Recently I read an article about the Army Squad Designated Marksman Rifle. Basically I "got the itch" and now I'm putting one together. This is what I've more or less decided on:

First of all I have an old Olympic Lower that has an A-1 upper with a 16" barrel. I also have an RRA ENtry Tactical and I don't need two 16" carbines. I'm going to set aside that entire upper/barrel/bolt and start over.



I'll get an flat-top RRA upper with bolt assy, a Surefire M-82 Rail Handguard, and a 20" Stainless barrel with a 1:8 twist. (Basically the same barrel the military uses) Like the real SDM-R I'll use the standard M-16/AR15 front sight post as opposed to a flip up sight. A BUIS like the ARMS #40L would also be nice....

I've decided to skip the ACOG that Uncle Sam uses (mucho dinero)....instead I'll use a NIKON 3-9X40 scope with the new BDC reticle. These type rings are a little new to me: LaRue apparently makes a throw-lever mount? Since I'm not familiar with it I need comments on that too!

I have a Harris Bipod around here somewhere....

I have a couple of questions of course:

I have read a lot about some manufacturing differences between makers. Some are not mil-spec..so will the RRA upper fit the Oly lower? Can't imagine it wouldn't but I'd feel pretty stupid if I didn't ask and then had problems!

The reason I want the throw lever set up is that I may, at a later date, add a Night Vision Device (I'm cheap...Gen1) Do the LaRues get that 40mm NIKON scope up high enough to "see" over that front sight?

What about the scope itself? I know the NIKON is a decent scope whatdo you guys think of it? Keep in mind I can't see taking out a loan on my house to buy this thing!
Comments? Suggestions? Ridicule?

I carried the real SDM-R during my latest tour in the Middle East.

Some comments for you:

You're probably going to want to use a free-floated rail system.  The point of the SDM-R is to provide accurate fire out to 500-800m, even while using accessories mounted to the handguard and a bipod.  The DD 12.0 SDM rail system is the real thing, but it's a bit expensive.  There are plenty of cheap free floats, the cheapest one that you might want to use being the YHM rifle-length free float.
Basically, if you don't at least free float, I wouldn't go so far as to call your rifle anything like an SDM-R.

The SDM-R's barrel has 12 flutes and uses an FSB attached by set-screws rather than the traditional taper pins.

BUIS-wise, if you want to be more accurate as far as the real thing goes, use the Matech 600m BUIS.  You can often find them in the EE here for $70-$80.

LaRue throw lever mounts are the best.  I won't go into detail, as there are a billion threads on them alread on the board

You don't need to raise the scope above the iron sight.  That would place it too high anyway.  It will see "around" the FSB, so don't worry about it.  You want the ocular at the same height irons would be anyway so you can use a consistent cheek weld.

For a cheaper alternative to the ACOG on your SDM-R, I recommend either the IOR 3x25 QRTS or the IOR 4x24 M2.  That second one has spectacular glass, a great reticle, and will run you about $350.

Here are some pics of a SDM gun I got to shoot at Ft. Benning.  WOW!  What a great piece!

http://img294.imageshack.us/img294/8773/p9250009of3.jpg

http://img209.imageshack.us/img209/2627/p9250008ft8.jpg

Quoted: Here are some pics of a SDM gun I got to shoot at Ft. Benning.  WOW!  What a great piece! img294.imageshack.us/img294/8773/p9250009of3.jpg img209.imageshack.us/img209/2627/p9250008ft8.jpg

If you were at SDM school, I hope the instructors realized the carry handle was on one notch too far to the rear

Quoted: I carried the real SDM-R during my latest tour in the Middle East. Some comments for you: You're probably going to want to use a free-floated rail system.  The point of the SDM-R is to provide accurate fire out to 500-800m, even while using accessories mounted to the handguard and a bipod.  The DD 12.0 SDM rail system is the real thing, but it's a bit expensive.  There are plenty of cheap free floats, the cheapest one that you might want to use being the YHM rifle-length free float. Basically, if you don't at least free float, I wouldn't go so far as to call your rifle anything like an SDM-R. What do you think of this? The SDM-R's barrel has 12 flutes and uses an FSB attached by set-screws rather than the traditional taper pins. BUIS-wise, if you want to be more accurate as far as the real thing goes, use the Matech 600m BUIS.  You can often find them in the EE here for $70-$80. LaRue throw lever mounts are the best.  I won't go into detail, as there are a billion threads on them alread on the board You don't need to raise the scope above the iron sight.  That would place it too high anyway.  It will see "around" the FSB, so don't worry about it.  You want the ocular at the same height irons would be anyway so you can use a consistent cheek weld. For a cheaper alternative to the ACOG on your SDM-R, I recommend either the IOR 3x25 QRTS or the IOR 4x24 M2.  That second one has spectacular glass, a great reticle, and will run you about $350. I'm not familiar withn either of those scopes. Can you link me to some info on them?

As far as that RRA rail system, it is just a YHM system but sold by RRA.  You can probably find them for cheaper from dealers on this board.

As far as optics:

IOR 3x25 QRTS

IOR 4x24 M2 CQB

You can usually find the 3x25 for around $600.  I know CS Gunworks has the M2 for $390.  I got mine for $325 or so from Green Mountain Tactical with a .mil discount.

Just FYI you can remove the rubber eyepiece from the M2.

The nice thing about the 3x25 is you don't need a separate mount, although it's not QD.  The 4x24 works best with rings rather than a LaRue mount, because it has short eye relief (like an ACOG).  I use mine with steel IOR QD high rings.

Here's a close up of the CQB reticle:



And here's a picture of one of my rifles with the 4x24 M2 on it:

Food for thought!

I like the price on that 4X scope a lot better than the ACOG.

By the way: I noticed on your rifle you used the flip-up sight as opposed to the standard FSB. Is there an advantage here or is it a user choice?

Also what is the reason fpr the set screws in the FSB as opposed to the other?


This is embarassing of course: at one time I was my unit armorer....of course the issue rifle back then was an M16A1...I have a lot to learn about the newer stuff!

We had Ma-Deuce however.....

Quoted: Food for thought! I like the price on that 4X scope a lot better than the ACOG. By the way: I noticed on your rifle you used the flip-up sight as opposed to the standard FSB. Is there an advantage here or is it a user choice? Also what is the reason fpr the set screws in the FSB as opposed to the other? This is embarassing of course: at one time I was my unit armorer....of course the issue rifle back then was an M16A1...I have a lot to learn about the newer stuff! We had Ma-Deuce however..... i133.photobucket.com/albums/q52/harley1647/mg-barbie.gif

The main reason I have a flipup sight on that AR is because that rail system is a 13.5".  It extends past the normal location of a gas block for a rifle-length gas system, and WAY past the midlength gas hole that this particular barrel has, so it's not possible to use a regular FSB.  That's just how I wanted to do the build, no real functional reason for it.

I'm not 100% sure on the reason for the set screw gas block.  Maybe they didn't want to drill pin holes in that expensive Douglas barrel!  That would be something to ask Sinister, he's a member here and with the AMU.

BTW I like that M2 graphic

Quoted: Here are some pics of a SDM gun I got to shoot at Ft. Benning.  WOW!  What a great piece! img294.imageshack.us/img294/8773/p9250009of3.jpg img209.imageshack.us/img209/2627/p9250008ft8.jpg

USA Shooting bottle?

Quoted: BTW I like that M2 graphic

Yeah, I always said Barbie was the perfect woman: Big hooters, flat belly, doesn't say much and can handle an .50 BMG!

Feel free to steal the graphic...I did! My sense of the absurd sometimes works overtime!

Im leaning towards the "SDM-R" look to my 20" gun also.
I just installed a YHM Flip front gasblock on it tonight.
Very nice solid unit. I had a YHM rear BUIS and just traded it for a
MATECH 600M sight.  Very nice sight!!
I will be going with a FF handguard in the near future.
I have a few scope options right now, but id love to put
my Bushnell 3200 Fixed 10X mildot on it, but its very much ot home
on my Savage 10FP .223 right now.

Who's FF rail does the real SDM-R use??

KyAKguy

Quoted: Im leaning towards the "SDM-R" look to my 20" gun also. I just installed a YHM Flip front gasblock on it tonight. Very nice solid unit. I have a YHN rear BUIS and plan on going with a FF handguard in the near future. I have a few scope options right now, but id love to put my Bushnell 3200 Fixed 10X mildot on it, but its very much ot home on my Savage 10FP .223 right now. Who's FF rail does the real SDM-R use?? KyAKguy

The real SDM-R uses a Daniel Defense 12.0 rail with a steel rather than aluminum barrel nut.

height=8

Quoted: height=8 Quoted: Here are some pics of a SDM gun I got to shoot at Ft. Benning.  WOW!  What a great piece! img294.imageshack.us/img294/8773/p9250009of3.jpg</a> img209.imageshack.us/img209/2627/p9250008ft8.jpg</a> If you were at SDM school, I hope the instructors realized the carry handle was on one notch too far to the rearI am actually a civi who has a small connection.  I was there shooting for fun/learning :D

height=8

Quoted: height=8 Quoted: Here are some pics of a SDM gun I got to shoot at Ft. Benning.  WOW!  What a great piece! img294.imageshack.us/img294/8773/p9250009of3.jpg</a> img209.imageshack.us/img209/2627/p9250008ft8.jpg</a> USA Shooting bottle?

At first I didn'tknow what you were referring to, but yes.  Belongs to my connection there.

Quoted: Quoted: Who's FF rail does the real SDM-R use?? KyAKguy The real SDM-R uses a Daniel Defense 12.0 rail with a steel rather than aluminum barrel nut.

You'll often see it listed as the AMU model.  

height=8

Quoted: height=8 Quoted: Food for thought! I like the price on that 4X scope a lot better than the ACOG. By the way: I noticed on your rifle you used the flip-up sight as opposed to the standard FSB. Is there an advantage here or is it a user choice? Also what is the reason fpr the set screws in the FSB as opposed to the other? This is embarassing of course: at one time I was my unit armorer....of course the issue rifle back then was an M16A1...I have a lot to learn about the newer stuff! We had Ma-Deuce however..... i133.photobucket.com/albums/q52/harley1647/mg-barbie.gif The main reason I have a flipup sight on that AR is because that rail system is a 13.5".  It extends past the normal location of a gas block for a rifle-length gas system, and WAY past the midlength gas hole that this particular barrel has, so it's not possible to use a regular FSB.  That's just how I wanted to do the build, no real functional reason for it. I'm not 100% sure on the reason for the set screw gas block.  Maybe they didn't want to drill pin holes in that expensive Douglas barrel! hat BTW I like that M2 graphicWho turns the barrels? Possibly, WOA with their 4-screw/windage adjustable fsb? I'm curious as well.

Quoted: I'm not 100% sure on the reason for the set screw gas block.  Maybe they didn't want to drill pin holes in that expensive Douglas barrel!  That would be something to ask Sinister, he's a member here and with the AMU.

From what I remember it was to allow the FSB to be used for intial windage adjustments, leaving the rear sight centered.

Quoted: Quoted: I'm not 100% sure on the reason for the set screw gas block.  Maybe they didn't want to drill pin holes in that expensive Douglas barrel!  That would be something to ask Sinister, he's a member here and with the AMU. From what I remember it was to allow the FSB to be used for intial windage adjustments, leaving the rear sight centered.

That makes some good sense.  I'm sure a lot of people who end up with canted FSBs or mis-indexed barrels wish they had a set screw FSB to begin with.

I know some would have durability concerns but I beat the hell outta mine and never had a problem!

ETA:  Love your sig line, M24!

Quoted: Love your sig line, M24!

Hey, it fits!

OK, I lied:




After careful consideration I ponied up the damn money and got a TA01NSN....now I just have to get it to the range and zero it!


You people have fucked over these rifles so badly, they will never fire again!