paltrypoultry

Hi are the 147 JHP V2s coming back anytime soon?

I'll take it.

I really like them too but not at 14.5 cpr. I figured maybe it was temporary while they worked through some supply chain stuff so I've been working through what I had stockpiled but now I'm gonna have to switch, too. Sucks.

Thanks for this great thread. I have two SP-01s. I sent one to CGW a couple years, who installed their pro package, and it came back really nice, and has only gotten nicer as it wore in. The other SP-01, I installed the pro package myself. It's much nicer than stock but not as nice as the gun that CGW did the work on. The most noticeable difference is that the gun I did has a more noticeable creep / rolling break in SA. The gun CGW did also has a nearly-imperceptible bit of creep (you have to go really slow and focus on it to notice). It's not terrible in the gun I did, but definitely much easier to feel than on the CGW-worked one. Any tips for what to focus on to try to get the one I did closer to the one CGW did? I had the thought to start swapping assemblies (hammer + disco / sear cage / trigger bar + trigger) around between the two guns to try to narrow it down, but I also wouldn't mind knowing what to look for. Thanks again!

I misremembered. It was 1.165 that cleared my 2 factory SP01 barrels' throats, but was too long for mags. 1.155 cleared mags, but then I had to drop it to 1.142 for a new CZC barrel with an even shorter throat. How did you end up at 1.125? That's 2 or 3 hundredths shorter than necessary for any of my barrels, including the super short throated CZC barrel. Did you work your way there testing accuracy, start with something super conservative, or is the s2o throat way shorter than others? I had good results with my n320 ladder too (7moa 5 shot group offhand with 3.6gn / 1.155, at 131pf)

Zero 147 JHPs have a profile that's very friendly to the CZ barrels. With a factory SP01 barrel and Zero 147 JHPs I found 1.155 would reliably plunk and spin. But that was long enough it'd bind up in the mag. This is the first bullet I found where the mag was the limit and not the throat. I backed it down to 1.142 for reliable mag feeding. 3.4gn of titegroup is what I'm using now, which just made 137pf at a chrono stage. 3.6gn of n320 should be in the same ballpark with the same OAL. Re: the other conversation about OAL and what's too short, it's not really OAL you should be looking at when considering what's dangerous, it's seating depth. Personally I stay away from anything that requires me to seat deeper than .300" but I'm just going by what someone told me on a forums once with that number.

I use a 11.5# CGW spring in my SP01 with CCI #500s. I got about 1-2% light strikes until I started seating the primers properly. By properly I mean .003 - .007 below flush. Now I get 0%. I've shot about 10-12k rounds with exactly 0 light strikes since I fixed this. You should be able to consistently measure the depth with just a regular calipers, but it's a lot easier to do it before seating a bullet. Just flip the primed case onto your bench/table, mouth down, primer up, then open up the calipers to .100 - .200 or so, and gently press the protruding bit onto the primer until the bottom edge stops on the case face. You should get the same reading every time, or at least within .001, unless the primer isn't level *and* you're hitting a different spot each time. I also got inconsistent results when trying to do it like the guy in your video does it. I can very clearly feel the difference in DA pull weight between a new 11.5# spring and a new 13# spring. It doesn't mean your 11.5# spring is worn if you can feel it too. It's very noticeable IMO.

Interesting. I think it might have been a comment from you in another old thread I turned up searching here that pointed me at Springer for this cut. It seems like a 90 degree screws should hold better since a 100 degree can't make nearly as much contact with the optic, and that does line up with my experience too (Springer-provided 100 degree screws held for 500, EGW-provided 90 degree screws held for 1000-1500). I'd like to be able to replace the screws if I need to, but I can't find those unicorn #6-32 90 degree screws anywhere. In the future I'd much prefer a cut using M4 for a DPP though, for that reason. Re: red loctite, too late! I've got red on there now, but I think it's an amount small enough I can remove it without heat. I started thinking about it after watching Dave Dawson talk about it: https://www.youtube.com/watch?v=6Hoqqp9mE60&t=260s Interesting re loads. I'm using a 135pf 125gn load, but I'm probably going back to my old softer 147gn load for other reasons anyway. Though I do want the optic secure enough I can shoot whatever load and not think about it. Do you ever shoot the matches at Richmond?

Thanks for the reply. Springer actually did that exact cut for me. I'm gonna write out my whole saga on this for the sake of other people searching for options. First I got an EGW dovetail mount, since I figured I'd see how I like CO and the DPP before I commit to cutting a slide. I installed it using their directions and the #6-32 screws they sent with the mount. The optic came loose from the mount while zeroing. I figured maybe I applied the loctite (blue) badly so I started over, cleaning everything well and making sure I did the loctite right. It came loose again. I looked harder at what was going on and noticed that on the top of the DPP, the screw holes are countersunk. The screws EGW shipped didn't have angled heads, so very little of the screw was contacting the DPP, which I figured was probably the problem. I couldn't find the right screw for sale anywhere, because the DPP factory screws are M4, so the countersink angle on the optic body is 90 degrees, but the EGW mount holes are #6-32, and you can only find screws angled 82 or 100 degree in non-metric threads, not 90. Anyway, I emailed EGW and they immediately replied that they're starting to use new screws for DPPs, and they shipped me out some, which turned out to be the exact unicorn screw you need for this: #6-32 with a 90 degree angle. I have no idea where they source them. I reinstalled with those screws and this held up for awhile, maybe 500 rounds, and then I noticed that my impacts were off, and I saw that the whole mount had started shifting in the dovetail. I decided to just get the slide cut. Not to throw shade on EGW here, their customer service was great and it's possible I dorked up the install of the mount into the dovetail somehow. I was just ready to move on to milling rather than mess with it more since that was my long term plan anyway. One thing I'll say though is that the dot does end up pretty high with the mount, which was a tough transition for me, coming from irons: EGW dovetail mount height: https://i.imgur.com/P7EU3Hj.jpg I emailed CGW, CZC, Springer, and Primary Machine asking if any of them could do a DPP cut while keeping access to the extractor. CGW said no. CZC said maybe but they'd need to get the whole gun in their hands to confirm the hammer would clear. Primary Machine said they didn't cut customer slides anymore (though I guess they do again now?). Springer said they could do it, and just needed the slide and the optic, so I sent those off to them. Springer turned it around super fast, I think it was like two weeks total from when I mailed it to when I got it back, and it was a reasonable price. They shipped it back with the optic installed. The first thing I noticed was the cut was exactly where I hoped, like you say, leaving access to the extractor pin, but also leaving some material at the back, too. The second thing I noticed was that they didn't use the factory DPP screws that I sent them, which I thought was interesting. I zeroed it, and shot a couple matches with it and then at the end of the 2nd match, I noticed one of the screws had started backing out (I'd put witness marks on them after my first problem with the EGW mount). I think it'd been about 400-500 rounds total. When I got it home I took the mount off and found that they'd tapped the screw holes to #6-32. This is why they didn't use the factory screws. I think maybe they did that so that they could use the screw holes in the DPP base as recoil bosses, since they didn't cut any of the other recoil bosses a DPP can accept (see pic): https://i.imgur.com/jbrW7uK.jpg Anyway, I think the screws they used are #6-32 with a 100 degree head, so I don't think they were getting as much abutment against the top of the optic as they should (as they would with a 90 degree head). So, I just used the #6-32 / 90 degree unicorn screws that EGW sent me and reinstalled it. I used blue loctite and 12 in-lb. That held up for 1000-1500 rounds and I thought I'd finally solved it, until a screw just started backing out again the other day. I did some experiments to find an amount of red loctite I could use and still be able to remove the screws without applying heat, and reinstalled with that, and 20 in-lb (which I felt safer doing since there's hardly any loctite on the threads). I shot 200 rounds with that and so far so good, but time will tell. One thing I noticed when reinstalling it this last time is if I hold it up to a light, there's a tiny bit of gap in the front (the screws are in the back). I didn't look for this before, so no idea if that's how I got it from Springer or if it happened when I re-installed or re-re-installed: https://i.imgur.com/O1vUSMo.jpg Anyway, I haven't contacted Springer about it yet, so no shade to them. I was really happy with price, the location of the cut, and how fast they turned it around. I also really liked how they put it absolutely as low as you can go on a non-shadow (notice the FPB plunger spring rides up against the DPP itself). If I were going to do another one, I'd probably start with them again, but ask them if they could leave dedicated recoil bosses and tap the screws to M4 to allow using the factory screws. If it comes loose again I'll reach out them for other ideas. Hope this helps someone.

It depends not just on your barrel but also hugely on the shape of the bullet. Even two bullets that are both round-nose and both the same weight can have very different shapes and means they have to be loaded to very different OALs. I have an SP-01 with an really short throat. I can load 147gn Berry's or Xtreme round-nose at 1.155" (and they'll be fine out to 1.165"). On the other hand, there's a 124gn round-nose bullet that I can only load to 1.100". There are 124gn flat-point bullets that I can only load to 1.020". There are other 124gn flat-points I can load a 1.090". It's all about the shape of the bullet. In general, the 'pointier' a bullet is, the longer an OAL you can get before it'll start touching the rifling.

Looks like you're talking about the MWs though; I'm talking about RNs. I'm guessing the 147gn MWs aren't seating .324" deep at 1.100" like the RNs are. Not that I know enough to say there'd be a problem seating .324" deep, but it wasn't worth it to me to mess with.

The regularly available 147 RN bullets I've found I can easily and safely load in that CZ with the short throat are Berry's and Xtreme plated (I target 1.155" for both of those), and Precision Delta FMJ (1.140"). I use 3.3gn of titegroup for all three loads which ends up around 130-133pf in the CZ SP-01.

I have some of the same RMR RN 147s and in my CZ 75 they'd need to be loaded to the same COAL as you found (1.100") to reliably stay out of the rifling. I ended up just not loading them since I couldn't convince myself it'd be safe to seat that deeply (it works out to a seating depth of .324" or so). Some day I'll load something with them for one of my guns with a longer throat.

Thanks! If you get a chance, would you mind dropping a pic of what yours looks like? None of the pics I could find are really trying to show off the gap

This is their #49402 for mounting a DPP on a SP-01. I was a little surprised by the amount of gap between the slide and mount, so before I push it the rest of the way in, does this look right to anyone familiar with these mounts? Thanks!