• Manufacturer: USMC using Remington 700 Action
  • Model: M40A3
  • Caliber: 7.62x51mm NATO (.308 Win)
  • Barrel: Schneider Match Grade SS #7
  • Barrel Length: 24" (610mm)
  • Magazine: 5 round internal box magazine
  • Stock: McMillan Tactical A4
  • Weight: 16.5 lbs (7.5 kg)
  • Overall Length: 44.25" (1124mm)

In 1996 the USMC started on the design for the replacement of the M40A1, the result was the M40A3. It uses a Remington 700 short action, with a steel floorplate assembly and trigger guard built by D.D. Ross. The Unertl rings and bases have been replaced with D.D. Ross base and G&G Machine rings. The rifles also come with a harris bipod and an accessory rail, also built by G&G Machine. The stock is a new McMillan A4, with adjustable cheek and length of pull.


As the M40A1’s rotate in for service and repair, they are replaced by M40A3’s. All M40A3s are built by USMC armorers at Quantico Virginia. The M40A3 is an outstanding replacement for the aging M40A1’s. The rifles are extremely accurate, very rugged, and are designed from the ground up to be a superb sniper rifle. Combined with the new M118LR ammo, it makes a system that is ranked with the best in the world.

m40a3b m40a3a M40A3


Mel Ewing

Well, you cannot actually buy real M40A3’s as they are only made by USMC armorers for USMC snipers. But you can buy replica ones from the likes of Texas Brigade Armory, Iron Brigade Armory, GA Precision and others. Typical cost is around $4000 plus or minus, for just the rifle.

Mel Ewing

Learn to work hard and respect authority, and you’ll do just fine in your quest.

John Sakowicz

G.A. Precision also makes a sweet copy of the USMC M40A3. Without a scope, it will cost you about $4,000. Contact info: G.A. Precision, 1141 Swift St., N. Kansas City, MO 64116, Telephone +1 816 221 1844

Jeremiah Johnson

I purchased the 300 win mag Texas Brigade version M40A3 and it shot .187″ group during test the fire. It cost around $3,700 that is with Dura Coat, pelican case, scope rings and extra mags.


If absolute period authenticity is not of paramount importance I would suggest different glass. I’ve used both the unertl and leatherwood and they’re kinda past their prime. If you have the funds a schmidt &bender, Steiner or us optics would serve you better. If funds are tight SWFA, Burris, Sightmark Pinnacle, even Vortex might work. Probably less money than a vintage unertl too. Don’t discount the value of good glass. Another tip… the cheaper scopes don’t have either erector build quality or sufficient elevation to hold a constant zero or twist to your firing solution so look for a good hold off reticle like the acss. For ranging within the reticle I would suggest a first focal plane so your reticle stays true with varying magnification levels. Hope this helps and doesn’t confuse.


I’m pretty sure that the M40A3 was replaced by what is now designated as the M40A5. I have no idea what the differences are, because when I fired one with snipers attached to my company, I thought I was firing an M40A3, until they told me otherwise. Perhaps it has something to do with the scope? By now, the only scope being used is a Schmitt and Bender something-or-other. I do remember a time, around 2001-2002 or so, when I was still in a sniper platoon, when we were playing with M40A1’s that had different (other than the Unertls) mounted on them, I seem to remember Leopold Mk 4’s, and eventually I saw my first M40A3! I didn’t initially like it because it looked too modern! Also, now a standard sniper platoon in the USMC will have an assortment of M40’s and M110’s, both with the same scope on them. I just thought that maybe the difference between the M40A3 and A5 was the fact that the system now comes SL3 complete with a suppressor, as does the M110 system. But I could be wrong about that. Anyway, I’m enjoying the website, perhaps you’ll end up building me my first long range rifle!


When I said “assortment” I meant they would have both types of rifles, not a bunch of different types. Say, 10 M40A5’s and 10 M110’s.


Amen. Right answer. Many people think the A3 came with a external magazine. That came years later. My favorite rifle of all time is the M40A3 with internal magazine.

Dave Wagner

I have a cousin who’s going to be retiring from the Marine Corps next year (MGS) who’s currently on his 5th combat tour. I was thinking about getting him a present; not sure if I want to go with an M40 clone or something new. What’s your thoughts on the Desert Tech bolt guns? Was thinking .338. Are these legitimate precision rifles like you review here, or something less?


They are a high quality precision rifle and we have fired an early sample of one in both 308 and 338 Lapua. They were accurate, the 308 very much so, and they worked. We did not like some things like the long bolt throw on a 308 rifle and some other ergonomic things for a sniper operating in the field, but they were well made. Unless their pricing has changed, they were very expensive.


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