Pf940sc issues

ItsWAWGaming

ItsWAWGaming

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Got a full oem 940sc running all oem internals and upper barrel etc, it racks, the barrel drops then it stops just before the barrel goes under the slide like a brick wall, I ruled out channel rub, a out of spec locking block lug by seeing if it has play and if the barrel alone fits and has free movement between it and the slide lock and the rear rails aren’t bad either, it doesn’t seem like the plunger is doing it either I’m extremely confused by this.
 
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Bobster said:
I had to remove a little bit of material on top of the block with mine. LINK
Click to expand...
Yeah that caught me off guard cause the block is damn perfect sits flush with posts and the rear rails aren’t perfect perfect but they’re just like on my g19 which runs fine, so yeah maybe it’s a bit high, cause it gets right to where the barrel drops but before it slides under it hits a wall, and the barrel has plenty of play when just dropped in there with no slide so I ruled that out initially but yeah maybe that’s the problem
 
ItsWAWGaming said:
Is there a way to tell if it’s too high or not visually?
Click to expand...
Try taking a Sharpie and "painting" the top of the block, install the slide and try to cycle it. Remove the slide and see where it touched. Then take a jeweler's file and lightly knock down where it was touching. Reassemble and try again. You might/should have to do it more than once. I didn't have to take off much, maybe .010"? Then polished with some fine sandpaper, 600grit? This issue initially presented as the barrel was super tight to the hood, as in it was too high so to lower it I knocked the block down. I can't guarantee this will solve your issue but it might.

I did have a few little issues with the trigger and slide release corrected by putting Glock parts in (I think). But now my SC runs reliably enough that I've run it a couple times in my club's "Action Pistol" shooting steel. :) That's a slide I got from a GB gunbuster with other internal parts for $130 shipped. I replaced the rear sight and firing pin safety plunger and spring. All else was fine.

PS: original build LINK

scxgrip1.jpg
 
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Bobster said:
Try taking a Sharpie and "painting" the top of the block, install the slide and try to cycle it. Remove the slide and see where it touched. Then take a jeweler's file and lightly knock down where it was touching. Reassemble and try again. You might/should have to do it more than once. I didn't have to take off much, maybe .010"? Then polished with some fine sandpaper, 600grit? This issue initially presented as the barrel was super tight to the hood, as in it was too high so to lower it I knocked the block down. I can't guarantee this will solve your issue but it might.

I did have a few little issues with the trigger and slide release corrected by putting Glock parts in (I think). But now my SC runs reliably enough that I've run it a couple times in my club's "Action Pistol" shooting steel. :) That's a slide I got from a GB gunbuster with other internal parts for $115?. I replaced the rear sight and firing pin safety plunger and spring. All else was fine.

View attachment 40042
Click to expand...
Yeah cause it stops right after the barrel is dropped and before it slides under the hood it just doesn’t move further even though it looks like it has enough clearance to pass through
 
ItsWAWGaming said:
Yeah cause it stops right after the barrel is dropped and before it slides under the hood it just doesn’t move further even though it looks like it has enough clearance to pass through
Click to expand...
I updated my previous post with a link to the build thread
 
Bobster said:
Try taking a Sharpie and "painting" the top of the block, install the slide and try to cycle it. Remove the slide and see where it touched. Then take a jeweler's file and lightly knock down where it was touching. Reassemble and try again. You might/should have to do it more than once. I didn't have to take off much, maybe .010"? Then polished with some fine sandpaper, 600grit? This issue initially presented as the barrel was super tight to the hood, as in it was too high so to lower it I knocked the block down. I can't guarantee this will solve your issue but it might.

I did have a few little issues with the trigger and slide release corrected by putting Glock parts in (I think). But now my SC runs reliably enough that I've run it a couple times in my club's "Action Pistol" shooting steel. :) That's a slide I got from a GB gunbuster with other internal parts for $115?. I replaced the rear sight and firing pin safety plunger and spring. All else was fine.

View attachment 40042
Click to expand...
So if there’s a spot it’s sticking on after I put sharpie on that sharpie will have scratches where it could be catching? Cause the barrel lug bottom rights over the top of that right?
 
Bobster said:
I updated my previous post with a link to the build thread
Click to expand...
Mines also running a 26.3 oem with oem guts too so yeah this caught me way off guard
 
Bobster said:
I updated my previous post with a link to the build thread
Click to expand...
I just noticed some abrasion like spots on the top of the lug ramp so I’m wondering if it’s too tall like on yours, cause without the barrel present it goes all the way back just fine with no trouble
 
Bobster said:
I updated my previous post with a link to the build thread
Click to expand...
I can also grab one for 19$ a new p80 oem sc block and see if it has the same issue and if the heights are different in that area
 
FrankenGlock said:
Make sure you post a link to the $19 SC block so others can get one if needed.
Click to expand...
Yeah I’ll put that up too, that’ll probably fix the problem I’d imagine, or should I try to just file the top of the lug ramp first, cause I do notice some scrape marks there, in that case do I just use a jewelers file on the scuffed areas?
 
FrankenGlock said:
Make sure you post a link to the $19 SC block so others can get one if needed.
Click to expand...
I could also test it with a 19 barrel to see if it replicates the same behavior cause if I recall I tested a 19 on it before it was completed and I don’t recall it having this issue
 
FrankenGlock said:
Make sure you post a link to the $19 SC block so others can get one if needed.
Click to expand...
Went ahead and ordered one, you can find them on noqrtr80 so I’ll see if that fixes it, more than likely will but yeah that was very unexpected since the rest of the block appeared perfect, sits perfectly flush and everything, but I did read last night those silver sc blocks were too high every here and there even though the rest were pretty solid
 
Bobster said:
Try taking a Sharpie and "painting" the top of the block, install the slide and try to cycle it. Remove the slide and see where it touched. Then take a jeweler's file and lightly knock down where it was touching. Reassemble and try again. You might/should have to do it more than once. I didn't have to take off much, maybe .010"? Then polished with some fine sandpaper, 600grit? This issue initially presented as the barrel was super tight to the hood, as in it was too high so to lower it I knocked the block down. I can't guarantee this will solve your issue but it might.

I did have a few little issues with the trigger and slide release corrected by putting Glock parts in (I think). But now my SC runs reliably enough that I've run it a couple times in my club's "Action Pistol" shooting steel. :) That's a slide I got from a GB gunbuster with other internal parts for $130 shipped. I replaced the rear sight and firing pin safety plunger and spring. All else was fine.

PS: original build LINK

View attachment 40042
Click to expand...
Just did the sharpie trick, none of the sharpie rubbed off, so now I know the locking block is fine even though I ordered a spare incase, but yeah I’m very confused now as to what’s causing this
 
I'm not sure I understand the description of the problem in the OP.

So, the slide stops dead on the way BACK? Before it slides over the barrel hood?

Photos / video would help a lot.
 
Racer88 said:
I'm not sure I understand the description of the problem in the OP.

So, the slide stops dead on the way BACK? Before it slides over the barrel hood?

Photos / video would help a lot.
Click to expand...
I’ll take one or a photo to show it but it won’t even rack past the point of the barrel drop, it drops right to where it is enough to clear the hood then refuses to go any further than that, and I ruled out the locking block causing it however I did notice the right rear rail is a little high, maybe that is enough to cause this failure
 
Bobster said:
Try taking a Sharpie and "painting" the top of the block, install the slide and try to cycle it. Remove the slide and see where it touched. Then take a jeweler's file and lightly knock down where it was touching. Reassemble and try again. You might/should have to do it more than once. I didn't have to take off much, maybe .010"? Then polished with some fine sandpaper, 600grit? This issue initially presented as the barrel was super tight to the hood, as in it was too high so to lower it I knocked the block down. I can't guarantee this will solve your issue but it might.

I did have a few little issues with the trigger and slide release corrected by putting Glock parts in (I think). But now my SC runs reliably enough that I've run it a couple times in my club's "Action Pistol" shooting steel. :) That's a slide I got from a GB gunbuster with other internal parts for $130 shipped. I replaced the rear sight and firing pin safety plunger and spring. All else was fine.

PS: original build LINK

View attachment 40042
Click to expand...
I may try it with no firing pin or plunger too just to see what it does, cause when I put the frame together initially and tested it with a 19.3 before getting the right one later on it went back unlocked no issue, so I wonder if maybe the plunger is causing a problem or even the trigger perhaps
 
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FrankenGlock said:
Make sure you post a link to the $19 SC block so others can get one if needed.
Click to expand...
Yeah I tried it without internals in the upper and it still stops right after the barrel drops, the sharpie trick came back clean too, no marker rubbed off, I’m starting to wonder if the rear rails are messed up, cause one side is slightly high but it isn’t causing the slide to stick aggressively either and a 19.3 racked back fine on it, this is just getting weird at this point.
 
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