TNW put it) is that the "gas trap" chamber delays unlocking until pressures have dropped. They say it only needs a "tap" at that point to unlock as opposed to "hitting it with a balpeen hammer" like other systems that do NOT delay.