cpa5oh Posted February 9, 2016 Author Share Posted February 9, 2016 Drill rod is interesting - does it need any kind of notch cut into it or just cut it to length and it's good to go? Link to comment Share on other sites More sharing options...
CZinZA Posted February 9, 2016 Share Posted February 9, 2016 So when you put in a hardened steel slide stop, what becomes the next sacrificial part to break? Or is the rest of the gun strong enough that it can survive infinite fatigue cycles? I would be interested if anybody has a good opinion on that Sent by Jedi mind control Link to comment Share on other sites More sharing options...
ohsevenflhx Posted February 9, 2016 Share Posted February 9, 2016 I'm going to use the CzechMate pin. I will start to use a match only pin, and cycle a match pin to a practice pin every 6 months.9$ every 6 months seems cheap enough to me. As far as using drill rod, I would imagine you would need some sort of notch cut into it to engage the slide stop spring, to keep it in the frame. Link to comment Share on other sites More sharing options...
Neomet Posted February 10, 2016 Share Posted February 10, 2016 So when you put in a hardened steel slide stop, what becomes the next sacrificial part to break? Or is the rest of the gun strong enough that it can survive infinite fatigue cycles? I would be interested if anybody has a good opinion on that Sent by Jedi mind control See post 19 above. :-) Link to comment Share on other sites More sharing options...
cpa5oh Posted February 10, 2016 Author Share Posted February 10, 2016 Yeah I'll use the czechmate pins also. I did order a Sprinco guide rod/spring just because I never heard of anyone try one on a TS...I'll shoot it Thursday and see what happens. Link to comment Share on other sites More sharing options...
busdriver02 Posted February 10, 2016 Share Posted February 10, 2016 Look at the break line. I'm running a 13lb recoil spring. The smooth part of the fracture surface (lower right on the right side piece) is a fatigue crack, the granular surface is a fast fracture from when the pin failed. In theory we should be able to inspect the pin and find the fatigue crack before it fails in use. Link to comment Share on other sites More sharing options...
MrPostman Posted February 11, 2016 Share Posted February 11, 2016 Yes you need to notch the end on the opposite side because there is a spring leg that engages to hold it in. Link to comment Share on other sites More sharing options...
BeerBaron Posted February 11, 2016 Share Posted February 11, 2016 Buy a #9 drill rod and cut it to the correct length with a dremel cutoff wheel. It is hardened steel with a diameter of .196, I put one of these in my Tanfo Gold Team after breaking the slide stop while shooting a match. this was very popular when P9s were the open gun to have. they smashed slide stops regularly and the guys I know who used to shoot them all bought drill rod and cut to length and notched them to serve as slide stop pins. They would replace one every match. Link to comment Share on other sites More sharing options...
Matt1 Posted February 11, 2016 Share Posted February 11, 2016 (edited) That's very old school BB. I've been shooting a TS (.357 Sig at 180+ PF) for 2 years now (and I shot a Checkmate for 18 months before that). In all that time (probably 35k rounds or so) I've only broken 1 slide stop (which had 10k+ through it). I tried the CZ pin in my TS for 6 months or so. Not because I was afraid of breaking it, but because I was trying to cure a problem with rounds diving into the feed ramp (I thought they might be hitting the slide stop). Turns out it was an ammo problem (it doesn't like flat points) but it did introduce another problem. With the pin only the mag wouldn't drop free as easily as it used to. I tried the CZC stainless mag brake. It made it a little better but didn't fix it 100%. I've just changed back to a stock slide stop in my TS Orange. Mags drop free every time now and I'll just put a new one in for big matches when they hit 5k rounds. Sent from my iPhone using Tapatalk Edited February 11, 2016 by Matt1 Link to comment Share on other sites More sharing options...
kneelingatlas Posted February 11, 2016 Share Posted February 11, 2016 Matt, your experience supports the idea that slide stop breakage has nothing to do with PF and happens on the slide's return to battery. I think it's a matter of barrel fitment and recoil spring choice, which would explain why some pistols never break slide stops and others break them frequently. I've been shooting CZs, most of which are custom Open guns of my own design for over three years and have never broken a slide stop. Link to comment Share on other sites More sharing options...
PRanta Posted February 11, 2016 Share Posted February 11, 2016 The CZ used to ship TS's with spare slide stops. The new TS Orange is fitted with thin clear plastic buffer and has no spare slide stops. They must believe this combo is durable enough. Link to comment Share on other sites More sharing options...
PRanta Posted February 11, 2016 Share Posted February 11, 2016 Look at the break line. I'm running a 13lb recoil spring. Could you take a picture of the break line so that it can been seen with the lever on back (not covered with fingers). I would like to see how the start of fracture is oriented. This could tell which slide direction is critical. Link to comment Share on other sites More sharing options...
CZinZA Posted February 11, 2016 Share Posted February 11, 2016 Good point Sent by Jedi mind control Link to comment Share on other sites More sharing options...
ohsevenflhx Posted February 11, 2016 Share Posted February 11, 2016 Look at the break line. I'm running a 13lb recoil spring. Could you take a picture of the break line so that it can been seen with the lever on back (not covered with fingers). I would like to see how the start of fracture is oriented. This could tell which slide direction is critical. Link to comment Share on other sites More sharing options...
ohsevenflhx Posted February 11, 2016 Share Posted February 11, 2016 That's very old school BB. I've been shooting a TS (.357 Sig at 180+ PF) for 2 years now (and I shot a Checkmate for 18 months before that). In all that time (probably 35k rounds or so) I've only broken 1 slide stop (which had 10k+ through it). I tried the CZ pin in my TS for 6 months or so. Not because I was afraid of breaking it, but because I was trying to cure a problem with rounds diving into the feed ramp (I thought they might be hitting the slide stop). Turns out it was an ammo problem (it doesn't like flat points) but it did introduce another problem. With the pin only the mag wouldn't drop free as easily as it used to. I tried the CZC stainless mag brake. It made it a little better but didn't fix it 100%. I've just changed back to a stock slide stop in my TS Orange. Mags drop free every time now and I'll just put a new one in for big matches when they hit 5k rounds. Sent from my iPhone using Tapatalk Why don't the mags hang up in the Czeckmate then? Essentially the same frame and magazines? Link to comment Share on other sites More sharing options...
Matt1 Posted February 12, 2016 Share Posted February 12, 2016 (edited) I never ran the CM with just a pin. I run my TS with an 18lb recoil spring and a stainless guide rod. I've never run buffer in any of my guns. Sent from my iPhone using Tapatalk Edited February 12, 2016 by Matt1 Link to comment Share on other sites More sharing options...
busdriver02 Posted February 12, 2016 Share Posted February 12, 2016 (edited) I think it's a matter of barrel fitment and recoil spring choice, which would explain why some pistols never break slide stops and others break them frequently. I suspect it's multiple things. The biggest one in my mind is a design that has a very small margin of safety. Making it very intolerant of minute flaws in the material and barrel fit. But I seriously doubt it's breaking going into battery, the speed differential is huge between recoil and feeding. Check out this link you can see the difference between time in portions of the slide cycling. It's a 1911, but illustrates the point. The fatigue crack growth on the previous picture would seem to support that, but it has been over a decade since since I learned this stuff. And the surface isn't in focus. In any event, 18# recoil springs aren't abnormal in a 1911 and the slide stop pins are around the same size (.195 in my CZ, .198 in a 1911 stop I have laying around) so I wouldn't expect CZs to gain a reputation as pin breakers while the 1911 has no such reputation. I would think the actual shape of the forward portion of the camming slot in the barrel would affect the stress on the pin and the barrel lug. With a more abrupt camming action having a higher impulse on the pin, while a smoother/more gradual curvature would reduce the stress. Likewise if most of the force required to actually stop the barrel's rearward motion is higher in the slot, the bending moment on the barrel lug would be reduced. This is actually very similar to some 1911 concepts. The vertical impact surface of the frame is frequently relieved (so called bow-tie) on non-ramped barrels. This is so the impact between the barrel and frame occurs away from the ends of the legs and reduces the bending moment. Also if the placement of the vertical impact surface is not correct and the link stops the rearward motion, links and stops will break. The CZ has no vertical impact surface so the pin is what stops the rearward motion by design. Edited February 12, 2016 by busdriver02 Link to comment Share on other sites More sharing options...
kneelingatlas Posted February 12, 2016 Share Posted February 12, 2016 I get that the front of the peanut hits the pin as the slide comes out of battery, but the rearward motion of the slide is stopped by the frame, not the pin. Link to comment Share on other sites More sharing options...
busdriver02 Posted February 12, 2016 Share Posted February 12, 2016 (edited) Barrel not the slide, sorry if I wasn't clear. The barrel begins with the same velocity as the slide, when it drops out of the slide the pin stops it's rearward motion. The recoil spring won't have had much to do at that point so the only big spring player would be the mainspring. But in the grand scheme of things, none of the springs in the gun are really stiff enough to do any sort of meaningful recoil impulse control from a preventing bending metal perspective. ETA: Didn't mean to come off as a condescending dick head. What I'm saying is I think the mass of the barrel hitting the pin at ~24 feet per second is enough to cause a fatigue crack over time. With all those little things making the difference between breaking one at 20k and one at 4k rounds. Anyone know if the normal slide stops start as castings? Edited February 12, 2016 by busdriver02 Link to comment Share on other sites More sharing options...
adamge Posted February 12, 2016 Share Posted February 12, 2016 Here's a video on their factory. Link to comment Share on other sites More sharing options...
PRanta Posted February 12, 2016 Share Posted February 12, 2016 Thank you ohsevenflhx. To me it seems very clear that in this case the slide stop has been broken from fatigue created by backwards moving barrel. The flexural stress has broken the pin in the middle of it. The crack will start from yield side of bending. Here it is barrel moving out of battery. I've also seen different types of failures, so there is also other reasons for them. The easiest way to make slide stops last longer is to polish the pin. The crack will start from small defect and when polished there is nothing to start with. This is also the reason why there is huge difference in how long slide stops last. Low cost dye penetrant test can be used to locate fatigue cracks. Link to comment Share on other sites More sharing options...
ohsevenflhx Posted February 12, 2016 Share Posted February 12, 2016 Thank you ohsevenflhx. To me it seems very clear that in this case the slide stop has been broken from fatigue created by backwards moving barrel. The flexural stress has broken the pin in the middle of it. The crack will start from yield side of bending. Here it is barrel moving out of battery. I've also seen different types of failures, so there is also other reasons for them. The easiest way to make slide stops last longer is to polish the pin. The crack will start from small defect and when polished there is nothing to start with. This is also the reason why there is huge difference in how long slide stops last. Low cost dye penetrant test can be used to locate fatigue cracks. I've never thought of that, I'll try it. Link to comment Share on other sites More sharing options...
ohsevenflhx Posted February 12, 2016 Share Posted February 12, 2016 A little better pics. Link to comment Share on other sites More sharing options...
PRanta Posted February 12, 2016 Share Posted February 12, 2016 Thanks, those pictures tell same story. Link to comment Share on other sites More sharing options...
ohsevenflhx Posted February 23, 2016 Share Posted February 23, 2016 (edited) [quote name="Matt1" post="2550936" timestamp="14551840 I tried the CZ pin in my TS for 6 months or so. With the pin only the mag wouldn't drop free as easily as it used to. I tried the CZC stainless mag brake. It made it a little better but didn't fix it 100%. I've just changed back to a stock slide stop in my TS Orange. Mags drop free every time now and I'll just put a new one in for big matches when they hit 5k rounds. I have been using the Czech Mate pin only for a couple weeks. Full mags, 1/2 full mags, and empty mags are dropping free fine. The $9 Czech Mate pin only seems to be a good alternative to the $35 TS slide stop. Edited February 24, 2016 by ohsevenflhx Link to comment Share on other sites More sharing options...
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