Shadow XR920 project. Sight math, optics mounting and other brain damage

[cornstalker]

Inspired by @Biggy I put a Romeo 2 on my XR920. It's huge, but it will be a home defense/field gun so I don't care. I am trying to figure out my strategy for BUIS going forward and would like to sort a couple of things out. The factory sights, measured from the top of the slide, are .280" rear, .255" front. The built-in rear notch in the R2 is .360". As a starting point, should I factor the same .025" offset with the taller sights, or does the height-over-bore difference change the math? (Should I order a .335" front to start?)

Two things I need to figure out before continuing the path. One, am I okay with a front sight that is tall enough to function as an ice axe should I happen to fall into a crevasse? Two, can I find a dovetail blank so I can remove the now useless factory rear sight?

I now have the R2 on my XR920, a HS407CO on the MR920 (my favorite reticle of all), and an EPS Carry on the P365XL. While doing the installations, I noted that the mounting holes on the EPS carry and the R2 appeared to have the same spacing. I was not smart enough to gently attempt to bolt the EPS Carry into the DPP holes in the Shadow optics pocket while everything was apart. Does anyone know for sure if the Holosun "K" bolt spacing is identical to the DPP bolt spacing? If so, I may consider getting an EPS and fitting it with spacers front and rear to enjoy a lower deck height instead of continuing with the R2. ( @JCN )

Gun porn.

[JCN]

@cornstalker the bolt pattern of the K and the DPP and the Romeo3Max / Romeo 1 are the same spacing… BUT….


The boss holes are different so if you have something with bosses they have to be ground down.

I put an RMSx on a DPP cut slide. Also put one on an R3M slide.

[cornstalker]

@JCN
There are no bosses in the Shadow cut. Should be good to go. Thank you.

[cornstalker]

This has been sidelined for quite a while due to just being too busy.
After removing the rear sight and taking careful measurements on the R2, I ordered a .350" plain black front sight from Dawson. I could not get the old front sight off and took it to my gunsmith. He had to wrestle with it enough to make me feel satisfied that it was truly difficult. The front sight hole in the Shadow slide is shaped differently than a standard Glock or it is misshapen. My smith had to do some filing and pounding to make the Dawson sight fit. The sights align with the dot so it should be close, but I have not tested POI with the irons yet.



I picked up a threaded barrel from a member here and a comp from Shadow Systems. At first glance, I thought the comp was a Suarez knock-off, but it actually has what I believe to be a much more sophisticated clamping mechanism. Basically, a tab that is pushed up onto the barrel threads by the set screws. The set screw torque spec is 20-30 inch pounds. I am going to run it with no thread locker on the set screws for a bit to see if they loosen. The instructions say that no thread locker is required, but it is included in the kit.







Here is the hideous beast. I hope to shoot it a little today. It easily fits in my light bearing and G34 length holsters.




Lastly, I picked one of these up when I ordered the comp. I plan to buy an EPS and put it on my MR920.

https://shadowsystemscorp.com/produc...-k-spacer-kit/