Mounting Holosun EPS Carry on a SIG P365 series - lets consolidate tech data

[RAM Engineer]

Since this is a pretty popular combo, AND because I just bought both, I had some questions before I proceeded to mount the optic. Not easy to find the straight info on here. SO, why don't we consolidate that info here?

1. What size bit to remove the factory P365 optic cover plate? - Torx T10
2. Optic riser plate or no riser plate for EPS Carry (using stock sights)?
3. What size screw for optic with riser plate? Without riser plate? - w/ Plate: , no Plate: M3 x 10MM FH
4. What torque for optic mount screws?
5. Recommended thread-locking compound? - Loctite 242 (blue)
6. What size screw for battery compartment?
7. Preferred/Recommended 1620 batteries?

[centex]

Since this is a pretty popular combo, AND because I just bought both, I had some questions before I proceeded to mount the optic. Not easy to find the straight info on here. SO, why don't we consolidate that info here?

1. What size bit to remove the factory P365 optic cover plate? - Torx T10
2. Optic riser plate or no riser plate for EPS Carry (using stock sights)?
3. What size screw for optic with riser plate? Without riser plate? - w/ Plate: , no Plate: M3 x 10MM FH
4. What torque for optic mount screws?
5. Recommended thread-locking compound? - Loctite 242 (blue)
6. What size screw for battery compartment?
7. Preferred/Recommended 1620 batteries?

Timely for me as I have a fresh 365x and an EPS Carry that need to be mated. Below was my plan, based on several 365xl to 507k installs:

1 - Torx T10
2 - no plate
3 - M3 x 0.5mm x 8mm flat head screws
4 - 15 in lbs (I error on a touch less than more using my analog Wheeler Fat Wrench)
5 - Loctite 248 (the blue "glue stick" Loctite)
6 - no answer, but interested to find out. I haven't yet had to replace one. Screw gets a bit of 248 as well for me.
7 - Duracell


Clean all surfaces with a degreaser prior to install, to include the screws before Loctite, and let cure for 24+ hours before use.


Will wait for more responses to this thread in case I'm not as squared away as I think before moving forward.

[RAM Engineer]

2 - no plate
3 - M3 x 0.5mm x 8mm flat head screws

Interesting about your choice of 8mm for a no-plate install. I think I've only ever heard of 10mm for no-plate, and 12mm for with plate.

[centex]

Interesting about your choice of 8mm for a no-plate install. I think I've only ever heard of 10mm for no-plate, and 12mm for with plate.

The 8mm length was based on some threads here and on the GenPop Sig forum. I have boxes of 6mm, 8mm, and 10mm from McMaster-Carr so if the hive mind here says 10mm I'm covered.

[RAM Engineer]

Basically what we need is a SIG P365 version of the stickied thread "Glock MOS RDS install thread (What has worked for me)", with the drastic increase in popularity of the P365 series guns.

[RJ]

Interesting about your choice of 8mm for a no-plate install. I think I've only ever heard of 10mm for no-plate, and 12mm for with plate.

It may be an old (captive rear sight) or new (dovetail rear sight) style slide thing?

I used 10mm McM-C screws for my old style P365XL slide, without a plate, EPS Carry install last year.

[RAM Engineer]

@GJM and @G19Fan you guys have lots of these guns and optics. Any info you can share?

[RJ]

1 - Torx T10
2 - no plate
3 - M3 x 0.5mm x 10mm flat head screws from McMaster-Carr, Part no. https://www.mcmaster.com/catalog/130/3479/94414A714
4 - 15 in lbs, Wheeler FAT wrench
5 - Blue threadlocker
6 - M2.5x0.45x5 mm https://www.mcmaster.com/catalog/91698A241 (per @Clusterfrack)
7 - Duracell CR 1620 https://a.co/d/byQkJNg
8 - Special note: Above is for an old style (captive rear sight) P365XL slide

[GJM]

Some people have reported issues with the supplied Holosun EPS Carry screws being a smidge long on some 365 slides. I believe those were the older slides that had the rear sight integral to the cover plate you remove to install the optic. Clusterfrack figured out the McMaster screws of the proper length, and I show those as M3 0.5 x 10mm Torx Plus flat head, part 384-0310-01-0100.

Biggest issue I have with the EPS Carry is the + and - buttons are so close, that if you grab the optic to work the slide, you can inadvertently turn the optic off. Putting it in lock out mode prevents that, at the cost of making dot intensity adjustments slower. I don't use lock out mode, but don't grab the optic to work the slide.

[RAM Engineer]

Clusterfrack figured out the McMaster screws of the proper length, and I show those as M3 0.5 x 10mm Torx Plus flat head, part 384-0310-01-0100.

That is for the current, separate sight and plate setup?