View Full Version : M4A1 Questions

July 10, 2008, 03:07 AM
First Question:
How do I zero invisible laser with night vision on my M4A1?

Second Question:
I use HK 30 round mags. Are there better ones out there which out perform Hk mags?

Third Question:
The suppressor doesnt kill the noise. It just reduces it. Whats that suppose be? Is it how it works, or have I been sold a bad one?

Fourth Question:
Whats the best visible laser for it that holds up it its zero after firing rounds after rounds?

There two more questions pertaining to M203 attachment which I will ask later on.

Thank you

July 10, 2008, 11:05 AM
For zeroeing your sight...maybe use a boresight and then line up your IR laser with that one?

HK mags are the best out there, but extremely expensive...a good compromise between cost and benefits is the Magpul PMAG.

Supressors do not kill noise. They only lessen it. About 30 decibels on average, I believe...

I cant really say for a laser...probably any decent laser over $50 mounted on a LaRue mount would hold indefinately...

Go ahead and let fly with your 203 questions!

July 10, 2008, 12:25 PM
Thats what I have been hearing about HK mags. So I ordered 20 of them today.

For zeroing IR through bore sight is not possiblr since I cant see thru bore sight in dark and thats only when IR will show up in night vision mounted on M4A1.

July 10, 2008, 04:51 PM
If you run sub-sonic ammunition, the can will be really quiet.

July 11, 2008, 06:02 PM
Take nods off the rifle, go to supply, get a zeroing target for the add ons like PEQ's etc. Zero rifle.

July 11, 2008, 06:04 PM
Do you have a NV compatible optic on your weapon? The way I did it was to look through my Aimpoint with my NV and adjusted the laser to the dot on the Aimpoint.

I set mine so that they came together about 45 or 50 yards out.

As for what lazer will hold it's zero I can tell you my Surefire L75 has held it's original zero. I wouldn't know if it's the best but it's damn good. I think the visible Surefire is the L72 if I'm not mistaken.

August 20, 2008, 04:08 AM

Whats the point of having a suppressor if its not eliminating the noise?

I dont have access to subsonic bullets. I am thinking may be I should sell the suppressor??? Or keep it as part of the kit?

August 20, 2008, 09:28 AM
The suppressor is designed to reduce the noise from the weapon it will not eliminate it. They are very useful on a two way range where others are trying to shoot you. A reduced signature from a weapon can disguise your location and make it harder for others to return fire.

It is not completely intended to make it quiet for you at the weapon itself though that is a great benifit. If you have someone else fire the weapon and you are a considerable distance away you will notice a dramatic difference.

August 20, 2008, 09:38 AM
So it means it will also hide the flash.

Does it effect the velocity or energy of the bullet?

Are there sub sonic bullets for M4A1? Do they eliminate the noise?

For those marines who have used m4a1, how do you rate this weapon in combat?

August 20, 2008, 10:06 AM
I teach the class on how to zero the PEQ 2 and PAQ 4 several times a year, so trust me that I'm giving you good info here.

1) In order to zero an IR laser correctly you must have some sort of night vision and a bore light. After zeroing the bore light you find the correct offset target for the correct weapon, mount, and accessory then line up the laser, sighting system, and bore light to the correct point on the offset target. Since the laser, bore, and sights are all on different planes, failing to use the correct offset will mean that, depending on the range, the laser will hit on one side of the bore lineor the other. If done correctly the laser, bore light, sights, and flood light will hit at points equidistant to each other throughout their range, except as the trajectory changes due to the ballistics of the bullet.

2) HK mags have a good reputation as do magpull mags. I like USGI mags because I think the biggest problem people experience with them is that they are often just very old and have been dropped and stepped on so many times they become out of spec Even these problems are rare. I'd rather have new GI mags than used HK mags and I can getnew GI mags whenever I want.

3) A suppressor only hides the noise of the bullet when it leaves the muzzle. a supersonic bullet in flight makes a noise as it passes by you (when you've heard it you don't forget it) By hiding the noise at the muzzle, it is harder to determine the directioin that a shot came from. Using cartridges loaded to subsonic velocities makes the bullet less audible over it's path, but reduces it's effectiveness to about the same as a .22lr. Even a suppressed M16 with subsonic ammo is going to make noise from the bolt cycling, and the redused power may make semi auto functioning problematic.

4) If a laser isn't holding it's zero it's more likely to be a problem with the mount than the laser. There is no way to hold zero with a loose mount. We always have students retighten everything after firing the first 2 shots.

IR will show up fine in a darkened room with enbough ambient light to read a newspaper. leave the lens cap on the NVD and turn the laser to the bright setting.

There is no such thing as subsonic bullets, only subsonic loadings for cartridges that result in the bullet travelling at subsonic velocities. A bullet is just the projectile that leaves the barrel; not the case, powder, or primer.

August 20, 2008, 08:18 PM
What brand of suppressor do you have, is it a wet or dry version, are you using it correctly?

I have used a surefire detachable on a M4orgery and it made shooting without ear protection very comfortable. it also distorts the report as you hear it away from the weapon, so that gunshot is very hard to detect from a distance away. Your mind does not say" aha, gunshot" it goes " what was that" and you think, air hose, tire leak, popped beer can etc, not "gun shots, get down."

Rant Casey
August 22, 2008, 03:40 PM
I have buddies who detested it, I for one think it is a fine weapon. I've heard "stories" of insurgents taking 5 or 6 hits from an m4 and continuing the fight, I've personally never seen it. In fact, one or two shots COM is enough to do the trick, i've seen people take more and continue to breath, but they were out of the fight for sure. The same people who complain that the 5.56 is weak are the very same people who would be complaining about having to clear a room with a longer rifle or having to hump an m14 all day long in 120 degree heat. Relability? I've never had my rifle die out in a fight, but I also maintained it as well as possible. In a situation where propper lubrication isn't always availible to the point where my CLP was from my family, it can get nerve racking but as long as you have the means to take care of the weapon, it runs perfectly. I'm attesting to it's function 100%, and this was with a carbine that had seen much better days. There was enough play between the upper and lower to watch a movie through, but it never affected function.

The only improvement I could see on the rifle as of right now would be to chamber it in something a little more potent, like the 6.8 spc but like I said, the 5.56 is suitable for the purpose at hand and I know many other men who can attest to that.

For those marines who have used m4a1, how do you rate this weapon in combat?

September 9, 2008, 06:17 PM
I also beleive that 5.56 is an adequate round. If anything more I rather go 7.62x51 than experimenting.

Last weekend I shot 30 mags without a single hickup. Pretty good.
Has anyone used Beamshot 1000S with M4 with barrel mount? If so, how well does it hold its zero when mounted on the barrel?

November 16, 2008, 12:59 AM
After about 1200 runds from my M4A1 (not all at the same time) I had my first jam on firing second mag in full auto. It FTE while trying to push a fresh round in chamber, thus jamming both.

Took off mag, pulled bolt back, cleared the malfnc, reinserted mag, bolted, and it good to go for the next 40 or so rounds.

However, I confidence in the reliability of the weapon has taken a dive.

How come I never had a jam in firing AK over past 19 years; and from various AKs?

If Russian could perfect a weapon 60 years back I think American should have as well. To many jams may not be problem since they are civilians not living in intense zones, but for those who actually use weapon on frequant basis for defense or those who are in service, are quite troubled with this problem.

Any marines here who might have some suggestions regarding M4 jams of this sort?

November 16, 2008, 11:24 AM
Jams happen, its a fact of life...when was the last time you cleaned it? The ARs arent like AKs, they need to be cleaned and lubed reguarly to function properly...

And you were firing full auto?

November 16, 2008, 11:41 AM
The only real problem I see if feeding problems. Some instructors suggest you load a cartridge, take out the magazine, and feel that the cartridge has switched sides. If the cartridge on the left was up and now the one on the right is up...you know you have one in the chamber. An effective way of checking at night. However I feel tht if the bolt is closed it is very hard to get the magazine back into place. When the BCG is open there is no tension when the mag is put into place. However when the BCG is in the way you have to slap the magazine up hard enough so the cartridges get pushed down a hair and THEN the magazine clicks into place. I have run this drill to see if I have chambered a round many times, and after the first shot the chambe loads empty because the magazine isn't properly set. This remedial action is needed. Not a HUGE deal...but I think its a big one. So when you insert the magazine, PULL on it. Make sure its in place.

This is my biggest failure with the ar15/M16 platform

November 16, 2008, 01:47 PM
I only load 29 rds in my mags. I hear alot of other soldiers say 28, but they're mostly old timers and the mags with green followers seem to be much less susceptable to magazine spring tension problems.

November 17, 2008, 01:59 AM
The last I cleaned before jamm was two month ago when I fired it last. The guns was kept in clean enviornment.

I used full auto mode.

Had 28 rounds in the mag which jammed.

B. Lahey
November 17, 2008, 02:20 AM
I like to apply a small amount of lube before firing if my AR sits unused for a long time, even if it was properly lubed after I cleaned it last. CLP tends to "migrate".

This is particularly true if it was stored muzzle-up in a rack or leaned against the wall. You end up with a bunch of lube in the spring tube and very little on and around the bolt.

December 9, 2008, 06:06 AM
whats the time frame we are looking at before applying lube to unused M4?
Also in a sudden use or emergency that could be a problem. Perhaps keep it well lubed all the time?
How much difference does lubing makes since even after lubing m4 did pretty bad in the dust test?

B. Lahey
December 9, 2008, 10:13 PM
When only target shoot with my AR now, but when I kept it ready to protect the homefront I would break it down and make sure there was lube in the right places about once a week.

They actually run better in dust when slightly sloppy. Not dripping, but a little extra lube improves things according to some military tests done not long ago. If I had to rely on an AR in a dusty area I would break it down and clean/lube it every day, using slightly more lube than usual.

February 7, 2009, 05:59 AM
Well I will lube it up and leave it in its airtight case.

Al Thompson
February 7, 2009, 07:57 AM
The jam you describe sounds more like a magazine issue. Try marking the magazine (Magic Marker) so if you have another jam you can determine if it's that same magazine.

Poor magazines are the curse of the M16 platform.

B. Lahey
February 7, 2009, 08:33 AM
That is certainly so. If that mag gives you a problem, beat it into a frisbee with a hammer or use it for target practice.

February 7, 2009, 09:57 AM
Hello there, Firepower. You don't seem very happy. Why don't you sell me your M4 and get yourself a few more AK's? I know that's not possible. It's a joke.


I guess I'm an old guy but I am a Viet Nam era Marine. You must certainly live in a threatening environment where you lose sleep over your rifle jamming every 1200 rounds. Perfection is in the realm of our Creator. Unfortunately, in a real world, we have to settle for something a bit less.

I would happily take any M16 variant out there into combat.

And I gotta say, "more lube"??? When in dusty conditions, you need more lube? Really ?? Who did this test?? I'd like to read about it.

I find that pretty hard to believe. In my experience, you use LESS lube in dusty conditions. Lube and especially extra lube causes the dust and sand and dirt to collect and even clump up. This is not conducive to trouble free operation. :cool:

Just my .02.

By the way, I'm looking for an M16 if anybody needs to move one.

B. Lahey
February 7, 2009, 01:26 PM
Yep, ain't that the damndest thing? Goes against all the previous wisdom, but it's apparently good to apply a little extra lube to M4s in dusty conditions. Lots of people have been talking about this test, and the reports from the field that came afterward that seem to confirm it.

Best I could come up with on short notice (there's lots more discussion out there, do a google search):

The dust test exposed the weapons to the same extreme dust and sand conditions that Army weapons officials subjected the M4 and M16 to during a “systems assessment” at Aberdeen last year and again this summer. The results of the second round of ATEC tests showed that the performance of the M4s dramatically improved when testers increased the amount of lubrication used.


And yeah, I know armytimes has a grudge against the M4, but they seem to have reported on this test correctly. They said pretty much the same thing as everyone else who covered it.

Bartholomew Roberts
February 7, 2009, 01:52 PM
What Al said. What you describe is typically a feed issue. Also you can load HK mags to 30, they are designed to be longer than USGI mags for just that reason.

I personally have little experience with the HK mags; but I know guys who shoot a LOT. They report the HK mags start out great but have short lifespans in heavy use. Turns out the stainless steel bends, dents and splits much like aluminium and the extra weight of the steel mags makes up for the extra structural strength.

February 7, 2009, 02:34 PM
Okay. I see what your source is.

Does NOT mean I agree. Aside from any possible agenda that the people doing the test may have had, the test just doesn't make sense.

They tested the guns heavily lubricated and overly lubricated. Where's their test on a dry gun?????

Take two pieces of glass ... glass is smoother than any part on that gun. Spray your favorite lubricant on one piece. Now dump sand on both pieces. Pick them up. Which one has sand sticking to it?

The whole tube system has been an issue since the gun was developed. I'll grant you that. And I was on the ground when the first 16's with FA's showed up. I know it's not a perfect gun.

But if you take reasonable care with it, it will sure do the job.

I can't get over the fact that they didn't test the gun dry. And when I say dry, I mean wiped off so that sand DIDN'T stick to it.

Bartholomew Roberts
February 7, 2009, 03:20 PM
45One, the Army did three lubrication tests that year alone in dust conditions and every single one replicated the results from the earlier 2001 Crane Dust Tests that compared wet lubes to dry lubes for desert use.

The Crane test summary is basically this: The wet lubes won every time because while they do attract more gunk initially, the presence of the wet lube allows the gunk to migrate to non-critical areas of the firearm. Dry lubes do not attract as much gunk; but once that gunk gets between the chambers and locking lugs (and that happens quick in blowing, fine, sand), it doesn't allow it to move as much.

The Crane test also tested a bone dry M16 as well. It malfunctioned about six times more frequently than the CLP M16 (although it still beat four of the other tested lubricants). I've posted a quick summary of the results of the Crane test as lubetest7.jpg and the chart showing malfunctions as lubetest22.jpg.

The key to reliable AR15/M16/M4 operation is:

1. Good lubrication. ARs can be run wet and dirty; but not dry and dirty. Key areas for lubrication (where you should see a visible sheen of oil) are every part of the bolt but the bolt face and face of the locking lugs, cam pin, and the rails of the bolt carrier.

2. Good magazines. I know USGI and PMags work, so I don't bother trying anything else.

3. Good ammunition. I've never had any stoppage with Black Hills. Beyond that, the ammo that has been most successful has been brass-cased, military type ammo such as Guatemalan 55gr, Federal XM193, Federal AE223, Winchester Q3131A, etc.

B. Lahey
February 7, 2009, 04:47 PM
I don't blame you at all for being sceptical, I didn't buy it either at first. But now it's not just a test result, those results have been duplicated in the field. It's no longer theory, it's just a weird fact that nobody could have predicted before it was tried.

Your thought experiments are valid for a lot of other arms, heck it's been the standard wisdom pretty much forever, but with the M4 in dust it's the opposite.

Like I said, it's the damndest thing. I don't expect you to take my word for it, go on and dig around some more. It's the way it has shaken out.

February 7, 2009, 07:25 PM
No ... heck ... I guess, it's okay if that's what they say.

It's really funny and I'm not making this up. I went to the gun show today. I haven't been in a while. Down at the end of one row was some guy selling some kind of dry lube. He was demonstrating how superior it was to wet lubes for this exact reason we are discussing.

You guys are specifically talking about the M4. My question would be is there something different about the M4 as opposed to other M16's that I don't know about? I'm not talking about FA's or slab sided vs A3's. I mean something that would explain why the M4? Or is it all the M16's?

I have a young friend who just got back from Iraq. He's a Recon Marine and a Mustang on top of that. We've talked about a lot of fun things he got to play with but we haven't really discussed the M4 much. I am going to email him and ask him what he and his buds thought about it. I'll report back.

Bartholomew Roberts
February 8, 2009, 09:37 AM
I mean something that would explain why the M4? Or is it all the M16's?

The better wet than dry results are for all M16-family of weapons, though I think only the M4 and M16A2/A4 have been tested officially.

B. Lahey
February 8, 2009, 09:32 PM
Pmags are the fancy new plastic AR magazines made by Magpul. I haven't shot mine much yet, but they seem to live up to the hype. Tougher than aluminum mags, lighter (and possibly tougher) than steel mags.

They were hard to find for a minute there, but they seem to have kicked up production and they are starting to show up for sale again.

February 9, 2009, 09:08 AM
I am taking out my M4 tomorrow. I am going to shoot about ten or so mags. Clean it good and lubafiy it heavily and store. Its not my to go weapon since its very expensive here. My to go weapon remains AKSU74.

February 9, 2009, 09:22 AM

March 11, 2009, 05:47 PM
You want to know how you know you are getting old? You forget where a thread is that you want to write to !:eek::eek:

Since I was on this thread and since I was the only guy left who thinks that too much oil is bad I decided to look around.

I have a friend who just got back from the sandbox. He's a Marine. He's been active the last fourteen years. He's done two tours in Iraq and is headed for Afghanistan soon. He's a Mustang. He came up through the ranks and is now a firebreathing Captain who keeps his men squared away. He's been a Recon Marine. Hell, he's done it all and continues to. If I could be younger I'd be trying to be him.

Anyway, without giving away anything about why I was asking, I asked him about the M4 and what he thought about it. This is what he had to say:

"When I enlisted and up until the beginning of the war we were using the standard M16A2. Right when the war began the USMC started buying the M16A4 which we still use. It has a 20in barrel and the rail system around the barrel. Since the war has been going on we've been using more and more of the M4. It's a good carbine for what it is made for. The government version is still 3 round burst and has a 14.5in barrel. The civilian version has to have a 16in barrel and no auto features. I have one myself. The Class 3 ones that you can get as a civilian are pretty expensive, but good buys and some are even investments.
"For days sights we use the Trijicon ACOG, but I use an Elcan Spectre on my own rifle. Its the new sight that the Army SF and many USMC Recon units are switching to. As for the night, we don't have a dedicated sight yet, but there gong to field one sometime this summer. Thermals are great, but if the ambient temperature is high (Desert) then they don't help so much. In the mountains, snow and cold weather they are probably great

"We use burst, but very very rarely. It is discouraged, unless you are first through a door or something like that. It is very hard to hit anything further than 10-20yds unless you practice with it. The way the trigger is set up, when you flip to burst and pull the trigger it fires 3 rounds at a very high rate of fire and then resets to fire another burst. You wont get stuck with a trigger set to just fire one round accidentally.

"Also, FN Herstal makes all of our M16A4s, M249 and M240 machine guns. Colt only has the M4 contract left and their M4s are generally lower quality than the M16A4s. The trigger on the M4 is horrible compared to the M16A4.

"The guns do ok in the desert, you just have to keep them clear and use very light lube. Too much and it will gunk up really bad. The M16 family of weapons isnt really too bad to be honest. I bought an LWRC upper and like it quite a bit. It is a piston driven type like the HK416. Ive had to send it back to LWRC for some quality control issues, but when it works, it works. THe HK gun is also really good and they've done some great bolt carrier and trigger improvements to allow for safe and reliable full auto fire."

March 12, 2009, 03:25 AM
I dont know why your friend thinks that the government model is still 3 round burst..... That was M4, which was replaced with a full auto version, M4A1 Carbine.

And I have it so there is no arguing that. That said, I assume that if your friend does not know the current model ho can he comment on something more complex with respect to maintainance.

March 12, 2009, 08:47 AM
And that's why I hate calling tech support....:)

I'd give anything for you two to meet and discuss it.

All of a sudden you know everything about the weapon when your earlier questions show otherwise.

It might interest you to know that I just bought a brand new M16A2 that is marked burst but is factory full auto. Now, how in the world did that happen?

Hint ... it wasn't an accident.