Colt .22 M4 Carbines and how to correct their deficiencies - pictures included

[Mutant Texan]

I bought the Colt .22 M4 Ops carbine when if first came out in 2009 on impulse during a visit to my favorite FFL.  I like the aluminum construction and how the carbine felt in my hands.  My joy turned into rage and frustration on the first trip to the range.  The gun never had issues eating ammo.  The gun was able to cycle most ammo that I fed it once I had the spring tension set correctly.  The only ammo that I was never able to get the gun to reliably eat was the garbage known as the Remington Golden bullet.  This Golden bullet junk ammo would also not correctly cycle in any of my other semi-auto .22 LR firearms.

The source of my frustration was the issue of not being able to zero the rifle with the O.E.M. sights.  The carbine always shot high even with the rear sight bottomed out.  I next tried to raise the front sight.  This failed because I had raised it so high that the detent and post would pop out and the rounds still went high.  There was only one quality about this carbine that made me stick by it and not sell it off.  It would put bullets in the same wrong hole over and over again.  It was extremely precise but inaccurate.  When I fired this carbine with it secured to a bench, it would put the holes in the paper all within 0.75" at 50 yards.  This would be about 1.5 MOA in .22 LR carbine at 100 yards!

The precision of this .22 LR firearm is the best of all the guns that I own in this caliber.  I solved my accuracy issue by throwing a cheap Tasco Pro Point on it, taking off the front sight post and accepting it in it's flawed form.  It would be many years before I decided to circle back and find a solution that would allow me to have iron sights on it. 

I later found out why this carbine is so precise.  The barrel is a match grade barrel in the form of a high quality steel liner on the inside of a cosmetic black aluminum barrel sleeve.  The flash hider in the front threads on it and actually tensions the barrel between the receiver and the flash hider.  Many people that don't know what they are talking about and know nothing about metallurgy make disparaging comments about the barrel of this carbine.  This is actually one of the best ways to make an accurate and precise barrel.  The thin profile of the steel barrel also allows the heat to diffuse through and dissipate quicker thus maintaining the high level of precision even when it gets hot.

I have had this Colt .22 LR carbine for almost 7 years as a "fun" gun.  I brought my trusty Wally World Stainless steel Ruger 10/22 with a Techsight upgrade to my first Appleseed.  This rifle has always been dependable but it was never quite as precise as the flawed Colt .22 LR.  I was able to score a 210 on an AQT using the Ruger 10-22 and decided to somehow engineer out the flaws of the Colt to allow me to use it at a future Appleseed.

I first had to figure out how to get a longer free floating hand guard with a rail on top of it.  The stock hand guard is only 7" long.  The barrel of this gun is 16" long.  Clearly this stock hand guard is one minor step above being useless in terms of maximizing sight radius.  I decided to figure out a way to get a longer hand guard on it. 

Installing a longer hand guard became a lot more difficult than I had originally thought it would be.  The barrel nut uses some weird non-standard threads.  I was able to measure the outside threads to be "about" a M37 - 1 mm.  I was never able to confirm this because I was unable to find any thing in that size to test it.  The 1 mm thread pitch bolts did seem to fit well as I held them together.  The inside threads of the barrel nut appear to be similar to that of a standard AR but I never measured it to confirm this.

I was trying to think of a solution for how I could possibly pay lots of money to a machinist to tap a raw hand guard with the non-standard thread dimensions required when I had a eureka moment.  Walther later made a Colt .22 M-16 SPR after the initial release of the M4 model.  I found a hand guard and barrel nut kit that allowed people to upgrade their Colt .22 M-16 rifles to the SPR model.

My fixed Colt .22 LR M-4 Ops now has a M-16 SPR hand guard on it.  The barrel is free floating perfectly in the center of the hand guard and I attached some Magpul Mbus Pro adjustable sights to it along with a Magpul QD swivel.  The sight radius is now 18".  The original sight radius was 12.5".  The tension of the sling is now completely off the barrel and on the hand guard because the front sight assembly, which had the original front sling swivel, is now removed.  I have not zeroed the rifle yet but based on my experience with how precise it is and the fact that these Mbus sights are designed for the 5.56x45 round, I should have no problems adjusting the rear or front sights to get the rounds on target by moving the rear sight up.

The Walther product ID for the new hand guard is:  Umarex 2245113 RIS for M16

The new mass of the carbine with no magazines inserted is 7.4 lbs

This carbine will eat the whole spectrum of ammunition if you correctly set the tension of the bolt spring.  It is a simple turn of an allen bolt using a supplied Allen key.  This gun is designed safely shoot the CCI Velocitor or Stinger round.

The stock trigger is not bad but I wish that I could install a 2 stage trigger with a lighter pull.

[Mutant Texan]

*Colt .22 M4 OPS update*

I was finally able to go out to the range and try out this new setup on my Colt .22 M4 OPS.  I discovered a new annoying issue with the carbine.  The last round bolt hold open device did not always disengage when pulling the charging handle back after loading a charged magazine.  The only way to fix this was to drop the magazine, pull the charging handle back to let the bolt close all the way, reloading a charged magazine and then charging it.  This was not repeatable nor did it do this on every magazine swap.  The only way that I see getting around this is to close the bolt each time I drop an empty magazine out before loading a new one.

Other than the above issue, the gun loaded and fired every round and had no other malfunctions.  I used Federal Lightning 40 grain rounds.  These are the same rounds that I used in a Ruger 10/22 last June to earn a Rifleman badge.  Unlike the bulk Federal ammo, this stuff has never given me a dud.  I plan to go back to the range and try the CCI Mini-mags, Stingers, and velocitors.

The Mbus front sight is not as good as the Tech Sight installed on my Ruger 10/22 IMHO.  The Tech Sight front post is thinner and allows the shooter to get a bit more precision/accuracy.  I think that the front sight post on this carbine will need to be addressed to shoot a Rifleman score in the future.  I do see that Mbus offers a "Match" width sight post that is 2/3 the width of the standard sight post.  I will order it and see how well it works.

The targets were setup at 25 yards and I shot prone with a USGI sling.  I know that Cadence will shake his head in disappointment at reading this.  I struggled to remember the 6 steps of shooting.  Once I got to step 7 and still had not pulled the trigger, I just started letting the rounds fly down range. 

The groups are not that bad considering how rusty I am.  I shot 10 rounds per target area. 

[TomM1Thumb]

Please let Us know how this rifle does after You install the  Mbus  "Match" width sight post. You should do well at Your Next Appleseed using that Rifle, on Sunday second AQT.

[maxwell]

The Mbus front sight is not as good as the Tech Sight installed on my Ruger 10/22 IMHO.  The Tech Sight front post is thinner and allows the shooter to get a bit more precision/accuracy.  I think that the front sight post on this carbine will need to be addressed to shoot a Rifleman score in the future.  I do see that Mbus offers a "Match" width sight post that is 2/3 the width of the standard sight post.  I will order it and see how well it works.

Thanks for the additional info on this rifle; I've not seen one on the line, but know at least one person who has one.

For what it's worth, the USAMU FAQ http://thecmp.org/training-tech/shooting-tips-from-the-usamu-service-rifle-team/usamu-faqs-equipment-and-ammunition/ says

I recommend that you use a wide front sight post. It will be easier to see and stay focused on. Most of the shooters on our team use a front sight that is .064" to .074" in width.

Personally, I find the Tech Sights post to be too narrow, though not as bad as the one a mall ninja at the local range proudly showed me: his "match" post, filed to a needle point . The wide post can make it easier to focus (one of those six steps!), and to center on your target blur (depending on the target width). The sight-in target you're using might be an exception; I think those work better with a scope or dot sight, at least for me. Practice the six steps and prone steady hold factors!

[Agrivere]

Maxwell is quite correct about front sight width. While i know a few good shooters who use a narrower front sight by FAR the vast majority use the fattest front sight they can reasonably get. On an AR this is usually a front post that's 0.072" wide, which covers about 12 Moa.

A thinner front sight post SEEMS more precise at first, but it's a fools errand, as most of us will very quickly lose focus on the tiny post and groups will suffer. Especially when eyes start getting tired the fat post is vastly easier to focus on, and I can assure you it's no less precise. Give it a try and I bet you'll like it!

[Mutant Texan]

I will leave the front post alone based on feedback from others.  I might look at coloring the post with something that will contrast with the AQT targets.

I do have a follow up question about the other Colt .22 M4.  Did that person have as many frustrations with their carbine as I have had with mine?  I know that many reviews of the first generation of this gun were not so good.  The reviews on the second generation seem to be a lot more positive.

The only reason I put up with this carbine is because it did shoot with precision and that means a lot.  I think it is actually more accurate than my 10/22 and I have never had problems with the 10/22.  I highly recommend the 10/22 for the first Appleseed.  I have also held a S&W MP22 and I saw how a tight sling can curve the gun.  This is a not starter for me.

I paid about $430 for this gun brand new in 2009.  I want to get the M16 version but I am a bit gun shy after all my frustrations.  If anyone has real world experience with the Colt .22 M16, I would love to hear it.  It is petty sad that it took me 7 years to correct this gun and get it right.  The only reason that I found the motivation to fix the iron sights and take off the Red Dot was going to my first Appleseed last May.

If any Walther engineers read this, please allow for standard AR furniture in future designs.  You guys could have a winner here if you could customize it more and get the price down to the $350 to $400 price point.

[Kosciusko]

I have seen 3 of the Walther/Colt rifles at the range, not during an Appleseed.    All were jammomatics.  I did not know about adjusting spring tension.  I will give them a second look.

[Mutant Texan]

I bought some new 20 round magazines recently from Umarex/Walther for my next Appleseed (I like the size of the 20 round when shooting prone).  I could not get either of them to insert correctly and lock in place in the mag well.  This is another annoying issue.  The 30 round magazine that came with the gun always required a good forceful slap to the bottom of the mag to lock it in place.  This was never an issue because this is habit that I do anyway.  The magazine always felt tight in thegun which was a good thing.

*Picture included* I called Walther up and explained the situation of the new magazines not locking into place.  He asked if I was using Walther made magazines and I told him yes.  He was able to look up some info and saw that I had indeed recently ordered new magazines from their online store.  The gun smith told me that he would send me a new magazine catch release to see if this would resolve the issue.  It did not.  The new magazines still failed to lock into place.  I decided to see where the magazine catch was hanging up and see if maybe some break in would be needed on the magazine.  I found the spot on the magazine where the magazine catch grabs on to the magazine.  It was a bit worn already because it had a nice shinny spot in the notch.

I grabbed a good knife and went to work shaving a bit of the plastic off the magazine.  The magazines did insert and lock in correctly with minimal plastic removed.  I tested the magazines and they all functioned correctly.  They did not have a single failure to feed malfunction.

I also painted the front sight with a Bright Orange paint marker.  You can see it in both of these pictures that I am posting.

I am not blaming the carbine for this magazine issue.  I think that it is the magazine's fault because the original magazine worked out of the box and the new magazine catch release did not resolve the issue.  I do think I have finally worked out most of the bugs on this gun.

I paid about $430 for this gun brand new in 2009.

My memory was clearly not accurate here.  I found the original receipt for this gun.  I bought it in June of 2009.  The gun cost me $609 from a local FFL.  With tax it was $648.59!  I have not priced one of these Colts recently but, had I known about the CMMG dedicated upper, I would have probably bought one of those and passed on this gun.  If I can find one of these new for about half the price, it may be something I would be willing to try again.

Considering how a good Ruger 10/22 is these days in terms of price point, accuracy and reliability; $648 for this Colt was way too high a price to have paid.  I bought the Walmart Stainless Steel Ruger 10/22 that has the longer barrel than the standard 10/22 before I bought this Colt.  I added quick disconnect swivels, a USGI sling, and Tech Sights to the 10/22 and scored Rifleman at my 2nd Appleseed. 

[TimBeatty]

I have 2 of the Colt  M-16 SPR versions. I had the triggers worked on so they are about 5 lb and crisp. I qualified with them many times. First time was Jan 2011 with open sights. I later put scopes on them. They are quirky to use. Before my first shoot i went to the range a lot with them to fully understand them. I have 6 of the 10 round mags that I use for Appleseed. I think they may be one of the most accurate 22s out there if you get the SPR model. Other models may be worse for accuracy because of how the barrel and hand guard is designed. The 15 inch free float hand guard makes the difference