TerryYu

So I did the test and the comp well, sucked. Going to try and machine my own now and was wondering if there’s any downside aside from weight if you build a comp that has an excess of ports and can dump all the gas before it reaches the last port. Also any opinion on angled side ports like on a muzzle brake? Was thinking of putting two in the last chamber to try and “pull” the gun forward to reduce the smack into my arm.

That looks like a fun test, i'll see what I can see!

It's a CZ75 Open gun that has a top end that kneelingatlas built. It shoots flat with that load but it also has a brazos thundercomp. I'll try 147 with AA7 and 124 with WAC and see how that feels. zzt, what is the brazos test? I don't think I've heard of that before.

I'm messing around with a p320rx/x5 based open gun (just for fun) and it's really light ~35oz with empty mag. I tried my normal open load 10.5gr aa7 115gr tmj through it and it kindof hurts! A ton of straight back recoil of the very sharp variety. I think I'm looking for a softer recoiling load or perhaps more side ports in my comp (I can mangle it up with my drill press)? Currently I'm running a no name steel comp with 3 top ports and no side or poppel holes. I have 115, 124, 147 and aa7, autocomp, cfe pistol, hs6, and blue dot in stock. Any suggestions?

Probably about 5 consecutive shots before it melts. The plastics that are used for 3d printing are stable up to about 70C before they start softening and losing strength. I think you could probably get enough shots to verify a design out of a plastic comp if you took breaks for cooling. @muncie21 I'm using a Creality Ender3 and Tinkercad.

I'll bite. Here's my CZ75 based open gun, I got started reading kneelingatlas's build threads and bought one of his SP-1 slides and slapped it onto my CZ75 SA lower. Had to file the barrel lug slightly to get it to lock up tightly but that's honestly all it took to make a working open CZ75. After a match or two I got tired of the Cmore being so high off the bore that I fired up my 3d printer and hacksaw and went to work. Converted my C-More serendipity into a slide ride and modeled up a 90 degree mount, forward set slide racker, and grippy grips and printed them on my 3d printer. The optic mount works much better than I expected, holds zero well, and actually is more accurate than the original serendipity mount. I printed out several future iterations that are stronger because I really thought that prototype #1 would self destruct during the first range session but it's been holding on strong so it'll stay until it falls apart.

I'm trying to figure out a solution to keep my optic on my gun. I bought a serenditipy and mounted it to my CZ75 with 4 6-32 screws with the front hole on each side of the mount open as the CZ frame tapers down at that point. The problem is that on a longer stage (30+ rounds) the shock and vibration is loosening the screws out of the frame. I've tried blue locktite but the recoil shock breaks it loose very quickly. I've also tried gooping it up with RTV Ultra Grey which is supposed to be ideal for high vibration and heat (up to 500F). That worked better and held up to a steel challenge match but yesterday I shot a 300 round match and the longer stages cause it to liquify and flow out of the threads! So I'm looking for another solution to my problem. If I have to I can probably rig up some sort of spacer and tap my frame for the additional screws, but I would like to hold off on that if possible. Any suggestions? I could try red locktite, but I think the heat and shock would eventually get to it and I wouldn't be able to remove it easily as I don't want to melt the polymer Cmore. I've also heard of something called Vibra-Tite, but don't think it could withstand the high temps.

If you have access to a 3d printer it's very easy to make your own slide racker in whatever shape you want. Mine has an upward cant to it and it's double sided (helps prop the gun up on table start). Plastic is plenty strong for the job and weighs very little, mine weighs about 5 grams, so you can build a pretty crazy looking one without compromising slide function.

Wow, a response from Dillon. Another reason why my home is a blue press home!

Is ~0.002" of variation normal for a 550? I'm running a Lee 9mm seating die and factory crimp die combo with a set screw modified toolhead and am getting COALs of about 1.158 to 1.162 for my normal 9mm major load of 10.3gr AA7 with 115gr FMJ bullet and mixed brass. I notice that the variation is worse when the shellplate is partially empty, which seems to indicate that the set screw mod isn't working. Thoughts? Perhaps a higher quality seating die?

Well the rest of us mortals don't have your fabrication skills or friends with machine shops!

Thread necro but Quickload has exactly the same physical properties listed for AA7 and D037.1 so all load data is identical.

Not that I've heard but I'll tell you that a promag 20 rounder with CZ 75 long base pad #10213 and follower kit seats 29+1 and is 173mm long so I'd bet their short basepad 10187 will fit in the gauge and be in the realm of 26 or 27+1. I've got one on order so once i get it I'll check back in with actual dimensions and capacity.

If I wanted to fit a SP01 slide with a comp to a TS frame how much would I have to cut the front end down by to get clearance for the comp? It would be nice to be able to use my TS frame for an open build as I've already butchered the grip with a DIY frame reduction.

My CZ TS (similar SA setup) is 1.5lbs with 100% reliability but it's a little light for my taste. At that weight there's enough intertia to AD on a drop (no fpb) and I've had a couple of close calls while moving between arrays. I resprung it to 2.5lbs and like it better at that weight. Sharper break and a real clean reset.

Just did. Thanks!

I'm putting together an open gun and can't seem to find anybody lolthat sells a thumb rest/*thumb rest [generic]* for lefties. Any leads would be appreciated! Edit: my Google is weak, found the Everglades thumb rest but would like one that is not pre drilled as my gun has the serendipity 3 hole pattern and not the normal 4 hole.

It was about 4 to 5lbs on mine from factory. CGW springs and light polish got it down to 2.5lbs.

16" barrels are plentiful and cheap.

Why not shoot your local USPSA/IDPA matches as intended and treat that as practice? Trigger time is trigger time and if your inclination is to "triple tap all the things" then go for it and when you start caring about scores that'll go away.

I'll raise you one for mythic ESP gun. CZ 75 LS-P with magwell. Weighs 42.5oz with mag and fits the IDPA box so tightly that you can't put a sheet of paper in edgewise.

I want to replace the standard flat black front on my ST IPSC (the TS's predecessor) with a fiber and need to know the correct part number on CZC's website. The gun comes with the rear adjustable kensight. The other gun is a CZ CTS LS-P 40 which also has the flat black front and the rear kensight. Also looking for the correct part number for a front fiber. Thanks everybody.

I have to say, reading about your build was convinced me that it could be done. How would you do it without butchering the gun?

Thanks. I suppose the next step would be to either find a 75 upper or chop down my slide to thread the existing barrel. Really starts pushing me towards those $2000 Czechmate people are finding for sale. Where can I find one of these $2000 Czechmates?

I'm thinking about the feasibility of converting my LS-B (TS slide/barrel fitted to a 75 small frame) into a Open gun. Mags and optic seem pretty straightforward but I have a question about the barrel. As far as I know CZ doesn't make a longer than 5.1" TS barrel for their guns and the Czechmate slide is cut down slightly to accommodate the comp and threads. I have found a 6" barrel that's compatible with CZ 75/85 but don't know if I can make it fit my LS-B. Specifically the external diameter of the barrel, I don't have a normal CZ75 anymore to measure. If it fits, than I believe it should be a simple process to get the extra inch or so threaded for a comp and away we go. Any thoughts? https://shop.cz-usa.com/ProductDetail/0420649201_Barrel-6-9mm