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Replica completed of a US Army M21A5 (aka M14SE "Crazy Horse" SDM rifle)

Random Guy

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Recently completed replica of a U.S. Army M14SE Squad-Designated Marksman (SDM) rifle, which was later designated as an M21A5 rifle (or informally referred to as an “M14SE Crazy Horse” rifle). I just got the barreled action w/ trigger group back from Smith Enterprise Inc (SEI). For anyone interested, here’s the list of parts used for this replica project, starting at the front of the rifle:

• SEI flash hider – M14 Direct Connect (DC) (#SEI Vortex 2000-V-A2)
• SEI integrated front sight and gas cylinder lock – (#2012)
• SEI “Warfighter” gas cylinder (MHT80 treated) – (#2072)
• SEI gas plug (MHT80 treated) – (#2076)
• SEI gas piston (hard chrome plated) – (#2075-SBR)
• SEI bipod (newer style with clamping lever) – (#2033)
• SEI/Hart medium weight barrel, carbon steel, 1:10 twist (MHT80 treated) – (#2025-9345-M14SE)
• SEI op rod guide (MHT80 treated) – (#2068)
• NM spring guide – AMU style fabricated NM spring guide
• Handguard – Standard USGI part that was painted to match the fiberglass stock
• SEI scope mount with large NSN number and ‘US Property’ marked – (#2006)
• SEI rings, EDM type, 30mm, medium height – (#7008)
• Leupold & Stevens Mk4, FDE 3.5-10x scope w/ M2 turrets and TMR reticle
• USGI (HRA) op-rod
• USGI trigger group (WRA housing & TRW hammer) w/ SEI trigger job – (#2088)
• Springfield Armory Inc. receiver (151k, ~ 2003 vintage)
• Springfield Armory Inc. bolt w/ USGI chrome firing pin & SEI extractor
• Springfield Armory 8-dent NM rear sight w/ M14 pinion & NM hooded aperture
• SEI Extended bolt stop
• USGI fiberglass stock (I restored it w/ new enamel paint and a clear enamel)
• SEI Tri-rail system (SEI had previously milled the stock and installed the tri-rail) – (#2050)
• SEI tan/FDE cheek pad – (Didn’t think I’d be able to find this discontinued part, but got lucky this spring on the M14 forum)
• USGI M14 faux selector lock parts
• USGI M14 cleaning kit
• 1907 pattern leather sling – Turner NM (stamped ‘Crazy Horse’ by Ron Smith)

Brief History: Per Lee Emerson’s reference book, M14 Rifle History and Development (2019), Vol 1, pages 206-212, approximately 200 rack-grade M14 rifles were re-built/re-configured by Smith Enterprise for various U.S. Army and National Guard units, and were used in Iraq beginning in 2005 by the 2nd Infantry Division (2ID).

It should be noted that these were not designated as sniper rifles, but rather as Squad Designated Marksman (SDM) rifles, and their intended use was to engage targets out to 600 meters. (Per Army doctrine, a sniper rifle has to be capable of accurately engaging targets out to 900 meters). Optics on the initial 110 M14SE rifles were either a Leupold 1.5-5x20mm scope, or Leupold Mk 4, 3.5-10x40mm scope. (The 2ID subsequently updated their rifles so that all had the higher magnification 3.5-10x scopes).

In 2006 a slightly updated version with SEI-manufactured trigger pins, connector locks, SEI op rods, etc, were provided to the 502nd Infantry Regiment/101st Airborne Division, and the 25th Infantry Division as well. Apparently the first batch of the 2006 rifles had stainless steel Krieger medium weight DMR barrels, as the carbon steel SEI/Hart barrels were temporarily not available in the quick turnaround timeline required before deployment. The Leupold 3.5-10x40mm scope with flat dark earth (FDE) finish was used on these rifles, along with SEI sound suppressors.

In 2007 the US Army changed the designation from M14SE to M21A5. In addition, from 2007 to 2010 a small number of M14 rifles were converted to M21A5 rifles for various units being deployed; including the 10th Special Forces Group (three rifles), Vermont National Guard (three rifles), and the Nevada National Guard (six rifles). It is not clear when the M21A5s were withdrawn from service, but my guess is that may have occurred as the SAGE chassis-based M14 EBR-RI rifles were rolled out as the standard SDM rifle during 2008-2011.

Synopsis: It’s not a perfect replica, as I would have preferred to use an SEI receiver and an SEI op rod (if I could find one), along with the earlier SEI bipod with round knob instead of the newer style with a clamping lever, but I had a budget in mind for this build, so I used my spare SAI receiver and spare parts instead. Overall it ended up as a reasonably close replica of what was used by the US Army in the mid-to-late 200Xs. (As funds allow I plan on adding an SEI ‘Wind Talker’ sound suppressor to this project, so it will then be configured similar to the rifles used by the 101st Airborne). The M21A5 fits in my collection as a replica of a US Army M14-based SDM rifle from the post-M21 era. It was also likely the last combat M14 that used the old USGI brown fiberglass stocks, after which the more robust SAGE chassis-based M14 rifles were adopted by the U.S. Army and other branches. SEI noted that it shot 1-MOA with Hornady 168gr ELD match ammo, and hopefully I can take it the range later this month and see how it performs.
 

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Absolutely beautiful...! I've always had a soft spot in my heart for the M-14 platform, ever since qualifying expert with it in basic. Mine was easy to shoot well and a real confidence builder. I'm running an LMT-MWS now, but I still miss the M-14. Nice work with the replica!!!
 
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Very cool, nails the look for sure.

I wonder if we have any members who used this configuration in the ME?
 
That's gorgeous. When we rotated into Diyala province in 09. There were two those on the fiberglass stocks. They were handed of to the unit we replaced and they handed them off to us.
I'm not sure what happened to them when we went home. Never did get to shoot them. I had a m24 that i never got to shoot either except for zeroing...
 
Thanks, the M21A5 wasn't all that hard to piece together, and fits my collection interests. I'm on a mission of sorts to complete my small collection of replica M14 sniper/DMR/SDM projects within the next year or two.

Attached are pics are my current project, the 'Mother of All Retro M1A' projects. A replica of a T44E4 (prototype M14) with the a prototype 1958 hinged mount with the little M84 scope. These were tested back in 1958 and again in 1966, and I found the top half of an original scope bracket marked "M84" on eBay, so that launched this ridiculous retro project. Main challenge is using a few pictures and a hand-drawing to try and reverse engineer the bottom bracket for the old hinged mount. Wish me luck...
 

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Thanks, the M21A5 wasn't all that hard to piece together, and fits my collection interests. I'm on a mission of sorts to complete my small collection of replica M14 sniper/DMR/SDM projects within the next year or two.

Attached are pics are my current project, the 'Mother of All Retro M1A' projects. A replica of a T44E4 (prototype M14) with the a prototype 1958 hinged mount with the little M84 scope. These were tested back in 1958 and again in 1966, and I found the top half of an original scope bracket marked "M84" on eBay, so that launched this ridiculous retro project. Main challenge is using a few pictures and a hand-drawing to reverse engineering the bottom bracket for the old hinged mount. Wish me luck...
I’ve never held or fired an M14 but it’s interest to note the offset scope. Was it so Irons could still be used?
 
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I’ve never held or fired an M14 but it’s interest to note the offset scope. Was it so Irons could still be used?
That's not an offset scope that is a "tip-off". Tip the scope off so you can use the irons. Or, (on different rifle types ) feed directly from clips instead of pulling a mag and changing it. A choice the shooter has to which is faster when he needs speed and continue firing. I do not know that the M14, or this M21A5, can do that.

Which, BTW, is very cool! Thanks for sharing these pics Random Guy! I did note that your action does not have a recoil lug. Did I miss it?

As noted above, the use of these seemed to be limited. I know we had stuff in our arms room that my first PSG was always drawing out. My second PSG drew it out only when it was specifically called for in that block of training, and my third PSG, never. Sometimes the stuff ended up with a lieutenant from another platoon (Co. arms room), who was NEVER gonna use it, but it looked cool as hell.
 
I’ve never held or fired an M14 but it’s interest to note the offset scope. Was it so Irons could still be used?

Iron sights could not be used with the hinged mount unless the scope was 'folded' over to the left. The hinged mount circa 1958 was really designed for the M14 so it could be loaded from the top via 5-rd chargers (aka stripper clips), which is how the M14 bandoleers were designed. This was of course how most 20th century military rifles were designed to be loaded - via stripper clips. (see attached pic #1) The exception was the M1 Garand and it's 8-rd enbloc clips.

The hinged mount was tested in 1958 at Ft Benning but it was not adopted. It was tested again in 1966 when the Army had a urgent operational need for a telescoped M14 rifle for Vietnam. (see pic #2, from Peter Senich book, The Long-Range War, page 13). The hinged mount was likely determined not sturdy enough for combat, so in 1967 Army Weapons Command then developed a more simple, fixed mount that was slightly offset to the left - and didn't allow the use of top-loaded stripper clips. In other words, the military accepted the fact that the M14 would be loaded by magazine changes, and dropped the requirement for top-loading via a cartridge clip guide, and so the hinged mount concept was dropped altogether.

I have one of the 1967 era AWC fixed mount for the M84 scope (see pics 3 & 4). Its offset to the left like the old M1C/M1D mounts on the M1 Garand sniper rifles, but it is not offset enough to allow top-loading via stripper clip. This mount however did allow the use of iron sights if the optic system failed...and M84s in the tropical climate of Vietnam apparently did not hold up very well. Apparently condensation on the internal lens was an issue (they pre-dated argon-filled scopes to prevent that issue). Anyhow, being a glutton for punishment, I decided to I should try to build a replica T44E4 of very first M14 sniper rifle that used the prototype hinged mount, since I had a spare M84 scope and found the top half of the prototype mount on eBay for $200. I kind-of like the retro stuff.

On EDIT: I should have mentioned that the hinged mount concept was likely based on the old Pachmayr 'Lo-Swing' mounts that were developed in the early 1950s for hunting rifles. They even developed one for the M1 Garand, which has to be loaded from the top, and attached are the only 2 pics that have ever seen of the M1 Garand mounted with a scope in the 'standard' and 'folded' position using the old 'Lo-Swing' mount. The downside is that mount required drilling and tapping 4 holes for the mounting bracket, and thus you don't see these mounts much anymore, except for some on eBay from time to time.

Which, BTW, is very cool! Thanks for sharing these pics Random Guy! I did note that your action does not have a recoil lug. Did I miss it?

Thanks, not sure exactly what you mean by 'recoil lug,' but if you are referring to a rear-lugged receiver, that is correct, the M21A5 (and my replica) used standard, non-lugged receivers, and they were not bedded in those USGI stocks either. The Navy and USMC however, did weld-on lugs to some combat weapons to extend the life of the bedding, but those rifles were true sniper or DMR rifles and extra time and effort was used to build them, etc.
 

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Iron sights could not be used with the hinged mount unless the scope was 'folded' over to the left. The hinged mount circa 1958 was really designed for the M14 so it could be loaded from the top via a 5-rd stripper clips, which is how the M14 bandoleers were designed. This was of course how most 20th century military rifles were designed to be loaded - via stripper clips. (see attached pic #1) The exception was the M1 Garand it's 8-rd enbloc clips.

The hinged mount was tested in 1958 at Ft Benning but it was not adopted. It was tested again in 1966 when the Army had a urgent operational need for a telescoped M14 rifle for Vietnam. (see pic #2, from Peter Senich book, The Long-Range War, page 13). The hinged mount was likely determined not sturdy enough for combat, so in 1967 Army Weapons Command then developed a more simple, fixed mount that was slightly offset to the left - and didn't allow the use of top-loaded stripper clips. In other words, the military accepted the fact that the M14 would be loaded by magazine changes, and dropped the requirement for top-loading via a cartridge clip guide, and so the hinged mount concept was dropped altogether.

I have one of the 1967 era AWC fixed mount for the M84 scope (see pics 3 & 4). Its offset to the left like the old M1C/M1D mounts on the M1 Garand sniper rifles, but it is not offset enough to allow top-loading via stripper clip. This mount however did allow the use of iron sights if the optic system failed...and M84s in the tropical climate of Vietnam apparently did not hold up very well. Apparently condensation on the internal lens was an issue (they pre-dated argon-filled scopes to prevent that issue). Anyhow, being a glutton for punishment, I decided to I should try to build a replica T44E4 of very first M14 sniper rifle that used the prototype hinged mount, since I had a spare M84 scope and found the top half of the prototype mount on eBay for $200. I kind-of like the retro stuff.

On EDIT: I should have mentioned that the hinged mount concept was likely based on the old Pachmayr 'Lo-Swing' mounts that were developed in the early 1950s for hunting rifles. They even developed one for the M1 Garand, which has to be loaded from the top, and attached are the only 2 pics that have ever seen of the M1 Garand mounted with a scope in the 'standard' and 'folded' position using the old 'Lo-Swing' mount. The downside is that mount required drilling and tapping 4 holes for the mounting bracket, and thus you don't see these mounts much anymore, except for some on eBay from time to time.



Thanks, not sure exactly what you mean by 'recoil lug,' but if you are referring to a rear-lugged receiver, that is correct, the M21A5 (and my replica) used standard, non-lugged receivers, and they were not bedded in those USGI stocks either. The Navy and USMC however, did weld-on lugs to some combat weapons to extend the life of the bedding, but those rifles were true sniper or DMR rifles and extra time and effort was used to build them, etc.
You got what I meant by the recoil lugs. I had never realized it was such an issue with these rifles until we had a thread on them and @buffalowinter showed where his receiver had a lug welded on. And, like I have said in the past, while running the sniper training, I've heard guys talk about shooting super tight groups with the M21's, but I also saw guys that went to a school shoot pretty bad with them. So, I never knew exactly what went wrong with them until these past few years.

An, A-Hah! moment and the light comes on. Back then (added: for us), most shot well but some didn't. The rifle went back to the Co. armorer, who I understand then sent it off. In S-3, we were responsible for the training, not the maintenance of the rifle. Later, after I got out a lot of what I did got shifted to the regimental level. I understand sniping was included in that shift. Add another layer to two hands washing each other in the dark with no idea what the other was doing.

As to the mount, it works very much like the Packmayr "tip-off" mount I had on my old Savage 1899 .250-3000. When pushed into position, it held very good groups.
 
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As to the mount, it works very much like the Packmayr "tip-off" mount I had on my old Savage 1899 .250-3000. When pushed into position, it held very good groups.
Do you have a pic of this? And have you ever seen one a these Pachmayr Garand mounts or know where to get one?
@Random Guy this couldnt be the same mount youre talking about for the T44 could it?
 

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Do you have a pic of this? And have you ever seen one a these Pachmayr Garand mounts or know where to get one?
@Random Guy this couldnt be the same mount youre talking about for the T44 could it?
I have no idea where to get one except keep an eye on ebay, AuctionArms and GB. Any other gun auction sites too. Never know when one will pop up.

I do have pics but not readily available. I'll see where they are and try and get them.
 
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@Forgetful Coyote

Here's a side pic of that tip-off. I'm looking for more pics. You can just barely see over the top of the front ring the 'stop'. It rests on the ring and gives you an exact return spot. The 'dial' in the center of the mount is the lock/tensioner. The rings are like a carriage and the backside has the pivots that swing the scope off the top of the rifle. So, it's a side mount that comes up and holds the pivot pin.
 
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Do you have a pic of this? And have you ever seen one a these Pachmayr Garand mounts or know where to get one?

I fond those 2 pics via a google search of "M1 Garand Lo Swing" or something like that. The Pachmayr Lo-Swing mounts have probably not been made in 50 or more years, so eBay is basically the place to find them. Just do a search for 'Lo Swing.' I might add that drilling 4 holes into an M1 Garand receiver for those old mounts turns a $750-$800 Garand into a $250-300 "Bubbaized" Garand... but chances of finding the mount for an M1 is quite low. I've never seen one for sale.

I will also note that the T44E4 mount was similar in concept to the Pachmyar Lo-Swing, but quite different in actual design. The thumbwheel on the Pachmyar is part of the scope base/bracket (bottom part in pic), whereas on the military mount the thumbwheel was part of the scope bracket or scope cradle (middle part in pic). Arrows show that orientation of the odd ball-and-cup design is different b/t the two designs.
 

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Great build, i keep having a weak spot for the M-14.
I still have an original Winchester M-14 that has most of the same mods that go in the Crazy horse, i only used a different stock for a better cheek weld.
 
Dang, makes me actually miss my M1a for the first time ever...

M-14E2 Stock just above...?

Greg
 
I have been fortunate enough to have picked up a SEI Crazy Horse build, SEI parts EDM rear sight, scope rings, mount, oprod, gas system, gas lock front sight, Vortex flash hider and SEI trigger mods.. I recently found a “Crazy Horse” marked extended scope mount for night vision attachments. Ron stated that these were only shipped with the deployment kits and are rare.. I have been on the lookout for the SEI cheek riser with no luck..
I had the tan Mk4 on my rifle but had a difficult time reading the turrets when dialing it in for extended ranges, sold it and picked up a black Mk4 .
Great Build Random guy!
 

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