Welcome. I’m don’t have the parts you listed, but I’m sure someone can help
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“Custom shop” fcu p320 failure to fire
Anyone have any opinions on what to check is more than welcome.
wilson combat full frame.
Killer innovations barrel and slide
Sig slide internals and guide rod and spring
Sig p320 custom shop fcu
got the pistol all out together, went to to the range and went to shoot “click” no round fired, primer not dented, sear definitely disengaged but no bang bang.
put that same fcu in my buddys p320 and it fires.
put his stock fcu in my p320 and it fires.
This one has me stumped pretty good, maybe the custom shop is interfering somewhere with the killer innovations slide somehow and won’t allow firing pin to protrude past the hole in the slide? I have no idea very confused. What do you guys think?!
P.s was the first time that custom shop fcu and p320 I built has been to the range.
wilson combat full frame.
Killer innovations barrel and slide
Sig slide internals and guide rod and spring
Sig p320 custom shop fcu
got the pistol all out together, went to to the range and went to shoot “click” no round fired, primer not dented, sear definitely disengaged but no bang bang.
put that same fcu in my buddys p320 and it fires.
put his stock fcu in my p320 and it fires.
This one has me stumped pretty good, maybe the custom shop is interfering somewhere with the killer innovations slide somehow and won’t allow firing pin to protrude past the hole in the slide? I have no idea very confused. What do you guys think?!
P.s was the first time that custom shop fcu and p320 I built has been to the range.
1 - 20 of 46 Posts
See if your firing pin will go through the hole from the outside and/or make sure the firing pin spring is on the pin correctly
It goes click but wont fire?
Check the firing pin protrustion like others said but its hard to say with aftermarket parts.
How many round did you try with your fcu and setup?
Check the firing pin protrustion like others said but its hard to say with aftermarket parts.
How many round did you try with your fcu and setup?
I checked by manually pushing the firing pin through the hole while it was installed and it definitely protrudes past about the same or even more than my buddy’s stock p320 slide. Just very weird my fcu won’t work with my p320 but works on his stock p320….See if your firing pin will go through the hole from the outside and/or make sure the firing pin spring is on the pin correctly
I never got my fcu to fire with my set up. Only worked on my buddys stock p320., clicked but no bang on my set up. But his stock fcu worked just fine on my set upIt goes click but wont fire?
Check the firikg pin protrustion like others said but its hard to say with aftermarket parts.
How many round did you try with your fcu and setup?
I put about 300 rounds with his fcu installed on my set up and he put about 125 with my fcu on his set upI never got my fcu to fire with my set up. Only worked on my buddys stock p320., clicked but no bang on my set up. But his stock fcu worked just fine on my set up
sounds to me like a swap is in order!!!I put about 300 rounds with his fcu installed on my set up and he put about 125 with my fcu on his set up
Do the pencil test.
Is that strictly to see how far it moves the pencil if at all I assume when you put it down the barrel?Do the pencil test.
Are you 100% sure the slide was going all the way forward?
In my experience some fcu's with different slides will hang up just a little and if you manually push it forward the last little bit it will work.
Its odd because they will still fire but with less strength.
Its from the disconnecter where it rides into the slot in the slide.
As they break in more they tend to wear in and this works itself out.
I have a surplus m17 that does this.
I hope that made sense
In my experience some fcu's with different slides will hang up just a little and if you manually push it forward the last little bit it will work.
Its odd because they will still fire but with less strength.
Its from the disconnecter where it rides into the slot in the slide.
As they break in more they tend to wear in and this works itself out.
I have a surplus m17 that does this.
I hope that made sense
Sounds like the striker safety lever isn't lifting the striker block high enough. Could be just a tolerance stacking issue which is why it works when you swap.
If you want, you could try swapping strikers only then try the pencil test suggested above.
If you want, you could try swapping strikers only then try the pencil test suggested above.
Have you tried a different slide on your frame with your fcu?
Have you contacted Killer Innovations ? its their slide so I would would give them a call.
I think this is what's happeningSounds like the striker safety lever isn't lifting the striker block high enough. Could be just a tolerance stacking issue which is why it works when you swap.
If you want, you could try swapping strikers only then try the pencil test suggested above.
Anytime I do anything to my pistols that involve the trigger or firing controls, I do the pencil test before anything else. The pencil test is putting the eraser end of a number 2 pencil down the the barrel, cock the pistol, and pull the trigger. A striker pistol will move the pencil slightly if it will work correctly. A 1911 will shoot the pencil into the ceiling.Is that strictly to see how far it moves the pencil if at all I assume when you put it down the barrel?
If the pencil does not move, then there is a problem.
Been doing this for test for 45 years; a very reliable indicator that the pistol will fire a live cartridge.Anytime I do anything to my pistols that involve the trigger or firing controls, I do the pencil test before anything else. The pencil test is putting the eraser end of a number 2 pencil down the barrel, cock the pistol, and pull the trigger. A striker pistol will move the pencil slightly if it works correctly. A 1911 will shoot the pencil into the ceiling.
If the pencil does not move, there is a problem.
my P320 FCU puts the pencil into flight, horizontally. it's not a "slight movement" in any sense. it's looking for an eye to put out.Anytime I do anything to my pistols that involve the trigger or firing controls, I do the pencil test before anything else. The pencil test is putting the eraser end of a number 2 pencil down the the barrel, cock the pistol, and pull the trigger. A striker pistol will move the pencil slightly if it will work correctly. A 1911 will shoot the pencil into the ceiling.
If the pencil does not move, then there is a problem.
Thank you for all the replies! After learning more about the function of every piece in the fcu and firing pin assembly and your input I think it has to do with the safety lever not pushing up far enough, I have to find one of those pencils and try that out! What would be the cheaper attempt at a fix if it is not releasing the firing pin safety? New firing pin assembly?
Did you try your buddies slide on your FCU and grip, and your slide with your buddies grip/FCU?
If both function do your FCU and slide on your buddies grip. It could be tolerance issues that add up to failure in your set up.
Without the gun in my hands/on my bench I can not be certain.
With the slide off try to dry fire your fcu a few times. See if the sear is actually dropping. You have to push the disconnector down and release to actually cock the sear. If it’s binding or not moving easily up into the slide it will not fire, the problem could also be the slide lock being stuck down from when the FCU is inserted in the grip. After installing the FCU, I rotate the takedown lever and ensure the slide lock is in correct position and not binding.
The problem is safety lever and disconnector fit and tends to go away as the parts wear in.
I had to fix a buddies 80% FCU he made, lots of sharp edges. Once I smoothed all his rough edges and assembled the FCU I found the safety lever/disconnector fit was tight. I lubed them and after some dry firing of the fcu only in the grip it smoothed out.
As I said earlier I can’t be sure without the gun in my hands, as a gunsmith and a Sig Armourer anything here is a WAG (wild *** guess)
If both function do your FCU and slide on your buddies grip. It could be tolerance issues that add up to failure in your set up.
Without the gun in my hands/on my bench I can not be certain.
With the slide off try to dry fire your fcu a few times. See if the sear is actually dropping. You have to push the disconnector down and release to actually cock the sear. If it’s binding or not moving easily up into the slide it will not fire, the problem could also be the slide lock being stuck down from when the FCU is inserted in the grip. After installing the FCU, I rotate the takedown lever and ensure the slide lock is in correct position and not binding.
The problem is safety lever and disconnector fit and tends to go away as the parts wear in.
I had to fix a buddies 80% FCU he made, lots of sharp edges. Once I smoothed all his rough edges and assembled the FCU I found the safety lever/disconnector fit was tight. I lubed them and after some dry firing of the fcu only in the grip it smoothed out.
As I said earlier I can’t be sure without the gun in my hands, as a gunsmith and a Sig Armourer anything here is a WAG (wild *** guess)
1 - 20 of 46 Posts
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