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Thread: 50,000 (now 88K) rounds and counting: Springfield Operator

  1. #411
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    Quote Originally Posted by Ned Christiansen View Post
    To give you a lighter trigger pull. Obviously you get a weaker hammer fall; maybe "less strong" would be better because I can't say misfires become chronic. But there's a whole sub-science where some high-end competitors will go lighter on the recoil spring and heavier on the mainspring to reduce forward-stroke movement while the heavier mainspring still modulates the back stroke. I have not really delved into this and not sure I'm sensitive enough to really notice the effect.
    You call it 'forward-stroke movement' - I call it 'slide dip'.

    The dip that the front of the gun takes when the slide returns home and things go back into battery.

  2. #412
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    Quote Originally Posted by Ned Christiansen View Post
    Not at all bothersome. Those are indeed Rob's guns. Here's a bit about the one in the foreground of the pic you refer to:
    https://forum.ltwguns.com/viewtopic.php?f=6&t=4079

    The other one is pretty much a spare..... I don't see and haven't seen a lot of it.
    Have you been able to put hands/eyes on the Springfield? Still just chugging along?

  3. #413
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    This thread has been invaluable. Thanks Ned for taking the time out of your busy schedule to answer some questions today !

    Matt in MN

  4. #414
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    Update on the high-mileage Colt I first spoke about in post # 167.

    This long-term, daily-use Colt got a going-over yesterday at a Patrol Rifle class. Since the last barrel change, which included a slide change due to the slide being cracked, it has fired ~ 50K rounds. Looks like it to me. For years now we have felt certain the gun has ~ 250K on it. One wants to stay conservative in the absence of carefully-maintained data but in the last five-ten years, tracking has improved and the rate of consumption has gone up. To peg it at this point at 250K is safe and conservative.
    Note the “topography” starting to show up on the breech face. After thousands of rounds you start to see an imprint of the case head. The ring around the primer where there is no contact on firing, that is, the area to include whatever chamfer / radius is in the case’s primer pocket and then whatever radius is on the rear face for the primer at the junction of that surface and the outer diameter of the primer, shows less wear. This area is becoming a raised ring that at some point can actually start to present a bump that the up-feeding case has to overcome. On this one it can be seen that the “ring” has a bit of a flat on the bottom of it—that is wear from up-feeding rounds. Eventually that flat becomes a little more radiused, matching the diameter of the case rim. No feeding issues yet on this one but it would get there ere long. It will get stoned flat. Total depth of the topography is probably only about .003-.004.
    Also on the breech face we’re starting to see the pitting or cutting that I believe comes from occasional primer “leakage”, where some of the primer flash manages to get through to the breech face. If I’m right here it’s like a micro particle beam. Primer compounds as I understand it are actually “brisant”. I hear the word “detonate” used often to describe a cartridge going off. A primer may detonate but as reloaders know, or should I say as students of reloading are told, cartridges expel a bullet not be detonating, but by expanding gas from the powder burning progressively. Real explosions happen at 18-25,000 FPS. Gunpowders burn at various rates, we've all seen the burn rate comparison chart but compared to something like det cord, they are slow.
    The frame is due for its third or fourth weld job; it was last welded in July of 2010 so it did last many tens of thousands of rounds.I have seen many of these that crack and get welded and then don’t crack again but of course that depends on the volume of usage. The usage meter on this one is pegged at 11. That last weld job might not have been the best ever. I never liked how the welded area went “grainy” after bluing.




  5. #415
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    Quote Originally Posted by Ned Christiansen View Post
    Update on the high-mileage Colt I first spoke about in post # 167.

    This long-term, daily-use Colt got a going-over yesterday ... included a slide change due to the slide being cracked, it has fired ~ 50K rounds. Looks like it to me. For years now we have felt certain the gun has ~ 250K on it. One wants to stay conservative in the absence of carefully-maintained data but in the last five-ten years, tracking has improved and the rate of consumption has gone up. To peg it at this point at 250K is safe and conservative.

    Note the “topography” starting to show up on the breech face. After thousands of rounds you start to see an imprint of the case head. The ring around the primer where there is no contact on firing, that is, the area to include whatever chamfer / radius is in the case’s primer pocket and then whatever radius is on the rear face for the primer at the junction of that surface and the outer diameter of the primer, shows less wear. This area is becoming a raised ring that at some point can actually start to present a bump that the up-feeding case has to overcome. On this one it can be seen that the “ring” has a bit of a flat on the bottom of it—that is wear from up-feeding rounds. Eventually that flat becomes a little more radiused, matching the diameter of the case rim. No feeding issues yet on this one but it would get there ere long. It will get stoned flat. Total depth of the topography is probably only about .003-.004.

    ... breech face pitting or cutting that I believe comes from occasional primer “leakage”, where some of the primer flash manages to get through to the breech face. If I’m right here it’s like a micro particle beam. Primer compounds as I understand it are actually “brisant”. I hear the word “detonate” used often to describe a cartridge going off. A primer may detonate but as reloaders know, or should I say as students of reloading are told, cartridges expel a bullet not be detonating, but by expanding gas from the powder burning progressively. Real explosions happen at 18-25,000 FPS. Gunpowders burn at various rates, we've all seen the burn rate comparison chart but compared to something like det cord, they are slow.

    The frame is due for its third or fourth weld job; it was last welded in July of 2010 so it did last many tens of thousands of rounds.I have seen many of these that crack and get welded and then don’t crack again but of course that depends on the volume of usage. The usage meter on this one is pegged at 11. That last weld job might not have been the best ever. I never liked how the welded area went “grainy” after bluing.
    Ned, we've never met -- but love ya, man (no homo). There are lots of IPSC gunsmiths out there who have built guns, but few who can document the wear and tear on specific customer weapons. This thread has and continues to be awesome.

    Bolt face (slide) pitting around the primer doesn't necessarily mean high pressures, rather the primer pockets from dozens of reload cycles may be loosening enough to start leaking. Here are a couple of photos showing the brisance of different primer mixtures. Magnum and military primers have a larger "Mixing" effect to ensure powder starts to burn at extreme low (sub-arctic) temperatures:

    Remington 7.5 Small Rifle Primer:



    CCI BR4 (Benchrest) Small Rifle Primer:


  6. #416
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    Thank you!

    Interesting primer photos. I apprenticed for a time with a guy who was a benchrest legend in the 60's-80;s, Bob Simonson. He made the bullet making dies that all the BR champs used including Walt Berger. Those dies were part of what led Walt to found Berger Bullets, now owned by Nammo.

    Bob told about early primer testing. They made a drum that a piece of 8 1/2 X 11 paper would wrap around. They had an action with a barrel stub in it fixtured-up to the drum apparatus. They would fire a primer onto the paper while it was spinning at high speed (no idea the speed). This way they could get something of a "read" on the primer and compare one to another.

    After I wrote the above post, I checked with my ammo industry pal and he said "CF primers are of low brisance". But didn't say "not brisant."

    Here is what I sent him:

    0000000000000000000000000000000000000

    "In very-high-mileage 1911's I see pitting on the breechface in a circular pattern that matches the primer diameter. These are guns with tens of thousands of rounds through them. I take this to be flame cutting from primer leakage, would you agree? Is it priming compound doing it, or from powder ignition? I'm guessing the primer is the culprit since it seems like the primer ought to obturate once we have ignition. Agree?

    Also, am I being accurate when I say priming compounds are brisant?

    I did a little experiment recently, part of my trying to answer why barrels that shoot only lead bullets (H&G68 mostly) still wear out (albeit only after tens and tens of thousands of rounds). On a clean white sheet of paper, I tapped fired .45 cases mouth-down so see what might break loose. Not much. I deprimed others and repeated the paper test-- not much. I primed them and retested-- a lot of black debris came out. My theory, seating the primer crushed and broke loose the crud in the bottom of the primer pocket. I'm guessing this is some hard stuff-- maybe even with a little ground glass in it? Probably behooves us to take measures in reloading to avoid putting that stuff down the barrel upon firing, agree? Primer pocket cleaning-- ew. I'll just change a barrel once in a while! My previous-and-still theory is that another contributor is tumbling media dust left in cases which then becomes part of the ejecta. I've been bad about keeping fresh media in the tumbler.

    Of everyone I know I suspect you have the least time for forums, not asking for your participation at all but I've written a bit about this and one of Jeff's 1911's here:
    https://forum.ltwguns.com/viewtopic.php?f=6&t=8365

    And also some here, pages 4 and 7 mostly, I'm also discussing the breechface "topography" that wears in: https://forum.ltwguns.com/viewtopic....=9992&start=90 "

    00000000000000000000000000000000000000000

    He also said, "no glass in CF primers", and, "yes, primers should obturate but rarely seal completely".

  7. #417
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    Now that is a high mileage 1911.
    A testament to the pistols design and the ‘smith doing the “patch jobs”.

    I’ve had breech face/firing pin tunnels “bushed” on a couple pistols.
    .38 Super seemed much harder on a gun than .45 ACP in terms of most wear and tear, no doubt due to higher operating pressures.

    And that frame crack seems to be pretty common on high mileage 1911’s.
    A true "Gun Guy" (or gal) should have familiarity and a modicum of proficiency with most all firearms platforms.

  8. #418
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    Ned, I've taken to wet-tumbling my brass and it seems to clean primer pockets much better. Not perfectly, but enough to get out what might be abrasive.

    The owner of the Colt shoots a lot. For me, when I was shooting Uncle Sam's ammo, I didn't care about cases. Now that I hand load my own (slave to the Dillon), I cycle .45 brass until primer pockets fail -- maybe the same as your buddy. Loose pockets are gonna leak gas.

  9. #419
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    Hey Ned, has the operator been retired??

  10. #420
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    Certainly not!

    I am just not running into Rob in training as much as I used to. Neither of us has slowed down, just branching out a little.

    So.... I have not had a chance to examine the Operator lately but always on the lookout for a chance. The good news is that Rob now lives 2-3 hours closer than he used to and eventually he will have some little thing that he will want me to look at. And he is to some degree temptable with Michigan Microbrews. Stay tuned for an update!

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