AZK Brock

Rdias & KS47 troubleshooting , need help

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15 posts in this topic

Posted (edited)

hi everyone I have a brand new psa ks47 gen 2 that I bought for a host for my RDIAS. I had to dremel the inner wall or the receiver to get enough space for it to clear and drop in. Once installed I get very sporadic moments where the trigger actually works to release the hammer. Below is a video I made showing exactly what my issue is 
 

 

if anyone has any idea what might be the fix please let me know..  

Thanks in advance 

Edited by AZK Brock

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Definitely it won't fire in FA if you can't even have the hammer drop.

Well assuming the BCG is not tripping it, it is likely your RDIAS is too far forward. Try shimming the RDIAS backwards, not forwards. Forwards pushes the trip away from the BCG..

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3 hours ago, Ryo said:

Definitely it won't fire in FA if you can't even have the hammer drop.

Well assuming the BCG is not tripping it, it is likely your RDIAS is too far forward. Try shimming the RDIAS backwards, not forwards. Forwards pushes the trip away from the BCG..

For sure, that’s what I’m assuming. The rdias is pretty new to me so I’m still trying to learn. I read the quarterbore website about timing but I’m going to be honest it didn’t make much sense. Any idea where you would shim to move it to the rear? There’s really nothing I can brace the sear body off to push it backwards aside from putting a shim on the rear of the takedown lug to push the whole thing backwards. Is that my only option? I may need to dremel back there more to give it more room to slide back?

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That would be my guess.. but at the same time you need to lock it down so it doesn't move. Remember the back portion of the carrier hits the trip to release the hammer. The timing is just when the bolt goes all the way forward would be the same time the trip releases the trigger. 

I'm not a expert at DIAS, I only have worked with 3rd hole auto sears.

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Posted (edited)

Stop dremeling and take whatever shims are on the rear lug of the upper off. 

Take the upper completely off the lower, turn it upside down, pull the bolt carrier (BC) back just a bit and install the RDIAS on the rear lug of the upper.  Push the BC forward and see how the trip surface of the BC interacts with the RDIAS' trip.  When you push the BC fully home, the trip on the RDIAS should pivot.  You're looking for 2 things:  that the RDIAS trip is tall enough to engage the BC -and- the RDIAS trip pivots fully.  You should be able to see this interaction with the upper upside down and completely off the lower.  If you want to shim the RDIAS for snugness...place a small piece of stainless tape on the back of the rear lug...and nowhere elseWhen you shim the upper's rear lug on the front and / or bottom...you're actually moving the RDIAS trip away from the BC's trip surface.

Contrary to what a lot of folks think...it is the rear lug of the upper which does the proper locating of the RDIAS.  As such, the proper way (IMO) to install a RDIAS is to turn the weapon upside down, pull the rear pin and pivot the lower up and away.  Then...pull the BC slightly back, place the RDIAS on the rear lug of the upper, push the BC closed and pivot the lower receiver down onto the upper and push the pin.

Good luck, give this a try and let us know how it works.

 

Edited by hkg3k

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1 hour ago, hkg3k said:

Stop dremeling and take whatever shims are on the rear lug of the upper off. 

Take the upper completely off the lower, turn it upside down, pull the bolt carrier (BC) back just a bit and install the RDIAS on the rear lug of the upper.  Push the BC forward and see how the trip surface of the BC interacts with the RDIAS' trip.  When you push the BC fully home, the trip on the RDIAS should pivot.  You're looking for 2 things:  that the RDIAS trip is tall enough to engage the BC -and- the RDIAS trip pivots fully.  You should be able to see this interaction with the upper upside down and completely off the lower.  If you want to shim the RDIAS for snugness...place a small piece of stainless tape on the back of the rear lug...and nowhere elseWhen you shim the upper's rear lug on the front and / or bottom...you're actually moving the RDIAS trip away from the BC's trip surface.

Contrary to what a lot of folks think...it is the rear lug of the upper which does the proper locating of the RDIAS.  As such, the proper way (IMO) to install a RDIAS is to turn the weapon upside down, pull the rear pin and pivot the lower up and away.  Then...pull the BC slightly back, place the RDIAS on the rear lug of the upper, push the BC closed and pivot the lower receiver down onto the upper and push the pin.

Good luck, give this a try and let us know how it works.

 

All of this, you don't need the lower to time it.

This is also where QB drill bit comes into play. Put in between the BCG and barrel. Push the bcg forward.  Adjust the sear until it just barely touches the BCG. Wherever that happens to be on the lug, is where the correct timing is.

If it doesn't touch the bcg at that point, you need a new trip

It really is simple.

 

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Posted (edited)

15 hours ago, hkg3k said:

Stop dremeling and take whatever shims are on the rear lug of the upper off. 

Take the upper completely off the lower, turn it upside down, pull the bolt carrier (BC) back just a bit and install the RDIAS on the rear lug of the upper.  Push the BC forward and see how the trip surface of the BC interacts with the RDIAS' trip.  When you push the BC fully home, the trip on the RDIAS should pivot.  You're looking for 2 things:  that the RDIAS trip is tall enough to engage the BC -and- the RDIAS trip pivots fully.  You should be able to see this interaction with the upper upside down and completely off the lower.  If you want to shim the RDIAS for snugness...place a small piece of stainless tape on the back of the rear lug...and nowhere elseWhen you shim the upper's rear lug on the front and / or bottom...you're actually moving the RDIAS trip away from the BC's trip surface.

Contrary to what a lot of folks think...it is the rear lug of the upper which does the proper locating of the RDIAS.  As such, the proper way (IMO) to install a RDIAS is to turn the weapon upside down, pull the rear pin and pivot the lower up and away.  Then...pull the BC slightly back, place the RDIAS on the rear lug of the upper, push the BC closed and pivot the lower receiver down onto the upper and push the pin.

Good luck, give this a try and let us know how it works.

 

is this what you mean? I tried to do what you said and recorded it. It seems to be tripping but didn’t close on the lower in that position, thank you all for pointers I do appreciate it
https://imgur.com/a/fj6UFMP

Edit: bubba got the dremel again lol. I removed some material off the lower in the rear corners so it could get deeper to the rear and a smidge of material from the upper so my sear could sit more flush to the lug and it does seem to be working now. Mostly reliable while hand cycling but still have to do it relatively forcefully compared to my 556 gun which I can get to drop the hammer by hitting the charging hammer to fully seat the bolt. I can’t really test it out as we are in a fireban so no shooting unfortunately. 

Edited by AZK Brock

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Posted (edited)

So it trips now? It sounds like it might work as long as it is not wiggling around. 

I'm also assuming you check the height of the fit of the RDIAS in the lower to meet the upper in the same area.

Edited by Ryo

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2 hours ago, Ryo said:

So it trips now? It sounds like it might work as long as it is not wiggling around. 

I'm also assuming you check the height of the fit of the RDIAS in the lower to meet the upper in the same area.

It seems to trip 95% of the time. I had to order some steel tape to try to get a good fit. I had used some metal rubber backed flashing tape for now. It seems like it will work I can make a video of it now later

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Posted (edited)

Some questions and observations...

Manufacturer of you RDIAS?  Manufacturer of the lower you use for your 556 (which has no issues)?  How is the fit/function/trip pivot (same technique) of your RDIAS to your 556 upper?  RDIAS fit to your 556 lower?  Did you have to "Dremel" out any material of your 556 lower so your RDIAS will fit?

The portion of the trip on your RDIAS which engages the BC is angle-tapered almost to a point...it is thinnest at its very top.  Like this RDIAS

post-1-1190562557.jpg

Most trips are full-thickness and rounded at the top.  This is how the top of the trip is shaped on all my RDIAS'.

post-1-1267033165.jpg

The shimming you've placed at the back of the lug is pretty thick...way thicker than I would've expected.  Also, unless the image(s) or my eyes are playing tricks on me, it appears the rear vertical leg on your RDIAS is a little "splayed"...and canted to the rear.  You have to be careful (even with steel RDIAS') not to force the RDIAS on an oversize or shimmed lug...you can bend that rear vertical leg on the RDIAS outward.  Note how the pocket of the 2nd pictured RDIAS is completely square?...that is ideal IMO.

It appears when your RDIAS is on your KS47 upper (upside down), the trip pivots properly (but maybe not completely?) when you push your BC home.  That's good...but what we don't know is if the pocket in your lower is allowing for a little "drop-down" of the RDIAS when everything is closed and that is giving you some inconsistency.  What you can do is put layers of thick tape or shim material on the bottom of your RDIAS, so that you reach a layer which gives resistance to complete closing and seating the pin.  When that happens, function-check again for improvement.  Doing this ensures the RDIAS is completely engaged vertically with the BC and the gun closed, where you can't visually check.

 I'll take a look at a couple of my RDIAS' tonight, just to take another look at fit to the upper's lugs and how the trips pivot.

You could have a collection of factors stacking up on you here...your RDIAS' trip configuration, how PSA specs their components and their interaction.

EDIT:  I just went back and looked at the your 1st video.  Originally, I thought the "shiny" surfaces on your rear lug was shim material.  Now after I look at it again...it appears it might be where the lug was dremeled?  Did you dremel the lug surfaces?

Edited by hkg3k

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Posted (edited)

 

1 hour ago, hkg3k said:

It appears when your RDIAS is on your KS47 upper (upside down), the trip pivots properly (but maybe not completely?) when you push your BC home.  That's good...but what we don't know is if the pocket in your lower is allowing for a little "drop-down" of the RDIAS when everything is closed and that is giving you some inconsistency.

Yep

He also needs to use a 3/32 drill bit and close it between the chamber and bcg. If the trip is not touching the BCG at that point, then its still not timed correctly. I tried looking at the video to see how far the trip pivots, but its impossible. If its only 95%, then more than likely it not timed perfectly, and the loose pocket are it allowing it to move around, not tripping the sear.

OP most lowers will need to be relived in the rear, unless the dias has been cut appropriately. I just sanded down my dias to fit vs mess with each lower

 

Edited by taylorwso

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With the widening of the lower pocket.. likely you should add material back.. maybe JB Weld? Otherwise you'll need to shim. I'd hate to depend on shimming everything since it will always be dependent on how well you shim and how stable the shim is.

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Guys shims are a thing of the past the lug should hold it in place a little.play is acceptable.  The key is most of the trips are beat to he'll and back and alsonwere made quickly back in the day not much quality control. We had one come in a while back we made a custom trip with a raised surface on it to file down and get the proper timing avoiding any shims.  The other issue is I believe the ks47 enhanced bcg in not to full auto carrier specs. It looks like a fa carrier but if you measure it it's off a little you have to actually pick some weld on and recut the carrier a little forward to be in spec could be the culprit also the bottm trip surface doesnt come down as far as a regular fa carrier on the new 7.62x39 palmetto enhanced carriers.  I know as I set plenty of these up dias for a rll with rll you mill back the surface ws add to it. Below is proof KS47 can be made to work.

 

Hope it helps 

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On 5/12/2022 at 11:34 AM, hkg3k said:

Some questions and observations...

Manufacturer of you RDIAS?  Manufacturer of the lower you use for your 556 (which has no issues)?  How is the fit/function/trip pivot (same technique) of your RDIAS to your 556 upper?  RDIAS fit to your 556 lower?  Did you have to "Dremel" out any material of your 556 lower so your RDIAS will fit?

The portion of the trip on your RDIAS which engages the BC is angle-tapered almost to a point...it is thinnest at its very top.  Like this RDIAS

post-1-1190562557.jpg

Most trips are full-thickness and rounded at the top.  This is how the top of the trip is shaped on all my RDIAS'.

post-1-1267033165.jpg

The shimming you've placed at the back of the lug is pretty thick...way thicker than I would've expected.  Also, unless the image(s) or my eyes are playing tricks on me, it appears the rear vertical leg on your RDIAS is a little "splayed"...and canted to the rear.  You have to be careful (even with steel RDIAS') not to force the RDIAS on an oversize or shimmed lug...you can bend that rear vertical leg on the RDIAS outward.  Note how the pocket of the 2nd pictured RDIAS is completely square?...that is ideal IMO.

It appears when your RDIAS is on your KS47 upper (upside down), the trip pivots properly (but maybe not completely?) when you push your BC home.  That's good...but what we don't know is if the pocket in your lower is allowing for a little "drop-down" of the RDIAS when everything is closed and that is giving you some inconsistency.  What you can do is put layers of thick tape or shim material on the bottom of your RDIAS, so that you reach a layer which gives resistance to complete closing and seating the pin.  When that happens, function-check again for improvement.  Doing this ensures the RDIAS is completely engaged vertically with the BC and the gun closed, where you can't visually check.

 I'll take a look at a couple of my RDIAS' tonight, just to take another look at fit to the upper's lugs and how the trips pivot.

You could have a collection of factors stacking up on you here...your RDIAS' trip configuration, how PSA specs their components and their interaction.

EDIT:  I just went back and looked at the your 1st video.  Originally, I thought the "shiny" surfaces on your rear lug was shim material.  Now after I look at it again...it appears it might be where the lug was dremeled?  Did you dremel the lug surfaces?

Sorry for the late reply I couldn’t get logged into the website and just realized it was because my VPN has been on. My rdias is exactly like the one pictured in the first picture from the HK94 board you posted. It’s also a SWD steel rdias like mine just identical to mine. My 556 setup is a psa upper and Anderson lower. I haven’t found a single lower yet that my sear drops into besides a colt SP1 all others need some minor material relief, even on the upper lug to close the upper fully it seems which is why they they also have been sanded down with a dremel sanding bit. The rear leg of my sear isn’t bent, it’s practically brand new less than 500 rounds it’s whole life, it’s just tapered just like the other SWD sear you pictured.

I really think it’s my trip shape then the fact that I’ve got to hand fit it to each lower. As far as pocket depth on all of them I checked them to my colt SP1 with calipers and they are all very very close to each other in depth  

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On 5/20/2022 at 6:25 AM, JECIII said:

Guys shims are a thing of the past the lug should hold it in place a little.play is acceptable.  The key is most of the trips are beat to he'll and back and alsonwere made quickly back in the day not much quality control. We had one come in a while back we made a custom trip with a raised surface on it to file down and get the proper timing avoiding any shims.  The other issue is I believe the ks47 enhanced bcg in not to full auto carrier specs. It looks like a fa carrier but if you measure it it's off a little you have to actually pick some weld on and recut the carrier a little forward to be in spec could be the culprit also the bottm trip surface doesnt come down as far as a regular fa carrier on the new 7.62x39 palmetto enhanced carriers.  I know as I set plenty of these up dias for a rll with rll you mill back the surface ws add to it. Below is proof KS47 can be made to work.

 

Hope it helps 

Hey, I follow you on YouTube. I did see this video when I checked the bcg with calipers to an m16 bcg length wise where it trips and it was identical I didn’t check depth though. It seems like it will work but only time will tell once they open up shooting in the desert again or if I manage to drive a few hours to a public range 

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