How To Build A Carbine For 3 Gun That Mimics My M4 (army Issued)

[Leozinho]

Hi folks,

I'm going to purchase/build a AR15 to be use in 3-gun matches. I'm in the military, and the reason I started competitive shooting in the first place was to increase my weapons proficiency. (But now I've been bitten by the competition bug.)

So, for the same reason's I shoot a Beretta handgun, I'd like to keep my carbine similar to a milspec M4. However, I would make some concessions, or changes, to make the rifle competitive, if necessary.

I'll be shooting iron sights in the limited division. (Later I'll put on an Eotech, but I'm not concerned with that now.)

Is there anything I need to do to a Rock River Car A4 (for example)? Add a compensator? How much will I be giving away by using the shorter sight radius that this rifle has?

Thanks.

[Jaxshooter]

Just change the bird cage comp/flash hider to a Cooley, Miculek or JP comp. You may want to change the trigger to a JP or Jewell. Unless you are out west most 3 gun local matches are relatively short range the barrel length won't hurt. My JP rifle only has an 18 1/2" barrel. I don't think many people are using much longer barrels due to the weight.

[uscbigdawg]

Hey,

Just start with a good carbine and swap the trigger and muzzle brake as mentioned above. The big thing is order a flat top with a removable carry handle. Make it easy the first time.

I'm with you...I love my duty M-4. He's got an TA01NSN on him most of the time, but when we are getting ready for MOUT I go to the armorer and put the Aimpoint on him.

No vertical grips and that crap, just keep it simple. I'd free float it, but that's me.

Other than that, welcome to the best disease you could ever contract.

SPC Richard A. White, Senior Medic

249th MP Detachment

[kellyn]

Competitve, Limited Division, and M4 do not belong in the same sentence. You'll struggle with the short sight radius on shots of any difficulty. I'd really consider putting a scope or dot on the rifle. Getting a Benny Hill Special (Simmons 1.5-5X) and a Larue scope mount puts you out $250, well worth the ammo that you'll save.

It is one thing to compete with your duty weapon (a noble goal to be sure) but another to struggle in an event by using inadequate equipment. If you use an iron sighted M4, you'll struggle. You'll increase your weapons proficiency greatly by simply competing in any division - even Open! So save yourself some grief and scope that rifle. Tell them I said you ought to scope your work rifle as well.

[Leozinho]

Thanks Jaxshooter and Richard and Kelly

Richard, I tried to send you a PM last week, but can't tell if it sent or not.

Edited May 10, 2006 by Leozinho

[George]

Kelly is right, get a scope and get a muzzle brake. A 16" bbl with irons is gonna' kick "your" butt on long distance stuff every time. Might as well be shooting a long barreled pistol at that point.

[11.43mm]

Leo,

Thanks for keeping us free.

TRY (read borrow first) an EOtech, and compare speed to iron sights.

Henry Avant can get you a good comp and dial it in.

I'd love to know how you do with iron sights.

DVC

[SinistralRifleman]

I'll have to respectfully disagree with several of the posters. If your mindset is such that you are using 3 gun as a venue to practice gun handling and marksmanship, I would suggest using your iron sights (if that's all you're issued). If the rifle/carbine has inherent short comings using it regularly will help you develope skill and perhaps techniques to work around those short comings. Start out with the flat top M4 with detach carry handle...buy optics later if you feel you need them or if you end up getting issued them, you can outfit your rifle to be the same.

On the other hand if you feel Uncle Sam is giving you enough training ammo and range time with your M4, by all means build whatever you feel you need to have more fun shooting 3 Gun in your free time.

It all comes down to what YOUR goals are, and what YOU are trying to accomplish by competing.

[EricW]

If you're trying to replicate your work gun, I'd pass on the brake and fancy trigger. If you do any trigger work at all, I'd talk to JP and ask how to make the triggers on both guns comparable without reducing reliability. There is nothing remotely comparable about shooting a 3lb JP trigger with a gritty 8-9lb military trigger, particularly offhand. See if you can get both to break somewhere in the 5lb range. At least that's a workable situation.

Take all the money you would have spent on trigger/comp and scope both rifles *identically*. I've got the holo figured out to where I can reliably get hits out to 350. I won't be as fast as everyone else, but I can get the job done - as long as I can SEE the target. If the target is very dull against the background, I'm screwed.

If the matches you're shooting have white plates on dull backgrounds, your only real hope is magnification.

[kellyn]

I both agree and disagree with SinstralRifleman. Leozihno, you obviously will set your own goals. They may be similar or completely different from my own. That's cool. If you WANT to shoot an M4, that's great. Get out and do it.

BUT, you decided to ask your question on Brianenos.com, lair of some of the finest (if not the finest) competitive shooters on the planet. This is a competitive shooting forum not tacticalforums.com or glocktalk or 10-8 or tactibillies.com etc. You are asking advice of the likes of Bruce Piatt, George, Kurt Miller, Tony Holmes, Todd Salmon etc. and yes even myself (lucky moderator that I am) about competitive shooting, people with years of experience and successful shooting careers. Competitive shooting implies -by its very nature - scores and ranking and who won and who lost and WHY.

So if you want to take your M4 and bring it to the matches to improve your skill with it, GREAT. But why even ask how to improve it? Why? Because I suspect, like most people you want to go to a match and do well. So I'm telling you that a stock M4 is not really competitive in our world - or the world of highpower for that matter.

I want you to do well. Shooting an M4 with a stock trigger and super short sight radius are not the ingredients to do well. If you and I were of equal skill and I was competing with a stock AR15/M16A2, I've already got you beat in Limited. Add a AccuracySpeaks/JP trigger, I've got you beat some more. Add a skinny front sight, I've got you beat some more. Add a Miculek comp, and I've got a little bit more. I've already got a huge advantage on you and I've only spent $250 more. So if you want to do well, I would take some of our advice.

Finally, ANY competitive shooting experience will serve you well in the real world. If you doubt that, ask Joe Foss why he thought skeet shooting with a 12 gauge O/U helped make him a deadly fighter pilot in a Wildcat. And I can't think a shooting sport more innocuous that skeet!

Finally, Finally, you are not going to see too many AMU shooters (some of whom have some real deal combat experience) at any three gun match with an M4 - although I hope they make Robbie Johnson, Greg Coker, and Daniel Horner shoot stock M4s. That will make my life easier.

[George]

I have to thank Kelly for including me in a list with those names on it (I am honored).

I would like to relate my experience with a stock Colt HBAR trigger and what it did for me. It strengthened my character by extending the time it took me to learn to shoot NRA HighPower fairly well, but it also discouraged me so much that I burned out on it before I got to be any good at first. I had to come back later with better gear to see the difference.

I started shooting NRA High Power Rifle way back in 86-87 with a box stock Colt HBAR and the Sierra SMK69 going downrange as fast as I cauld smack it with WW748 (2900ish in those days). It took me almost 18 months of hard work to earn a Sharpshooter card and I was getting pretty darned frustrated by then. It was primarily due to the lack of trigger control on the slowfire prone and offhand portions of the match. I had started the quest determined to make Expert within a year and with that rifle, just as it was, no moodifications. It was a poor choice in the end because I never mastered that gawd damned awful POS stock trigger and it is now in a parts bin where it belongs.

I could make good points on the rapids but always threw some random 5's and even on-paper mikes in offhand when the trigger stumped me while I wobbled on hold (hadn't learned to shoot on approach yet, and that trigger wouldn't have been capable of it anyway). X's and 10's were hard to pull off on slowfire prone with any consistency, so 8's and 9's were my acceptable shots and 6's and 7's were the oucher's (9's need to be your ouchers in slowfire to get anywhere at all).

About then I got introduced to IPSC rifle and pistol shooting where trigger mashing a stock basher could get you a good score if you did it real, real, fast and I was hooked on the feeling I was getting from being competitive in and winning the local rifle sidematches after just a short bit. Next I discovered 3gun and I haven't looked back much since.

It was quite a few years before I came back to HighPower at all after that. By the time I did, I was sportin' JP triggers on all my AR's. The result was amazing, I know I had improved in many ways, but the differences were striking. I was shooting 9's and 10's all the time on offhand using the shoot on approach method behind a great trigger on the exact same Colt HBAR I had been campaigning back in the 80's (with a few mods though).

This would have been impossible with it's previous trigger. I was feeling like I had all the time in the world between shots on my rapids now because I wasn't trying to carefully prep a crappy pull as soon as possible after each shot and instead was concentrating on settling properly for the next shot. Slowfire prone became a chase the X game with nines being the occasional ouches like it should have been all along.

I still only shoot an Expert score because I don't practice the discipline much (if at all nowadays) and only shoot a match, or two a year if it's a good year, But I do feel like I am shooting to my potential whenever I am on the line now, not just to the limits of the gear and then getting stumped.

If I'd had a great trigger system way back when, I probably would have stuck with High Power instead of jumping wholeheartedly into IPSC. The disheartening accuracy chase in Offhand and Slowfire was very discouraging to say the least. Using the SMK 69 in the wind was bad enough at the 600 end of things, the HBAR wasn't tuned at that time, but the trigger was the worst impediment and it's probably the main single reason I am a pretty darned good IPSC shooter that dabbles in High Power Rifle now, instead of the other way around.

Interesting Anecdote on crappy AR triggers: I was weighing in my trigger for a High Power LEG match back in 87 and the retired Gunny running the trigger scale had some fun with me and my HBAR (the M-14/M1-A was the rifle of choice back then and I was treated to a lot of ribbing about my little black "mousegun" when I was on the line back then). When my trigger didn't break immediately after he hung the 4.5 lb weight on it, he shook the rifle a bit to see if it would break and then some more and it still didn't. He checked the safety, flipped my HBAR upside down, hung the rifle from the weight and finally the trigger broke. He then announced loudly so everyone could hear (everyone was watching by now), "Yeah, you pass sonny!".

Moral of the story, get a good trigger "before" you get serious about trying to get good at shooting a rifle, not "after" ;-/

[ArnisAndyz]

On the M4...in addition to the other changes mentioned I would change the collapsable stock and carbine buffer to an A1 with the rifle buffer. Some people say you can't notice the difference, but it did seem smoother to me, it also has a better cheek weld. Not sure if this is correct or not but I think its like a coil spring of a car. The shorter spring has to have a higher spring rate (stiffer) to handle the same weight as the longer spring. The longer spring can distribute the shock over a longer area, so it can be softer. Riding in my nephews customized Honda is definately more jarring than before he lowered it!

[Paule]

If you are planning to shoot a true M4, make sure your ammunition allows you to make minor power factor with the 14.5" barrel. M193, M855 and Mk262 will, but a lot of the commercial loads that are used at 3-gun matches won't, especially the 50-55 gr loads.

Most matches don't chrono rifle, but it can happen.

[Leozinho]

Again, I appreciate the responses.

Kellyn is correct, in that I did ask the question here on BE because I am interested in being "somewhat" competitive. But I have a long way to go before I have to worry about my equipment holding me back and being the reason I'm not placing.

As far as keeping it iron, I have this vague idea that if I can improve my iron sight shooting it will carry over to a dot. I do feel strongly that one should be able to shoot iron sights well, in case optics go down, etc, hence I'll start with iron sights and look for matches that a separate category for iron sights.

(I actually can have any optic I want, and so far I like the EOTech and will end up putting one on my personal weapon.)

Thanks.

[ryan45kim]

Don’t forget one of the best parts of the AR-15 system; you can snap on any upper you

want for that particular match.

So put a good trigger in it, and get two uppers (or three or four).

[Leozinho]

Here's an update.

Well, I went with a 16" LMT, with a LMT bolt and CMT/Stag lower parts kit. (A bit of a Frankengun, if you consider that I bought the upper from one vendor and the lower from another.)

The 16" barrel is a small concession from a true M4gery. It's a govt profile barrel and the sight radius is the same as a 14.5", but I'll have the option of easily putting a comp on it if I want to play around with one. (I'm also putting on a A2 stock, because I found one cheap. )

I took somebody's advice of staying away from a fancy trigger for now. What I may do is figure out how to do a DIY trigger job, much the same way I've done with my Brigadier. (Not sure how much, if any, the trigger can be cleaned up and remain reliable. I'll work on that much later.)

Thanks.

Edited May 24, 2006 by Leozinho

[George]

Glad to hear you made a decision and are happy with it.

A fancy trigger is not what you want, it's a trigger that breaks when "You" want it to, not unpredictably. A 6-8 lb trigger that is 100% predictable and smooth will allow accurate LD shooting, a 3 lb trigger that creeps spastically and breaks unpredictably will not. That's the difference you are looking for in a trigger group. A stock trigger can be tweaked, but because they are almost always pot-metal under the hardened sear surfaces, they don't last once you start grinding on those surfaces, or setting them for less engagement. The "fancy" triggers are what you want mainly because they are much better metal that can actually handle the job safely without requiring 10 feet of scratchy sear engagement to be safe over the long haul.

[Dustdevil21]

Leozinho,

Being new to the sport myself, and the 3-gun bug bit me hard, I broke down and got a used 16" HBAR DPMS. It is just plain jane with iron sights, collapsible stock. I did the standard Army sight-in with it and was happy with my results.

Then I shot my first 3-gun match this last sunday. That 10" plate on an MGM Flasher is "reeaallll" small at 200 yards with iron sights. Needless to say I didn't hit the targets (there were two of them). It was hard to compete with all of the scoped rifles, but I gave it a try.

I am in the process of building up an RRA A4 upper with 20" Stainless Match Barrel (1-8 twist), some hard earned money went toJP Rifles for a Bennie Cooley Comp, free-float hand guards, and a JP fire control package in the lower. Then I got a good deal on an Aimpoint CompM red-dot, so I am going to try that and see how I do.

Plus a whole lot more practice with the rifle!!!!

Good Luck with yours!