Previous Post
Next Post


Last month, I asked a question about how to get into CMP rifle matches using equipment that I have or could purchase. I already own an M1 Garand and an M1A (M14 clone) as well as a SIG SAUER 516 piston gun. I wanted to know if any of those would work or if I should instead be look at picking up an AR-15 platform gun. The general consensus was that the 516 would not be legal for Service Rifle CMP matches, so that’s out. Either the M1 or the M1A would be the way to get started without laying out any additional coin. I hate to admit it, but that was not the answer I was looking for . . .

See, I suffer from the terrible condition of holophilia: I regularly get the unnatural desire to go out and buy guns simply because I haven’t bought one in a while. Fortunately, I’m also able to sell guns that I no longer use to fund this disease. I’ve even sold several guns that I never even got around to shooting. The AWB scare of a couple of months ago was rather helpful in this regard as I was able to actually make some money on a few of my sales as opposed to losing cash on my flips.

With that as background, I was really looking for some folks to say, “Jim, go ahead and get that SIG SAUER M400 Hunter you were looking at and trick it out into a CMP match gun.” Guys, you let me down. Fortunately, my aforementioned affliction overrode the common sense that was so prevalent in the comments and I went out and got myself the M400 after all.

Now, what I could have done would have been to go out and pick up an Armalite AR-15 in the National Match Configuration such as the one that Foghorn reviewed a couple of years ago.  Then again, maybe not.

Foghorn reported some interesting problems with his gun that he traced to some manufacturing issues a few months later and ultimately fixed with a new bolt carrier (at least $200).  Either way, the chances of picking up a National Match Armalite at this time of the year with the high power season shifting into high gear and the backlog from the Great AWB Panic of 2013 still impacting the market was pretty slim.

So I decided that if I’m going to do this, I’ll need to build it myself. And I’m starting with the SIG SAUER M400 Hunter as my base platform.


I chose this gun for several reasons. First of all, it has a 20” match grade barrel, rifle length gas system and a fixed stock – all requirements for the Service Rifle category. It also has an unthreaded barrel and no bayonet lug which is nice because I can take it across the border into Massachusetts if I want to compete there.

Unfortunately, SIG aimed this rifle at the hunting market and assumed that users would just slap a scope or other optic on the flat top and be done with it. That means no front sight was integrated into the gas block. Furthermore, since the rifle shipped with a Magpul MOE hand guard with an integrated front sling mount, there’s no place to mount a sling once I changed out the stock for a CMP-legal classic hand guard. And the final reason I chose the rifle was that it was in stock at the local SIG dealer.

The first step was to change out the sights. I bought a Colt detachable carry handle from my local gun shop which had just gotten in a batch of surplus units so I got a good deal on a new piece of kit.


For the gas block, I decided to go with a JP Enterprises JPGS-2FS front sight with gas block.


I went this route for two reasons. First, it mounts to the barrel with screws rather than pins, so nothing special had to be done to the barrel to swap out the included low profile gas block for this one. Second, it has an adjustable gas system so the gun had just enough gas to cycle the bolt and no more. When I explained this advantage to one of my colleagues, he sneered at me and pointed out the gas ports built into the Ar-15 bolt.  These, he told me, already regulate any excess gas so you don’t need an adjustable gas block.

While that’s technically correct, he overlooked one thing. The JP block isn’t designed to vent excess high pressure gas from an overloaded cartridge. Rather, it’s designed to tune the gas system so that the bolt doesn’t come flying back with any more force than it actually needs to cycle. This reduces the shock of the bolt hitting the rear of the gun and should help to improve accuracy on those 600 yard shots. The only downside to the block is that it doesn’t feature the standard sling mount one usually finds attached to the A2 front sight.

This is actually less of a problem than you’d think because for highly accurate shots, you don’t want a sling pulling directly on the barrel, as it will cause deflection and a change in point of impact. What was needed was an attachment that doesn’t actually pull on the barrel – afree floating solution. For this, I turned to the folks at White Oak Armament and their Service Rifle Float Tube.


This little gem attaches to the receiver of the upper and allows attachment of a sling and the hand guards so they don’t touch the barrel. This is certainly something that an experienced person could install, but I’m not that sort of person. Plus, I suspected that I’d have some clearance problems where the sling attachment point met the gas block, so this was something that I referred to the professionals at Wicked Weaponry in Hooksett, New Hampshire. Just as I thought, some milling was indeed required to get the float tube to properly mate with the gas block.


In addition to the float tube fitting, the Service Rifle hand guard needed to have its heat shield removed and the end milled to properly fit into the hand guard cap. By the way, the SIG M400 came configured with a round cap, but the hand guards I bought needed a triangular one. Fortunately Wicked Weaponry had one in stock.

Since this had to fit the Service Rifle as-issued specs, I needed to replace the Magpul hand guard and pistol grip with a stock rifle-length hand guard and A2 pistol grip. These were bought from Fulton Armory.

The trigger that came with the SIG wasn’t bad, but it was also not competition grade. I’ve had a lot of success with Geissele triggers, so that was the next thing that was swapped out. I went with their two stage SSA trigger. The rules of Service Rifle competition state that 4.5 lbs of pull is the minimum and since their SSA-E model has a slightly lighter trigger pull, it didn’t make the cut.


The final pieces of the puzzle were replacing the front sight post with an Armalite National Match post and the rear sight with an Armalite National Match Rear sight. One minor problem that I noted is that the Armalite rear sight screw extends further down than the sight screw that came with the Colt carry handle. What this means is that when the carry handle is attached to the rifle, the rear sight cannot be brought all the way down.

I suspect this may be a problem for long distance shots.  I’m in the process of investigating my options.  I may attempt to grind off a bit of the bottom of the sight screw so that it is flush with the bottom of the detachable carry handle.  Alternatively, I could drill a small hole into the rail mounted on the receiver of the rifle, but I am loathe to make that sort of modification to a gun.  I’m in the process of figuring this out with Armalite now.

Total cost for the build: about $1,700. For comparison purposes, an Armalite National Match rifle with a nearly identical part list would have cost around $1,200 before Newton. I know because I owned one. I sold it during the height of the AR-15 panic for $2,000, so depending on how you look at it, I either paid a bit more or saved a bunch. I’d estimate that today, if you were able to find one, you would probably be looking in the neighborhood of $1,700, so overall the cost was not too bad.

The JP adjustable gas block and Geissele trigger are nicer than what Armalite ships on their NM gun, but if you chose to forego the trigger upgrade, you’d have a price around $1,500. Geissele also offers the Geissele 2-stage trigger which they claim is the same as the SSA. That would save you $45 over the SSA. Since I already had an SSA in my SIG 516 and liked it, I decided not to roll the dice with the cheaper model.

I’m pretty pleased with the way everything turned out. I have an accurate rifle that qualifies for the Service Rifle category on the CMP competition circuit for a reasonable price. If you’re looking to build one yourself, this would be a decent place to start.

Bill of Materials

  • SIG SAUER M400                  $940
  • Colt Detachable Handle      $50
  • JP GS-2FS                            $130
  • White Oak Float Tube        $105
  • Handguard & A2 Grip        $30
  • Gunsmithing & Cap            $130
  • Armalite NM Sights            $95
  • Geissele SSA Trigger          $219

Total build cost                          $1,690 

Previous Post
Next Post


  1. What a bunch of screwing around to end up with a sub par DCM rifle. Plenty of rifles available better than a butchered SIG.

    • Well, I’m always open to learning something new. I’m of course assuming that you have personally shot the 20 inch barrel version of the Sig and have done an exhaustive comparison to some of the other rifles out there. If you want to point me to a link for this info, I’d be grateful.

      Or, are you simply regurgitating something you read that was penned by another keyboard commando? Are you one of those “all Sig rifles suck” kind of guys? Maybe you had a Sig once or knew a friend of a friend who had one and it didn’t shoot well?

      Basically, its a free country and you can certainly share your opinion, but you would have a lot more credibility if you named names and backed up what you had to say with facts.

      • Classic case of building a rifle without attending any matches or even visiting the CMP forums.

        Maybe he’ll get a sling for it when he figures out he needs one and write another newb article.

        • Note that CMP and NRA have different rule books. It is not uncommon for guys/gals to only compete in one organization or the other, primarily based upon the matches their local club offers.

          But anyway, the rules on equipment are different under the two organizations, and the courses of fire are slightly different….

        • FWIW, I did read the rules. Twice actually.

          I do appreciate the advice. I understand your point of view. I took offense at the assumptions you made about me and the process I undertook.

          First of all, as I noted, I wanted a working rifle now. Now in six weeks, not in twelve weeks, etc. I spent some time looking for whole rifles and pre-built uppers and could find nothing interesting that did not have god awful lead times.

          Is the Sig the best thing out there? Of course not. It was however available and was something I could play with while feeling my way around CMP matches. I can always get something else down the road. On the other hand, this particular model Sig is relatively serviceable in stock condition and with the changes I made, should be half way decent.

          I did by the way spend time on the various forums. That was where I learned about such things as the JP Edwards gas block and the White Oak Armory float tube.

        • Glad you took the advice to hit up those forums Jim. Make sure to keep any eye on them, as the m-16/m-4 style matches’ rules aren’t set in concrete yet and are subject to change. Thankfully most of these changes are looking to loosen the rules (such as weight limits), but keep an eye on it.

    • the Sig M400 seems like a great rifle at a great price. I don’t own one but I would like to. My Ex-navy seal friend has a great Noveske that might be superior (shooting < 0.5 MOA) but then again he paid a few thousand for his.

      Your post was interesting. What in your opinion is not a sub-par DCM rifle? You should elaborate rather than just dumping out "butchered SIG." He took what he had with aim to make it more accurate. I don't see anything wrong with that.

      • I don’t know exactly what DCM stands for..all I can say is that to my knowledge nobody uses an M4 configuration in High Power competition due to the shorter sight radius and barrel than a standard “Service Rifle” (M2?) configuration.

        Nobody is saying the M4 cannot engage targets out to 200 and 300 or even 600. But a longer barrel and and sight radius makes this easier to do accurately in other configurations.

    • Which one were you referring to? The LAR-15 is the cheapest and you are at $1,165 once you add in the chrome lined barrel, free float tube, and A2 upper (or carry handle) My cost for those components would have been $1,375, so yes, a bit cheaper, but hardly a lot less. Bear in mind the LAR-15 does not have National Match sights nor is the RRA trigger a Geissele.

      One other thing – what is the availability on a RRA? As I noted, one of the advantages here is that I got this gun now – not in 6-12 weeks.

      • Did you consider just buying a complete upper from WOA, CLE, etc.? I don’t know what their wait times are, but typically this is the easiest and most cost-effective route for a match-grade Service Rifle, i.e. get a complete upper and do the lower (trigger, buffer tube, stock, etc.) yourself in the garage.

        • Absolutely. Unfortunately, seeing announcements such as this one from the WOA website kind of turned me off on the whole complete upper thing:


      • If you are going in with the best accuracy in mind – I wouldn’t go with the chrome lined barrel.

  2. Just a couple of observations.

    The specs on the SIG say the chamber is 5.56 X 45mm NATO. You might have wanted a .223 or Wylde chamber. This opens up the whole endless “chamber” wars.

    The other is that from the weight spec it doesn’t look like you have “heavy match barrel”. My RRA weighs in at 9.7lbs as opposed to your 7.8lbs. Plus you might want to look for the lead weight that goes in the stock. This brings the weight up around 14Lbs overall.

    Finally don’t forget your sling. Buy a good quality 1907 sling and it will be worth it.

    • Thanks for the suggestions. Got the sling covered – Have a nice leather 1907 style sling.

      Can one put a lead weight in the stock? I thought that might be a disallowed modification.

      • Yes you can put lead in the stock, several sources sell a wedge to trim to need and slide right in. Others use buckshot in a baggie.

        You can also put lead weights under the hand guards.

        • Umm, no. Most CMP matches have a max weight of the weapon specifically to keep lead weighting out as this is a SERVICE rifle match.

    • You are probably right, but for me this was as much a tinker project as anything else. I do need to solve the rear sight problem though and they might be of help.

      • Probably going to tell you to ditch the Colt carry handle and get the RRA, or I believe WOA sells one too.
        1) 1/4 minute clicks
        2) Turret only moves in one direction, perfectly…often accomplished by vertical pins the cheaper sights lack.

        Also one of the issues you don’t mention is the twist rate on your barrel. If it is too slow it may not (so they say) stabilize the heavier bullets popular for the 600 yard line.

        Don’t get me wrong, you’ll probably be fine for the first year or two no matter what you do…just about any rifle can get you to Expert or maybe Master and have fun along the way.

      • Also, with your sight problem, the fact the rear sight won’t come all the way down may not be a problem. With iron sights, the POI moves with the rear sight. So for long distance shots, the rear sight will need to move UP many clicks. Although it is possible to adjust (most) front sights for elevation this is typically not done in competition and most guys adjust the rear sight only.

        If you can get a 200 yard zero, you will probably be ok at 600 yards if your rear sight can come up another 16-18 minutes or so from your 200 yard zero. You need to know whether you have 1/4 or 1/2 minute elevation clicks to test this.

        If anything, the fact your rear won’t come all the way down means you would have a problem getting zeroed at 100 yards, where many rear sights start to bottom out.

        • Thanks for the advice. I spoke with Armalite today and they confirmed that is how their rear sight is designed. Their guns have a hole milled in the rail to allow the sight to come all the way down.

          If I remember correctly, a 50 yard and a 200 yard zero are roughly equivalent, correct? So I should be able to initially zero at 50, then move out to 200 to get it properly dialed in.

        • As to the equivalency of 50 vs. 200 yards zero…those are “battle rifle” minute of enemy estimates. It might get you on paper at 200, but do not count on it to be in the black when you get to a match. I think it is better to get a 100 yard zero and know that 90% of the time 1.5 to 2 minutes up will get you squared away at 200.

          The better approach is to try to determine your muzzle velocity, then use a ballistics calculator to figure where at 200 your 50 yard zero will hit.

          But don’t worry, just show up for your first match with some kind of known-distance zero, know the click values on your sights, and the other folks will be patient with you and get you squared away.

  3. I get the impression that there is no “service rifle” left in a competition service rifle. Sort of like the line “there’s nothing stock in stock car racing”.

    • Yes and no. The practical effect of the Service Rifle division, IMHO is that it puts a ceiling on how much $$ one can dump into the rifle and gain an advantage. But yes, there is a floor as well, as a practical matter.

  4. Nice project. Let the haters hate.

    What some fail to realize is, that its not about the money, or the fact that you could get a cheaper or better rifle somewhere else. It’s the fact that you designed it and you built it. As far as you’re concerned, it’s the best damned rifle ever made.

    I once built a scout rifle from an old FR-8, because I wanted to and because I could. Yes, I could have gone out and got the Ruger GS scout, probably for cheaper. But I didn’t build it, and that’s the point.

    • Question for you. Did you get an after market mag kit for your fr8?
      I love my fr8! Just can’t find stuff for it.

    • Brad-

      I agree with you in spirit, but having been in NRA Highpower a number of years, one of the things the whole community tries to do is make sure newcomers are squared away with gear from the get-go.

      It happens quite often where a guy reads about the competitions, runs out and buys the first AR-15 he sees, only to show up and find out that what he got is not really suited to the course of fire. Just like (I’m guessing because I’ve never shot 3-gun) the way we configure the rifles are probably not ideal for say 3-gun. One can know a lot about AR-15s, but it’s important to be able to apply that knowledge to the particular specialized application.

      So I’m hoping things work out for Jim, they probably will. You’re right there is something about building your own. But if after the fact he feels like, “yeah I should have asked around first…” then hey live and learn and hopefully someone will learn from it.

  5. I’m wondering if there is a requirement to have a bayonet lug for service rifle?

    Also, I paid about $1000 for my rock river nm A4 pre Newtown.

    • I can’t speak definitively on that question, but if there is a requirement for a bayonet lug, then CMP sanctioned matches cannot be held in a number of states. Places like MA do not permit threaded barrels or bayonet lugs on anything that was not made prior to the date the AWB went into effect.

  6. Hey, being a gun enthusiast isn’t cheap. Neither is being a car guy. If you’re having fun and responsibly enjoying your freedom, more power to ya.

  7. The problem with your rear sight is that it is made for the A2 upper receiver. There’s nothing you can do that you don’t already know… shorten it, or mill a hole in your flattop. You will want to get it lowered down some more, or else you won’t have enough elevation for 600, without adjusting the front sight. For a club level gun you did just fine, go shoot it and nobody will care about details. If you go to Perry and win, you might be in trouble for the front sight base and barrel.

    • Maybe I am missing something…but as I understand Jim his rear sight won’t move all the way down, and the POI moves with the rear sight.

      If the front sight won’t move down (with irons the POI moves opposite the front sight), that is usually because there is a set screw accessible from the bottom that needs to be backed out (learned that one the hard way!).

      • If the rifle is zeroed @200 with the rear sight sticking up midway, there won’t be enough up travel left to get to 600, without a front sight change as well. This is the reason the upper receiver needs milled, to get the sight down all the way. It’s best to set the rifle up such that you only have to make rear sight changes during a full across the course match. If the author is only going to shoot a reduced course, it won’t matter.

  8. When prices return to normal, I think you could build up a rifle that is DCM legal for a less than that if you start with parts.

    The place to not scrimp is the barrel, trigger and sights. The furniture, receivers, etc… feh. There’s too much attention paid to these items on AR’s in the “quest for cool.” The Sauer has the right twist (1:8), but saying “match grade barrel” doesn’t make it so. Krieger sells a 20″ barrel for about five bills that’s actually a match-accurate barrel with a 1:7.7 twist. I agree with JM above – you could have probably been money and time ahead to purchase a ready-to-go upper/barrel/sight setup, and slapped on a lower and done the furniture and trigger yourself.

    • Yes, yes….but remember in our game the 10 ring is 2 minutes, and most of the course is at 200 and 300 yards. He’ll be OK….for a while. Heck, a lot of guys burn out their first barrel (3K-5K) rounds before they make Master anyway, even with a top shelf upper.

      Whether or not the SIG barrel even has that much life in it…only time will tell…

  9. Jewish Marksman was right on the money with the rear sight – the author mentioned he would have issues with long shots but not being able to lower the sight *could* cause an issue with a 100 yd. zero – assuming you could get a 100 yd. zero, or settled for a further distance, you’d be fine with longer shots.

    While some of the comments are a bit harsh, I’d agree that thoroughly reading the rule book (multiple times, then once more for good measure) and getting some match experience are going to help you more than anything.

    • Yes and no. Just learn to shoot well, worry about the rules and details later. Heck, we get guys showing up with M4s, its all they have, and it’s fine to get started with.

      The “problem” with High Power is we get a lot of guys, former leo and military, who show up who thought they knew how to shoot because they learned to strip and reassemble the M4 blindfolded. They can barely keep it on paper, and some skinny little guy or gal next to them is shooting nothing but 10s. So they are either inspired to come back, or we never see them again.

      Sooner or later the person decides whether they want to get classified, have a “real” match gun, etc. Most clubs will let you shoot no matter what you brung, but may or may not send in your scores to the governing body depending on whether your rifle was “legal”. So if you’re just testing the waters, don’t sweat it.

      It’s like showing up to your first triathalon with a walmart touring bike. Just ride the damn thing, do your best, it will get you from a to b. If you get serious, then yeah, you’ll upgrade.

  10. Seriously doing things the hard way.

    Take lower of your choice and add a fixed A1 or A2 length stock.
    Install decent trigger group such as a Rock River arms 2-stage. The Geissele 2-stage qualifies as a “very nice” trigger and is a good choice if you can afford it.
    Drop in a match upper designed for DCM shooting. (Rock River or WOA would be the top picks) These will have the free float tube already installed.

    • You unfortunately left one thing out: Wait until the 2014 high power season because all the companies that make decent uppers have 4 to 6 month waits.

  11. If you want the number one sold competition rifle at Camp Perry, one should go to Rock River Arms Inc. They have two models of DCM/NRA approved match rifles available. One with the standard fixed A-2 Carry Handle and one with the DCM Competition approved removable carry handle. Both are 100% legal competition rifles ready to go out of the box. The good thing about the removable sight model is if a guy wanted to remove the sight and put a scope on the rifle in the off season he could and then remount the Carry Handle for competition. They also run Competition & Shooter Specials on thier complete line of rifles each year at the Camp Perry National Match in Ohio. And also parts! One can not beat the deal there. They do it to promote the shooting sport and the youth programs as well. They usually sell several hundred of the NM Rifles while they are there each year for the couple of weeks of rifle competition. It is also a great place to go compare NM Rifles since Armalite, DPMS, Fulton Armory and many other manufacturers and providers are there. Plus there are other vendors like Springfield Armory and M&A Parts, and others who run their own Camp Perry Stores on Shooter’s Row as the previous ones mentioned. Also the DCM Store is there that sells M-1 Garands, 1903s, Kimber 22 Match Rifles, and other military rifles. If you have not been there you need to go! Check the website but I think Pistol week Starts the last of July followed by Rifle Competitions. Be sure to call the area in advance for Hotel and Motel Rooms.

  12. Lol. Just got home from CMP & NRA weeks at Perry. Armalite NM rifles $850-$1250 all day long, price depending on what day you walked by. Sales restrictions sucked, unless you happened to live in Ohio or a neighboring state; whoever was responsible for that should be replaced. Great two weeks though.

  13. One issue that will pop up if you shoot actual CMP (Civilian Marksmanship Program) matches is that the SIG M400 has QD attachment points forged into both sides of the lower receiver at the rear. Most of the time at NRA sanctioned matches, the match officials will let you ‘slide’ on this unless you’re actually placing in your division. You will always be subject to a technical objection by another shooter since the receiver isn’t mil-spec. The rifle will fail the CMP technical inspection, though. At an NRA match, the only thing that happens is that you will be moved from SR (Service Rifle) to Match Rifle in the results. Since at first, you’ll be shooting for personal best instead of competing against the other shooters, that’s no major problem.

    One illumination as well. The acronym DCM refers to the Director of Civilian Marksmanship, the old name for the ODCMP (Office of the Director of the Civilian Marksmanship Program) which is often abbreviated as CMP.

  14. I have been reading this blog with some interest. at this time. Look at dates of post. you can get a rifle for $1200 that will win any service rifle comp you wish to go to. I said the rifle will not the shooter. To build a good rifle, one can spend around $800 and have a real nice one to start with and even win club matches. one rule that has been said but not pushed in the blog, is it must look like an M16.
    Im am going to repeat, say again, some of the things that have all ready been said, This is coming from a guy that has helped set up several people with rifles. About 200 in the last few years. I shot my first match in about 1974 and still shoot. I shot on the Ft. Bragg AMTU for several years. Army service last part of 1972 , ret. in feb 2000. I run NRA high power and NRA small bore matches, the next match is March 7, as in 2015. I will be shooting in the nationals this may. So here I go.
    First thing is shut up, second thing is to get off you butt and go shoot some local matches. Next is quit thinking that you have the best answer, you don’t. Hell I don’t so why do you think you do. what I do know is you can talk this to death and then go play your video game and go no where. Get to a local match, we do not care what your shooting at first and then only if you want to move up do we say very much. The cmp is at the bottom end of matches, the only one that means any thing to most of us is the EIC matches. NRA matches are the way to go, They just are, cmp could if they wanted but most of their matches deal with old stuff. Even their small bore is low key, My SB rifle can not be used in their matches, (anny 1813 rifle) Yes I am old school as they have out the 2013s, I just don’t want to spend $4000 for a new rifle when mine does just fine. I see this build a rifle, or test ammo bs all the time. I had a guy start with a win. 30-30 , shot it for a year before he went to a ar15, (got it with tax money) we supported him all the way. These blogs should be a sounding board for good info not a who’s who of how dumb can one be when the rule books can be down loaded.
    AS I stated , I am only repeating what has been said, I just put it in simple terms. I am still located in the Ft. Bragg Fayetteville are, any one wanting to shoot give me a call or a email, be happy to get you started with out all of this BS
    Rick Smith
    [email protected]
    we shoot high power, small bore, 3 gun / 2gun and pistol.
    you guys should try the small bore, its a great way to learn and train in the off season , I shoot it year round.
    we also have classes for shooters.
    See you on the firing line but not much of this on line.


Please enter your comment!
Please enter your name here