M-14 DMR rifle advice

[wild_wild_wes]

I have an all-TRW M-14 parts kit and I've decided to build it as a DMR-type scoped rifle. Why? Because it is a semi-auto, and I can legally use detachable mags with it (I'm in California). I have an AR10, but must use "non-detachable" mags of no more than 10 rounds with it, since it is not a CA registered assault weapon. So, there is the background about why I'm using an M-14 instead of some other more easily scoped rifle.

The typical range I will be using it at would be up to 300 yards, as that is the max at my shooting club unless your are shooting in the Tactical match, which rotates between 600 and 1,000 yards. I might try the 600, but not the 1,000 with this rifle. I would also like the rifle to conform to DMR specs, just because.

I would like some advice about what barrel and optic to use.

The TRW G.I. barrel is 1 in 12 rate of twist, and I think I'd be better off with 1 in 10, correct? I'd prefer a stainless barrel or a chromed bore, but am open to ther types. I'm not sure about weight- Smith makes a Medium-Heavy contour, but would that be suitable for a DMR rifle? As far as length, 18" or 22" seem the way to go. So...what are my choices here, and what would you recommend?

Now on to the optic...the choice for DMR would be a low-power variable in the 3-9X range, right? Or would a fixed 6X or 10X be suuitable as well? I have my eye on the Super Sniper scopes, because I have one and really like it, but I'm open to other relatively inexpensive brands too.

I will be using a synthetic GI stock fitted with 3" rails at 3 and 9 o'clock and a bipod stud at the 6 for my Harris. I also have a variable-height cheekpiece that will be installed to help with cheek weld. I'm trying to keep costs on this project down, so the more expensive but capable stocks are out.

So, there you have it. I hope you guys can help me out on barrel and optic choice, and whatever other advice in general you might be able to furnish.

[BrigandTwoFour]

Heh, seems we keep running into each other.

I built up a M14 DMR for the exact reason you did, I was being sent to California and didn't want to deal with the AW hassle. I've since moved and expanded the collection, but will (rather ironically) be ending up back in CA early next year.

Are you going for an exact copy of what the M14 DMR program rifles look like? Or are you going for your own interpretation of it? I may have an old combat arms magazine around here that talked about that program if you want details on exactly what was done.

For the range you specified (300 yards, maybe up to 600) you can use 168gr SMK loads. The 175 loads seem to be preferred for reaching that magical 1000 line. I think you would be fine for now with a 1-12 barrel, but there would be nothing wrong with getting that 1-10 (or 1-11 if you get it from Krieger). If you've looked at Smith's website, their Crazy Horse modifications are generally considered very good. I think you'd be fine with either the medium-heavy or the standard contour. I am limited to the medium (G.I.) due to my stock, and I've never had an issue.

In the optics thread, I pointed you to the SS 6x and 10X scopes. The 6X would be fine for up to 300, but if you want to stretch it to 600, then I would say definitely the fixed 10X or the variable 3-9x42. The 10X fixed will not be so great inside of 200 yards or so, but that can be overcome with training- a la using an ACOG for CQB.

[sinister]

I would strongly recommend (since you're in California) as a starting point a forged LRB receiver with integral scope base. It will provide the most secure rock-solid scope mounting for the M14/M1A platform possible without the frustration/annoyance of all other engineering compromise Band-aids.




There's enough rail length that you could also mount a 1-o'clock base and put either a JP short-range iron or a red-dot on right or left side (depending on your dominant hand-eye side). Unfortunately with the M14/M1A, mounting a scope will also require you to add a little comb height to the stock -- either a foam pad and hundred-mile-an-hour (duct) tape or some other add-on like an Eagle stock pack.

A 1-12 barrel will be more than sufficient for both the 168 and 175 Match Kings. A 1-10 is nice but not necessary unless you're planning on shooting formal NRA-style prone bullseye matches. The heavier the barrel the more it will affect pointing and handling (especially when you start adding weight, i.e. the scope). You'll want all 22-inches if you're planning on shooting to 1,000 down in the valley or in the desert in California in the summer (you want 2550 fps or more with a 175).

The Super Sniper is a fine scope for the money. Find an older one with side focus for around $350-400 and you'll be set.

The M14/M1A has both advantages and disadvantages over the AR-10. Do your research. You can sink a boat-load of money trying to get one to shoot like an AR-10 -- just remember it has a lot more moving parts, can be finicky, can be heavier, and requires a talented gunsmith to get everything working well. It will also require periodic maintenance over the long run.

Its saving grace is it's California OK.

[BrigandTwoFour]

A big +1 to the LRB M25 receivers, if you don't already have a receiver (I assumed you did).

Having the integrated scope mounting will save you a lot of headache and trouble down the line with other mounting solutions (see my review of the CASM mount in the optics section)

[wild_wild_wes]

Crap! I have an Armscorp reciever already, and a Smith scope mount. But that LRB does look tempting; I'd much rather have a forged reciever. This will rquire some thought. I have a very talented gunsmith and will ask how difficult it would be to sell the reciever I have. Hmm...

[wild_wild_wes]

Are you going for an exact copy of what the M14 DMR program rifles look like? Or are you going for your own interpretation of it?

For the range you specified (300 yards, maybe up to 600) you can use 168gr SMK loads. I think you'd be fine with either the medium-heavy or the standard contour. I am limited to the medium (G.I.) due to my stock, and I've never had an issue.

I'm doing my own interpretation. I'm adding things like the Smith brake (the one with all the little ports on it, not the CA-legal Vortex-type Direct Connect with ports instead of slits) and the front sight that sits in front of the gas block.

I'll look into the 168s I have no intention of taking this rifle to 1,000.

How much weight does the medium-heavy add? It will work wth the synthetic G.I. stock, right?

Thanks for your help!

[sinister]

The medium-heavy doesn't add too much, but the overall aggregate with the GI fiberglass stock, a scope, and whatever you add to the gun (i.e., a National Match guide rod, flash light, bipod, etc.) may/will shift center-of-gravity forward. An 18-inch gun will shift weight back some, but then you'll probably want an efficient/noisy California-compliant muzzle brake or compensator.

I would try to wear out the TRW barrel first. TRW was/is considered as having the nicest overall machining precision and quality of all (genuine government) M14s.

The Smith and any number of other receivers are good options but you will have to go through a lot of research and experimentation before you settle on a compromise optic mounting system. There are a lot of options out there with varying amount of rigidity and hole/screw security that do not rival the fixed rigidity of an AR or the LRB.

Like the booby trap manual says, you are only limited by your imagination (and in the case of the M14/M1A depth of your wallet and patience).

Do your research -- someone has already tried doing what you want to do to an M14/M1A. The design has been around a long time -- pissing off people trying to figure how to efficiently and rigidly put a scope on it. The LRB was specifically designed to fix the need for work-arounds.

[wild_wild_wes]

I would try to wear out the TRW barrel first.

^ wisdom

[BrigandTwoFour]

FWIW, I just reviewed the article I mentioned earlier about the Rock Island M14 DMR build ups. They all used the USGI barrel, so long as the barrel wasn't in bad shape. I imagine your TRW will be fine, probably around 1 MOA or slightly better. Nothing wrong with that.

[wild_wild_wes]

I was a bit confused...the M21 used National Match barrels, but I just re-read the Collector Grade Publications M14 book where they discuss the genesis of the XM21, and nothing about a Medium-Heavy barrel was mentioned. But later I think some were rebarreled, or had medium heavies put on by the unit. The vast majority of M21s though used the regular G.I. weight barrel, which is quite skinny indeed.