Proto-type weapons.

[wugguswhompus]

I have been tasked with some new projects for the Marine Corps and I am asking for some of your experiences. I am currently working on on designs for an magazine fed shotgun....I know...re-inventing the wheel, but I do as Im told.....and I am looking at modifying an AR platform to improve sight over bore to minimize changes in point of aim and point of impact. I know some of you out there are magical with guns, and I ask that you not be afraid to share your past discoveries so that I dont burn your tax dollars covering old ground. Thank you so much.

[Dan Sierpina]

I know that the .308 platform was looked at, for 20 gauge. I don't think the Marine's would be interested in that though.

[HRider]

I wish you the best. I hope that you can design an AR type shotgun that is Inertia operated and has a wide enough magwell to accept the Pmags that I hope Magpul makes for it.

Hurley

[PistoleroJesse]

Does box fed have to mean autoload? If not I'd base the design on the already used 590 and modify the action of the lifter somewhat.

That's probably going to be your most reliable option.

[Jesse Tischauser]

Good luck man!

[joelogic]

Isn't there already a mag feed AR based shotgun? Akdal MKA 1919

Edited May 18, 2012 by joelogic

[wugguswhompus]

Yes there are already several designs currently used.....i was asking about any issues with them....the Corps will not go the way of the Saiga, but the Mk1919 is being looked at closely. I am looking at modifications to a standard tube fed shotgun that can allow for magazines as well. I am mainly concerned with issues on the operating system. IE...the Corps is currently fielding Benellis M4 or the M1014 which runs on a gas piston....this has several problems and can be rough on even the saltiest of shooters....

[bushmeat]

Yes there are already several designs currently used.....i was asking about any issues with them....the Corps will not go the way of the Saiga, but the Mk1919 is being looked at closely. I am looking at modifications to a standard tube fed shotgun that can allow for magazines as well. I am mainly concerned with issues on the operating system. IE...the Corps is currently fielding Benellis M4 or the M1014 which runs on a gas piston....this has several problems and can be rough on even the saltiest of shooters....

Several years ago, I saw a Browning A5 that had been modified to take a BAR mag (12 gauge rounds fit nicely). Was told project shelved due to lack of funds or access to CAD/CNC.

However, a long, bulky magazine would be a liability in vehicles and CQB. IMHO, you might be better served with an Xrail type system that was right up to the receiver instead of hanging out way at the end of the mag tube.

Haven't played with the SRM but it seems along these lines.

[Kali]

IIRC, a while back Knoxx Industries made something called the "Sidewinder." It was a kit that converted a Mossberg/Remington pump shotguns to accept box or drum magazines. you might want to give them a call since most of the R&D had already been done.

[Chuck Anderson]

FYI, Knoxx is now owned by Blackhawk Industries.

Also the AA-12 seems to be a viable mag fed gun.

[Hi-Power Jack]

Depending on what you're doing with it, I just

saw the "new" KelTec 12 gauge pump shotgun with

a double tube mag, each tube held 7 rounds - a

total of 15 rounds to start in the gun.

You could keep #2 or #4 shot in one mag, and

slugs in the other, and switch back and forth

with the flick of a switch

AND, it's a Bullpup - very short - very handy.

Incredible gun - I didn't get to shoot it, but

saw three guys shoot theirs at a multi-gun match.

That looks like a tremendous opportunity for

someone needing flexible, light, concealable

firepower -

Put some fast bright sights on it, and it's

ready to go ...

[mpom]

The Kel Tec KSG has a lot of good features for a combat shotgun, as mentioned above.

Being a bullpup design, its going to be a lot shorter that any 14 round capacity non bp design, important for cqb mout or vehicle based operations.

Picatinny rail on top lends itself to sighting system choice based on actual requirement, and tool less mounting.

If it meets your requirements, would save big bucks and speed up availability. Unfortunately Kel Tec is a very small company, so us civilians would suffer

while the USMC gets their order filled, if it comes to that. Just kidding, as I have the highest respect for the guys willing to put their lives on the line.

Link is to a review. Maybe too "country" but covers the basics.

http://www.gunblast.com/KelTec-KSG.htm

Mark

[Charles Bond]

One thing the Saiga did right which applies to a combat weapon was not to install the front sight at the end of the barrel where it is more likely to be damaged in hand to hand or a door breach or other rough use. Of course giving the gun a longer sight radius makes it easier to hit targets that fly but IMO that is relatively unimportant for your project. My suggestion would be to mount the forward sight at the end of the forward rail rather than on the barrel. I also see no reason not employ flip up front and rear sights that would co witness with an optic presently employed on the M16 or AR15 platform.

The problem with the AA12 is that it was too heavy and full auto. But my experience is that it worked rather well and is an operating system that you should consider starting with.

There are opinions here I respect that note the disadvantage of a longer mag in a close environment like a vehicle. But you could shorten the mag and still have it holding ten rounds if the magazine was designed on the same concept as the Surefire giving it a double column feed. Making the magazine wider than a single column would not be a disadvantage but it would need to be robust enough to be able to be used as a mono pod.

One thing that might bear some consideration with the feed issue is the basic design of the ammo. Were they to design shells with a head more like a 9mm (rimless) and less like a conventional shotgun shell they would feed better and my sense is that this would not be a problem to design an extractor or a chamber to function even better than what is used presently.

I happen to like the Xrail system a great deal but I doubt that given the way the Marine Corp looks at things that they would adopt it. And its one big limitation is being able to change out from one type of ammo to another. Sure you can always insert a slug as needed but trying to load more than one at a time would be difficult and my sense is that the ability to be able to change from one type of ammo to another is central to your project.

Last observation is that were you to make this all a bull pup design you would be way ahead of the game. Going compact would give a Marine the ability to use his rifle as his primary weapon system and then swing the shotgun into action as needed. While they can do that now, having it more compact gets it down to the size of his pack and makes it less likely to hang up on a door way during an entrance or exit from a vehicle or structure. For it to be a bull pup is really only viable if it is inertia operated which I would recommend regardless of whether you use a bull pup or conventional design.

[gose]

However, a long, bulky magazine would be a liability in vehicles and CQB. IMHO, you might be better served with an Xrail type system that was right up to the receiver instead of hanging out way at the end of the mag tube.

Haven't played with the SRM but it seems along these lines.

Then make it with a few different mag sizes and pick the right magazine size for the situation.

[Sleepswithdogs]

I've often wondered why a tube fed semi auto 12g couldn't be modified, machined, welded to accept a box mag. I'd think the mag would do the job of lifting.

The x-rail system is nice, but the weight being carried at the end of the barrel, it would seem to me, to presents some handling problems. Keeping the mag mid-ship is a very good way to keep the weapon in balance. If the rail replaced the entire tube and hand guard, leaving the cylindrical mag close to the receiver would seem an attractive solution, but it still doesn't load as quickly, and ammo isn't carried as easily as a box mag.

TAR

Edited May 18, 2012 by Sleepswithdogs

[Charles Bond]

I've often wondered why a tube fed semi auto 12g couldn't be modified, machined, welded to accept a box mag. I'd think the mag would do the job of lifting.

The x-rail system is nice, but the weight being carried at the end of the barrel, it would seem to me, to presents some handling problems. Keeping the mag mid-ship is a very good way to keep the weapon in balance. If the rail replaced the entire tube and hand guard, leaving the cylindrical mag close to the receiver would seem an attractive solution, but it still doesn't load as quickly, and ammo isn't carried as easily as a box mag.

TAR

As to the box replacing the rail on a conventional tube fed, it would work but the tube would have to push the shell back and then reposition to push in the next shell. Making it move both way would be the complicating factor.

Xrail does make a unit that replaces the entire rail and the forearm and they make them in more than one size so you could have a shorter gun without nearly as much weight. and better balance but as you note you can not reload as quickly after you use all 15 shots or 23 shots or 29 shots.

[Sleepswithdogs]

I've often wondered why a tube fed semi auto 12g couldn't be modified, machined, welded to accept a box mag. I'd think the mag would do the job of lifting.

The x-rail system is nice, but the weight being carried at the end of the barrel, it would seem to me, to presents some handling problems. Keeping the mag mid-ship is a very good way to keep the weapon in balance. If the rail replaced the entire tube and hand guard, leaving the cylindrical mag close to the receiver would seem an attractive solution, but it still doesn't load as quickly, and ammo isn't carried as easily as a box mag.

TAR

As to the box replacing the rail on a conventional tube fed, it would work but the tube would have to push the shell back and then reposition to push in the next shell. Making it move both way would be the complicating factor.

I was thinking that the mag could replace the shell lifter, that the lifter is only used because it's tube feed and the shell has to transition from horizontal, rearward movement to vertical movement. The box magazine simply lifts the shell in to place for the bolt to move ahead into the chamber.

Xrail does make a unit that replaces the entire rail and the forearm and they make them in more than one size so you could have a shorter gun without nearly as much weight. and better balance but as you note you can not reload as quickly after you use all 15 shots or 23 shots or 29 shots.

[Sleepswithdogs]

I've often wondered why a tube fed semi auto 12g couldn't be modified, machined, welded to accept a box mag. I'd think the mag would do the job of lifting.

The x-rail system is nice, but the weight being carried at the end of the barrel, it would seem to me, to presents some handling problems. Keeping the mag mid-ship is a very good way to keep the weapon in balance. If the rail replaced the entire tube and hand guard, leaving the cylindrical mag close to the receiver would seem an attractive solution, but it still doesn't load as quickly, and ammo isn't carried as easily as a box mag.

TAR

As to the box replacing the rail on a conventional tube fed, it would work but the tube would have to push the shell back and then reposition to push in the next shell. Making it move both way would be the complicating factor.

Xrail does make a unit that replaces the entire rail and the forearm and they make them in more than one size so you could have a shorter gun without nearly as much weight. and better balance but as you note you can not reload as quickly after you use all 15 shots or 23 shots or 29 shots.

I was thinking that the mag could replace the shell lifter, that the lifter is only used because it's a tube feed and the shell has to transition from horizontal, rearward movement to vertical movement. The box magazine simply lifts the shell in to place for the bolt to move ahead into the chamber.

Edited May 19, 2012 by Sleepswithdogs

[Alaskapopo]

Does box fed have to mean autoload? If not I'd base the design on the already used 590 and modify the action of the lifter somewhat.

That's probably going to be your most reliable option.

Going with a pump seems a bit counter productive.

Pat

[StealthyBlagga]

Box magazines and conventional shotgun ammo do not play well together. Yes, they can be made to work, but feed malfunctions due to shell deformation are a significant risk. They may work OK for our game, where the mag is loaded for a few hours, but leaving one loaded for days on end in a HUMMWV that reaches 140degF inside is likely to present significant challenges. The rims can also cause stacking problems, which I assume is why the HK CAWS of the 80s used proprietary ammo that was rimless, belted and brass-cased. There are valid reason that most shotguns still use tube magazines.

If you want a box magazine fed shotgun for breaching etc., what is wrong with the C-More M26 ?

Are you getting the sense that you are walking down a well-trodden path yet?

To address the M16 sight-to-bore offset issue, unless you want to adopt a completely new weapon system, about the only realistic option is a custom optic that offsets the objective lens below the ocular lens. Call Trijicon and see what they think of the idea.

Edited May 19, 2012 by StealthyBlagga

[Sleepswithdogs]

Box magazines and conventional shotgun ammo do not play well together. Yes, they can be made to work, but feed malfunctions due to shell deformation are a significant risk. They may work OK for our game, where the mag is loaded for a few hours, but leaving one loaded for days on end in a HUMMWV that reaches 140degF inside is likely to present significant challenges. The rims can also cause stacking problems, which I assume is why the HK CAWS of the 80s used proprietary ammo that was rimless, belted and brass-cased. There are valid reason that most shotguns still use tube magazines.

If you want a box magazine fed shotgun for breaching etc., what is wrong with the C-More M26 ?

Are you getting the sense that you are walking down a well-trodden path yet?

To address the M16 sight-to-bore offset issue, unless you want to adopt a completely new weapon system, about the only realistic option is a custom optic that offsets the objective lens below the ocular lens. Call Trijicon and see what they think of the idea.

Very well put.

[fastshooter03]

FYI, Knoxx is now owned by Blackhawk Industries.

Also the AA-12 seems to be a viable mag fed gun.

I've always wondered why the folks who make the AA12 don't have a semi auto version?????

I've heard the way the mags go in is a little ackward on those as well???

Why not have a semi auto version with AR style flattop and AR style mag insertion?

Nick

[mike cyrwus]

Does box fed have to mean autoload? If not I'd base the design on the already used 590 and modify the action of the lifter somewhat.

That's probably going to be your most reliable option.

Going with a pump seems a bit counter productive.

Pat

Pat, call me up next week when you get a chance, want to touch base on the shotgun.

thanks,Mike

[TonyRumore]

FYI, Knoxx is now owned by Blackhawk Industries.

Also the AA-12 seems to be a viable mag fed gun.

I've always wondered why the folks who make the AA12 don't have a semi auto version?????

I've heard the way the mags go in is a little ackward on those as well???

Why not have a semi auto version with AR style flattop and AR style mag insertion?

Nick

The AA12 has a super slow rate of fire that allows you to easily fire singles if you want. Firing from an open bolt, it still would not be legal for civilians in semi auto.

They would have to redesign it into a closed bolt semi in order to sell it on the civilian market. And even then, I'm not sure it would clear the DD opinion of the ATF for size. I think it is too tall, top to bottom. Could be wrong though.....I don't have one.

[Toolguy]

I have a red dot sight base that eliminates the scope height problem and gives you 10 separate elevation settings for different distances. My test guy, John Pride has shot slugs accurately to 120 yards with this setup. You can see pictures in the Protocall Design vendor tent under the "New for 2009" heading. This is for a flat top AR or other Pic rail mounting.

Edited May 31, 2012 by Toolguy