Forget Miroku's '92

Chiappa, Marlin, Mossberg and non-Rossi Manufactured Pumas plus anything else with a leveraction.
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Re: Forget Miroku's '92

Post by GasGuzzler »

Mortorq fasteners are pretty tough to deal with. GM uses some put in but can't take out stuff on some emissions related devices now (PCV tube on both the Duramax and the 1.4L 4-cylinder DI turbo of all things).

I digress...
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Re: Forget Miroku's '92

Post by Reese-Mo »

Mine are on lightning detection devices, where the inventor/manufacturer - who I've met on several occasions - is so anal-retentive, that he actually grinds the tops off the ICs to "hide" their function. Idiot never realized that anyone who wanted to "reverse engineer" his creation could look at the circuit and tell he had common 741's and a 555 in there. Not rocket-surgery stuff.

Back to the Miroku......

The safety system is a horse, designed by committee, which invariable results in a camel. Everyone had their input.

Must be tang activated, and "forward" must be fire, "rearward" must be safe
Must have a heavy sear notch at the rebound point, so if dropped, it cannot fire
Must be able to be unloaded without danger of accidental discharge
Must have a disconnector so the lever must be fully "reset" before the trigger will function.

Its needlessly complex.

I shall digress a bit...

The oft loved, oft hated Colt .45 Government Model Automatic (which the gun-hipsters insist calling a 1911 these past decades). As designed by JMB, it had a rebounding firing pin. It passed all US Army drop tests, which included a drop of 12 feet, considered slightly beyond what was considered max for a cavalryman standing in his stirrups on a horse that was on its hind legs with front legs in the air. That tid-bit was revealed in the biography of JMB, I think the one by Curt Gentry (teaming with Val Browning). So why did Colt change to a locked, captive firing pin? Lawyers only had a little bit to do with it. Marketing had most of the blame. I don't know specifics, but it was very common in gunsmithing circles to use a lighter mainspring as part of tuning of the .45 as one of the ways to achieve a lighter trigger. Not a ridiculously light spring, just a few wire gauges thinner. Those springs were available by several companies, fledgling Wolff, now long gone Kings Gunworks, etc. The problem was, the lighter hammer hit caused misfires through light primer strikes. So... the same companies had "kits" of mainspring, sear spring, and firing pin spring. All good, except the .45 no longer passed the drop test. The work around there was exotic alloy firing pins, like titanium, which as you know is know generally not stronger, but much lighter than its counterparts, and therefore has less inertia.

Miroku could have done a much better job of it. I'm a fan of the heavy spring rebounding FP. That would not have taken much redesign. As it is, they have a 5 piece firing pin. And one that is prone to breakage at that. Hammer down on a rebounding FP is safe (if designed correctly). They could have locked the hammer very easily if the "safe" position was forward not rearward. They could have done a lot different and had a 92 that was easy to lever, like the originals. I'm not impressed.

And.... my 45 Colt Miroku, 20", short rifle, weights 7.8 lbs. Jeeze-o-Pete thats a heavy 92. Hold the 44, 20" Rossi and the 45 20" Miroku, one in each hand, night and day difference.

I will probably be selling that Winchester/Miroku. I have no need for safe queens at my age. Just things I like to shoot.
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Re: Forget Miroku's '92

Post by Reese-Mo »

GasGuzzler wrote:Mortorq fasteners are pretty tough to deal with. GM uses some put in but can't take out stuff on some emissions related devices now (PCV tube on both the Duramax and the 1.4L 4-cylinder DI turbo of all things).

I digress...
Yah, and Ford's "security torx" head fasteners on certain engine sensors..... just did the MAF on my '99 Ranger (310,000mi). I've got the bits, no issue, but why Ford? Its not a calibrated-to-the-ECM part.
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Re: Forget Miroku's '92

Post by Archer »

The great thing about security Torx fasteners, those with a central pin that are designed for hollow core driver bits, is that if you smack the pin with a punch a time or two you snap the pin off and it becomes a standard Torx. I first encountered those on a Jeep tail light housing when I was in high school. Those security bits aren't hard to find at all and I've got at least one set of them but the WHY factor is still there.

Is Ford still putting the 60K Mile automatic Check Engine light in their vehicles so you have to go in to get the code reset?

I once got halfway through changing the spark plugs on a Ford (The hard or awkward side) and took it in for a recall before finishing the other side. They routed so much pollution control crap over and down the side I needed to install the remaining spark plugs on that instead of a straight shot with a ratchet and maybe a 2" or 4" extension I needed a couple three extensions and according to them a 1/4" universal joint. I found a 3/8" U joint worked a bit better. I had been looking forward to doing the easy side and they screwed it up royally.

One reason for the tang safety forward being OFF that makes sense to me is if it is REAR off and you are holding the wrist of the gun recoil might move the gun in your grip enough to engage the safety. With FIRE being forward the gun will be ready to lever into the next shot.

I have never been a particular fan of multi part firing pins. The first one I had that I knew about was the one on the Beretta 92 that ensures the decocker doesn't function as a trigger. I probably had one or more before I bought that gun but that was the first one I knew about as such.

I've never been much of a fan of the series 80 firing pin safety. I might agree that system was probably marketing driven. I am not sure the Schwartz system was driven the same way. I'm not sure folks were really lightening up the springs when that system was initially developed. I do think Kimber adopted it from a combination of marketing/legal/regulatory reasons and went that route over the series 80 because of the general disapproval of tying the actuation to the trigger. Not much of a fan of that system either. I think I have two or three series 80 pattern guns from Para Ord one from Armscor/Rock Island. I think I've got 5 Kimbers including 4 of their Schwartz system series II guns and one that is a pre II series gun. One Army Colt and 4 Springfields. I think the Springfields use the heavier springs with lighter firing pins on some of them. They also have the idiot ILS lockable mainspring housings. Much like the locks on the Smith & Wesson revolvers and the Rossi/Taurus guns and on some of the more recent Rugers like the LC380/LC9 I think those are solutions that aren't solving problems.

As for titanium, I've had to read and explain the specs to more than one yahoo that keeps running around chanting that 'stronger than steel' nonsense. Based on WEIGHT or based on VOLUME and in what application under what conditions it makes a difference!
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Re: Forget Miroku's '92

Post by Reese-Mo »

Is Ford still putting the 60K Mile automatic Check Engine light in their vehicles so you have to go in to get the code reset?

It's not on mine that's all I can say. I had an 88 Isuzu truck who's light came on at 50,000 miles. There was a switch under the dashboard to reverse the action of the relay that controls the light.
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Re: Forget Miroku's '92

Post by Reese-Mo »

And also... agreed on titanium. To me, when weight matters, its good, but I prefer just plain ol' steel of some sort. Dunno the coefficient of expansion of titanium, never really did much except some sheet metal which was really tough, spring tempered titanium. And my own mfg firing pin for an experimental shorty (pre Colt Officers).

Its weird, because the online "book" for the R92 shows the Taurus lock, but doesn't mention it. Mine doesn't have it (thank God).

Like the misnomers of titanium, two other peeves... folks who through out some odd bit of "thousandths of an inch" when they have really no clue, and its obvious. I've only worked, ground metal that is, to a half a thousandth (give or take... jeeze), but in fine grinding, you can get better than that I'm sure. But folks through out that "off by .002" or whatever. The other is that the initials CNC add validity to some part. As in "it was CNC produced, so it has to be of high quality". Obviously they've not met the programmers / operators at some of the shops! Oh, maybe a third peeve is that anything not "cast" in some manner is automatically "forged", and the general pooh-poohing of any metal injection molded part as opposed to, say, investment cast. They have no idea of the limitations, and excellent traits of each process when used correctly. But I digress....
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Re: Forget Miroku's '92

Post by Reese-Mo »

Buds had a 45Colt 20" R92 for $573 on Friday and Sat. It moved to $603 on Sunday and sold. Go figure. I might get one of those, then ditch the Win/Miroku, which is unblemished, except for the SureHit sight addon (which is pretty nice actually, and can be taken off if need be).
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Re: Forget Miroku's '92

Post by Archer »

In terms of temp I'm generally talking extremes.
Sitting inside the combustion section of a jet engine for example or possibly inside the thermal conduction zone in the engine bay OR slapped on the exterior of a vehicle that flys at 45 Kft after taking off from an airport when its 110 degrees on the ramp or 150 degrees under the radome. CTE becomes a factor for things like that. I was also thinking more about the fact that Ti may become brittle at some extreme cold point when certain steels might not or vice versa. Something I recall from a project 20 years ago that I might be remembering incorrectly but I'm not going to pull out the handbook to check the graphs right now.

Tolerances vary depending on the task as you are aware.

Standards I tended to work with were something like 1 decimal +/- .10", 2 decimal +/- .030", 3 decimals +/- .010, and 4 decimals +/- .0005 on most projects although I've seen some where they tightened it up using the same tolerances for one less decimal vs. some earlier drawings where 4 decimals was considered EXACT (I seem to recall having seen that on some old McDonald drawings. The current standard for that is to box the dim. At some point Boeing got to the lazy and untrained point where they slapped 4 decimals on everything in the drawing and then covered the actual tolerance in the notes.) 'unless otherwise stated' and we often stated other tolerances when the interface mattered.

I got a call once from a government rep who was reviewing some drawings I put out. He seemed surprised I'd left the tolerance of some sheet metal parts to +/- a tenth. Guy was filling in for a subordinate and was apparently board out of his mind. He said he didn't think he'd seen that low a tolerance in many years and it just made sense not to waste any money on getting it any tighter.

On another project we had a disgruntled trouble maker looking over our shoulders. He had bid on the project and lost out to doing it internally. His normal job with the company was the liaison with the government regulators and he put out a number of stupid memos that cost us time and money. On one memo he complained about our +/- .25" sheet metal tolerance for generic sheet metal parts that we were stocking before the job and demanded we tighten it up to ".25 thou". So the stress guy (who was signing off that the drawings complied with government requirements) proceeded to reply all interested parties in the company and the government that the new mandated tolerance, per this rep's direction, for all parts was changed to .00025" BEFORE any trimming to fit during installation.

I think all three of my Rossi R92s have the hammer lock but I have never used it and have no intent to do so.
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Re: Forget Miroku's '92

Post by Reese-Mo »

My tool learnin' was all in the mold-making trade. Now its all in China. I knew guns, the mold makers _had_ guns, so it was a match made in heaven. They were more than willing to share their experience over the 15 years I knew 'em. Fplks ask what I remember from those days. Answer is easy. The smell of EDM!
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Re: Forget Miroku's '92

Post by Archer »

Still some Aerospace composite stuff being done in the states. Mostly prototype.
I've been involved in that a little as an engineer.

Boeing has the Japanese do a lot of their sheet metal work now or at least they did a bit more than a decade ago. Had a discussion with a group of Boeing engineers about how their drawings were toleranced and how that meant the rivet hole we were interested in was plus or minus 3/8ths of an inch from where they said it was. I was told the Japanese were generally better than that. I replied that it didn't matter how GOOD they were only how BAD they could get and the drawing allowed that hole to be anywhere in the range the drawing said it could be and Boeing would still buy the part and put it on an airplane. More discussion ensued but the in house Boeing airframe engineer backed me up that on any given aircraft we couldn't BET on that rivet being dead nuts where it belonged or even +/- .030 because when you multiply .030 a dozen or twenty times you get a very different number.

Had an older engineer tell me that the Boeing 707 (I think) when it was built was +/- 1 foot. That tolerance stack builds up over the 150 ft length of the airplane.
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