A forum member asked me if I would give some insight into how our M4's handle on the range because I've started threads on the AK's, pistols and .50 Barretts.
Here's a little background on what we do. We operate a high-volume range in Las Vegas. You can't bring your personal weapons in and rent lanes for an hour. Customers use only our weapons and our ammo. We only use factory new ammo and zero reloads. We keep maintenance log on EACH and every weapon to include cleanings, parts replaced and any other issues that need to be noted. We shoot approximately 400,000 rounds down range each month and the numbers have actually gone up a bit for May and June. Tourists get to shoot everything from Type 99 Arisaka's, M1 Garand C and D's, MP-44's, G43's, M2HB's, 240's, 249's, MG42's, MG34's, M-14's, Luger's, Swedish K's, M203's, M79's and you get the point. Some weapons are very rare historical weapons that rarely come out of collections or museums and see the light of day.
Here are some "facts" about OUR experience with M4's on the range.
- Some of our M4's have well over 200,000 rounds down range. Barrels have been replaced, gas tubes have been replaced, BCG's have been replaced but what sets it apart from the AK47's is that upper and lower receivers continue to function. AK's get to about the 100,000+ round count and rails on the receiver will start to crack. It's an easy fix with tig welding but they crack. We have yet to lose an upper or lower receiver from cracking.
- We get about 20,000 rounds out of bolts before we start experiencing issues. The headspace gauge will start getting closing on NO-GO but not close on field. We will lose a lug on the bolt. The bolt will start skipping over rounds in the magazine and fail to insert a round. We use LMT and Daniel Defense bolts and some will actually go longer but at about 20,000 rounds is when we will start to see issues appear.
- Gas tubes will erode away at the FSB after 12+ months
- Charging handles will "stretch" allowing the locking lever and spring to fly out
- Hammer pins and disconnectors on the 8.5" full-auto's will break after approximately 4,000-5,000 rounds regardless of the buffer weight
- We have yet to lose a single flash hider as compared to muzzle brakes on an AK-47. The muzzle brakes will literally split in half, looking a like bird with his beak open and go flying down range.
- We no longer use ANY piston conversions or factory pistons guns with the exception of the HK-416 "knock-off" TDI upper. I purchased a FACTORY brand-new MR556 and it started keyholing after only 10,000 rounds. I was SO pissed because I spent all that money on the gun and it couldn't last 10,000 rounds. I had barrels from before we even opened the range with 1,000's of rounds on them from J&T Distributing (chrome-lined) that didn't keyhole well into the 80,000-100,000 range. I don't know who makes or made the J&T barrels but I was so pissed that actually wasted the money on a MR556 and that's all I got from it. I purchased two of the 14.5" TDI knock-offs approximately 6-8 weeks ago and they have been on the line daily with ZERO issues. I only purchased them because people will come in specifically request the "416" and even they've never handled a weapon their entire lives, they KNOW that the top half isn't the "416 like in COD/MW".
- USGI mags have outlasted all of the other brands. We use UGSI (Brownell's with tan follower) and on a mag for mag basis, they have outlasted Pmags and a few of the other mags that we get from mfg'ers with new weapons. We don't have to worry about various generations with different weapons like the MR556, SCAR, F2000, Tavor or a couple of others that use AR15/M4 magazines.
- Cleaning bolts and carriers is such a pain in the ass as compared to our AK's, G36's, SCAR's, ACR's and most other platforms. We throw them in the ultrasonic cleaner filled with Simple Green (EPA, OSHA and disposal concerns for us) and they never full remove the carbon from the bolts. The armorers spend so much time cleaning them and keeping all the parts together as compared to most other platforms.
- The only piston system to last on the range so far is the HK416 and TD415 system. Ever other systems we have tried has failed in one way or another. I won't say who's broke or how they broke so PLEASE don't ask. Each mfg has their own system for cleaning intervals and we may not follow their way. We have a way of cleaning and keeping records that suits our needs because of so much use.
- There is company that has an AR system that has some "parts don't need lubrication" and that failed before the end of the first day. I don't think some mfg's understand that people REALLY use their weapons and when you're rocking full-auto all day they NEED lubrication. My armorers and RSO's were laughing when it seized it up because we knew there was NO way it would last on our range.
- The parts that we see break more often are the bolt cam, bolt lugs shearing off, firing pins and gas keys shearing off the bolt carrier.
These are just a few of the things that I can think of on the top of my head. Please feel free to ask questions and I will try to respond sooner than later depending on my schedule.
ps: I am sure there are some grammatical errors as I tend to read the words into a sentence that are not there. Some sort of dyslexia-type of issue that plagued me through eight years of college.