KS-47 kit build issue FTF

AR-15 » AR Variants

AR Sponsor:

Site Notices

[ARCHIVED THREAD] - KS-47 kit build issue FTF

Posted: 5/27/2021 6:44:58 AM EDT

So here is the issue, I bought 2 of the PSA KS-47 kits, with the upper, lower, and complete BCG. I built one in 9x39 and it runs great with Csspec mags. The other I built with a 7.62x39 KAK carbine length tube 10.5 inch barrel. It does not run great and will not feed from the left side of the mag.

I have tried three metal mags, a Tapco mag, palm, and an AC unity 60 rnd. So far they all do the same thing with a majority of the rounds not feeding from the left side. I have not tried a magpul mag but I will the next time out.

Some times I can get 3 rnds to run with the Ac unity and the palm does not insert in the rear enough for the bolt face to catch the rnd at all.

I have a mutant and it runs these same mags no problem as well as my drums.

So, my question before I start grinding and hacking on this, is has anyone else had this issue and what was your fix?
Is the bolt the issue and maybe PSA mods are not correct on the bolt?

Posted: 5/27/2021 10:36:10 AM EDT

[#1]

Is it catching the round on the left side sometimes, then hitting the feed ramps and stopping, or not catching the round at all? If it catching and jamming, does your barrel have the "trough" feed ramp like our barrel does? Below is a picture of our feedramp. Also, here is a list of magazines that our KS47 is guaranteed to work with. Just trying to give some thoughts.

Magpul AK-47 Pmag
Romanian Stick Magazine
Romanian Drum Magazine
Chinese Drum Magazine
Chinese Stick Magazine
Korean Drum Magazine
Korean Stick Magazine
Yugoslavian Stick Magazine
Bulgarian Stick Magazine
Circle10 Stick Magazine
Hungarian Stick Magazine
Russian Stick Magazine

Posted: 5/27/2021 4:25:55 PM EDT

[#2]

To answer your question first the bolt lug does catch the back of the shell for the first third of travel then slips off on to the side of the round, causing it to jamb in the breach face. No it does not have that trough, I was thinking that is where I might need to start grinding.

Posted: 5/31/2021 11:46:55 AM EDT

[#3]

Quote History

Quoted:
To answer your question first the bolt lug does catch the back of the shell for the first third of travel then slips off on to the side of the round, causing it to jamb in the breach face. No it does not have that trough, I was thinking that is where I might need to start grinding.

View Quote

It seems to be a combo of a magazine and feed ramp issue. I would try the Magpul Gen 2 mags, or any of the ones we recommend. Also, the trough feed ramp is needed to make it run reliably.

Thank you,

Josiah

Posted: 6/2/2021 10:14:50 PM EDT

[#4]

Rgr I will try those suggestions out, don't have time this week maybe next week I will get to grinding.

On another note has anyone tried AK-74 mags in these lowers, I have in mine and they don't seem to want to lock into place, I have not had time to study this and look further into but I will. I was thinking of trying to find a 5.45 barrel and see if I could swap this out to make it run in 5.45.

Posted: 6/13/2021 5:19:20 PM EDT

[#5]

Does anyone know where to find an actual 5.45x39 chambered AR15 barrel?

Posted: 6/15/2021 8:01:42 PM EDT

[#6]

Quote History

Quoted:
Does anyone know where to find an actual 5.45x39 chambered AR15 barrel?

View Quote

Here are a couple places.

AR-15 5.45X39

E.R Shaw 5.45x39 16" Heavy Barrel

AR-74 5.45X39

Posted: 6/15/2021 8:19:27 PM EDT

[#7]

that's it. I am done with PSA.

...making 47's in the USA.

hey do ya think if you get you're production line ramped up you can out manufacture another country? how bout a medium sized one like old Yugoslavia?

goals are good.

Posted: 6/15/2021 9:06:03 PM EDT

[#8]

thanks I will check those out

Posted: 8/13/2021 12:35:38 PM EDT

[#9]

Finally getting time to gt back on this project and will be grinding out the trough today or tomorrow, then function check. I bought 10 magpul mags gen 2 to run with this. not a big deal if I don't get it going as I can use the mags in other stuff and I can just change this to 9x39.

Posted: 8/23/2021 12:52:11 PM EDT

[#10]

I finally got that ground out I just need to test fire, and now stupid ammo panic, this is just dumb

Posted: 9/13/2021 12:56:12 PM EDT

[#11]

I got some loading dies and made some dummy rounds, now that I ground the barrel nut and made the trough, the dummy rounds are cycling without issue from a magpul mag.

Posted: 9/18/2021 11:37:56 PM EDT

[#12]

I got out to shoot this and again it does not seem to load from the right side of the mag.
I used a palm mag and a magpul, I could not get it to cycle more than 4 rounds without a stoppage.
Through out an entire 30 rnd mag it would periodically just over ride the right side round and not load anything.
I also had the mag fall out from recoil.

The one I built in 9x39 functions without a problem but it uses completely different mags.

Maybe the trough I ground out has the wrong angle I still need to do some work on this. Why its not catching the right side round I will have to study that more.
It's possible during recoil it is dropping down just enough to not catch.

Posted: 9/20/2021 12:32:53 PM EDT

[#13]

Here is the magpul jamb issue again feeding from the right side of the mag

Here is the Palm mag again ride side feed. Both mags fit and lock in without issue

Posted: 9/24/2021 6:23:49 PM EDT

[#14]

I test fit and modified an AK74 mag to fit but it was not quite locking in, there is a small gap on each side in the mag well. I am thinking of making a 5.45 upper plus a bolt and seeing if that would run better. or going 5.56 and running Galil mags or 5.56 AK mags.

Posted: 10/9/2021 10:08:19 PM EDT

[#15]

Ok so did some more grinding and I half ass polished the ramp, it’s good enough for steel cases Ammo. I opened the gas port up so I will see how it runs hopefully tomorrow.

Posted: 10/10/2021 6:16:47 PM EDT

[#16]

It is alive! and running without issue 2 30 round mags fired perfectly

Posted: 10/10/2021 8:45:13 PM EDT

[#17]

Quote History

Quoted:
Here is the magpul jamb issue again feeding from the right side of the mag

https://www.ar15.com/media/mediaFiles/58658/A94C9369-BC62-45B1-99DE-415ED5E0A8C6-2098177.jpg

Here is the Palm mag again ride side feed. Both mags fit and lock in without issue

https://www.ar15.com/media/mediaFiles/58658/094A6FA5-3BB7-4CA9-9B78-076BBBA41E9F-2098178.jpg

View Quote

THIS HAS NOTHING TO DO WITH THE FEEDRAMP! Your bolt is over the cartridge rim! Have you tried repeatedly firing 1 round on an empty mag to see if it consistently locks the bolt back? Make sure it's locking back on the bolt not the carrier.
You are either (1) short stroking. (2) cycling to fast, unlikely, but possible. (3) you could have some sort of issue with how the bolt pushes the round off the mag. I don't own an AR that uses AK mags, but you can see if the bolt is stepping rounds.

Posted: 10/10/2021 9:13:48 PM EDT

[#18]

good advice, next time I am out I will test that out and see how far back it goes via slow mo video, thanks. it is cycling but however the KS47 does not have a BHO.

Posted: 10/11/2021 1:19:23 PM EDT

[#19]

on your barrel extension, it looks like the bottom of the bolt is no longer supported, the bottom bolt lugs, kinda hard to tell. If you look at the PSA barrel extension, there's still a little bit of support for that bolt lug.

Attached File

Posted: 10/11/2021 5:42:57 PM EDT

[#20]

might be the angle but I believe the bolt lug is supported by the inner ring, and the teeth hold it into battery. not sure I will keep running it and see what happens. I have more 7.62x39 bolts and one more barrel.

[ARCHIVED THREAD] - KS-47 kit build issue FTF

AR-15 » AR Variants

AR Sponsor:

Warning

Confirm Action

About AR15.COM

Stay Connected

Newsletter

Contact Us