The Convertible Desert Eagle Pistol: Potential Issues and Resolutions...

[MrBlackCat]

The “convertible” Desert Eagle Pistol. Swapping Calibers.


Earlier this year (2017), I decided to expand my shooting a bit starting with my single and only 1993 Desert Eagle Mark VII .50AE pistol. At that point I had only put about 4000 rounds through it, which isn't a lot since 1993.


First: Baby Steps...
I got a .44 Magnum barrel... nothing needed but barrel and magazine. Not owning another .44 Magnum, I went to Walmart and got two brands of .44 Mag ammo, two boxes each. Worked great with those... The experience was exactly as it should be... or so I thought at first.


Second: Further Out on the Limb...
With the seeming full success of the .44 Magnum conversion, I decided I would have a muzzle brake installed for the .50AE. Not wanting to alter my original barrel, I bought a brand new .50AE barrel from Magnum Research. I decided I should test fire it before sending it in, JUST to be sure all was ok. It didn't work. With the new barrel, the slide would not fully cycle. About 40 hours of testing, photography, a half gallon of DyKem and a few hundred rounds, I determined the Gas Cylinder to be a couple thousandths larger than my original Israeli .50AE barrel. Think of this... my original gas cylinder had 0.0025 (two and a half thousandths of an inch) clearance between the piston and cylinder. I verified this with gage pins, bore gages and simple calipers. I returned the barrel to Magnum Research and they said it was fine, stuck the muzzle brake on it and asked for their payment. (not even sure what to say to this.)

Second: Part 2, Resolution… because this isn’t funny. Strangely, I was told they polished the lugs and chamber or something along those lines, but when I received it, it still had the DyKem I used when I was testing it… so that wasn’t true. So I got abandoned by Magnum Research on that one... whatever.
Being a reasonable machinist, I produced a new gas piston with the same fit as my original Israeli .50AE Barrel. The gun works perfectly now... there is no bottoming out, and no amount of limp-wristing will cause the gun to fail.
In fairness, the modern/new .50AE barrel WILL cycle the slide if you put some seriously hot rounds in it. But Samson, American Quality, or anything in the lower half of factory loading, and will barely cycle the slide enough to stove-pipe. This is caused when the bolt only travels far enough back to catch a round between the rim and the casing... far short of a correct cycle. As far as the piston I made, for comparison, the piston I custom made is so much larger it will not fit into the cylinder of my original/old Israeli made barrel. Not much more you can say about that one, BUT I was able to produce a resolution at roughly the cost of a new barrel, considering all the test ammo, new test parts (springs, pistons, etc) Moving forward.


Third: Further Down the Spiral
Some time goes by and I am feeling pretty good about the Desert Eagle and my ability to resolve the issues I experienced so far. What are the odds of other issues at this point, right? So I wanted to go to .357 Magnum. I got a new bolt and a couple of new barrels. (I got two as I decided to re-chamber one in 10mm Auto, but that is a story for another thread, and I am just starting that project at the time of this writing.)
I got four brands of .357 Magnum ammo initially to test with, as I also don’t own another firearm in .357 Magnum. With all brands, I didn’t get through five rounds without a failure to feed. These were almost all stove-pipes. Tried the other barrel. Same issue. Talk about let-down.


Third: Part Two, Resolution...
I wasn’t sure what to think at first... New bolt, new magazines, new barrels and new ammo… nothing known to be working. I learned toward the bolt because of having two barrels. I dyed some shell casings and cycled them manually and most would jam, usually damaging the case. It seemed as though the bolt was really gouging the rim, so I compared it to my other bolts and it was quite sharp when sliding upwards, so I polished it a bit until it felt about like my others. This helped a bit, but was not “the problem”. I still never got through a whole magazine at any point, without a failure.
So... a few days later, with all barrels laying on the shelf, I picked up a .357 barrel and inserted a round into it... I noticed a slight bit of friction when inserting a round at a steep angle. I picked up every other barrel in other calibers and they did not have this. I thought maybe the shell had a sharp edge at the crimp, so I got another .357 round which was crimped really tight, and realized this was not the issue at all... the chamber was “rough”, compared to all my other barrels. I grabbed the second .357 barrel and it was the same.
I polished the chamber of one of the barrels... with jewelers rouge, and finished with leather... a lot of time in baby steps was spent here. Issue resolved. I can dump magazines for hours now without issue with that barrel.


Fourth: The .44 magnum Caveat...
I got a different brand of rounds for the .44 Magnum “one day”... it started having issues ejecting… weak ejections, random case trajectory etc. Long story short, over-sized gas cylinder. It was somewhere between my original IMI barrel, and the barely functional .50AE in extra clearance. One custom gas piston later, and the weak ejection problem is gone also.


Lessons Learned: Retrospect…
My original .50AE Mk VII from 1993 was well made.
Modern barrels might not be made as well.
Magnum Research doesn’t always pay attention to customers letters of issue explanation, even if the customer sends a crazy-detailed letter explaining the issue as verbose and thorough as the one I sent with my malfunctioning, out of spec barrel. (Note: This barrel was tested on another modern Mk19 Desert Eagle and had exactly the same failures as mine, so it isn’t anything relative to my gun, just sayin’)
Desert Eagles can be extremely reliable when their specs are maintained!
Desert Eagles that “only like one round” are probably out of spec. (If you listen carefully to the owners, you will see that these Desert Eagles that only like one round, always like the hottest rounds. Maybe drag/friction, maybe gas cylinder issues like with mine?)
Limp wristing is probably mostly a myth caused by out of spec guns, unless the shooter is under 120 pounds or is very inexperienced with magnum handguns. (really the limp-wristing thing never made sense to me on a gun with this much mass anyway... unless you let it come out of your hand, or the slide and springs are crazy dirty, my gun can't be limp-wristed into malfunction without dropping the gun, and never has.)


A Little More: Notes…
So I wanted a .41 Magnum. Got a great old .44/.41 with 6” and 10” barrels. My frame slides right into its slide/barrel. Gun runs great with a range of ammo. What do you know... the gas cylinders are almost exactly the same as my original IMI .50AE barrel. All the Israeli barrels are two part type. Maybe being two part barrels has to do with accuracy of the gas cylinder diameter? So now I have 9 barrels running on the gun(s) without issues, but it took a lot more effort than I think is appropriate, considering the cost of these firearms and their components. For someone without a shop, the knowledge and experiences that enabled me to determine and resolve these issues, this would be a REALLY negative experience and failure over all. Someone suggested that the modern barrels might be made by a third party that isn’t maintaining quality. Very possible, but still just speculation.


The End: Finally made it... I don’t expect most people to read all of the above, but I sure hope the pieces read will help some people understand issues they might be having with their Desert Eagle. This might also give some insight into what might be experienced should you consider the “convertible” aspect of your Desert Eagle Pistol. My experience of converting to the other two calibers has simply not been a positive experience, to say the least.


This has been my experience exploring the convertible aspect/potential of the Desert Eagle Pistol.


MrBlackCat