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Discussion Starter · #1 ·
Hello all first time poster long time lurker.
Build:
P320 Custom Works FCU
FDEZ works xfull grip
PMM barrel and comp 3.6 gen 1
Killer Innovations sig p320c v1 slide
p320c/ ca recoil spring
ghost precision pin and ejector

i recently put together a p320 on a FCU an was having trouble cycling by hand. like 1 in 5 snap caps get stuck in the chamber and it wont cycle easily by hand making you have to force it back to eject. i was looking at some other forums with people having similar issues but when live firing and i didnt see anything about not cycling by hand. ive noticed it seems the front end of the slide is higher and wobbly. and there is lots of barrel movement when cocked back.

this is the first time i have attempted anything like this and was wondering if anyone could point me in the right direction.
 

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There seems to be a pretty large range of manufacturing tolerances. Although you you can't hand cycle, does not mean anything bad, just a real tight fit. You will need to run a couple hundred rounds through it, to have everything seat up. Full power 124's would be best, but we can't be too choosy atm. Don't be alarmed by a hang up at first, it will loosen up. Make sure it is cleaned of factory grease, and lubes, and lube to spec before you shoot with live rounds.
 

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Mix and match a bunch of parts and this is often what happens. You will pribably need to shoot it quite a bit to get it all to wear together and fit itself more or less.
Even some factory guns may require some break in as they are just such tight tolerances
 

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Some will hand cycle as they understand a collection of untested parts my have anomalies. You'd like to know that the parts actually do work and not massively hang up or jam.

Snap caps may not dimension the same as a brass case. A pair of digital calipers from Harbor Freight are good enough to check without destroying all of your discretionary spending for the month. You are making comparative checks, not absolute. Caps also dont weigh the same, and if loading out of magazine, act differently.

Next is testing with live ammo, carefully at a range, just cycling by hand, and that may give you different results. Nonetheless approach what you experience with hand cycling with a due amount of caution. First, you can't cycle by hand at the same speed as a live round pushing the slide back. It is remarkably faster. Second, at hand speeds the rounds push up in the magazine faster than when being fired live. That can cause them to pop up faster with hand cyling - along with faster because cap weigh less - and that isn't a true test of live fire at accelerated speeds.

Other than a function test, hand cycling isn't really valuable testing how a gun feeds.

If things appear to be working ok, time to shoot it. If the slide appears wobbly - compared to stock - it bears more checking. All the after market parts should measure very closely to stock, but that doesn't mean that a slide made Here works with a FCU made There very well. And that is where the calipers tell you what numbers are off.

When assembling a lot of parts from various makers, two things happen: You are now the factory assembly tech, and, you are also the Engineer and QC inspector. Nobody at the various makers sits down with every combination of parts to see which ones don't work well with the other. WE do that and we try to report it so others will know.

It's the down side of all those cool parts that they don't put in the ads.
 

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Nice looking project you got, I agree with other posters not posers as to shooting that thing. Go shoot a couple hundred rounds of different brand ammo from 98gr fragmenting to 150gr hollow points, just shoot it get her hot. You'll be surprised how smooth it will get. Have fun.
 

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Discussion Starter · #12 ·
okay thanks for the responses. makes sense what you all are saying. ill try it outa nd let you know what happens thanks again
 

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P226 9mm Legion LE, P229 9mm Legion LE, P229 357 Sig, P320 X-Vtac, P320 X-Carry Pro, CZ TSO, SP-01
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okay thanks for the responses. makes sense what you all are saying. ill try it outa nd let you know what happens thanks again
I hope there are no issues for you with live firing. I'm usually not crazy about guns with colors, but this is a damn good looking pistol.
 
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