User Panel
Posted: 12/3/2005 12:34:17 AM EDT
This one appears to be the latest revision, it has screws for the HG extension up front, and the insides widened for use with AK mags and their modular lower.
Overall, I like it. Everyone I showed it to today wants one now. The finish on the aluminum parts are nice and dark, nearly matching my Stag lower in blackness. It fits really well into my lower with little play. But I do have a couple of gripes. I am not much of a rail-fan, and was looking forward to removing the 9 and 3 o'clock rails as they make the for-end a bit to wide for my tastes. Unfortunately they rails are applied to the HG before the sprayed on coat of enamel is applied, thus when the rails are removed there is bare aluminum there, its whiteness clashing with the very dark nature of the gun. I'll live with the rails I guess till I decide whether or not to totally re-finish the gun. The other grip is minor-ish I guess, it was just a little disconcerning to see how much material they removed on the inside of the receiver. I heard that this is one of the updates to the design, meant for better compatibility with the AK magazines when the modular lower comes out. I would have pics to show, but once again my 2 year old has found the camera and has done his best to make sure that each and every shot has a custom blur effect using his special peanut butter on a finger technique. As of now you will have to use you imagination, an MGI upper, stag lower, rra parts kit, colt A1 buttstock, dpms charging handle, buis, and bolt/carrier, bushy lightweight barrel, phantom flash hider, and arms #23 vfg just because I have one here, I do not know if it is a permanent addition. The goal here is to make a packable ar for when I am on the road and be a discreet little buddy to keep in the Bug Home/Out Bag. Next on the list of things to get is a small red dot, pri or yhm flip up front sight, better rear buis, and an ace ultralight stock. |
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Glad you like it.
We finish the forend after rail mounting, to ensure that the rails mount flat against the even surface of the tube. I have used barbecue black high-heat paint on my forend for touch-ups, and that works out pretty good, and it is quick and easy. The finish applied to the fore-end is actually a powder-coat, which should hold up better than a simple spray paint in that application. Regarding the relief-cuts inside the upper receiver for using it with AK mags, it has been tested with higher-recoiling calibers than the 223 with no ill-effects seen. |
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This might not be your forte', but how 'bout some take down pins with a split ring in them to make it easier to pull them out and disassemble the gun? No more stressing the finger nails or looking for a punch. The perfect accessory for those who like to tear it down alot.....yea. Why did you guys go with a powdercoat instead of anodization? It is pretty thick and makes it tough to crank down an ARMS mount. My vfg's mount has already taken the paint off of where it mounts just from being attached. |
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I think that the improved take-down pins are a good idea. I've already mentioned that to Mack a while back, because I feel the same way you do. He's too busy right now, but we may get around to something like that. As for the powder coating, it is strictly a cost saving process that helped us to keep the price of the QCB unit in the affordable range. We could have done a fancy railed fore-end, but we didn't want to have to price the unit at $1000. We wanted to make it so that as many folks as possible could afford it. |
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Tom, Is anything done to refinish/protect the area of relief cuts? Do those cuts remove the anodizing? Thanks... |
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At this time, the relief cuts are done after anodizing, and they are not re-anodized after cutting.
In the future, when we have the new forging dies made, they will be finished with anodizing on these cuts. These are not areas which have any wear, and anodizing would only provide additional corrosion protection anyway. It is an evolutionary process that is being undertaken. We have additional things we are incorporating in this new forging die we are having made, and these will all appear in a future upgrade at a later date. I know that we'd all like to have everything done in one process, but we cannot do it all at once, and we are making the product available to people while we are still in the evolutionary process. |
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I use a bicycle tire lever(its plastic) from Park tool as a pushpin starter and hook as a puller on my takedown pins. I had it laying around and it works great for this, now I always have a few scattered in with the gun stuff. Dummycord one to your case. Cartridge works too, but the lever leaves no marks.
www.jensonusa.com/store/product.aspx?i=TL707I04 |
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I suppose this message is directed more at TWL, but any MGI owner can help.
Can someone post detailed pictures of the barrel retaining mechanism on the MGI? Also, I would love to see a MGO upper disassembled and the components laid out. Thanks. |
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Zissou,
Here are the photos that I have of the operational area of the locking block for the MGI QCB upper receiver unit. This unit shown in the photos is a very early model when they first came out 2 years ago. There are several changes that have been made to clean up the appearance of the system over the years, but this illustrates the basic design and operation of it. First, this is a photo showing the levers opened up halfway. They must be rotated fully out toward the sides(90 degrees from the barrel axis) to allow barrel insertion/withdrawl. Next, is a photo shwing the system with the levers closed, and held captive by the spring loaded capture plungers. This is how the levers are positioned when a barrel is inserted, holding the barrel in place. I have no photos of the unit disassembled at this time. It is a simple rotating-cam arrangement, which has sections of the lever-operated cams that hold the barrel in tight against the barrel extension flange when closed, and rotate open to allow room for the barrel to be removed/inserted when opened. It is all steel, except for the handguard components, which are aluminum. Weight of the entire upper receiver unit with handguards and rail system all toghether is approximately 26 ounces in the current form. The unit is field-strippable by the user, for cleaning or maintenance, should that become necessary. Simple tensioning techniques on the levers allow for adjustments and take-up for any wear over time. The entire system is very strong, robust in design and materials. Over 2 years of use in the marketplace is showing very good record for the design overall. Regular AR15 barrels are used, so you can use any of your existing barrels, or any typical AR15 barrel, as long as the barrel nut, delta ring, and handguard keeper are removed, much like most other free-float tube systems. Barrel changes are very quick and easy, in the field by the user with no tools required. Probably about 15-30 second time of barrel change, once you get used to using it. Our system is what we feel is best for returning to zero, because there are no screw-torques to worry about changing the POI if different torque is applied. In our system, barrel holding pressure is always consistent when returning barrels into the system, because of the simple cam tension principle. This was designed by Mack Gwinn, who designed the quick-change barrel system for the current model of FN-M2-HBQCB 50cal heavy machine gun in use all over the world today. He is an expert in quick-change barrel systems, and it shows with this simple but very effective design for the AR15. In fact, it is the simplicity of the design that provides the strong points of the system, and also its robust and long lasting qualites, as well as the great overall performance characteristics. It is the most affordable quick-change barrel system for the AR15 that is available today, by far. We feel that it is also the very best performing system at any price, and certainly the fastest. |
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I will vouch for the simplicity of the system, infact it is almost "Stupid Simple" as in, why the heck didn't someone think of this years ago?
I have to admit that though the idea is simple, it does look like alot of skill and thought to bring it all together. It would have been pretty easy to take something like this ond over engineer it to the point of being a liability, but it isn't, and as it sits, it is appears that the QCB part of the assembly is probably the most durable and resiliant part of my whole gun. I tore mine apart and it is robust to say the least. After breaking it down I do have some commentary. I found that the little detents that fit into the pieces that actually hold the barrel to be kinda surperflous as I did not even know they were there till I took it apart. Since the HG's are removeable, there are some possibilities there for options at a later time, such as dedicated rifle length HG's, HG's w/o rails or screwholes, possibly even full railed HG's with a top rail, or square bottomed HG's. I am going to disassemble it, and remove the spray finish on it and the rails, and have it either parked or anodized. I am not a super big fan of blacktical guns, so I am tempted to do something off the wayy, but time will tell. Like I said before this thing has made the AR for me. The possibilities are endless. Cleaning is going to be a breeze, and I am able to stuff the whole thing and 4 loaded mags into a Camelbak HAWG, which isn't the ideal size, but it works, so I can transport it without drawing attention. I admit, it seems like alot of $ for one, and it is, but it opens up a whole new arena for the AR and adds yet another level to the AR's ability to be personalized and customized to the task at hand. MGI has shown a great desire to constantly update the design with suggestions from customers. I look forward to what the future brings. Next year I'll get the Lower..:). |
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Mack strives for functional simplicity in his designs.
In fact, as Yekimak mentions, it is almost deceptively simple. The fact that he could include all the benefits that are in this system into such a few parts is very commendable. Even I, as an assistant designer, am continually amazed to see the total functionality of this system. Especially, the fact that this type of locking of the barrel extension with the cams provides a better lockup with virtually perfect consistency in barrel pressure, that is essentially passive to the user. He just closes the levers, and the exact correct pressure on both sides of the barrel is automatically performed, without any attention to screws or wrenches or torque-settings, and they cannot back-out under use like screws can. They are alot faster than screws. They cannot strip out or get lost like screws can. It is really an amazing piece of design work, which is so simple-looking that it would be easy for a non-designer to totally overlook just how comprehensively well-designed this basic cam system is. It's not until you try to sit down and design any improvements into it, that you find out how close to functionally-perfect this idea is. I have tried that, and Mack is a pretty tough act to follow. When you are a designer, you soon learn that there is no such thing as perfect. Any design can be "nit-picked", no matter how good it is. The success of a design will relate to how well it performs, and how few compromises it makes, at the price point target. Ultimately, it is the consumers who will decide how well we did. We know what people have said that needs improvements for better market acceptance, and we are moving in that direction with some upgrades as we go along. At the same time, we are making products that give even more versatility to the QCB, by adding the modular lower for different magazines, and working on barrel packages for other calibers. We have a "high reliabillity" action-parts line coming along, which will help to deal with sand and dust like the military is encountering in Iraq. We have several select-fire fire control groups coming up. We have plans for a piston-operated system option too, for those who want to go that way. We have belt-feed under development. We are some very busy folks right now. |
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It looks like Brownells likes the QCB's design. Looking at their new update catalog.
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Well I got to take it out today. Feed issues galore. Ammo used was 40gr winny white box HP varmit ammo. My barrel extension does not align correctly with the feed ramps in the upper and so there was a lip in the middle of the feedramp that the first round would catch on, and intermittently catch on during firing. Some work with the Dremel and thing feed smooth by hand now.
This is all due to me not checking it before I went out and using a used mish-mash of parts as well, so it is not the fault of the upper, but if you do get one, definitely make note of the barrel extension and how it sits in the upper. Other notes: This is the first time I have used a Phantom Flash Suppressor. After years of shooting my Clinton era AK's, I have grown accustomed to a nice fireball....I kinda miss that. Hardly a spark exits the barrel, and there is no muzzle rise. .223 has always impressed me with how loud and throaty it sounds out of shorter barrels. This gun is no exception. Sure don't sound like a mouse gun. The ammo I was using was in many ways not conducive to reliability. I guess that makes it the perfect test ammo. the nose has a star shaped crimp on it that catches everything. I do not think I would have had trouble with FMJ's, but then I would not have known that my gun wasn't totally reliable. |
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Our MGI QCB uppers are all coming now with true M4 feedramps in them.
In standard rifle barrel extensions, there will be an overhang over the M4 ramps, which could present a feed problem in certain guns. Generally, in most guns, it does not present a problem, because the cartridge should feed directly into the barrel extension, and not contact the upper receiver walls at all. If the mag feed lips are bent down at all, or if the mag catch is loose, or if there are overcycling issues, causing the ammo to be at the wrong feed angle during cycling, this problem can occur. The barrel extension should be perfectly aligned with the front wall of the receiver. If this is not the case, please contact me about it. Thanks, Tom |
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I wish I had known that it came with m4's, or at least noticed it beforehand. All the mags are brand new, never used D&H usgi's, and the lower is new with a new lpk. I did dremel the barrel extension to match the ramps in the upper, and it feeds now, and the ammo I used is something that would definitely find every fault in the set up. |
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Sounds like you have everything under control now.
I'm happy that were were skilled enough to handle the issue. |
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Do you have any more pictures of how the levers are attached to the barrel locking assembly. Did they use Gorilla Snot and a grinder to try to smooth it out?
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took a bit of grinding and polishing, but I got it...ran the last of my 40gr varmit, and then a mag of 55gr reloads, and then a mag of 60 gr Barnaul....all flawless. I need to get more ammo now...darnit.
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The levers are welded into the locking cams as far as I can tell. 'cept they are not welded to the ends like in the pics above, but there is a hole drilled in the cam and the lever is welded in and then ground smooth. |
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Timantaor,
The newer systems have updated lever assemblies, and no longer look like those older photos that I've posted. The levers now go thru the cam shafts. We no longer weld the levers to the bottom of the cam shafts, like the older units were. Here is a shot of the newer lever arrangement, that is lifted from another thread, of LArifleMAN's MGI upper with a 357 Sig setup. |
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Cool, was wondering how something that belongs on the prototype made it out as a final product.
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I know, that welding bugged some people, so we changed it a while back.
I still have my original QCB unit, which was one of the first ones that ever came out, and it has the welded levers on it. Still working like a champ. While my unit may look a bit like a prototype, it still has the same functionality, and there's nothing from anywhere else that can match it for performance. Even after more than 2 years on the market, it still stands at the top of the list in quick-change barrel systems for the AR15. It is the fastest, requires no tools, uses regular AR15 barrels, and provides the best accuracy and return-to-zero of anything out there. It is still the lowest cost changeable barrel system for the AR15, too. |
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<removed> I took some fresh pics to answer some questions for the folks out there. Locking bars locked Unlocked Feedramps I cut, just to show my Dremel prowess Everything apart Cam block right side Cam block from the front Cam block with the cams in place (sorta) |
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What self respecting gun nut wouldn't want to show off his dremel prowess.
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great pics. ive been kicking this upper around for sometime just wish they would come out with a midlength rail or their carbon fiber one. from the looks i might be able to have one done up myself.i wonder if a gen 1 pri tube would fit over the cams.if not how about the yhm handguard. let me know the outside diameter of the cams. maybe i can rig another handguard on there and have exactly what i need. i ordered a carbon midlength barrel and i want to get the mgi but the standard handguard will leave the gas tube exposed.still i love the concept
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MGI sells an extension for the handguard for rifle length gas systems that slips inside the stock handguard and is held in place by screws. It is a simple Aluminum tube and it would not be too difficult to cut it to the proper length for a mid length. As far as replacing it, the major hangup is that the doohickies (that is the correct technical term, I assure you) that jold the locking bars in place are in an assembly that is welded into the handguard. IT would be somewhat difficult to modify an existing HG to accept the locking system, and I doubt that a carbon HG would be up to the task either. That is not to say that it cannot be done, it would just take alot of work. |
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mgi has a carbon fiber one in the works. i know about the tube extension but then the rails dont extend all the way. can you take a picture of the part you are talking about. is it the tabs that hold the bars in place?
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im not to worried about the top rail but it would be nice for the side and bottom rails to go to the end of the tube if the extension was in place. i stiil might ge the upper and mod the tube and change the position of the rails. can you show a pic of the rails removed. can the extension be cut and rails moved forward?
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I do not have the extension. I do not have much use for a rifle length AR. The rails are simple and just use 3 screws each for the sides and it would not be much to remove them, and drill and tap new holes in the extension sleeve and move the rails down or find other rails that will work. |
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Ouch. Nice pictures Yeki. Take care and have a happy holidays. Regards, Justin |
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Oh, I've slowed down completely to a full-stop right here days ago.
I stop posting when it becomes clear that my input is not needed. |
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Twl your input is appreciated. I am always happy to have the input of someone who is directly involved in manufacturing of new and interesting parts. FMJs
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I IM'd twl to apologize for the car salesman thing.
This is part of what I sent him: "I know the upper is a good product. I think most everyone else does as well. Your input on the technical aspects of your products is invaluable. I got a little frustrated with the "it's the best" and "it's the only" stuff but it was out of line for me to chastise you in the forum that way." TWL, I am sorry for being a jerk. I apologize for insulting you, and I apologize to everyone else whom may have lost out on some of your insight because of my comments. |
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Why the trilux sight?
I'm not saying it's a bad idea- I just don't have any experience with them. |
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Thanks Yekimak, I appreciate your IM'ing me about it. Sometimes I get a bit too excited about the products we make, because I use them and really do like them alot. Maybe that sounds like a sales line, but it is how I really feel. Anyway, no hard feelings, and I'll try to keep to the technical side of things on your thread. Best regards, Tom |
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I wanna know too, but also where he got it and how well it works... |
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Mack isn't designing anything specifically for the M1A at this time. However, we are friends with Sadlak, and we offer the Sadlak competition parts for the M1A. Sadlak makes some of the finest M1A parts available. |
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I've got my eye on these uppers and the modular lowers with interchangeable mag wells. I could replace all my ARs except the A1-style rifle (I need one of those for sentimental reasons ) There are so many competing demands for my toy budget!
I understand MGI and Alexander Arms are discussing the possibility of Grendelizing this system. |
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What's wrong with your gas tube? It just don't look right. |
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