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Post by HMC710 on Dec 30, 2012 21:43:28 GMT -5
Here it is...... our new 45 upper Had the blank for a while just never the time. Had a customer interested in a M1 Carbine adapter that he wanted to use for a 45 Win Mag upper he is building. After talking back and forth the subject of 45 uzi mags came up so I ordered a couple. With a slight mod they worked fine in our 9mm Cuzi mag set ups. Problem was I didn't have an upper. Dug out the blanks from storage and after I remembered where I put the reamer I cut a 10" barrel with the same profile as our 9mm gas set up. I left the 16" blank for the 45 Win Mag barrel. Chambered the barrel and put the 9mm gas system on it. After the typical tweaking stage the unit has run about 50 rounds through it. I got some Pro Mag 45 Uzi mags from Midway and cut an AR slot to use in the modified Cuzi adapter. I also have a 41AE sten mag set up that will work with slight mods to the feed lips. It sits a bit higher as it is made for a blowback set up and also sits at the front of the magwell. I'll check it out after a while to see how it works. Plan on modifying our Cuzi mag adapters so we can use stock uzi mags so we'll do the same for the 45's. Got the Lee Pro1000 set up and running 5.7gr of Bullseye with 200 gr cast swc bullets. That is a full load of Bullseye but may be a bit fast compared to a factory load. Don't have any 230 FMJ's so will verfiy operationi next time I get to a gun shop and run some factory loads with it. One interesting note: Had to lighten up the buffer spring compared with the 9mm. Definately a fun round to play with!
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Post by HMC710 on Dec 31, 2012 17:46:43 GMT -5
Did some more playing today. Picked up a box of factory ammo and definately has more punch than the reloads I've been running. Bullseye definately a bit faster than optimum for this gas system. The 230 FMJ feed better of course than the 200 SWC's and the Pro Mags are double stack / single feed. Getting a bit more carrier drag using my standard mag height data so will play with those a bit. Big issue was the factory ammo ran fine with standard buffer springs. Also have some 250gr cast bullets that I'm running some Quick Load comparisons on to turn this into a real sledge hammer!
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Post by HMC710 on Jan 14, 2013 22:41:38 GMT -5
Doing some research on the 9x23 and 9mm Super Cooper plus pulled some of my old data on the 45 Win Mag and the "45Super" When the 45 Win Mag came out we all took the cases and cut them down to acp length to see what they would do in our 1911's. Now that we have a 45acp AR, using the Win Mag case with its 39000 pressure limit can add about 300 fps to std acp rounds. Will dig out my old cases and load some up.
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Post by HMC710 on Apr 7, 2013 10:46:20 GMT -5
Looked on the Promag site and 10 round mags are $34 and the 22 round are $45. Still looking at the 1911 mag option plus wide body models like Para and STI to feed this fantastic upper. Uzi mags are just out of this world in price. So, just to prove we can't do it, I'm looking at some grease gun mags from Keep Shooting, $24.95 ea and see what happens.......
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Post by HMC710 on Apr 27, 2013 7:44:20 GMT -5
Got the M3 Grease Gun mags in. Great looking mags. At 1.070" wide, much to wide to fit the AR magwell. Have a Calvary Arms lower that is on the oversize of things so we'll take a look and see if any effort is worth it.
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Post by HMC710 on May 5, 2013 10:44:39 GMT -5
Well of course I had to modify a GG mag to fit a standard lower. You can make them fit, but is it going to be worth it and is the function going to be the same? Maybe I should just start making mags........ The reloads I was using definitely are tuned different than the factory rounds. Haven't had a chance to load up some new rounds yet but hope to rectify that issue in two weeks as I have some 250gr cast bullets I would like to try. At that point I will try them in a stock Tok mag and see how many we can get in there to feed reliably. You can put 5 or 6 in without issue, even 9mm and 10mm, but you start really filling them up the curve causes some issues. We'll find out.
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Post by HMC710 on May 26, 2013 10:53:58 GMT -5
Did some more testing with this upper and different magazines. The Pro Mag 45 Uzi is a double stack - single feed. Gas ARs are designed for double feed mags. I got a lot of carrier drag when I loaded up the 45 uzi mags. I put the Tok set up back in and ran 10 rounds without issue. Seeing how I have a couple bricks of large pistol primers, will do some more work on this thing so see how many 45's will feed from a Tok mag. Also have the M1 Carbine mags to try....
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Post by HMC710 on Jan 29, 2015 21:24:49 GMT -5
Here's the latest version of the 45 acp upper
Had a few builds between this one and the last version so it took me some tweaking to get things back up and running. Was having some ejection issues so pulled the bolt apart and had a busted extractor spring. Replaced the spring and cases ejected by hand just fine so will get to the range tomorrow to give it another try.
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Post by HMC710 on Jan 31, 2015 11:05:12 GMT -5
Still having ejection issues so trying different modes here to get it worked out. These short cases, 45acp, 9mm, etc use up a lot of ejector travel coming out of the chamber when they get to the extension. You can see where the extension lugs cut into the side of the case and grabs the case mouth / neck if you don't put a bevel on there. Others have actually ground the bolt lug down a bit and put a pin in the side of the extension to prevent the case from "prematurely ejecting" before it exits the barrel extension. When I first did my DI9 I kept saying, "This thing is fighting itself to get out." and it was. The bolt was trying to pull it out and the barrel extension was grabbing the case and holding it in. The 45 acp is getting past the extension but is just falling out of the bolt after that on occasion so have some things I'm going to try today ONE MY FIRST SATURDAY OFF IN 8 MONTHS!
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Post by kiwicollectorar15 on Feb 1, 2015 23:01:36 GMT -5
Both of my 45acp DI AR's have run 100% ejecting and have never had a problem throwing the cases out around 2-3 feet.
I did do the pin mod to the 9mm DI and that fixed my problem with weak ejection, I put the roll pin into the barrel face parallel with the bore, very simple easy to do mod that works.
I noticed with my 9mm if I run a hot load of slow powder, the ejection is quite erratic in arc running anything from 2 o clock to 4.30 and the distance it throws the case's but with a another load of faster powder that is quite soft and mild it seems to be the sweet spot for functioning and all the case's eject in the same arc about 3.30 o clock and same distance away from the rifle.
It could just be that the slow burning powder is not burning completely and thats causing the erratic pattern but the other load is a joy to shoot with almost no recoil or muzzle lift.
My only problem is I'm shredding a tiny piece of bullet jacket that is deposited in the carrier.
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Post by HMC710 on Feb 2, 2015 19:42:29 GMT -5
What extractor are you running on your 45's? Did you grind a lug off your bolt with the pin mod? Crimp and brass length play a part with the slower powders to ensure consistent ignition.
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Post by kiwicollectorar15 on Feb 2, 2015 22:22:06 GMT -5
223 extractor but re-profiled for the 45 acp case.
The lug was ground off the extractor to allow room for the pin
With the case full of slow powder load I was getting the odd case that hung up inside the receiver and caused a jam, but with the other load it just run like a sewing machine, never missed a beat, it just seem to be the sweet spot for cycling.
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