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Discussion Starter · #1 ·
Okay - here goes! Modifications I've done so far to my 580 Target Model are:
  • Polished bolt wear points to mirror finish
  • Used a jewelers file (lightly) on major slide parts to flatten out the (in places) very rough and uneven surfaces. Ruger does a poor job of cleaning up after the casting process.
  • Polished and removed rough areas (lightly) in receiver - all bolt tracking grooves, etc
  • Polished underside of barrel - there were scratches in the bottom of my barrel from the slide assembly
  • Polished slide assembly wear points - top, sides and bottom - chamfered the hole edges as mine had collected metal due to the rough and sharp edges
  • Installed buffer on both ends
    After doing all this - I ran two hundred rounds through it to check for malfunctions and because it felt like a completely "new" rifle. Cycled much cleaner and reduced felt recoil. Didn't do any accuracy testing at this point. Really happy with it.

    The reduction in operating friction seems to have improved the functioning of the weapon. There is still a couple areas of possible improvements that I'd like to work on. First is the slide assembly - I don't have access to an CNC machine - if we could make up a teflon insert to guide the slide assembly as it rips back and forth, this would reduce/get rid of the slop currently built into its' operation. In lieu of a teflon insert, I am planning on building up a channel on three sides of the stainless steel forearm liner with titanium putty. I would then use a teflon coating to provide as friction free movement as possible. The trick will be to get the slide assembly to accurately engage the gas port pipe. Unsure as to the durability of this but am curious if it will work. If it does it may be worth coming up with a teflon insert. Reducing friction and smoothing out the cycling operation even further, would I also be able to reduce the weight of the slide assembly and use a lighter recoil spring which would again further reduce operating forces?? Of course, gas port size would have to be reduced accordingly. While recoil is not an issue, the increased efficiency and reduced movement of the operating parts should provide a much more accurate and cleaner operating weapon. Please fire at will - just thinking out loud at this point!!
 

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Seems logical to me. Sounds like what you're planning to try is completely reversible if it doesn't work out -- remove your bushing from the op rod and install a new forearm liner and it's like it never happened. ;)

My only concern is how well a Teflon bushing is going to hold up in the hike in the op rod. Those gases are HOT. You might be better off going with some sort of brass bushing to reduce the I.D. of the op rod hole. A friction/interference fit should hold it in place well enough. If/when you need to remove it, it'd be easy enough to run a tap in there, thread in a bolt, and gently work it out.

EDIT: I don't remember now if you were talking about reducing the I.D. of the op rod hole (Tapatalk won't let me see your post while I'm replying...), but it seems there may be some slop there, as well.
 

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;)Hey MxSenior:I did a similar "polishing" to a couple of 180+...series minis about 20 years ago,both were mediocre shooters(3-4"@100)and I was disatisfied with that performance.I broke out my smithy kit a started to work!Glassbedded,triggerjob,wolf recoil spring,and finally the polishing......got a variable speed dremel and some abrasive wheels of various shapes named "Cratex".Those things are amazing they can reach into all sorts of hard to reach areas,and smooth or polish to mirror finish,also you can use them for "jewelling"areas on the underside of the barrel where the slide touches.Both of these guns will shoot -1MOA!- slow fire with hand loads!Good enough for me with these pencil barrelled older minis!Have fun!;)
 

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Discussion Starter · #4 ·
Forgot to mention the trigger job (3 LBs) and action bedding in the stock. All components were coated in Teflon liguid and dried. For a primary lubricant, I used -very lightly - Amzoil Synthetic grease on all sliding and contact surfaces. The Amzoil has extremely high shear resistance which I felt is needed in this situation. Yes, I know it will attract dust and dirt, but for this experiment in friction reduction, I thought it best. Spent too much time in the sandbox to not know about dirt/sand getting into things.
Another area I looked at was where the "Fingers" of the trigger group engage the receiver. The fingers are a stamped part, which has one flat side that provides a ribbon line contact with matching grooves on the receiver. Smoothed that out to provide a wider contact interface between the two parts. Trigger group goes in much easier and seems to be a more solid mounting.
I appreciate the comments and suggestions above. I hadn't planned on reducing the hole for the gas port pipe - didn't think of it actually - but it may be worth looking at. At far as the teflon being able to withstand the high gas temps, my thinking is those peaks are short term events with the residual heat being dissipated by the surrounding components. Going from memory, teflon should tolerate sustained 250 degrees F along with temporary spikes with no problem. May be wrong - if somebody more knowledgeable in that area is out there - let me know. Gonna go ahead with puttying up the liner and see if things will line up properly. Let the games begin!!
 

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My bad, I was thinking of something like a Delrin or solid Teflon bushing an inch or so long to press into the op rod. I see you're talking more about Teflon-coating the parts (and not anything to do with the hole in the op rod...:lol:), which should be no problem at all.
 

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just so ya know...

At 600 or so degrees Teflon releases Phosgene (nerve) gas.
I've seen report of pet Parrots dying from a fry pan left on a range burner and getting hot.
Richard
 

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At 600 or so degrees Teflon releases Phosgene (nerve) gas.
Worse than phosegene, but not chemically identical to it:
Teflon offgas studies | Environmental Working Group
Teflon Decomposition Products:
Studies show that thermal degradation of Teflon leads to the slow breakdown of the fluorinated polymer and the generation of a litany of toxic fumes including TFE (tetrafluoroethylene), HFP (hexafluoropropene), OFCB (octafluorocyclobutane), PFIB (perfluoroisobutane), carbonyl fluoride, CF4 (carbon tetrafluoride), TFA (trifluoroacetic acid), trifluoroacetic acid fluoride, perfluorobutane, SiF4 (silicon tetrafluoride), HF (hydrofluoric acid), and particulate matter. At least four of these gases are extremely toxic - PFIB, which is a chemical warfare agent 10 times more toxic than phosgene (COCl2, a chemical warfare agent used during World Wars I and II), carbonyl fluoride (COF2 which is the fluorine analog of phosgene), MFA (monofluoroacetic acid) which can kill people at low doses, and HF, a highly corrosive gas.
Teflon pans bad for birds when over heated:
http://www.ewg.org/node/8299
 

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Discussion Starter · #8 ·
Okay - Nasty - Nasty!!! I have a Thermocoupler with an electronic readout. Hooking that up to the gas port and barrel, then running forty or fifty rounds quickly through the weapon should give a pretty good idea on the temps we're dealing with ------ unless someone has that info already??? This'll be before we play with the teflon!!
 

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before we play with the teflon!!
Before we scare each other, doesn't Breakfree CLP contain teflon? Surely all of us have used this in areas that get really hot and not noticed any ill effects from it?
 

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Discussion Starter · #10 ·
Seems like everything will get you one way or another. If you cook bacon or a steak too hot, the nitrates in the meat turns carcinogenic. But it's good info. Better to know now than to vapor lock at the firing range. The EMT's would never figure it out!!!!
 

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Everything looks good but it is a target model already and you may be over thinking the slop issue in the slide assembly. Basically you are stepping up from a target to a match rifle by jeweling the working surfaces and as long as you are careful and don't go to far it is a go. Beyond that if the barrel and the fit in the stock is right you are good to go. Just keep it clean and lubed properly, excess lube is not an advantage and I'm betting you already know that.
 

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Discussion Starter · #12 ·
I think that if I can minimized the "slop" of the slide assembly in the forearm, less energy will be needed to move it. If the forearm puttying works out and I can get the slide to track properly, I'm gonna slowly reduce the weight of the slide assembly, lighten the recoil spring and reduce the gas port size. I realize at some point the reductions will interfere with the action's reliable operation. I'm just curious where that point is. Should be a fun rabbit trail to run down!! And "Yep" too much oil is as bad as too little. Did a number of tours in the sand box - learned a lot about the damage oily sand can do! Dry lubricant with very light synthetic oil over it is the slickest stuff I've found.
 

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The weight of the operating rod assembly is designed to delay the operation of the bolt. The delay allows excess gas pressure to bleed off before the cam slot opens the chamber and allows the extraction process to begin. I would not lighten the op-rod assembly unless you have a specific purpose in mind, like shooting only low power .223 and no 5.56's. Even then, I would certainly not undertake this lightly and without performing the appropriate calculations to determine if you are actually smarter than the Ruger engineers.
 

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Discussion Starter · #14 ·
The weight of the operating rod assembly is designed to delay the operation of the bolt. The delay allows excess gas pressure to bleed off before the cam slot opens the chamber and allows the extraction process to begin. I would not lighten the op-rod assembly unless you have a specific purpose in mind, like shooting only low power .223 and no 5.56's. Even then, I would certainly not undertake this lightly and without performing the appropriate calculations to determine if you are actually smarter than the Ruger engineers.
As far as being smarter than ANY engineer - I'd have to say engineers in various fields I've met and worked with are definitely smarter than I am. However, I've successfully achieved a number of things those same engineers said that either couldn't or shouldn't be done. When you're locked in a box, it's hard to see outside it. ----- Excellent point you made about the delay of the operation of the bolt, but could the same timing be maintained if the reductions in weight of the slide assembly, recoil spring and pressure thru gas port are relatively the same?? Lastly - assuming it is possible to reduce the energy necessary for the mechanical processes to operate correctly - would the smaller bleed off of needed gas pressure result in an increase in pressure in the barrel - possible higher FPS for the round?????? Again - Just thinking out loud???
 

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assuming it is possible to reduce the energy necessary for the mechanical processes to operate correctly - would the smaller bleed off of needed gas pressure result in an increase in pressure in the barrel - possible higher FPS for the round??????
Somewhere on PU there is a guy who turned off the gas with his Mini-30 completely (with an adjustable gasblock) and chronographed bullet velocity at different settings. The difference between "single shot mode" and reliable semi-auto was something like 15 FPS bullet velocity. This suggests it takes less than 5 foot-pounds to operate the action, so you are not going to gain any significant performance from your mods.

That said, the ratio of oprod to bolt mass is important: If you reduced the oprod weight too much you make it necessary for it to operate at higher velocity to achieve the required momentum to cycle the action; even with a soft recoil spring (too soft and it won't feed reliably). A light oprod will still work, but the increased impact speed at the oprod and bolt cam surfaces is likely to increase the risk of peening the parts or of accelerated surface wear.

Also, if the oprod needs to move much faster to operate the bolt it does mean unlocking would start earlier while there is more residual pressure in the barrel -the oprod would travel further in the same amount of time and use up the "slack" in the cam slot sooner. When will this become a problem; at a 25% weight reduction or 50%....? How much are you aiming at removing?

Compare this to a big truck pushing starting a little car - it will work even if the truck makes contact with the car and starts pushing from zero speed. However, the little car may not even be able to move the truck unless it takes a run at it - which way round is more likely to cause some unwanted distortion at the interface?

You can buy a new Mini-14 oprod for $90 so I say go ahead and hack yours up:
Ruger Slide Assembly Ruger Mini-14 SS .

Sometimes things don't behave the way they are "supposed to" and new worthwhile discoveries are made.
 

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Interesting thread. It reminded me of an older thread I ran across as I mined the archives upon my arrival here.

http://www.perfectunion.com/vb/ruger-mini-14-mini-30/69962-slide-assm-modification.html

This thread might provide some additional insight since you seem to be playing in the same arena covered in the thread linked above.

Ultimately, I think any changes to the slide assembly mass, slide friction, or even spring or gas port bushing size affects the barrel response to cartridge detonation. The bolt is connected to the reciever ring. The slide assembly is connected to the bolt. Slide assembly is resting against the gas block. So additional vibratory energy is traveling to the gas block and hence the barrel as fast, or almost as fast, as it travels down the barrel by virtue of it being attached to the receiver ring. And there is no doubt that this barrel response is acting on the muzzle when the bullet arrives at the muzzle.

Using the target model for this is a good idea. I think the end result will be a different dampener setting (for a given load) than what it would be without making any rifle mods.
 

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I'm definitely not one to discourage experimentation; i've hacked up and ruined enough junk to understand the desire to improve the breed. Just saying be careful about it. I once received a faceful of burning powder from a semi-auto 22 LR chamber when the bolt opened prematurely after improper reassembly. That little old rimfire made a hell of impact on my thinking, and my good looks.
 

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Discussion Starter · #19 ·
Man!! Really appreciate all the feedback from everyone. Read the post on work that had been done previously by other members. Good stuff. Somehow I didn't think my addled pea sized brain had stumbled on a miracle cure. Still going ahead with getting the slide assembly tracking as smoothly a possible. Once I'm happy with that - on to the reduction efforts on the slide assembly, recoil spring and gas port size. I realize with that though there is a point of diminishing returns. May ultimately prove to be futile and I'll have to replace the slide assembly and forearm liner - Oh well!! Will post pictures and range reports as the project continues!!
 

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Polishing definitely helps, the less binding in the action the better. I did the bolt cam too and the part of the op rod that works the cam and slides in the receiver rail. A lot of good info in the old thread. ;)
 
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