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My p320 Problem Child … parenting advice requested

3196 Views 39 Replies 21 Participants Last post by Dholiday666, 8 mo ago

Flysart

Discussion Starter · May 15, 2022

I built this bratty little xcompact during covid, and it won’t behave… advice needed.

Build details: Icarus Precision xcompact grip, Norsso ported reptile slide, barsto ported barrel, DPM recoil rod, trijicon SRO, Wilson combat slide release.

She cycles reliably, and the ported barrel definitely keeps things much flatter and on target than without.

But something must be off, because things keep breaking. First, the OEM (MIM) slide release bent under fire and became unusable. So I replaced it with the higher quality Wilson Combat version. Then, the SRO mounting screws sheared under fire and the optic yeeted off into the range. Still held zero, so there’s a win. So I replaced the screws with titanium aftermarket. So far so good. Finally, today the streamlight mounting screw sheared off under fire, and the light took a similar trajectory to the optic.

I will replace the streamlight mounting kit, but at this point I have to ask: what did I do wrong with this build, that everything is breaking? Is the ported barrel sending recoil force the wrong direction? Or the DPM rod? Or is the aluminum grip transferring too much force into these small parts?

I don’t perceive any insane amount of force that should be overwhelming these parts, but they do keep breaking, so …

Any thoughts?

Trigger Air gun Lego Gun barrel Ammunition

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Reactions: 1

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gchinsr

· #2 · May 15, 2022

A couple questions please. Did you torque the screws, or just quesstimate ? What ammo are you using? Before the slide release failure, did you notice any light grinding of the slide against it?

Reactions: 1

Flysart

Discussion Starter · #3 · May 15, 2022

I didn’t torque the screws, so that’s one possibility- although I have taken the same approach on all my optics, and haven’t had any issues despite much higher round counts. Mostly shooting factory 115. I think there was probably some light wear on the slide release, but nothing extreme …

Reactions: 1

SpartanGoat

· #4 · May 15, 2022

What spring weight are you using? Do you have a pic of the slide release damage?

Reactions: 2

HanSoulo

· #5 · May 15, 2022

I am curious about the slide release as well. The larger oem one is more robust. I purchased a lower profile one from Sig that felt flimsy in comparison as soon as I installed it. Immediately took it out and decided against it. I would torque your other screws and keep an eye on them. Seems more like coincidence honestly.

Reactions: 1

Rexorcist

· #6 · May 15, 2022

Nice rig..Had same problem w tlr8..hard to torque down

KenBry

· #7 · May 15, 2022

Sounds to me that the recoil spring needs to be stiffer, to much inertia on the slide during recoil. The shearing of screws makes me lean this way.
What kind of ammo are you running? Plus P?
@Willard might be able to help

Reactions: 1

Sub1moa

· #8 · May 15, 2022

KenBry said:
Sounds to me that the recoil spring needs to be stiffer, to much inertia on the slide during recoil. The shearing of screws makes me lean this way.
What kind of ammo are you running? Plus P?
@Willard might be able to help

Flysart said:
I built this bratty little xcompact during covid, and it won’t behave… advice needed.

Build details: Icarus Precision xcompact grip, Norsso ported reptile slide, barsto ported barrel, DPM recoil rod, trijicon SRO, Wilson combat slide release.

She cycles reliably, and the ported barrel definitely keeps things much flatter and on target than without.

But something must be off, because things keep breaking. First, the OEM (MIM) slide release bent under fire and became unusable. So I replaced it with the higher quality Wilson Combat version. Then, the SRO mounting screws sheared under fire and the optic yeeted off into the range. Still held zero, so there’s a win. So I replaced the screws with titanium aftermarket. So far so good. Finally, today the streamlight mounting screw sheared off under fire, and the light took a similar trajectory to the optic.

I will replace the streamlight mounting kit, but at this point I have to ask: what did I do wrong with this build, that everything is breaking? Is the ported barrel sending recoil force the wrong direction? Or the DPM rod? Or is the aluminum grip transferring too much force into these small parts?

I don’t perceive any insane amount of force that should be overwhelming these parts, but they do keep breaking, so …

Any thoughts?
View attachment 455000

Well, I’m new to here but not guns but I would start with torquing the screws down and using some clear nail polish (just a tiny bit) to help them stay in place. Then replace that spring. Maybe you have a spring that was built on a Friday at 4:59p and it is bad.

Sig slinger

· #9 · May 15, 2022

So you bought a Sig pistol, replaced about 90% of the parts with parts other than Sig, and you wonder why it’s giving you trouble?
I’m no firearms engineer, but I think i figured out your problem 🤔

Reactions: 5

steveac7531

· #10 · May 15, 2022

Lots of aftermarket parts and lots of tolerance stacking. Maybe start replacing each part with its oem replacement to isolate your issue. I would definitely start with the factory recoil spring.

Reactions: 5

sigmpx2017

· #11 · May 15, 2022

There is a whole bunch of extra mass on that slide/barrel assembly.

Reactions: 4

Flysart

Discussion Starter · #12 · May 15, 2022

SpartanGoat said:
What spring weight are you using? Do you have a pic of the slide release damage?

I do have photos of the slide release damage. See below.

Automotive lighting Motor vehicle Rim Bicycle part Automotive exterior

Tire Automotive tire Bumper Bicycle part Rolling

I am using the DPM recoil system, and using their heaviest spring for the xcompact (they don’t provide a spring weight - it’s a 2-spring system). The website says that this provides 9.25 pounds of slide on battery force, and 19.8 pounds at the “slide full open position.”

FWIW, here’s a photo of the sheared screws on the trijicon.

Hand Light Finger Bumper Auto part

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3

Flysart

Discussion Starter · #13 · May 15, 2022

Sig slinger said:
So you bought a Sig pistol, replaced about 90% of the parts with parts other than Sig, and you wonder why it’s giving you trouble?
I’m no firearms engineer, but I think i figured out your problem 🤔

It may be that simple. I’m taking the modularity thing for all it’s worth. But at this point I’m curious to learn what exactly is causing the problem. It cycles perfectly, so aside from these issues I have no reliability concerns.

Reactions: 1

Flysart

Discussion Starter · #14 · May 15, 2022

sigmpx2017 said:
There is a whole bunch of extra mass on that slide/barrel assembly.

That’s interesting. The SRO may be too heavy for this design.

Flysart

Discussion Starter · #15 · May 15, 2022

steveac7531 said:
Lots of aftermarket parts and lots of tolerance stacking. Maybe start replacing each part with its oem replacement to isolate your issue. I would definitely start with the factory recoil spring.

Thanks, I think that’s good advice

John D2

· #16 · May 15, 2022

Interesting,
I have over 7000 rounds on my 320 including lots of +p ammo and I have never had an issue with the stock slide release. Something is not kosher in Denmark.

Reactions: 1

gchinsr

· #17 · May 15, 2022

Ooking at your pic of the FCU, the front left ear shows unusual wear. The slide for is way off, causing the damage to the slide release. Hopefully it did not do enough damage, that is not repairable. Frankenbuilds have issue, more often than not.

Reactions: 3

robertchandler58

· #18 · May 15, 2022

Flysart said:
I built this bratty little xcompact during covid, and it won’t behave… advice needed.

Build details: Icarus Precision xcompact grip, Norsso ported reptile slide, barsto ported barrel, DPM recoil rod, trijicon SRO, Wilson combat slide release.

She cycles reliably, and the ported barrel definitely keeps things much flatter and on target than without.

But something must be off, because things keep breaking. First, the OEM (MIM) slide release bent under fire and became unusable. So I replaced it with the higher quality Wilson Combat version. Then, the SRO mounting screws sheared under fire and the optic yeeted off into the range. Still held zero, so there’s a win. So I replaced the screws with titanium aftermarket. So far so good. Finally, today the streamlight mounting screw sheared off under fire, and the light took a similar trajectory to the optic.

I will replace the streamlight mounting kit, but at this point I have to ask: what did I do wrong with this build, that everything is breaking? Is the ported barrel sending recoil force the wrong direction? Or the DPM rod? Or is the aluminum grip transferring too much force into these small parts?

I don’t perceive any insane amount of force that should be overwhelming these parts, but they do keep breaking, so …

Any thoughts?
View attachment 455000
[/QUOlook at

Flysart said:
I built this bratty little xcompact during covid, and it won’t behave… advice needed.

Build details: Icarus Precision xcompact grip, Norsso ported reptile slide, barsto ported barrel, DPM recoil rod, trijicon SRO, Wilson combat slide release.

She cycles reliably, and the ported barrel definitely keeps things much flatter and on target than without.

But something must be off, because things keep breaking. First, the OEM (MIM) slide release bent under fire and became unusable. So I replaced it with the higher quality Wilson Combat version. Then, the SRO mounting screws sheared under fire and the optic yeeted off into the range. Still held zero, so there’s a win. So I replaced the screws with titanium aftermarket. So far so good. Finally, today the streamlight mounting screw sheared off under fire, and the light took a similar trajectory to the optic.

I will replace the streamlight mounting kit, but at this point I have to ask: what did I do wrong with this build, that everything is breaking? Is the ported barrel sending recoil force the wrong direction? Or the DPM rod? Or is the aluminum grip transferring too much force into these small parts?

I don’t perceive any insane amount of force that should be overwhelming these parts, but they do keep breaking, so …

Any thoughts?
View attachment 455000

Look at the barrel I've never had any issues with all OEM parts

Flysart said:
I built this bratty little xcompact during covid, and it won’t behave… advice needed.

Build details: Icarus Precision xcompact grip, Norsso ported reptile slide, barsto ported barrel, DPM recoil rod, trijicon SRO, Wilson combat slide release.

She cycles reliably, and the ported barrel definitely keeps things much flatter and on target than without.

But something must be off, because things keep breaking. First, the OEM (MIM) slide release bent under fire and became unusable. So I replaced it with the higher quality Wilson Combat version. Then, the SRO mounting screws sheared under fire and the optic yeeted off into the range. Still held zero, so there’s a win. So I replaced the screws with titanium aftermarket. So far so good. Finally, today the streamlight mounting screw sheared off under fire, and the light took a similar trajectory to the optic.

I will replace the streamlight mounting kit, but at this point I have to ask: what did I do wrong with this build, that everything is breaking? Is the ported barrel sending recoil force the wrong direction? Or the DPM rod? Or is the aluminum grip transferring too much force into these small parts?

I don’t perceive any insane amount of force that should be overwhelming these parts, but they do keep breaking, so …

Any thoughts?
View attachment 455000

Look at the barrel ported can create issues

Reactions: 1

DBX

· #19 · May 15, 2022

Having read various posts, from various forums, about reliability troubles of different builds, I notice one pattern -- the DPM recoil system seems to be the common denominator. I have zero experience with it, and am just stating what I observed.

I would suggest you try Sig OEM recoil spring assembly.

Reactions: 4

M1A2tanker

· #20 · May 15, 2022

With the shearing, I’d guess extra mass and recoil spring is causing an extra hard slam forward.

Reactions: 1

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