New KNS pins are a loose fit???

DayneA · #1 02-12-11, 02:54

Since day one have had problems with EXTREMELY loose trigger pins in one of my lowers. After loosing a set of trigger pins I bought some locking DPMS pins. Those were walking back and forth so much that I was fearing wear on my lower so I finally bought a pair of KNS anti rotation pins and just got done installing them. Problem is that fully tightened down, I’m still able to push the entire KNS assembly from side to side on my lower. I can get a fairly sizeable gap, enough for me to slide the edge of the plastic bag the pins came in between the receiver and the side plate. Although this is my first set of KNS pins, I have had some experience with friends guns, and I cant recall ever feeling even the slightest side to side movement from any KNS pins before. It’s not a huge amount of movement side to side but if there is any movement at all it seems like it defeats the purpose of having them. Is it possible that my lower is out of spec, or that I may have received a faulty set of pins???

Iraqgunz · #2 02-12-11, 03:29

Greetings. Please tell us what type of lower you have (make and model). Also, why did you go to KNS pins? They are garbage. Unless your receiver is out of spec, or something is assembled wrong, you shouldn't have a problem with pins walking.

Quote:

Originally Posted by DayneA

Since day one have had problems with EXTREMELY loose trigger pins in one of my lowers. After loosing a set of trigger pins I bought some locking DPMS pins. Those were walking back and forth so much that I was fearing wear on my lower so I finally bought a pair of KNS anti rotation pins and just got done installing them. Problem is that fully tightened down, I’m still able to push the entire KNS assembly from side to side on my lower. I can get a fairly sizeable gap, enough for me to slide the edge of the plastic bag the pins came in between the receiver and the side plate. Although this is my first set of KNS pins, I have had some experience with friends guns, and I cant recall ever feeling even the slightest side to side movement from any KNS pins before. It’s not a huge amount of movement side to side but if there is any movement at all it seems like it defeats the purpose of having them. Is it possible that my lower is out of spec, or that I may have received a faulty set of pins???

DayneA · #3 02-12-11, 03:34

Lower is the Spikes Tactical ST-15, with a timney trigger group (so nothing really to install incorrectly there). Installed the KNS to stop the constant walking around of my trigger pins, but im starting to think I may need to scrap this lower altogether.....

Iraqgunz · #4 02-12-11, 03:40

I believe that I have read elsewhere it is not recommended to use KNS pins with certain triggers- Timney may be one of them.

With a standard trigger and hammer assembly if the pins were walking loose that means that either the lower is out if spec, or it was assembled wrong. That's it.

I would contact Spikes' and address the issue with them. Don't just scrap the lower and take it in the shorts.

Quote:

Originally Posted by DayneA

Lower is the Spikes Tactical ST-15, with a timney trigger group (so nothing really to install incorrectly there). Installed the KNS to stop the constant walking around of my trigger pins, but im starting to think I may need to scrap this lower altogether.....

DayneA · #5 02-12-11, 03:55

Thanks for the advise, I'll look into that stuff a bit more and probably end up calling ST in the morning. Its not totally unbearable the way that it is, I’m just a little obsessive when it comes to my rifles

Iraqgunz · #6 02-12-11, 04:05

Trsut me. The last thing you want is for your trigger to fail. If it isn't right- have them make it right if it is their FUBAR.

Quote:

Originally Posted by DayneA

Thanks for the advise, I'll look into that stuff a bit more and probably end up calling ST in the morning. Its not totally unbearable the way that it is, I’m just a little obsessive when it comes to my rifles

DaBigBR · #7 02-12-11, 05:58

If you have the same issue with standard pins (and you might, since they walked out on you once), you may want to seek out some .155 diameter pins. If you really want KNS pins, they make them in that diameter for out of spec receivers. Otherwise I'm sure there are some .155 standard pins out there as well.

Iraqgunz · #8 02-12-11, 06:00

He already tried .155 diameter pins.

Quote:

Originally Posted by DaBigBR

If you have the same issue with standard pins (and you might, since they walked out on you once), you may want to seek out some .155 diameter pins. If you really want KNS pins, they make them in that diameter for out of spec receivers. Otherwise I'm sure there are some .155 standard pins out there as well.

asme · #9 02-12-11, 06:10

If there were pin-walking issues before you got the KNS pins, then the problem lies with your lower. I had a Stag lower with way oversize pin holes. I could get a drill bit that measured .157 to just fall through. It happens sometimes. They sent me a new one.

Don't stress any further, call up Spikes. They have excellent customer service.

M90A1 · #10 02-12-11, 11:40

Quote:

Originally Posted by DayneA

Lower is the Spikes Tactical ST-15, with a timney trigger group (so nothing really to install incorrectly there). Installed the KNS to stop the constant walking around of my trigger pins, but im starting to think I may need to scrap this lower altogether.....

If you're having problems with pins walking and are using a Timney trigger, you're not installing the trigger according to the instructions. The Timney unit has set screws that tighten against the bottom of the receiver that puts pressure on the pins to keep them from moving. If the set screws are not tightened correctly, there is nothing to keep the pins from moving around. Once those set screws are tightened, the pins have so much pressure on them that they're not going anywhere.

The KNS anti-rotation pins do have some side to side play when installed. This doesn't hurt anything, because they were designed to keep the pins from rotating, not necessarily having a few thousandths of side-to-side play. The play will vary from receiver to receiver, because of tolerances in manufacturing.

mpom · #11 02-12-11, 11:50

Not sure if the OP is saying his original pins were moving side to side vs fitting loosely in lower receiver holes. If the first, this is not the fault of the pins, as they are made long enough to fit lowers of various widths. Sounds like his lower may be narrower on the outside than most, if first scenario. No reason to dump it, if all else is good. Easy enough to shorten pins, original and/or KNS a few thousands off each end and check until satisfied. Will have to shave down the flanges on the KNS pins as well, as they control how close the blackened external "dumbells" or flat logs, get to the lower receiver. Found out from experience...

Mark

M90A1 · #12 02-12-11, 12:13

Quote:

Originally Posted by mpom

Not sure if the OP is saying his original pins were moving side to side vs fitting loosely in lower receiver holes. If the first, this is not the fault of the pins, as they are made long enough to fit lowers of various widths. Sounds like his lower may be narrower on the outside than most, if first scenario. No reason to dump it, if all else is good. Easy enough to shorten pins, original and/or KNS a few thousands off each end and check until satisfied. Will have to shave down the flanges on the KNS pins as well, as they control how close the blackened external "dumbells" or flat logs, get to the lower receiver. Found out from experience...

Mark

Umm, he said they were "walking back and forth". If the set screws in the Timney are tightened correctly, the pins can't move in any direction.

DayneA · #13 02-12-11, 15:20

Quote:

Originally Posted by M90A1

Umm, he said they were "walking back and forth". If the set screws in the Timney are tightened correctly, the pins can't move in any direction.

Set screws are down tight. Timney was installed according to the manufacturers instructions. The screws are locked down super tight and my pins are generally staying semi tight for a few hundred rounds before really starting to loosen up again. i considered the possibility that the timney set screws could be walking out on me, but i dont see how this would be possible with the second set of set screws on top securly tightened down with locktight. After each new trigger pin instalation i have done, ive been carefull to reinstal the trigger again (rolling back the set screws to flush and tightening again once the trigger pins are in). Is it possible that i am still having set screws walk out on me even with all these precautions?

M90A1 · #14 02-12-11, 16:44

Quote:

Originally Posted by DayneA

Set screws are down tight. Timney was installed according to the manufacturers instructions. The screws are locked down super tight and my pins are generally staying semi tight for a few hundred rounds before really starting to loosen up again. i considered the possibility that the timney set screws could be walking out on me, but i dont see how this would be possible with the second set of set screws on top securly tightened down with locktight. After each new trigger pin instalation i have done, ive been carefull to reinstal the trigger again (rolling back the set screws to flush and tightening again once the trigger pins are in). Is it possible that i am still having set screws walk out on me even with all these precautions?

I doubt the set screws are backing out if you're tightening per the instructions. It's more likely that they are losing tension by gradually embedding themselves into the lower receiver. Remove the trigger and check where the set screws locate. Maybe you are actually overtightening them and displacing the aluminum receiver. That said, I can't imagine you ever having a problem using KNS pins and the Timney set screws both. With the KNS parts installed, the Timney screws are redundant anyway.

Why worry about it at all when the KNS pins will solve the walking problem. As I said before, the slight side play in the pins will hurt nothing. They are designed to not rotate, but I doubt if a small amount of side play was a big concern.

markm · #15 02-12-11, 17:40

Weird that aftermarket CRAP wouldn't fit right.

Throw the junk away.

Chaotica · #16 02-12-11, 17:41

Not advising this, but what i would do, if i was concerned with side to side play would be. (personally i would be)

Check the length of the pins without the lock screws while in the lower putting something flat (a straight edge ruler or something small and flat, something solid you know wont move), on one side of the lower with the pin in place to see if it is sitting above on the other side, run my finger to see if i feel an ever so slight difference in the hight of the pin to the lower, if it is sitting above, i would trim the pin slightly, if sitting flush or lower, i would trim the lock screws a tad bit, NOT MUCH!.

If you are uncomfortable or incapable of doing such, then i would advise contacting both KNS and or Spike's about this, or have someone else (with the tools and knowledge) check the specs on the lower and pins.