Ludde

1911/2011 does behave differently compared to CZs based on the limited testing I have done. I do not know if it has to do with the "geometry" of barrel lock up / unlocking, hammer/spring strut geometry when cocking the hammer etc.

I have a good working design for 170mm base pad for the 18rnd (old) tubes, and I am working on a base pad for the 17rnd chromed (newer mecgar) mags also. Tested the gun yesterday with a tad heavier main spring. The result got worse in my opinion, too slow slide action and the gun returns even higher than before. Next up is back to the lighter main spring and one step stronger on the recoils spring to snap the slide forward. The combination of lightened slide (for open) and heavier muzzle weight really highlights the "lack" of forward rotating inertia when the slide moves forward into battery. Which I think is a good thing, easy just to tweak the springs and load to get the correct snappiness and perfect return. A couple of guys that shoot Major 2011 guns tested it and was quite impressed of it. Now I just need to get it to my liking. Coming from a season of shooting open, everything feels slow and sluggish..

This gun started its life as a regular Shadow production gun, then I got bored and designed a compensator cone thread adapter to fit off the shelf bull barrel comps. Cut the slide and frame, threaded the barrel, modified it to allow the barrel to be removed from the front. Lightened the slide. Did not like the off the shelf comp and designed a couple my self that worked better. Got completely bitten by Open division (nothing else is fun or fast anymore) and will now modify my Shadow 2 to become a compensated open division gun. So that had me thinking what could I do with my old shadow that is already modified. Let's make a sight block gun to shoot IPSC Standard Division minor with. I designed the sight block to have as much meat as possible and still fit the box. With the spring setup you see in the video I actually got better and faster return to zero with some more snappy Maxxtech 115grain factory ammo. And the best part is, they didn't feel that snappy at all compared to a regular Shadow without a sight block.

Still some spring tweaking to be done but quite good for the first time out. 130pf 123gr N320 8lbs recoil 9 lbs main spring. Going to test 11 lbs main spring next.

I am starting a new Open gun project and decided to convert my "old" Shadow Open gun into a IPSC Standard Division minor gun with a sight block configuration. I have not shot it yet but I look forward to seeing how it behaves.

Those are reference marks so I know how much to compress the spring. The 93mm mark is when slide is fully forward. This is for my Shadow that is stroked and thus moved the reverse plug more forward than the original recoil system. If I remember correctly its stroked 6.5mm total travel of 53mm. The 3.5mm mark is with a 3.5mm buffer. The 40mm is when the reverse plug (slide) bottoms out on the frame in its most rearward position.

There has been lots of rumours on what rating the factory recoil spring is. I created a spring tester and here is my result using the Czechmate reverse plug stroke as reference and slide in locked/ready position. Measure 9.1lbs and locked/ready 4.0lbs of force. As a side note, I was note pleased with the Ultimate Springs (Eric G.) springs the rating was very off from the rated value. Rated 11lbs and 9.12lbs measured. What is also interesting is that the locked/ready position the tension is only 2.7lbs which might indicated that the length of the spring is rather short also. EemannTech springs where very close to rated.

Have you read this thread. There are several CZ 75 type guns in 9mm running major. There is no 40 S2 available to my knowledge. Have you seen my videos in this thread? That's a regular 75 SP-01 Shadow barrel. My Shadow 2 allows for the same OAL. Choose bullets to fit your purpose.

I was comparing CZ triggers not CZ vs 2011. 2011 are sure better in terms of trigger but will that be the factor holding you back... If we then ask the question why people don't use Shadow 2's instead of 2011's as open guns. How many gunsmiths or custom shops specialize in 2011 Open guns compared to CZ type Open guns....

More tweaking and more getting used to it! Out of all the setups I've tested thus far this setup requires the least amount of effort to control. I get the best result with a what I would call medium strength grip and somewhat relaxed elbows and shoulders. This setup gave me confidence to shoot tight shots rather quickly. Setup: 165 PF 3n38, 20lbs Main spring (WOLFF) 9.5 lbs Recoil spring (Eemann Tech) Some training with tight no shoots and poppers while backing up. And yes regarding the basepads, they have been working well the whole season and I've made a second small batch that others have tested with good success.

The trigger has nothing to do with it. Its easy to convert to SA. As a matter of fact my personal opinion is that a SA Shadow new or old version usually has a better more tactile feeling SA trigger than the TS. I plan to build an open gun based of my production gun i.e. a Shadow 2. Ive already done the ptototyping so to say on my old SP-01 Shadow. It has a ~600gram SA trigger. The gun or dot movement is still a bit bouncy but I am getting closer to my goal all the time by doing more tweaking n testing.

What powder and amount are you using with those 3 popple holes? What is the wheight of the slide?

I know it's hard to get a good representation of the dot sizes on camera but could you place the different MOA dots on a row and take pictures of them for reference?

Now this is a cool project! Get it done...

My Open divison modifications journey continues.. I have to hand it to kneelingatlas, his comp design sure works well. I took the liberty and copied his port design and made my own version of it (keeping the port design intact) and the results speaks for itself. It is quite flat now and I do nothave any popple holes. Now I've tried 3 different comps, stroked the slide more, lightened the slide a bit and tested with a bunch of spring combinations. Now my slide weighs 275grams (9.7oz) empty (no extractor, racker, firing pin etc). In total it is stroked 6,5mm but the reverse plug takes up 2mm of that so effective stroke is 4,5mm compared to original. 11lbs recoil (Ultimate spring EG) and 9 lbs main spring (Eemann tech, heavier than WOLFF). Extra power extractor spring with adjusted pinch depth for smooth feeding. The gun also feeds reliably with a 7lbs recoil spring when tested. And my extended 170mm open division base pad mag combo has been running flawlessly for several thousands of rounds. Comps tested so far: McLearn, Own design with gradually larger ports angled 5 degrees forward and one bleeder port, kneelingatlas butt shaped port design and angles. Slow motion video:

They are actually really good. Built the same way as the DAA Alpha X hanger and DAA inserts fits perfectly. I have used mine quite a long time and I am not being kind to it.

Get this holster assembly and buy the DAA Shadow 2 insert. https://www.aliexpress.com/item/4000030286047.html?spm=a2g0s.8937460.0.0.7b392e0eKh18pL

I like it in the Shadow 2 but not in the SP-01 Shadow. Test thin, thick and different recoil springs, setup a target, different distances, different split times, recoil control, stance etc and determine what works for you and gives a better result on the target and timer!

Update on my projects progress. Own designed aluminium compensator. Wolff 16lbs main spring and 11 lbs recoil spring. Back to Shadow original strength extractor spring. In this video the splits clocked .16-.17s Still on 8.2grain VV3n38 ~168pf

More testing with little improvement. Bumped up the load to 169PF 8.2gr 3N38. Increased hammer spring tension.

So far I've not had to ream the chamber. Loading .355 bullets 124gr to 29,55-29,65mm oal. Tested an 30mm oal would still fit before hitting the rifling. Let's see how it behaves with some more powder.

What would you be willing to pay for a steel magwell made for Open/Limited for the CZ 75 series or Shadow 2? I am actually drawing a version but initally planned to have it made out of aluminium.

Now I have got it to run reliably with major 165-167pf 124gr bullets. Initally I had problems with the empty cases getting stuck in the chamber and the extractor slipping off the rim. Since then I've polished the chamber and added a Wolff extra power extractor spring. The gun feels soft and does not slam into the hands, I am going to test a little more powder to see if I could decrease some of the muzzle flip. If that does not help it's probably due to the design of the comp having many sideports and small up ports. Some slowmo...