Project SALVO and the M198 Duplex

If the United States Ordnance Department learned anything from Project SALVO it was that nothing works quite as well as a conventional rifle, chambered for a conventional cartridge, shooting one bullet at a time. Of all the SALVO cartridges tested, the only ones that proved to be even marginally successful can be counted on one finger.

Following the SALVO II trials in December 1957, Operations Research Office (ORO) recommended the development of a standard length Duplex cartridge based on the 7.62x51 NATO case. By 1958 Frankford Arsenal had assembled a prototype, the FAT314E2. It was loaded with two 77 grain bullets and had an OAL of 2.500". Development continued and in 1963 the FAT314E3 was adopted as the standard, and designated the Cartridge, 7.62MM, NATO, Duplex Ball M198. It was loaded with two 80 grain copper plated steel bullets with an OAL of 2.790".

A cartridge that appears to be an intermediate step in the FAT314 development is known to exist. One from my collection is pictured below. It is loaded with two 88 grain copper plated steel bullets to an overall length of 2.650". Anyone with information on this cartridge is encouraged to share it (the information, that is).

The M198 proved to be a disappointment. In real-life it did not deliver the desired hit probability and production was stopped. By the early 1970s further attempts to increase performance were halted and the concept was abandonded - for a while. It was resurrected a few years later as part of the Advanced Combat Rifle (ACR) program with the same disappointing results. There is no doubt in my mind that the concept is still being considered today. Maybe nothing was learned from Project SALVO after all.


I have to ask…what does the T314E1 look like ?


Good question. A drawing has not been found as yet.


Ray - was the M198 ever used in combat?


The cartridges were issued but whether or not they were actually used in combat I cannot say.

Here are a couple of previous threads from the Forum that discuss this.

Ray … light=m198 … light=m198

One detail that I did not mention in my origiginal post concerns the mystery, intermediate sized cartridge. Unlike most other Duplex cartridges, the lower bullet does not have a canted base. Until more information is found we can only assume why this is so. Your guess is worth as much as mine.


It is possibly of no significance but I have two M198’s with noticeably different finishes to the surface of the bullet jacket.
The round on the left is from Frankford Arsenal in 1965. It has the usual smooth finish to it’s surface.
The round on it’s right is from Winchester in 1964 and this bullet has a very rough surface and has the appearance of having been turned on a lathe.
Hopefully these marks will show on the scan.

According to an article in the January 1968 issue of “The American Rifleman,” the Long Range Reconnaissance Patrol (LRRP) Company of the US Army 4th Division used M198 in Vietnam. Their three man sniping teams were equipped with M14A1 (the automatic rifle variant) fitted with M84 scopes. Each man carried two magazines of M118 Match and seven magazines of M198 Duplex. The M118 was used for sniping, and the M198 was substituted if they needed to break contact. It sounded like some bodged together kit, which was a pretty common situation until the AMTU started to turn out XM21.


I have the same WRA 64 cartridge with the “turned” finish on the bullet. Also a WRA 64 where the marks are not nearly as evident. And a WRA 66 with a normal bullet finish. I don’t know if it means anything. I am going to pull the bullets on a trurned one to see if it’s any different, as soon as I find another one. If you have more than one why don’t you do it?



Does that arrangement seem as strange to you as it does to me? Snipers are supposed to be the epitome of marksmanship and yet they were issued ammunition that was designed to make up for the lack of marksmanship.


Nice idea Ray but I only have the one specimen!
Forgot to ask - what’s the headstamp of your ‘intermediate’ Duplex round?


I should have posted it. It is FA 66. That would seem to make the arguement that it was designed as an improvement of the M198 rather than an intermediate between the T314E2 and E3.

I’ve sent all the information to HWS, BTW. S is going to make drawings of the bullets and maybe they’ll find something before VolIII is published.



Yeah, like I said, it was a pretty bodged together set of kit. But there is always the risk of stumbling across an enemy unit that is too large and too close to leisurely snipe. As I understand it, “Break Contact” drills typically do not place a real high value on individual marksmanship. It is more about firing a lot of ammo to convince the enemy not to chase you once you make a run for it.

During the early years of Vietnam, sniper training, deployment, and equipment was very informal, if not nonexistent. It was nothing like the formal schools they have today.

I read somewhere a long time ago (I wish I could recite the source) that the M-198 was used by the Sniper’s spotter, who was armed with the M-14. It was the spotter’s job to provide security and lay down covering fire when things got hot. As I recall, the M-198 was well regarded in this capacity.


Ray - I’ve asked Bill W about this ‘intermediate’ round and he felt that it was steel cored with lead base (like the T314E2) and suggested I ask Frank H. Here is what Frank provided:

“We do know that during 1966-67 FA was still working on a FMJ steel cored bullet and assume this loading is from that late effort. No record of this specific loading could be located and apparently no test designation was assigned. The Ordnance Dept. and FA was very concerned about the manufacturing base for the WRA steel bullet, since the plants were facilitized for making conventional jacketed bullets with lead or steel cores on Bullet Assembly Machines (BAM’s). Under the circumstances, the cost to add metal turning or forming machines to these lines was very costly.”

Here’s a picture of sectioned T314E2 and T314E3/M198 rounds (maybe these can count as my Cartridge of the Month!)


Yes, the “intermediate” bullets are steel core with a lead base. I mailed them to Gene S today so I don’t have them in front of me to look at but here are my notes that I sent to both Gene and Frank:

[i]FAT ??? OAL=2.651"

hs = FA66
Brass primer, red seal
Case weight = 190.7 gr
Powder = Ball type, 44.0 gr
Top bullet = 88.6 gr, magnetic with lead plug, boat-tail, .820" long
Bottom bullet = 88.6 gr, magnetic with lead plug, flat base (not canted), .810" long [/i]

As you can see from my photo they are very definitely different than the T314E2 bullets although they share the same construction.

I had previously sent Frank all of the info that I had on all three of the cartridges. He was not able to find any drawing of the ?? one but now he has the dimensions and will keep looking. I have not been sending Bill anything since I assumed that Gene would be sharing it with him.


Fine work as usual Paul.

I cleaned my computer screen TWICE before I saw the marks were on that last picture -not my computer -Ha!



Here is probably the explanation for those “turned” WRA bullets.


Certainly a feasible explanation.
Thank you Ray…again!