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Thread: Limp Wristing. It might not be your fault...

  1. #1
    Join Date
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    Default Limp Wristing. It might not be your fault...

    Limp-Wristing sensitivity might not be your fault...

    I bought my Desert Eagle some 23 years ago. I didn't know what limp-wristing was back then, but with the explosion of the internet, I began to read about the concept. I go to a half dozen gun shows a year locally, and over the years I heard a lot of talk of Limp-Wristing issues relative to Desert Eagles. I understand the physics, but it never made much sense to me that these Desert Eagles would be as sensitive to Limp-Wristing with all that mass... It doesn't make sense... no, really it doesn't. I found out why my gun doesn't have this issue AT ALL, and yours might.

    Here is my story and how I experienced it for the first time recently... and resolved it completely. Simple to do? Not at all. Simple to understand? Yes, now that I have done the math, literally.


    Me...

    I am not a gunsmith. I am however, a competent machinist and quite motivated. I have pages of details of this “journey” detailed in another thread if anyone is interested in how I arrived at this point of “Inconvenient Resolution”.


    How I got here…

    This year I decided to finally buy a .44 Magnum barrel for my Mk VII .50AE Desert Eagle so I can shoot it more, and more comfortably. It worked great. I also wanted a muzzle brake for the .50AE, but didn’t want to modify my original barrel, so I bought a new .50AE Barrel to have a muzzle brake installed on. Before I sent off the barrel to Magnum Research to have the brake installed, I test fired the barrel, and it didn’t work... meaning it would not load the next round from the magazine, almost every time… because the slide would not come back far enough. The end result was that the barrels gas cylinder was too large. How did I know this? My original barrel has about three and a half to four-thousandths of an inch of clearance between the gas piston and gas cylinder. (0.0035 to 0.0040)

    The new .50AE Barrel has about seven-thousandths+ (0.007+) clearance. See the problem? Too much gas is escaping between the piston and cylinder on the new barrel... but I am no gunsmith, so how I did I know? Who am I to say this? I built a new over-sized piston with 0.0035 clearance to the new .50AE gas cylinder, and it works perfectly. You can limp-wrist this thing with one hand shooting and it now works with the highest and lowest power rounds I have, JUST like my original barrel.


    Lets back up a bit…
    I talked to Magnum Research about this. I sent the barrel back to them with all of my research and proof. They said they would test the barrel and if it was out of spec, they would repair or replace it and while it was there, they would put the muzzle brake on as well. A few days later, it had a muzzle brake and “was test fired and worked fine, and the barrel was in spec.”

    No it isn’t... or if it is, their specs are too broad and enter the realm of extreme malfunction... and I can prove it. Maybe if they used a gun with super-weak springs and the hottest rounds you can get, then it might have functioned through a clip if you locked your elbows… MAYBE… So whatever. Magnum Research... blew this one in my opinion.


    A little further now...
    So my .44 Magnum barrel worked great with my first two brands I tried. I bought six different loadings for it and now I know about “limp-wristing”. You see, some of the lighter loadings don’t want to cycle the slide well. Imagine that… but it does work with even the lightest loading IF you iron-grip it or lock your elbows. This was rather annoying to me though. I NEVER experienced any slide travel related failures with my previous 4000 plus/minus rounds in my original .50AE barrel. There is NO WAY to Limp-Wrist this gun with my original .50AE barrel. So why is the .44 Magnum barrel not “perfect” as my original .50AE? The gas cylinder is a couple of thousandths larger than my original .50AE Cylinder. It has about six-thousandths (0.006) clearance… right in the middle between the full-functioning barrel and the almost non-functioning barrel.


    We are here now...
    Today, my Desert Eagle Pistol is ridiculously immune to Limp-Wristing with all barrels. How? I made two new pistons to match the cylinder of my two modern barrels... each gas piston has 0.0035 clearance to the gas cylinder wall.


    Thoughts...
    I should not have to change my gas piston each time I want to change barrels. These are premium priced gun barrels, and they should, and obviously can, work.

    I now believe that all these ideas like how important grip is, and “most failures are the fault of the operator”, and this one... “Desert Eagles usually like only one particular round.” and finally, “Desert Eagles seem to like really hot rounds”... are all the fault of manufacturing tolerances. So now I can say “My gun doesn’t have any of these issues, because I fixed or compensated for the manufacturing tolerance deficiencies.”


    To put this in perspective...
    The new piston I made for my new .50AE barrel, in order to give it the SAME amount of clearance as my original gas cylinder to gas piston clearance, is so much larger, it will not even FIT into the .44 Magnum barrels gas cylinder, nor my original barrels gas cylinder. That is a pretty damning fact if someone wanted to argue the point of the gas cylinder being in spec on the new barrel.

    Also, note that I ordered some new Gas Pistons from Magnum Research and they are almost perfectly matched to each other, and my original gas piston... 0.3915. (yes, they are within a 1/2 a thousandth of an inch of each other... excellent) So if the gas pistons are SO consistent and accurate, why would the gas cylinders on the barrels not be? I don’t know, but they are all over the place. Maybe 0.0035 I took from my original gun is the magic number? It works for all my barrels now.


    In closing...
    My IMI .50AE Pistol I believe was made with good precision, based on its relentless reliability with every factory round I have been able to buy for it. Because of this, I used its gas system specs for the new parts, and they work as perfectly as my original. I will also add, from the perspective of a machinist, every dimension I could compare between all three barrels is very consistent, but the gas cylinders not only varied, but were also inconsistent.


    Is this a solution for you? Maybe so, maybe not. I am not sharing this experience necessarily to show others a way to resolve this issue with their own Desert Eagles, as this is not like safe for most anyone who would not have figured it out as and carefully resolved it, as I did. I know my gun well enough to be comfortable with repair. Because of the potential hazards, attempt this option for repair at your own risk. I am sharing this journey and its results because I want people to understand how even the mighty Magnum Research is not infallible, and sometimes you need to check things for yourself. Situations like this is why I sometimes question the professionals.

    If you are unlucky enough to have a finicky Desert Eagle, just break out the bore gauges, gauge pins, calipers and micrometers, (and whatever else you have) and check your cylinder to piston clearance. Maybe this could resolve your issues also.


    One last thing...
    In testing, I borrowed another Desert Eagle (modern MkXIX) and it experienced the exact same failures and successes as my own gun. My .50AE barrel worked fine on their frame, the new .50AE barrel would not load anything. It was even worse on that one. I don’t expect anything different, but if I don’t get the identical results with that gun, I will come back here and update this.


    I hope all this effort is of use to others out here on the internet.

    Good Luck...

    MrBlackCat

  2. #2
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    Apr 2012
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    Interesting post, thanks for sharing. Perhaps the barrels are "vendor built" parts. I build fighter jets with ALOT of vendor parts. Parts built by us, in house are very consistent.
    I recently had to compare a pile of parts, a few of ours, a group of ones built after the "first off-loaded" and a few from the "new guys" that our vendor offloaded his work to...
    What a mess!
    Good luck on the journey, I cant wait to hear how it turns out.
    I was once asked if I was "a paranoid for carrying my Kahr".
    "Nope" I said, "just prepared".
    " prepared for what" he asked?
    "more stuff than you are"
    God Bless our Troups!

  3. #3
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    Someone on another forum asked about where the barrels were made... by IWI, or made in the US.
    They are "current production" I suppose, and there is no indication of foreign manufacture on the packaging, so I would guess they are US made... but that is only a guess.

    There are no markings other than the caliber designation on these two new barrels. My gun is of course IMI and was bought new by myself. (Slide marked, unmarked two part barrel)

    I will be doing some extensive testing as soon as I can find some more lower power ammo. I am going to get some more of that Armscor or American Quality, as they are pretty low powered. (FPS in the 1200's) This to me is the important test, as this is what caused my .50AE Barrel to completely fail to load second rounds, and with new springs, also failed to eject cases occasionally.

    I would love to get some gas cylinder measurements from some peoples Desert Eagle which are sensitive to limp-wristing. With that .44 magnum barrel and light rounds, or ultra-limp wristing even hot rounds, I experienced what I have heard people talk about for all these years.
    Now, mine will load a weak round, with new springs, as limp as I can hold it without dropping it... but when I lock my elbows, it isn't violent or bottoming out. When I put in my weakest springs, it will bottom out in a way you can feel, so I know what it is like.

    If someone only had one barrel, on a problematic gun, this could be a solution for them.

    Think of this also... every person that has told me their Desert Eagle only liked one round, it has always been "hot" rounds. That tends to lean toward the issue with my barrels.

    I am still curious as to what Magnum Reasearch considers "in spec" for a gas cylinder... there is no way mine is within spec.

    There is nothing on the paperwork from my returned barrel after Muzzle Brake installation, but on the phone, I was told they "polished the bolt area". My barrel had the same red dye on it that it left with. I had cleaned and dyed it, then operated the slide and checked for marks to see how it was making contact with the bolt, to rule out drag. The dye is still on the inside of the bolt lugs. I see no indication of anything was done.

    MrBlackCat

  4. #4
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    Quote Originally Posted by MrBlackCat View Post

    We are here now...
    Today, my Desert Eagle Pistol is ridiculously immune to Limp-Wristing with all barrels. How? I made two new pistons to match the cylinder of my two modern barrels... each gas piston has 0.0035 clearance to the gas cylinder wall.

    MrBlackCat
    that's very impressive that you're able to fabricate DE pistons. are they hardened steel? are the originals hardened steel? maybe this is the start of a cottage industry? heck, DE's have been selling since the 80's (i think), so there ought to be a lot of them out there. and there ought to be a certain percentage (albeit small) of folks that would be interested in having a "blue-printed" piston for their barrels. especially since you can mix-n-match barrels, mags to quick-change calibers, as a DE selling point.

    i measured the combo that i have mounted right now, and the piston is .392 (for sure Israeli-made), the cylinder is .396 (6" 44 w/ IMB, most likely US made), so that combo is good. will have to dig out my other barrels (44's and 357's) to see what their cylinders measure out at.

    depending on price, of course, and if they were at the fuzzy edge of the spec, i wouldn't mind having a blue-printed piston for those cylinders, it ain't that difficult to swap out at the same time you do a barrel swap. just have to remember which piston goes with which cylinder. just like blue-printing an engine assembly. one-thousandth, two-thousandth over, and under.

    "They" are always drawing comparisons between the DE and the AR-15 due to the gas system and the rotary bolt. so how bout gas rings? wouldn't that solve the problem? or, they wouldn't last? i've often wondered. but then again, my Adams Arms piston conversions for the AR don't have gas rings either, but rely on the mfr's "precision" fit, works fine. AK's don't have gas rings AFAIK, and i'm sure Ahmad's bicycle shop in Darra probably only uses his well-worn finger tips for measuring, and his products work fine also.

    thanks for posting your findings.

  5. #5
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    Quote Originally Posted by rpoL98 View Post
    that's very impressive that you're able to fabricate DE pistons.
    Really they aren't that complicated relative to the simple machining.

    Quote Originally Posted by rpoL98
    are they hardened steel? are the originals hardened steel?
    They are fairly hard, but I don't know the material, and I haven't cut one in half and then tested for hardness to see if it is case-hardened. So basically, I don't know what the originals are.
    I have made them from multiple materials, and in multiple ways. First, just for short term testing, or proof of concept, I built up an original piston with weld, then turned it down. It was rough an imperfect, but it worked fine. This of course would ruin the hardness, if heat-treated. Second, I just used a reamer shaft of similar diameter, and turned it down. this also has potential to fail, as they are case-hardened, but the steel is quite hard anyway. They work fine, but this is only short term. I have no idea what would happen after say 500+ rounds. Honestly, based on the pressures involved, mild steel could almost handle the compression stress, but will likely flare over time where it "beats" against the front of the slide. Then there is stem strength to consider. I am shooting what I have for now. So far, I have been putting checking them for flaring or any sign of issue. So far, none is detectable, but I have only shot them less than 200 each probably. I need to track them more carefully.

    Quote Originally Posted by rpoL98
    maybe this is the start of a cottage industry?
    I enjoy precision, but I don't enjoy liability with anything surrounding firearms. You are welcome to take over the business.

    Quote Originally Posted by rpoL98
    heck, DE's have been selling since the 80's (i think), so there ought to be a lot of them out there. and there ought to be a certain percentage (albeit small) of folks that would be interested in having a "blue-printed" piston for their barrels. especially since you can mix-n-match barrels, mags to quick-change calibers, as a DE selling point.
    I agree with this in concept... very much so. But the potential for issues from putting the wrong piston in the wrong barrel are too great.

    What I would do... because the original pistons seem to be extremely consistent, repair/match the barrels to factory pistons. Maybe the gas cylinders could be hard chromed or built up in some other way, then brought into specification. This would be SO much better than custom pistons to me. I am going to do this in some ways on my own barrels, as I don't like the changing of pistons as I have been doing for the last couple hundred rounds.


    Quote Originally Posted by rpoL98
    i measured the combo that i have mounted right now, and the piston is .392 (for sure Israeli-made), the cylinder is .396 (6" 44 w/ IMB, most likely US made), so that combo is good. will have to dig out my other barrels (44's and 357's) to see what their cylinders measure out at.
    Thank you for checking and posting these measurements... it is of value to myself and possibly others. As stated before, the factory gas pistons I have several of, all match very very closely from my original IMI 23+ year old piston, to the ones I bought a month ago... 0.3914 to 0.3917

    Quote Originally Posted by rpoL98
    "They" are always drawing comparisons between the DE and the AR-15 due to the gas system and the rotary bolt. so how bout gas rings? wouldn't that solve the problem? or, they wouldn't last? i've often wondered.
    I have been considering this also... I have several ideas that are not so much engineered, but based on "what I know how to do" and what I have time to do, relative to machine work. Moving parts in the Desert Eagles filthy, tiny gas system is not likely a good idea though... the volumes and masses are so compressed in this handgun vs the gas system on a rifle. I think the required precision would be too hard to maintain, but I am still thinking on it. I could fairly easily put rings on a custom, modified piston however. In my original testing I stuck an o-ring in the piston groove to see if what would happen. It made the gun cycle fine for a few shots, showing that the issue I was having could be resolved by decreasing clearance, therefore raising gas pressure to the slide.

    Quote Originally Posted by rpoL98
    thanks for posting your findings.
    Thank you for replying. I am hoping my efforts will help others get their Desert Eagles with poor manufacturing tolerances, get them running like mine.

    I just got my relatively low powered American Quality ammo in, so I tried it with my "new barrel" which was just "tested" to be within spec by Magnum Research... two rounds in a row max would feed. Stove pipes from the bolt catching between the shell tube and shell rim. When it did manage to load another round, it ejected so weakly, it would roll off my hand sometimes. Let me be clear... this is a SLIDE TRAVEL ISSUE CAUSED BY EXCESSIVE CLEARANCE between the gas piston, and the gas cylinder... nothing more, it is that simple. The gas cylinder is OVER-SIZED is the cause... nothing more, it is that simple. I dropped in my custom over-sized gas piston, and I can limp-wrist the gun excessively with NO ISSUE, every time. And no, it isn't bottoming out... even shooting Federal and the rather potent Underwood .50AE.

    To further the point... my new .44 Magnum barrel also has bit of extra clearance compared to my IMI barrels gas-cylinder. I can take the piston I made for the .44 Magnum which is only slightly larger than the original, and run it with my new .50 AE barrel... and the failures are proportional to the clearance. Hotter stuff cycles good, weaker stuff works "fair" with some failures... weak inconsistent ejections, failures to slide lock etc... all slide travel issues.

    Again, I am so thankful I didn't send my gun in... I will never return another product to Magnum Research, I can tell you that. I am happy for others that do so successfully. Missing this gas-cylinder clearance issue is a deal-breaker for me.

    MrBlackCat

  6. #6
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    finally got around to it.

    6" Israeli 44 Mag std barrel: .394" cylinder ID
    6" Integral Muzzle Brake 44 Mag: .396" (mentioned above, current shooter)
    10" 44 Mag: .397"
    6" Integral Muzzle Brake .357 Mag: .397"
    10" .357 Mag: .394"

    and as mentioned earlier, my piston is .392", which came fitted to the .394" 6" standard 44 Mag (i purchased the Made-In-Israel version). so i can see that on 2 of these barrels, i'd have 5 thousandths clearance. i haven't had the opportunity to shoot the 10" 44 Mag barrel yet, but 5 thou should be okay.

  7. #7
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    Excellent. Thank you for taking and posting these Gas Cylinder measurements.

    In my experience, with two Desert Eagles, five thousandths clearance will work with rounds like Speer/MRI, Federal, Hornady 1400+ FPS ammo as far as function, but you might find more in the face ejections and random placement of ejected casings. (in .50AE) However, in my gun, five thousandths clearance will not function consistently with .50AE Speer/MRI 350gr, American Quality, Armscor, and original Samson ammo... basically all the .50AE around 1200 FPS.
    There is one exception to this... if I take out my inner recoil springs, or have extremely weak recoil springs, then a cylinder to piston clearance of five thousandths clearance will function reasonably.

    On .44 Magnum... my modern .44 magnum barrel has close to 5 thousandths clearance and I didn't know there was a problem until tried some lower power rounds in it. It shoots the standard WalMart Winchester and Federal 240gr stuff fine. When I got some relatively slow 180gr stuff the gun would not cycle it well at all. It was again verified that this was caused by failure of the slide to move backward far enough. When I put my old weak springs in it, it worked fine. So I made a new piston with three thousands clearance to this barrel, and you can limp wrist it with any round now without failures.

    Thank you again for posting the gas cylinder measurements.

    MrBlackCat

  8. #8
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    now it makes me wonder. i bought some Magtech 240gr ammo, and it didn't cycle worth a damn (6" 44IMB .004" clearance), so i sold that off at a loss, and i also bought a box of HPR 240gr ammo, and that wouldn't cycle. so now i'm thinking maybe switching to a barrel that's got tighter tolerance (.002") to see if it makes a difference.
    ----------------
    ETA: switching to the barrel with tighter clearance (.002"), the HPR 240gr TMJ ammo still didn't cycle. also tried some Blazer 240gr JHP, and that didn't cycle either. so, in conclusion, it's the ammo being underpowered, and not the Desert Eagle. oh well.
    Last edited by rpoL98; 07-14-2017 at 04:27 PM.

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