Hammer/Trigger Pins in Varying Diameters ???

[August]

Installing a Geissele trigger today got me to thinking about the availability of hammer and trigger pins in varying diameter. It seems that the backlash and "creep" associated with standard triggers might be largely eliminated if the hammer and trigger fit the pins with closer than typical tolerances.

Does anybody supply oversized pins in graduated diameters???

Thanks.

[E53001]

wouldnt making the fitting tighter increase the wear on your components? I thought thats why theres a little bit of play to allow the less than ideal movement to reduce the wear?

[PRGGodfather]

Some manufacturers make oversize pins, and Rock River comes to mind.

Still, it is worthwhile to remember tighter pin tolerances are not a good thing, since the trigger and hammer pins are held in place by the legs of the springs, which are under tension.

Some pin movement is part of the original design, and the risk of making your pin holes larger and out of spec with larger pins is likely not worth any of the perceived benefits.

It would be a great way to ruin an otherwise good lower and egging out the holes.

[mpom]

Brownell's sells slightly oversized pins, but unless you have a lower with worn holes, it makes more sense to use the KNS system of preventing pin rotation, and I believe, pin movement in general, for the most consistent trigger pull and reduced receiver wear. Yes, the hammer spring rotates around the trigger pin and the hammer j spring in the center of the hammer rotates around the hammer pin, but even with non rotating pins, there should be no problems, with a little lube.

MP

[August]

Brownell's sells slightly oversized pins, but unless you have a lower with worn holes, it makes more sense to use the KNS system of preventing pin rotation, and I believe, pin movement in general, for the most consistent trigger pull and reduced receiver wear. Yes, the hammer spring rotates around the trigger pin and the hammer j spring in the center of the hammer rotates around the hammer pin, but even with non rotating pins, there should be no problems, with a little lube.

MP

So, are you saying that your experience is, that by installing KNS gizmos, slop and backlash were eliminated in your FCG??? If so, that is a great piece of information! Please confirm your comment means that you've actually experienced this improvement with KNS pins.

Thank you for your suggestion!!

[mpom]

I need to be precise. I mean the KNS non rotating pins with stabilizing arms can only remove slop and backlash that you may or may not feel, which comes from movement of the pins moving in holes slightly larger than the pins themselves. You will ONLY notice this movement if you have a relatively clean and crisp trigger pull to begin with. I doubt you will notice any benefit in trigger pull with the KNS system in a stock GI setup, with its long pull, due to large engagement areas and camming action.
I went with the KNS system after installing and adjusting a JP FCG, to eliminate any possible creep or backlash from pin movement, as well as possible wear to the receiver holes (aluminum vs steel pins). Ended up with a very crisp 4 lb pull, and short reset. I did not check the OEM hammer and trigger to see if the original pins were a sloppy fit in them, but there is no play in the JP FCG and the pins, outside of the receiver.
A downside to the KNS system is slow takedown of the FCG, requiring Allen wrenches. I keep the proper Allen wrenches and 2 standard pins in my MIAD grip, should this become necessary; popped primer jamming FCG.
Since you are installing the Geissele, I would think you might notice a difference in the trigger pull, but only if the stock pins have any motion in the holes other than rotation or coaxial slide. Never seen a Geissele, but guess the pin holes are only .001" larger than the pins, if that.
Is the KNS system necessary? Hardly, but I like it so far.
MP