u/BreadDisastrous3066

For context I made a post a week or two ago asking for suggestions for things to try to trouble shoot my issues Ive had getting this ARC frt to work in this gun.

The set up I had for this gun originally was just a kaw valley 10oz buffer weight as well as I trimmed the bolt weight to size.

The issues i was having was I was only getting semi auto fire, OR, if the lever tripped it would get 1-2 bullets and then dead trigger due to light primer strike not setting off the next round. I had noticed that when taken apart and im manually pushing the bolt back to trip the lever (my last post on this sub has a video of this) The lever would not trip anywhere within the whole range of motion of the bolt, at first I thought maybe the buffer weight was preventing the bolt from going back far enough to trip the lever, so i sanded the buffer weight and tested it after each little bit of sanding until the length went from 4.125in to I think its around 3.83in (probably a wee bit too much sanding lol) but at each length there was still no luck getting the lever to trip within the range of the bolt. I was stumped and looking for new information or things to try. I had seen multiple mention firing pin springs and so I tried that. (I tested 3 different springs in total, the stock PSA spring, a Wilson Tactical AR-9 Spring, and the Amazon spring BB9 mentions in his cheat sheet) all of which didnt solve my issue,

BB9 then commented on my last post and provided a link to BoreBuddys arc fire shim for .22.

https://borebuddy.com/product/arc-fire-timing-advance-shim/ is this link

I just got this shim in today and install it and before even shooting it I manually pushed the bolt back and viola! it tripped it, I then was able to assemble the gun and pull the charging handle while holding the trigger in SS mode and it was passing that function check.

I was pumped to go test shoot it as it was the first progress I have seemed to make so far, first test got a 5 bullet burst (biggest I had gotten since i started this build) then followed it with a 2 round burst before getting dead trigger. Cool. its now tripping the lever consistently and the problem now seemed to be something else. After a little messing around I noticed that every time I got good bursts it was after I had already shot a little bit from that magazine. This was notable for me because the last 4-5 bullets to load into the stock 27 rnd mag that came with my gun were very very hard to load and with a full mag my gun even had issues feeding the first bullet.
So I loaded up a new mag fully and began testing this.

First bullet - dead trigger

Charged the handle to eject round with light primer strike - second bullet

I then shot a 2 round burst before dead trigger and then ejected the one with light primer strike - bullets 3 4 and 5

Then I went to shoot again and boom went through the rest of the magazine in burst with relatively no issues.

I loaded my magzine up to 22/27 bullets and right off the bat it start shooting reliably without having to eject any rounds with light primer strike.

I have not tested shooting all 22 rounds it succession yet but between the shim and loading my magazine less I have fixed my issues and my gun in now gunning!

I was just going to reply to the comments in my last post but figured a whole new post would be better for others in my same boat trying to trouble shoot.

So hopefully this can help someone else out and thanks to BB9 for putting me in the know on this shim to help trip the lever a little sooner

I want to start by saying I am brand new to 3D printing all together and all that I have printed before this was a few small ducks just to make sure my printer was working after I swapped the hot end and flashed new firmware.

This SL-9 finished last night and well before it was done I could tell there were gonna be some problems. There is a lot of stringing I believe and I don't think I dried my filament for long enough, the outer layers of the spool seemed to be dry but there's a line in the print showing where the inner (not as dry) layers of the spool started printing and the texture is a bit more rugged.

I did my best cleaning up the print to the best of my ability. The supports (especially the ones closer to the print and in the tighter areas) were quite the challenges to get off and as I'm sure you can see its still not perfect. (ignore the scratches and sanding marks I left lol)

I have not taken any drill bits and cleaned out the holes as it is not worth my time because there's not much more I can do with the print other than learn from it.

A few other more concerning issues I've found with the print is for starters, the magwell is very tight and I have to use a considerable amount of forces to push the magazine all the way into place as well as without the catch, the magazine is just staying in place despite me not touching it (I have sanded the walls inside the magwell like crazy and its not making as difference)

Then another more concerning thing is the back takedown pin section on this 9mm PSA Gen 4 upper, doesent even seat far enough down in the lower to lock together. (I believe this upper and lower are supposed to be compatible, unless I'm wrong). I feels like the whole inside of this lower is just a smidge too small?

Im hoping someone might have the answer to some of my issues im having?

I printed this is PET-CF (before learning its not ideal, I have PA6-CF ordered)

I printed this on a Creality 3 V3 SE with a all metal hotend and .4mm hardened steel nozzle.

I am using Cura Slicer

My print settings are

Layer Height - .2mm

Line Width - .4mm

Outer Wall Line Width - .4mm

Inner Wall Line Width - .5mm

Top/Bottom Line Width - .4mm

Infill Line Width .4mm

Wall Line Count - 3

Top/Bottom layers - 4

Infill Density - 100%

Infill pattern - Lines

Print Temp - 300C

Bed Temp - 85C

Print Speed - 40mm/s

Infill Speed - 40mm/s

Outer Wall Speed 30mm/s

Inner Wall Speed 40mm/s

Top/Bottom Speed 30mm/s

Travel Speed - 180mm/s

Retraction Distance - 1mm

Retraction Speed 30mm/s

Fan speed - 5% after layer 7

Support Z Distance - .1mm

Support X/Y Distance - .6mm

Support interface Thickness .4mm | Density - 100% | Pattern - Lines

If more information is needed let me know. (pictures, settings, etc) Thanks!