View Full Version : National Match Bolt Carrier
What are the real pros & cons of using a National Match bolt carrier over a standard bolt carrier? Does the NM carrier show an improvement of accuracy or consistency over the standard carrier? If so, is this something that is consistent from rifle to rifle, or is it a trend- that is something that shows up when tracking the performance of a large sample of rifles?
Does the NM carrier cause reliability problems? The nose is a bit larger in diameter, the theory being it reduces the play between the carrier & receiver, but will that make it more susceptible to stoppages from fouling or debris? Again, is this something that will happen, or is it a trend that tends to show up when taking a large sampling? I understand about the necessity for staking the gas key and that Young, one manufacturer of NM carriers, does not stake their keys. Let's leave that issue aside.
Molon, do you have any experience with NM carriers compared to standard carriers?
Dangerousdan
12-18-10, 21:29
I would compare it to a internal combustion engine. You can rebuild a engine with off the shelf parts and it should give many reliable miles. with proper care. The next step might be a Blue printed engine. This process you fine tune every part of your motor checking the fit and correcting any problems you find until all your pirces are find tuned. (NM) Items are finely tuned for the areas your working on. I think this is what your asking.
i think they're machined to the upper end of the spec, and are otherwise just heavier. YM NM carriers are chromed, so reduced friction and easier cleaning..
aside from those two or three things, i think it's mostly gimmick. the bolts are not special, nor should they be trusted.
I would compare it to a internal combustion engine. You can rebuild a engine with off the shelf parts and it should give many reliable miles. with proper care. The next step might be a Blue printed engine. This process you fine tune every part of your motor checking the fit and correcting any problems you find until all your pirces are find tuned. (NM) Items are finely tuned for the areas your working on. I think this is what your asking.
What I'd like to know is if NM spec carriers show any kind of improvement in accuracy or consistency in an AR rifle and if so, what kind improvement can be expected.
Using your automotive anology, is it as important as say- increasing your compression (yes, you'll see an improvement in performance, or balancing the crank/piston assembly (average owner won't see a difference but you'll appreciate it if you run it hard), upgrading the seats (Ah, yes! That feels better.) or installing a better stereo? ("Hey, that's really cool, bro!")
BufordTJustice
12-18-10, 23:36
What I'd like to know is if NM spec carriers show any kind of improvement in accuracy or consistency in an AR rifle and if so, what kind improvement can be expected.
Using your automotive anology, is it as important as say- increasing your compression (yes, you'll see an improvement in performance, or balancing the crank/piston assembly (average owner won't see a difference but you'll appreciate it if you run it hard), upgrading the seats (Ah, yes! That feels better.) or installing a better stereo? ("Hey, that's really cool, bro!")
I can't imagine it would have much of an effect on accuracy unless the previously used carrier was machined grossly out of spec. Further, the Yankee Hill carrier are not properly staked per milspec. They aren't even staked at all. A YHM NM bolt carrier with a BCM or Fail Zero bolt would be a better setup, IMHO.
What I'd like to know is if NM spec carriers show any kind of improvement in accuracy or consistency in an AR rifle and if so, what kind improvement can be expected.
Using your automotive anology, is it as important as say- increasing your compression (yes, you'll see an improvement in performance, or balancing the crank/piston assembly (average owner won't see a difference but you'll appreciate it if you run it hard), upgrading the seats (Ah, yes! That feels better.) or installing a better stereo? ("Hey, that's really cool, bro!")
the point is simply to reduce recoil and increase lock time for hot loads used in NM competition, if i'm remembering my history. they don't, and cannot, increase shot precision.. nor do i think any claim to
Young Manufacturing does claim an increase in accuracy. From their website-
Our signature product, the National Match Bolt Carrier by Young Manufacturing, Inc. This bolt carrier is 1/2 oz heavier and has more surface area at the carrier front. These additions provide improved alignment of the bolt carrier as it moves in the receiver, tighter tolerances, more consistent bolt-lockup, and generally much smoother operation. This bolt carrier causes less wear, improved accuracy, and overall better function. All Y/M carriers are made using these high standards. The extra precision, quality, and post production processes are among the reasons Les Baer Custom and other top custom companies choose Young Manufacturing, Inc bolt carriers. You should too! (Available in AR-15 and M-16)
They also offer a National Match "Light" BCG
Emphasis mine
i'd email 'em. i like the YM NM carriers- i can be quoted as saying a young chromed NM carrier with an LMT bolt is the "perfect BCG," in fact... but i don't believe they increase accuracy one iota.
BufordTJustice
12-19-10, 03:00
i'd email 'em. i like the YM NM carriers- i can be quoted as saying a young chromed NM carrier with an LMT bolt is the "perfect BCG," in fact... but i don't believe they increase accuracy one iota.
That would be one hot setup. The difference being that you have perfectly reasonable (and realistic) expectations about its performance.
It would also be a great opportunity for you to share some pix. ;)
i'd email 'em. i like the YM NM carriers- i can be quoted as saying a young chromed NM carrier with an LMT bolt is the "perfect BCG," in fact... but i don't believe they increase accuracy one iota.
What is it that you like about the YM NM carriers coupled with the LMT bolts? Except that I had no trouble with my Colt HBar all the years I've owned it, I have no knowledge or experience with the details of various BCGs
i'd email 'em. i like the YM NM carriers- i can be quoted as saying a young chromed NM carrier with an LMT bolt is the "perfect BCG," in fact... but i don't believe they increase accuracy one iota.
I’m curious myself. What advantages do you see over just a standard LMT BCG?
What is it that you like about the YM NM carriers coupled with the LMT bolts? Except that I had no trouble with my Colt HBar all the years I've owned it, I have no knowledge or experience with the details of various BCGs
the extra weight and chrome of the YM, with the radiused lugs and HPT/MPI of the LMT
I’m curious myself. What advantages do you see over just a standard LMT BCG?
as above- just the extra weight and chrome. this isn't exactly science, just my opinion, but based on a lot of fudging around with action timing. having a little more weight in the carrier helps slow down unluck, and i think this makes the weapon more versatile with ammunition and a bit of a reliability increase in general.
and obviously the chrome is easier to clean. you can also argue that it reduces action friction, perhaps increasing reliability as the weapon gets drier/dirtier, but that's not really anything i have the ability to verify or even explore
I thought the accuracy claims stemmed from it being machined to tighter tolerances leading to more consistent and concentric matching of the boltface and chamber. Gas guns are going to suffer in this respect by design... which is why nobody holds any benchrest accuracy records with a semi-automatic rifle.
Or something like that anyway. I don't own a Young NM Bolt Carrier, but the next time I rebarrel my highpower upper I might get one just to add some sex appeal to the rifle. I like the classic A2 upper look but when everyone else on the firing line has the same look going I feel like a little bling wouldn't hurt. I can't imagine that it is going to make the gun any more accurate, though the extra weight on a NM rifle never hurts.
Alpha Sierra
12-19-10, 14:09
Nobody who's serious about National Match shooting uses one. It's freaking easy to build a NM AR that will hold 1/2 MOA elevation at 600 without useless gimmicks such as that.
Nobody who's serious about National Match shooting uses one. It's freaking easy to build a NM AR that will hold 1/2 MOA elevation at 600 without useless gimmicks such as that.
I've never seen anyone with a fancy BCG at a HP match. Nor do people on NM forums talk about them. I would think that most use whatever BCG came with their upper, probably a semi-auto BCG. I doubt that a BCG can make any difference accuracy wise.
I don't know that products like the NM BCGs are geared towards NM shooters, but rather to the non-competition shooting public and just given names like "National Match" to hint that if you put one in your rifle you can shoot like David Tubb.
The gas key isn't staked like a tactically "acceptable" BCG, but they are chrome and so are probably easier to clean.
m1a_scoutguy
12-19-10, 17:18
I don't have the NM Bolt but I did buy the Chrome FA Carrier & Bolt,,,so I guess I bought into the Chrome thingy !!!;) Mine is actually Staked pretty good,,but will compare it to my DD FA Carrier to see the difference !! I can get a pic of it if anyone was intersted !!! I bought it almost a year ago,,probably about 10 Months or so !!! I have close to 2K on it at the moment !
Dangerousdan
12-20-10, 11:42
As I said earlier. Sorry about the engine as an example but I'm a retired machinest and know if you purchase a NM item your getting something with tolerences that are closer to the orignal specs. Production parts are just that production. Whether a NM part will give you better performance, Again that is up to the user, but the quality is suppose to be a higher standard. My $.02
No worries, Dangerousdan. If I can get away with aviation references, you can get away with the same as a machinist. No apologies required.
From what I understand from reading the fluff from a couple different makers, the front of the carrier is larger in an attempt to take out slop. I found a site dedicated to NM shooting and they tell me the answer is NM carriers are pure snake oil. They don't even give it enough credibility to be in the "Cool stereo!" category :D
The NM Carriers are pretty awesome imo. I have one with the Dennys ion-bond bolt. Mine is staked by Rainier. When charging my rifle slowly it is extremely smooth, like butter. Not that it wouldn't be with another bcg. I have had no issues with it and it looks nice. I kind of :rolleyes: over YM's explanation of why they don't stake and all of that. Putting that aside, most will agree they are extremely well machined bcg. I would not hesitate to buy another.
I thought the accuracy claims stemmed from it being machined to tighter tolerances leading to more consistent and concentric matching of the boltface and chamber....
This is my understanding as well. In theory it makes sense. In practical application I am not a good enough shot to test the theory.
I have a friend (who Markm and Iraqigunz knows as well) that holds a 500 yard record with a Wylde chambered Lothar Walther barreled AR. The barrel came with a "mated bolt." Skeptical, I asked him if the mated bolt made any difference. He told me that he shot groups with that bolt and several others in the gun and surprisingly it did make a difference. Again, I doubt I am a good enough shot to have noticed a difference.
From all the talk here about the bolt and bolt carrier I think the last post sums it up. Like the custom built engine were the parts are machined to work together for better performance. I think and matched bolt and barrel could improve the accuracy. Would shooters be able to tell the difference. That I do not know. I have a mil-spec MPI no name Bolt and Bolt carrier in my 16" AR-15 and I am getting great accuracy with it so far. I do plan on getting another Bolt and bolt carrier for it. I will be getting a chrome bolt at least. Plus a chrome lined bolt carrier if I can afford it. The chromed lined carrier and bolt will help with the cleaning but proabbly will not increase accuracy. I have no experiance with the NM Bolt and bolt carrier so I can not comment on it. Too me the MPI bolt and bolt carrier work just fine for me.
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