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Posted: 4/10/2014 10:27:28 AM EDT
[#1]
Quote HistoryQuoted:
See how this hits you... If I were a Colt engineer on a budget I'd go pull a carbine barrel blank from the production floor to tinker with for my PDW. Late 90's that'd be an M4 carbine. Here's a picture (http://img.photobucket.com/albums/v204/kenc3/DSCN0813.jpg) from someone who cut a M4 barrel to 11.3" or 11.5"ish length. Seems to me if you were to go with 11" you'd bypass the taper of the M4 cut and have exactly what we see on the MARS PDW, an 11" carbine barrel. Sounds reasonable enough - but at the same time I think late-90s, before GWOT, the M4 would probably have been a pretty low-density production item, barely anyone really even knew about it, I dunno how many barrel blanks they would've had to spare. What would probably have been plentiful, though, along the same lines might be the R6520 Gov't Carbine .625 16" barrels, though, which had been a pretty steady production item and would probably have been the most popular/plentiful carbine barrel they had? ~Augee |
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Posted: 4/10/2014 10:39:03 AM EDT
[#2]
Quote HistoryQuoted:
Sounds reasonable enough - but at the same time I think late-90s, before GWOT, the M4 would probably have been a pretty low-density production item, barely anyone really even knew about it, I dunno how many barrel blanks they would've had to spare. What would probably have been plentiful, though, along the same lines might be the R6520 Gov't Carbine .625 16" barrels, though, which had been a pretty steady production item and would probably have been the most popular/plentiful carbine barrel they had? ~Augee Quote HistoryQuoted:
Quoted:
See how this hits you... If I were a Colt engineer on a budget I'd go pull a carbine barrel blank from the production floor to tinker with for my PDW. Late 90's that'd be an M4 carbine. Here's a picture (http://img.photobucket.com/albums/v204/kenc3/DSCN0813.jpg) from someone who cut a M4 barrel to 11.3" or 11.5"ish length. Seems to me if you were to go with 11" you'd bypass the taper of the M4 cut and have exactly what we see on the MARS PDW, an 11" carbine barrel. Sounds reasonable enough - but at the same time I think late-90s, before GWOT, the M4 would probably have been a pretty low-density production item, barely anyone really even knew about it, I dunno how many barrel blanks they would've had to spare. What would probably have been plentiful, though, along the same lines might be the R6520 Gov't Carbine .625 16" barrels, though, which had been a pretty steady production item and would probably have been the most popular/plentiful carbine barrel they had? ~Augee I'm totally on board with it being .625". The only nagging doubt I have is 11" being too perfect (to clear the m4 cut), and that they used a flat top receiver. Were there any other late 90's Colt guns that switched to a flat top upper before the M4? |
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Posted: 4/10/2014 10:47:29 AM EDT
[#3]
As cool as I think a MARS clone would be, I'd start from scratch if I were to make a PDW.
Trying to mod all those AR parts to work just keeps you confined in a box. Mine would look like an AR-180 and a Daewoo K1 had a midget love child. Hell, there might have even been a MAT49 at that party, but they were all very drunk at the time........................... 
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Posted: 4/10/2014 10:55:26 AM EDT
[#4]
Quote HistoryQuoted:
As cool as I think a MARS clone would be, I'd start from scratch if I were to make a PDW. Trying to mod all those AR parts to work just keeps you confined in a box. Sacrilege! This is the retro forum! Burn the Heretic! |
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Posted: 4/10/2014 11:26:04 AM EDT
[#5]
Quote HistoryQuoted:
Sacrilege! This is the retro forum! Burn the Heretic! Quote HistoryQuoted:
Quoted:
As cool as I think a MARS clone would be, I'd start from scratch if I were to make a PDW. Trying to mod all those AR parts to work just keeps you confined in a box. Sacrilege! This is the retro forum! Burn the Heretic!  
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Posted: 4/10/2014 11:32:27 AM EDT
[#6]
A lot of people have tried to make a better rifle than the AR15.
No one has succeeded. |
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Posted: 4/10/2014 12:22:01 PM EDT
[#7]
It's definitely a .625 FSB barrel, and they're 11" or so - longer than the 10.5s for sure. Some of the prototype photos appear to be a little longer than 11", maybe closer to 11.5", but that may just be perspective in the photo.
I'd be much more comfortable with reworking the bolt and front end of the BCG so that the standard FCG parts and geometry would still work. Take 0.550 off the bolt wouldn't be trivial but not unreasonable I don't think... changing to a shorter balanced-style extractor like the ACB uses, and a smaller diameter cam pin like the E3 bolts would both allow a smaller bolt design. If folks need a shorter trigger reach that could easily be accommodated with a modified trigger. |
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Posted: 4/10/2014 12:37:40 PM EDT
[#8]
Quote HistoryQuoted:
A lot of people have tried to make a better rifle than the AR15. No one has succeeded. It's my favorite. 
But the buffer tube/recoil spring arrangement does limit the potential compactness. |
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Posted: 4/10/2014 12:42:42 PM EDT
[#9]
Quote HistoryQuoted:
It's my favorite.
But the buffer tube/recoil spring arrangement does limit the potential compactness. Quote HistoryQuoted:
Quoted:
A lot of people have tried to make a better rifle than the AR15. No one has succeeded. It's my favorite.
But the buffer tube/recoil spring arrangement does limit the potential compactness. A folding LAW stock would work, but perhaps a blow-back set-up with no real buffer tube would work? Not sure how case length compares to .22 LR - just thinking aloud. With a side-folding ACE stock it would be the shizzit. |
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Posted: 4/10/2014 12:51:17 PM EDT
[#10]
Quote HistoryQuoted:
A folding LAW stock would work, but perhaps a blow-back set-up with no real buffer tube would work? Not sure how case length compares to .22 LR - just thinking aloud. With a side-folding ACE stock it would be the shizzit. Quote HistoryQuoted:
Quoted:
Quoted:
A lot of people have tried to make a better rifle than the AR15. No one has succeeded. It's my favorite.
But the buffer tube/recoil spring arrangement does limit the potential compactness. A folding LAW stock would work, but perhaps a blow-back set-up with no real buffer tube would work? Not sure how case length compares to .22 LR - just thinking aloud. With a side-folding ACE stock it would be the shizzit. If the whole thing could be got working in the "standard" configuration, I think something like the M231-ish NEA stock could probably be adapted without too much more trouble. ~Augee |
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Posted: 4/10/2014 12:53:30 PM EDT
[#11]
And DOE HGs with a shorter barrel would make more sense to me. If you are going for ultimate shorty, do it.
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Posted: 4/10/2014 1:12:40 PM EDT
[#12]
As an individual I have uses for a folding stock. Institutional users should mostly avoid them.
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Posted: 4/10/2014 2:19:35 PM EDT
[#13]
Quote HistoryQuoted:
As an individual I have uses for a folding stock. Institutional users should mostly avoid them. Just curious, how many broken buttstocks have you encountered in the service? I've heard reports of the M4 tubes breaking but have never seen it personally. In my 10+ years I can only recall one M16A1 with a user caused failure. And he was an idiot. 
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Posted: 4/10/2014 2:22:53 PM EDT
[#14]
Only thing I see break on a regular basis is the KAC hand guards.
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Posted: 4/10/2014 4:39:21 PM EDT
[#15]
 Getting closer... I'll try to figure out a proper mag this week end but the internals are sound. |
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Posted: 4/10/2014 5:31:02 PM EDT
[#16]
Quote HistoryQuoted: As cool as I think a MARS clone would be, I'd start from scratch if I were to make a PDW. Trying to mod all those AR parts to work just keeps you confined in a box. Mine would look like an AR-180 and a Daewoo K1 had a midget love child. Hell, there might have even been a MAT49 at that party, but they were all very drunk at the time........................... |
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Posted: 4/10/2014 8:46:55 PM EDT
[#17]
Quote HistoryQuoted:
https://dl.dropboxusercontent.com/u/1702248/MARS-WIP1.jpg Getting closer... I'll try to figure out a proper mag this week end but the internals are sound. Yer killin me  It's as if it's actually possible. I've wanted one of these since I first found out about them. Roughly 15 years. Frankly I thought no one else would see the appeal.
Might as well mock up a 16" barrel midlength while you're at it for the no-SBR folks. Just had a thought. I wonder if they have an original MARS prototype at the Knight's museum? |
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Posted: 4/11/2014 6:02:03 AM EDT
[#18]
Quote HistoryQuoted:
https://dl.dropboxusercontent.com/u/1702248/MARS-WIP1.jpg Getting closer... I'll try to figure out a proper mag this week end but the internals are sound. Lookin' great, rock on! I've been staring at pictures of 30 round mags and pictures of MARS mags trying to figure out what sort of zig zag shape they'd have to cut to make that mag. There's got to be some clues in where the ribs are placed. |
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Posted: 4/11/2014 6:48:40 AM EDT
[#19]
Here's a website with a really good comparison of the various PDW cartridges.
http://www.quarry.nildram.co.uk/PDWs.htm Pic from site. 
Experimental PDW cartridges: 1 = 5.56mm NATO (for scale); 2 = .22 APG; 3 = .221 Fireball (IMP); 4 = 5.56mm Colt MARS; 5 = 6x35 KAC PDW; 6 = .17 Libra; 7 = .22 SCAMP; 8 = .224 Boz; 9 = .225 JAWS MicroMag; 10 = .250 JAWS MicroMag; 11 = .224 VA; 12 = .22 TCM; 13 = .223 Timbs; 14 = 6.5x25 CBJ; 15 = 9x19 (for scale) |
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Posted: 4/11/2014 7:09:18 AM EDT
[#20]
Compare these 2 images:
http://i271.photobucket.com/albums/jj149/halpark/pix825141966_zpsfdddbdbc.jpg http://www.firearmsprostore.com/images/products/detail/Brownells30rdAR15Mag.jpg (for additional reference for the feed lips: http://farm8.staticflickr.com/7165/6697579995_6a096b2420.jpg) **None of this explains the small mag catch slot and cut in the spine of the mag. That spine cut looks like where a pivoting catch would go, think really long AK catch, or the kind of catch people make for 9mm mags (like this: http://img.photobucket.com/albums/v43/fatcat/AR15/P8080143.jpg). So, if you compare the 2 thin ribs they're in the same position on both mags in relation to the feed lips. Noting that it's nearly centered (is a little to the left) in the mag catch slot should give a good idea of how much material was removed. I haven't drawn it out yet but I'm envisioning a cut between the ribs, around the mag catch slot, and then cutting and leaving out the lower part of the rib. It also looks to me like between the big rib and front of the mag that there is some material missing, where the feed lips flatten out for a hair at the front is missing on the MARS mag. So the ammo changed by 15mm (.59") from 5.56x45mm to 5.56x30mm. I'd be willing to bet you wouldn't be able to chop .59" from the feed lips so they took as much as they could from that area and trimmed the rest (little as it may be) from the front. Looking at the follower they chopped a hair from the back and a majority from the front. eta: For the bottom of the mag: http://farm8.staticflickr.com/7175/6697578853_eb838e1151.jpg The tabs for the floor plate are just BEHIND the middle (thin) groove. So from the top to the bottom, if you cut between the ribs, then around the mag catch and then remove the middle rib from the middle of the mag down it looks like you'd end up with the same rib pattern that's on the MARS mag, all tabs intact, and shorten the mag almost enough. As always, 
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Posted: 4/11/2014 7:14:06 AM EDT
[#21]
Just had an idea for the mag.
Cut a standard mag along the back edge of the "large rib" at the front of the mag. Then flatten the reduced width lip so it nests on the inside of the back half of the body. Then weld the seam or rivet the front to the back. This would keep you from messing up the feed lips and the standard mag catch interface. |
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Posted: 4/11/2014 7:49:04 AM EDT
[#22]
Quote HistoryQuoted:
Just had an idea for the mag. Cut a standard mag along the back edge of the "large rib" at the front of the mag. Then flatten the reduced width lip so it nests on the inside of the back half of the body. Then weld the seam or rivet the front to the back. This would keep you from messing up the feed lips and the standard mag catch interface. That's what I've been saying... I still think building a curved swage plate assy to fit in a press would be a bitch...but doable. I'm going to look for mags today and pull some out.
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Posted: 4/11/2014 8:02:05 AM EDT
[#23]
Quote HistoryQuoted:
That's what I've been saying... I still think building a curved swage plate assy to fit in a press would be a bitch...but doable. I'm going to look for mags today and pull some out.Quote HistoryQuoted:
Quoted:
Just had an idea for the mag. Cut a standard mag along the back edge of the "large rib" at the front of the mag. Then flatten the reduced width lip so it nests on the inside of the back half of the body. Then weld the seam or rivet the front to the back. This would keep you from messing up the feed lips and the standard mag catch interface. That's what I've been saying... I still think building a curved swage plate assy to fit in a press would be a bitch...but doable. I'm going to look for mags today and pull some out.Once I get a chance to do some measuring of dimensions I mentioned above, I might go as far as scrounging up a 10 round mag to break the spot welds on and split in half and mock up at about the right size. |
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Posted: 4/11/2014 8:04:36 AM EDT
[#24]
More web pics
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Posted: 4/11/2014 1:20:53 PM EDT
[#25]
With all this talk of shortening things I completely forgot about the charging handle
 Chop chop choppity chop!
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Posted: 4/11/2014 4:02:56 PM EDT
[#26]
Would it be possible to use HK 416 steel mags?
Cut and weld them to length, they are also less tapered. |
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Posted: 4/11/2014 6:41:00 PM EDT
[#27]
Quote HistoryQuoted:
https://dl.dropboxusercontent.com/u/1702248/MARS-WIP1.jpg Getting closer... I'll try to figure out a proper mag this week end but the internals are sound. I would like to see what the bolt and carrier group would look like. Here's a few pics of the round: 
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Posted: 4/11/2014 9:21:11 PM EDT
[#28]
Quote HistoryQuoted:
With all this talk of shortening things I completely forgot about the charging handle Chop chop choppity chop!I was wondering about the MARS furniture. If the buttstock and PG are smaller, are the HGs reduced in length also? |
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Posted: 4/11/2014 9:33:35 PM EDT
[#29]
Quote HistoryQuoted:
I was wondering about the MARS furniture. If the buttstock and PG are smaller, are the HGs reduced in length also? Quote HistoryQuoted:
Quoted:
With all this talk of shortening things I completely forgot about the charging handle Chop chop choppity chop!I was wondering about the MARS furniture. If the buttstock and PG are smaller, are the HGs reduced in length also? They were standard pistol grip and carbine handguards, the stock just had the forward part cut off. |
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Posted: 4/13/2014 9:36:04 AM EDT
[#30]
 Just need to design a real magazine and draw the prints. |
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Posted: 4/13/2014 10:08:16 AM EDT
[#31]
Quote HistoryQuoted:
https://dl.dropboxusercontent.com/u/1702248/MARS-WIP2.jpg Just need to design a real magazine and draw the prints. That would make a great looking print to hang on the wall. |
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Posted: 4/13/2014 1:16:30 PM EDT
[#32]
Quote HistoryQuoted:
https://dl.dropboxusercontent.com/u/1702248/MARS-WIP2.jpg Just need to design a real magazine and draw the prints. Can you use standard carbine handguards instead of the M4 style
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Posted: 4/13/2014 7:52:13 PM EDT
[#33]
 Just a few more parts... |
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Posted: 4/13/2014 9:52:01 PM EDT
[#34]
WOW. That is the best rendering of all, so far.
Ditto re the smaller HGs, why did you choose the M4s if I may inquire? Were they specced for the MARS? |
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Posted: 4/14/2014 4:20:22 AM EDT
[#35]
Quote HistoryQuoted: WOW. That is the best rendering of all, so far. Ditto re the smaller HGs, why did you choose the M4s if I may inquire? Were they specced for the MARS? Also, while it looks like the prototypes had CAR HGs the illustrations for the final product look like M4 HGs. I'll get around t doing some hand guards, I've been putting off modelling them my self as they are pretty complicated. |
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Posted: 4/16/2014 5:18:36 AM EDT
[#36]
Quote HistoryIt's wonderful....
I wonder if it might be useful to migrate this to the BIY or pistol caliber sub-forums - I too thought the appeal would be limited, which is why I broached it from a "unique retro prototype clone" angle, but now I've got fantasies of the potential for a modern PDW-caliber "short action" carbine... ~Augee |
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Posted: 4/16/2014 5:36:13 AM EDT
[#37]
I'm trying to work a few angles to get some detailed pictures of a real MARS mag.
Augee: For a "modern" PDW I imagine the mag well would be much like what Bazooka Bro's has been doing but with that space between the mag well and BHO removed. The good news is you'd be able to use the short action for a MARS gun and modern PDW without much of a fuss, it's really just barrel, caliber, and buffer tube that make it a MARS gun at that point. 
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Posted: 4/22/2014 6:03:02 PM EDT
[#38]
This thread kind of fell by the way side and I relized that I still owe some pics and weights on my AR57 bolt and upper. As a peace offering I throw this idea out there.
What about a dedicated 9mm lower like this: 
or this 
and then modify it to be more like the correct lower. Chamber it in .22 TCM which already works with 9mm mags in the RIA 1911 Just an idea for those more talented than me |
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Posted: 6/6/2014 6:38:39 AM EDT
[#39]
I've been thinking about this a bit more, I was browsing through my copy of "The Black Rifle" and realized how incredibly similar 5.56x30 MARS is to the first military experiments with a .222 Remington based SCHV round, the .22 Gustafson Carbine, the case length is about .100" longer but OAL is about the same as it was designed around 22 Hornet bullets.
I'm temped to have some reamers and dies made, I think 5.56x30 MARS with a 40gr VMax bullet would be a hard combo to beat in the realm of PDW cartridges. |
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Posted: 6/6/2014 7:33:06 AM EDT
[#40]
Quote HistoryQuoted:
I've been thinking about this a bit more, I was browsing through my copy of "The Black Rifle" and realized how incredibly similar 5.56x30 MARS is to the first military experiments with a .222 Remington based SCHV round, the .22 Gustafson Carbine, the case length is about .100" longer but OAL is about the same as it was designed around 22 Hornet bullets. I'm temped to have some reamers and dies made, I think 5.56x30 MARS with a 40gr VMax bullet would be a hard combo to beat in the realm of PDW cartridges. In the mean time I finished some (regular) 80% lowers to assess being able to mill out a custom lower. Apparently it's not out of the realm to mill your own 0% A2 or A3 upper receiver (http://www.cncguns.com/projects/ar15a2upper.html, http://www.cncguns.com/projects/ar15a3upper.html). I'm sure it would cost buku money for someone to make you a custom sized receiver from scratch... or for someone to custom mill a 80% lower (http://www.cncguns.com/projects/ar15lower.html). So to review: It's possible for someone to mill a shortened upper / lower receiver combo and make it an 80% lower We have the loading data for the MARS cartridge We have the measurements / idea of how much to shift the FCG We have the diagrams / measurements of how to modify the BCG's Magazines are still an issue. We can have reamers made but will be pricey(?) We have a good guess on barrel length / profile We have an acceptable replacement for the receiver extension. I would love a MARS rifle! |
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Posted: 6/6/2014 7:43:34 PM EDT
[#41]
My contribution to the world for tonight:
 https://dl.dropboxusercontent.com/u/1702248/Cartridge%2C%205.56x30mm%20MARS.PDF |
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Posted: 6/7/2014 6:55:56 AM EDT
[#42]
You guys are hopelessly sick!
The talent around here AMAZES me! |
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Posted: 6/7/2014 10:18:43 AM EDT
[#43]
Quote HistoryQuoted:
My contribution to the world for tonight: https://dl.dropboxusercontent.com/u/1702248/Cartridge%2C%205.56x30mm%20MARS.PNG https://dl.dropboxusercontent.com/u/1702248/Cartridge%2C%205.56x30mm%20MARS.PDF So wonder what it takes to get SAAMI listing
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Posted: 6/7/2014 3:11:17 PM EDT
[#44]
You know, a red anodized dedicated blank magazine with the spacer might be a starting point.....
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Posted: 6/7/2014 4:07:22 PM EDT
[#45]
Quote HistoryQuoted: With all this talk of shortening things I completely forgot about the charging handle Chop chop choppity chop!Actually, if anyone here has a charging handle write up for a CNC machine....you could just alter the length dimensions of the model. The ears and the nose of the handle should be the same dimensions...it's just the length that need to change. copy file edit file XXXXX profit? |
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Posted: 6/7/2014 7:31:10 PM EDT
[#46]
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Posted: 6/8/2014 8:51:40 AM EDT
[#47]
How does the 22 TCM cartridge/case fit into making this project happen with an affordable round?
Seems like you could use the TCM cases for affordable brass and standard 223 bullets to get your ovarall length up a tad and you'd probably be at your 5.56x39 sized round: http://en.wikipedia.org/wiki/.22_TCM Wes |
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Posted: 6/8/2014 11:19:46 AM EDT
[#48]
How is 22 TCM better than 221 Fireball.
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Posted: 6/8/2014 4:44:57 PM EDT
[#49]
Quote HistoryQuoted:
How is 22 TCM better than 221 Fireball. 22 TCM is being mass produced by Armscor in the Philippines for use in their 1911 pistols and bolt action rifle, all currently sold world wide, vs 221 fireball that's being mass produced by who for use in what that is sold where? I'm not saying 22 TCM is the best choice out there but it is in production and the guys at Armscor USA are pretty good about working with customers so if you wanted to order 5000 primed 22 TCM cases with no powder or projectiles for a special project, I suspect they could make it happen. Wes Edit to note: I realize that 221 fireball has been a wildcat case that's been developed out for use by other manufactures such as Knights. That said, price 1000 cases of brass through midway, backordered you looking at almost $500 for just the brass. For $420 you can order $1000 of ready to fire 22 TCM from Cheaper than dirt, manufactured by Armscor. That's why I'm thinking you might find the 22 TCM platform more affordable. |
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Posted: 6/29/2014 1:44:32 PM EDT
[#50]
So anyone made any more progress?
~Augee |
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