I'd rather have a 22 magnum than the TCM.

I would only buy a MARS if it was useful.

The true MARS cartridge should be pretty useful, and quite a bit more powerful than the TCM or .22 WMR or something like that.

I agree completely. I've been an advocate for that cartridge since I learned of it.

Ya know...a MARS would actually get me interested in an SBR.

 

I imagine both the mars and the fireball would probably have longer brass life than the tcm, shoulder angle etc. I think the mars cartridge is the winner here. Converting 556 brass would be no more difficult than .300 and someone like CH4D would make us dies to a print.

I think this should project should adhere to cloning the mars. This is turning in to a design a PDW thread and if you look at the length, weight and ballistics the mars doesnt do anything a 7.5in AR with an LWRC stock wont do with cheap off the shelf parts. If you want a good pdw you can build one cheaply. I want a mars.

Point of fact the MARS has 200 FPS on a 7.5 with dramatically better...everything.

If ammo was available locally for $0.30/ea no one would want 5.56mm SBRs.

I agree

I can build a 7.5 tomorrow for about $600 and feed it 45gr jhp or 52gr tsx and have something that works. If I did a 10in the mars advantage disappears. I was just trying to illustrate why this should be a clone project in the originally intended caliber and not a 22tcm project or a 30carbine project. I want a MARS not an expensive, difficult to build rifle in another caliber. If this turns into something else I would probably lose interest.

Well stated. MARS in, MARS out.

+1

http://www.scribd.com/doc/108526806/Black-Rifle-II

Scroll to page 137 for the Mini Assault Rifle System.

Have a look at the prototype on page 141, cut through the upper and lower receivers and GTAW'ed back together.

Fellas... I brought up the TCM due to the case size being so close to the original MARS spec.

Look here:


Compare to the TCM:
TCM case specs

Put a 5.56x45 type projectile in the TCM case and you will have a darn near identical MARS round without having to tool up custom brass.

If you guys would spend a little time working with the Rock Island Arms reps, you might actually convince them to manufacture a MARS platform rifle with Armscor resources.

Wes

I'm with you Wes. I would like to see a closer side by side comparison of the two rounds however, as well as a comparison to the .224 BOZ. The TCM has the advantage of being currently produced. I am a big fan of the M1 carbine as a PDW, but clearly there are better round now. I say let the best round win.

ETA: I think ti would be really interesting if Armscor actually could build this weapon. I bet it would sell.

I think expecting anyone to start cranking these out is a fantasy. Kinda like when ever someone posts whatever their pet "want" is, a few people say "I would buy one" and think that constitutes market demand. The best we could hope for is a small niche filler like Nodak to make us a run of receivers and a couple of members draw up plans for jig to modify mags (cut, refold, weld) and someone like CH4D making us some dies and someone forking out for a chamber reamer and doing a run of barrels. Who would do that without a fairly large commitment? I have no idea.

That's probably the most likely path to success here and even then we are looking at a couple grand per MARS, no resale value and having to handload exclusively. This is pretty hardcore as far as projects go.

Hate to say it, but I guess you are probably right. They do love their shorties in the Philippines though... They've built some similar weapons around the 5.56...

I have doubts that the TCM cases are safe to be loaded to the kind of pressures that would be needed to be close to the MARS cartridge performance.

I don't think thats as big an issue as you might think.  Pacific Tool and Gauge (who surely have the most Retro emblem out there) do custom reamers all the time.  They're not cheap but they're not so expensive as to be cost prohibitive.  Especially compared to the receivers and BCG that would be required for the project.

Folks like Sinclair can furnish blank reloading die bodies that can be finished using the chambering reamer.  Any decent smith capable of chambering a rifle can handle that little chore.



OK, OK, I know.  It's an A2 and doesn't belong here.........

I'd propose if we want to move forward that we make a working barrel on a "full sized" receiver with the MARS cartridge.  I'd venture a guess that we can get a functioning mag that would feed at least 5 rounds by shimming the back of a 10 or 20 rounder and trimming the follower.

If it comes down to numbers to bring down the cost of reamers and head space gauges I'd be in to buy a set.  I'd also be in to "burn" a 80% lower to test shifting the FCG pins on a lower to work with a modified BCG (just the firing pin area mod).

Following that path the barrel (depending on if the gas port size translates to a shortened lower / could use an adjustable gas tube), the BCG (after being ground down in the back side), and the FCG would be put in to a shortened upper and lower to complete a MARS gun.

As for a shortened upper / lower I'd think we'd need the likes of braceman to CNC a shortened 80% lower and upper.  From the measurements for how short the receiver needs to be I almost wonder if a 30% lower (forging with a solid mag well, etc) has enough meat to be shortened (I think it does), but again that'd be a CNC job.  I think figuring out the shorter lower and upper would be a lot easier with all the working parts mocked up and working on a "full sized" receiver.

Do we have anyone on the board handy that can neck down cut 5.56 cases and mount a bullet in them for testing (obviously after a reamer and die have been procured)?

As for magazines... I'd settle for trimmed and welded 5  - 10 rounders to get a functioning gun.  I have an idea of how a 30 rounder could be cut apart to match how a MARS mag looks, but don't own a welder to put it back together again.  Might have to settle for plastic mags unless you REALLY want to be hard core.

Edit:  Back in April I had emailed Compass Lake Engineering and it did not sound like they were setup to chamber a barrel in a custom chamber size.  I had asked about them chambering it given certain specs but not if they could produce a reamer.

If someone wants to contact Pacific Tool and Gauge please post here if you have.  Otherwise I might end up doing it sometime this week to see if they'd even have the interest or capability of making a reamer.

If you guys can round up enough people to buy 100 Kits of of the MARs specific parts I might be able to get them made Ive got everything figured out design wise. The magazine is the only thing that scares me.

I don't know them, but have a couple bolt guns chambered using their reamers and the guy who did the work certainly knows them pretty well.  Let me see can I get hold of him and find the best way to proceed.

.  
OK, I touched base with the guy who has done my bolt gun work in the past and he is also no slouch when it comes to AR's with non-223 calibers.  He thinks [for reasons we will not go into here] that it might be better to get in contact with JGS Tools, price list here:

JGS Tools

Look like you're talking $230 or thereabouts per reamer and $120 or thereabouts per headspace gauge for rimless wildcat stuff.  I am guessing at least a rough and a finish reamer at minimum would be necessary and GO and NO-GO gauges also at minimum.  But, I am not a precision funsmith nor did I stay at a Motel 6 last month so whoever knows about that kinda stuff needs to give them a call personally and work up the budget accordingly.

I will note that their website indicates they have quite a few drawings of obsolete and non-standard stuff, so you might get lucky and they might have, or know of, the MARS cartridge already.

Also, it might be good to talk to both companies to see what they say independently.  Just sayin'.

I'll draft up an email to JGS today or tomorrow before the weekend is over (so I have a chance to be more knowledgeable about the reloading / sizing side of things) and let you guys know once it's sent off.  I'm guessing if they make the reamer it would be economical to get the reloading dies / reamers to make those from them as well.  If it's sub $1k to get a working MARS barrel with a "full sized" receiver I'd consider that a deal!

God you guys are sick

Ya think?

This thread has more than just a little bit of a circular firing squad feel to it.

Some testing and eval of the 22 TCM round from a RIA 1911 pistol by an AR15 member can be seen here:
http://www.ar15.com/forums/t_1_5/1641062_The_Box_O__Truth___The__22_TCM_Pistol___Lots_of_Pics.html

Keep in mind that the above tests were from a full size 1911 barrel with only a 40 grain bullet.

Wes

Just FYI I'm printing a MARS lower right now, Ill have pics in the morning when it's done.

I screwed up the trigger guard area but other than that I'm pretty happy how it came out, this was also my longest running print I've ever successfully printed at 14hr15mins.

That is pretty cool....I haven't been keeping up on this thread at all with the busy summer (are you looking at functional or mock-up?)

Just a mock up for now, I've got to find someone to help make a real magazine, then I'll get barrels and AL receivers made. Everything else can be easier made from AR15 parts at for functional prototypes.

That's beautiful.  

~Augee

Holy $%@&

YES!

Mocked up the receiver extension and butt stock this morning.

Fantastic work!

I love it.

I think I will design a 30Carbine version of the lower this week.

This is fantastic work, JBowles.  

Did you leave off the case deflector and forward assist for ease of printing?  

I hope you didn't actually chop up a Colt N/1 stock.  

Is the A2 grip printed as well, or is it just scuffed up?  

Great work, once again!

~Augee

Still aiming to do this, got bum rushed with work

Yeah I did a slick side just to make it a bit easier, still took 12hrs for the upper.



The A2 grip is printed, I'm using that as sort of my base line part for improving and tweaking my print setup.



I'm going to get some reamers and sizing dies made for the ammo, I know a guy who makes weirdo steel magazine for fun, once I have some ammo in hand I'm going to see if he's up for a project. In the meantime I'm going to work on a plastic mag and 30 Carine lower.



I'm thinking about head more of a Stoner63 direction with the mag over just a smaller AR mag, if the story of the magazine picture earlier in this thread are to be believed Colt was on the same path.



 

Nice work JBowles!



IIRC, Colt used a continuously curved magazine for the MARS--I'll look for a reference.  FWIWThe original 30-round magazines for the M16 were continuously curved, but they were not compatible with the magazine wells of all of the weapons then in service.  As a result, Colt had to produce the familiar 30 round magazines with a straight section inside the mag well.  See Black Rifle page 377.

Wanted to see what a contemporary MARS would maybe look like, under 21.5" OAL with a 8.2" barrel







 

This is amazing progress, and has implications for the youth model AR15 market, as well as PDW market.

Superb work.

20 VarTarg, 19 Badger and 221 Fireball are all great varmint cartridges that would fit very well in this weapon.

I'm trying to find velocities for the 55 grain Berger from the 20 VarTarg.  It has a BC of .381.

This is completely off the top of my head as I haven't looked at any dimensions, but I wonder how close a polymer MARS mag would be dimensionally to a standard 30 carbine mag?  To where the same lower would work.

Then again I mentioned earlier the idea of having the magwell be wide enough for .45acp mags, so that would be contradictory. Too many ideas.

Length wise a M1 Carbine magazine and a MARS mag would be almost identical, however the MARS mag would be notably wider as it is the same as standard M16 Mag.



.221 Fireball and its wildcats are would likely be just a hair too long to work in a MARS clone.
 

Awesome!