I cant pull back the slide all the way. The thing is completely built… trigger pin, charging handle, etc. However, I cant pull the slide all the way back… The slide fits onto both front/rear rails. I just cant pull the slide beyond that. I can take the slide down using the takedown button. So… what am I missing here ?
Ive built numerous glock frames… so not a newbie…
Thoughts ?
You must log in or # to comment.
I had that same issue. I was working off the strength of a room full of beta testers saying they didn’t have any issue with the Glock 19 internal geometry so I left it.
Now that I’m working through my pistol versions of the 19 I’m seeing the same issues. Whatever typo’s may or may not exist in the BOM / ReadMe (sorry!), I think if you’re not new to Glock, it’s not you - it’s the design needing a revision to be more inclusive to other parts.
FWIW, I had the same issue with the 17, and just finished fixing it in the CAD. The 19 is next on my chopping block, and I’m about to throw all of his CAD out and replace it with my tested Block 19 CAD and then start micro-adjusting all the imperfections until I love it.
So, in summary, my apologies if it’s not working for you - there must be some magic “stars aligned” situation going on with the 19 / Franken-9 CAD.
Notes:
- try taking out your front or rear rail pin (or maybe both), could be the holes needing to be drilled out
- try removing your takedown spring, you can’t shoot it this way, but you can elevate the takedown with your fingers during install and confirm whether or not there was an issue with takedown pressure (this never happened to me before the Franken-9 assembly)
- make sure it slides smoothly back and forth without a barrel installed, bad rails, bad friction, bad support junk left in the cavity can angle the rails and make everything bind up like wild (you probably already knew this)
My “Hammer Fired Glock” handgun series (including 17 and 19) are just around the corner though, so if you’re not having luck, you’re not at a loss for long.
BTW, thanks for all the work you’ve put into this! I really like this style for a PDW and your improvements are really clever. I’ve wanted to do a Recession Ruger for some time, but I prefer to shoot suppressed and threaded Ruger barrels are completely impractical. Being able to do a similar build with Glock parts is awesome since it opens a boatload of aftermarket options.
yeah… i use my R3 almost every range trip… and thats 4-5x per week. i have a r45 built, but for some reason i cant get it to feed… so it just sits… using g21 mags. its as if the mag sits too low or maybe the slide sits too high…
I think I recently got a P90 kit, I’m happy to make an R45 v2 if it’s being poopy.
are you aware of any issues with the r45 ? its possible i may be doing something wrong.
I am not! But that doesn’t mean they don’t exist.
yeah… let me try troubleshooting some more… the 45acp builds kinda are on pause at the moment… i already spend wayy too much on this hobby. so these days i just focus on 22lr/9mm builds.
even my 556/300/x39 ar builds dont even get love these days.
You’re very welcome! Hoping to move this 19 forward sooner rather than later.
I just built up my Franken9 frame and have a very similar problem. The root cause is the recoil spring stop in front of the slide lock. The back of the recoil spring guide rod is supposed to butt up against this:
In the Franken9, this is V-notched for some reason.
That lets the guide rod pass through the stop and butt up against the slide lock. Depending on your parts, the barrel may then bind on the guide rod when it’s trying to drop into the locking block. Even if it doesn’t, this isn’t the way you want to run the gun since the slide lock isn’t designed to do double duty as a guide rod stop.
It’s possible to get the current frame working correctly by cutting an appropriately sized steel washer in half and epoxying one half to the front of the guide rod stop.
“appropriately sized steel washer in half and epoxying one half to the front of the guide rod stop.”
ill just wait for the corrected design and/or an official USK release. thanks for your support here … glad i wasnt the only one who experienced the same.
Mine worked the first time until I disassembled it and reassembled it. I figured out the same thing you did, but I messed with it a bunch (including not installing the recoil spring assembly just in case it was the barrel lug and locking block–now obviously not it)
I can see how the beta testers could have missed it because it got stuck 4 out of 5 times at first (my first successful try was a fluke), then I was able to figure out a technique to get it seated correctly every time. But even if seated correctly, if you just nudge the guide rod a teensy bit you’d hear it slip and it would get stuck, lol
It’s good it’s fixed now but the struggle to figure out what was going on was actually pretty useful to me, I’m now way more familiar with the internal workings than I was at the start (not the first time this kind of thing happened in 3D2A, of course)
the one piece I trusted was using good cad, sigh
yeah i’ll hit it hard and it will be fixed ASAP
yeah i figured there was a design/cad issue… especially when i tried a slide that hadnt been modified. ive since just put the 9/10 completed build in its build bin… will wait until an official release is published by you. espeically the g17 varient… as i have too many g17 slides and a g17/22lr conversion slide i want to put to use.
The 17 is done and ready. I’m tackling the 19 today. If you’re super eager, toss me a DM on element and I’ll slide you the 17 as a pre-release.
Wild guess (best I can offer with limited info) is slide hanging up on the ejector. Easy to test – remove the ejector and see if the problem persists.
yeah… ive even tried a non-modified slide from another build. same issue… so something is getting caught up… looks like the guide rod asembly… or maybe the locking block… ill figure it out by process of elimination.
i do wonder how popular this build will be… the firing pin modification instructions are a bit confusing. not as clear… i should probably start an odysee page noting some of my observations and ‘discoveries’ with the builds i complete.
I suspect a lot of folks are in “wait and see” mode. Needs a couple of successful builds posted to get momentum. I finished the slide assembly today. I just followed the picture in the docs and it seemed pretty straightforward. I’ll probably print the lower tomorrow, but won’t receive FCG parts until next week.
Id love a real photo of the firing pin with it’s new printed parts installed before inserting it in the slide. I looked at the included step but only the printed parts are represented. Am I correct in assuming the spring needs to be moved so it then pushes the firing pin in the direction opposite of it’s normal iteration?
i just removed the plastic pice seen in the attached. and replaced with the printed part. im able to shoot out a pencil from the barrel… so functional trigger/firing-pin testing works.
You are correct. Remove the firing pin spring cups, remove the spring, remove the stock plastic spacer. Put the printed sleeve over the firing pin and push it all the way to the rear. Put the spring over the firing pin (no cups) and insert the assembly into the slide channel (make sure you already have the stock channel liner installed in your slide). Lastly, put the M3 through the printed donut and put that into the channel head first behind the firing pin. Install backplate (don’t forget the extractor spring assembly) and you’re good to go.
I wouldn’t go as far to say you’re a life saver. But you certainly saved me a lot of frustration! Thanks.
youre sure the cups arent needed ? the illustration seems to imply the spring is captured behind the cups. although the cups arent clearly shown in the illustration.
I’m sure. With that spacer sleeve you couldn’t install the cups if you tried. The spring would be fully compressed before the end reaches the spot on the firing pin that retains the cups.
Normally the cups are there so when you pull back on the firing pin, the cups (which are locked to the firing pin) cause the spring to compress. As a result the firing pin is held almost all the way forward (it free-floats with no spring pressure the last few mm of forward travel).
The Franken9 works “backwards”. You want the spring applying rearward, not forward, force on the firing pin. So the channel liner, not the cups, becomes the forward spring stop and spring compression holds the firing pin all the way to the rear. It’s a really clever design in how it reuses the firing pin and spring in a completely different way.
ok… reconfigured the fiing pin assembly per your response. fraken9 fix build is completed… now just need to get to the range this afternoon.
thanks!
I wouldn’t go as far to say you’re a life saver. But you certainly saved me a lot of frustration! Thanks.
In the BOM of the pdf the Spring loaded bearing is listed twice with the same parts number but it says only one is required in each entry. I just wanna confirm this is a typo and I’m not over looking something.
i think its referring to the striker spring cups.
Definitely a typo. SP00308 is the part number for a two-pin G17 locking block. The spring bearing LCI should be part number SP02714, and there should be only one. Actually, most of these Glock parts appear to have incorrect part numbers (several of which don’t even show up on the Glock Armorer’s Parts List):
Depressor Plunger - SP00337 (should be SP00112) Extractor - SP01903 (should be SP01895) Firing Pin (Striker) - SP01193 (should be SP00063) Locking Block - SP04361 (should be SP07894-1) Locking Block Pin - SP04368 (correct) Slide Lock - SP02919 / 2912-3 (should be SP00301) Spring-Loaded Bearing - SP00308 (should be SP02714) Spring-Loaded Bearing - SP00308 (should be Depressor Plunger Spring SP33522) Trigger Pin - SP00408 (should be SP00420) Firing Pin Spring - SP00063 (missing from BOM)
Good catch. I was searching the part number and the provided part name so that discrepancy was flying right over my head.
this is no bueno… thanks for the correction. i noticed the ‘typos’ as well, but figured i was searching incorrectly. but im familiar enough with glock parts that i was able to read through the BOM typos.
Strip the slide and try it.
yeah… stripped slide(barrel included), just minus the guide rode assembly, is able to fully ‘slide’ back. so looks like guide rod is getting caught up somewhere… ill sort it out.
In case anyone is still seeing this post / comment, the Franken-9 frame issue has been identified, fixed, and re-released. The file name is called “Unseenkiller and Corbat67 - Franken 9 - 1-2-2026 Fix.zip”, so when you download it, you need to ensure that’s what comes down. The post should also be renamed to “Unseenkiller and Corbat67 - Franken 9 (fixed)”
I’ve given the fix to Moderator Gage and he should be updating the BLC release file shortly as well.
Sorry again for any wasted filament or time, folks - this is my bad.
Never a waste when you learn something in the process.
yes sir… plus ive been using up my spare pla+ spools.
so ive put the fixed version together. slide is fully functional as expcted. now to test this afternoon.
thanks!
printing now… thanks! will test tomorrow
