Top-mounted magazines

[cluttonfred]

Well, as you have seen in some of my other threads, I like those funny-looking Australian Owen SMGs with the top-mounted magazines, which got me thinking, what other guns have used top-mounted magazines and why?

There's the crazy Villar Perosa double gun (originally meant for shooting at aircraft with a weak 9mm pistol cartridge, believe it or not) and the Beretta Modello 1918 SMGs made from remanufactured Villar Perosas. And there's the Pedersen device to turn a Springfield rifle into the world's biggest SMG.

There's the Bren LMG, and it's Czech forefather, and a number of other LMGs like Madsens and a French one and even recent Stoner SAW-type configurations. The LMG seems to about the only category of gun in which top-mounted magazines could be called anything like common, I imagine because the top-mounted magazine facilitated two-man magazine changes for sustained fire and, like the Owen, helped reliability by letting any dirt that gets in fall right back out.

More recently there are a couple of bullpup rifles with horizontal magazines across the top of the barrel, like the H&K G11 and FN P90.

How about it? Besided the LMGs, can anyone think of any other rifles, SMGs, pistols or shotguns with Owen-style top-mounted magazines?

 

[daniel (australia)]

Well there was the Owen's successor the F1. I shot with this a bit in the very last years of its Australian service. It was good fun but long rendered obsolete for most purposes in Australian service by the M16A1, and later by the F88 Austeyr.

There was also the Boys Anti-Tank Rifle. One of my relatives fired one of these at an Italian tank in North Africa, but the two rounds he fired succeeded only in marking the paint on the enemy machine so he gave that up as a bad idea and dumped the useless thing.

 

[cmidkiff]

American 180.

I'd love to have one... Imagine, a squirt gun I could afford to feed!

 

[Chipperman]

Japanese Type 96 and 99.
The Lewis is top-mounted, but is a pan.

 

[transformerguru]

Bren light machine gun, used by the Brits in WW2. I would love to get my hands on at least a semiauto version, don't think I can afford a full auto

 

[foghornl]

Hmmmm

Didn't the late 1800's hand-cranked "Gatling Gun" use a top-mount magazine

 

[Bwana John]

why?

Gravity

 

[cluttonfred]

Thanks, all, but the question was...

Besided the LMGs, can anyone think of any other rifles, SMGs, pistols or shotguns with Owen-style top-mounted magazines?

F1 and American 180, I'll give you, but the rest are all LMGs or bigger, and heck, the Gatling is almost artillery.

I am looking for inspiration and ideas in designing a rifle or carbine with top-loading magazine, so the big boys don't really apply. Anything else smaller than an LMG come to mind?

 

[kfranz]

Stoner 63, Robinson M96, Lewis gun

 

[Vaarok]

You forgot the Soviet DP-28.

 

[hoghunting]

There are the Calico carbines and pistols. The 22LR holds 100 rounds, and the 9mm holds 50.

 

[tntwatt]

calico pic from gunbroker.com

 

[cluttonfred]

Hmm, it occurred to me that a modern top-mounted magazine could have an advantage that the Owen didn't.

Translucent polymer construction of the magazine (preferably just the back so the only the shooter can see) would allow instant checks of remaining ammo while still in firing position.

Yes, I know that witness holes do the same thing, but they also let in dirt.

 

[Tony Williams]

Not a real gun, but I design proposal I came up with in the article on bullpup assault rifles on my website:

Another solution could be to turn the action upside down so that ejection is downwards. The top-mounted magazine would be a drum rather than a box type, and could do double duty as a cheekpiece so that the firer could switch shoulders without needing to make any adjustments. This would incidentally provide a larger-capacity magazine without the usual disadvantage of excessive length under the gun, and the gravity-aided feed and ejection processes should be more reliable than a conventional gun's.​

 

[cluttonfred]

Tony, do you have a sketch? I don't quite get how the drum would serve as a cheekpiece unless it were flat drum like a DP (see image above) rotated 90 degrees to one side, but then it would feed from the side.

On the other hand, I could definitely see a simple conventional or bullpup assault rifle along the lines of the TRW Low-Maintenance Rifle using top feed, bottom ejection and offset sights.

 

[Tony Williams]

I don't have a drawing, but the idea is a small-diameter drum (like a mini version of the Oerlikon) rather than a flat pan type.

 

[Quiet]

FN P-90 & PS-90 have top mounted magazines and the MSG 5.7 AR15 upper utilizes a top mounted magazine as well (it's the same magazine as the FN P-90/PS-90).

 

[Famaldehide Face]

That MSG 5.7 is very much like a Calico carbine except with a different stack magazine.

Not to forget the Itallian OVP submachine gun and shotguns like the Neostead & some russian pump thing.

 

[Vern Humphrey]

Bren light machine gun, used by the Brits in WW2. I would love to get my hands on at least a semiauto version, don't think I can afford a full auto

I had one of those when I was a lad living in Egypt in the mid-50s. One of my dad's oil-exploration crews found a dump at Siwa Oasis, and I spirited out a Bren and all the ammo I could load in a Powerwagon.

It was great fun, but Dad turned thumbs down on my idea for smuggling it back into the US. (Spoil-sport that he was, he also stopped me from smuggling back a blowgun, complete with curare, from Peru a couple of years earlier.)

 

[Dr. Tad Hussein Winslow]

The basic engineering tradeoff involved is this:

1. Advantage. You can rely upon gravity to HELP with feeding, in addition to spring pressure, rather than relying upon spring pressure to OVERCOME gravity, which is working against you pushing the rounds up, in a bottom-mounted mag.

VERSUS

2. Disadvantage: Varying degrees of interference with line of sight.

Obviously, the disadvantage outweighs the advantage, 99% of the time, as 99% plus semi-auto gun designs use bottom-mounted mags. But the mentioned top-mounted ones are interesting. Either with a "flat magazine" that allows you to use a line of sight *over the top* of the magazine (P90, American 180, etc.), or a standard box mag where you use a line of sight off to the side (Bren, etc.). Didn't Japan also have a top fed standard mag machine gun?

 

[Tony Williams]

The Madsen LMG had a third solution: the magazine was offset to one side of the line of sight, rather than the sights being offset.

 

[Vern Humphrey]

One point to be considered -- magazine-fed LMGs are pretty much dead ducks. A belt fed gun is more effective.

 

[Tony Williams]

One point to be considered -- magazine-fed LMGs are pretty much dead ducks. A belt fed gun is more effective.

Tell that to the Marines

The USMC is planning to shift its belt-fed M249s back to the support level, and replace them with more compact magazine-fed LMGs at the sharp end.

 

[cluttonfred]

That MSG 5.7 AR15 upper in the photo above gives a good idea of how compact a box fed automatic rifle could be in the support LMG role if it used a horizontal box magazine aligned with the bore.

On the other hand, a very light Bren-style could be very handy, and still used the standard STANAG magazines. See Max P.'s article on the Stoner 63 (scroll down a little) for an idea of what it might look like. With the significant velocity loss of the short-barreled M4 carbines in service, and the fact that most are burst only, not full auto, just having one guy in the squad with a long-barreled, full-auto option must be pretty handy. Realistically, though, I imagine a belt-fed, heavy barrel version of the M16 that retains the box magazine option would be even simpler.

 

[Quiet]

Tell that to the Marines

The USMC is planning to shift its belt-fed M249s back to the support level, and replace them with more compact magazine-fed LMGs at the sharp end.

USMC IAR program
Synopsis:
The United States Marine Corps is currently seeking information for a non-developmental, 5.56mm, Infantry Automatic Rifle (IAR). CAPABILITY DISCUSSION. The IAR will enable the fire team to rapidly suppress point and area targets of immediate concern. The IAR will replace the infantry’s M249 Squad Automatic Weapons (SAWs) with an automatic rifle easily operable by a single infantry Marine that emphasizes lightweight and portability in order to maximize dismounted maneuverability.

The IAR shall utilize a magazine with a capacity of 100 rounds (Threshold). The magazine shall permit rapid visual determination of the number of rounds remaining (Objective). Magazine Compatibility. The IAR shall accept and function with the current Marine Corps service rifle (the M16A4) 30 round magazines.

So far there are only three entrys for the IAR program.

Colt entry (gas-piston AR)

CTK entry (Ultimax 100 Mark 4)

H&K entry (MG-36)