DesertTortoise

Is your seating die backed out so that you are not crimping during the testing process? You could be crimping & and crushing the case while seating. It sounds like that's where the problem is happening and it's the most likely error I can think of.

Very nice work Here is mine from a GI Rock Island. I'd like to get the sights machined one day.

I understand that. I've got standard pressure .45 ACP for 1911, 12.5k psi loads .45 acp for my ww1 Webley, and am now looking to load 40k psi .45 acp loads (460 Rowland levels) for a bolt action rifle. I really don't want to mix those up.

I haven't loaded 45 that light, but it looks like they have data from the bullet manufacturer here https://lehighdefense.com/ld-load-data If you end up using another source of data for 135s just remember that solid copper projectiles are longer than similar weight lead bullets so it would be easy to end up with over pressure.

Just a guess but I wonder if the extra mass from the red dot combine with the extra energy from the heavy recoil spring is jolting the hammer off of the sear. You could maybe put in a new sear spring and trigger return spring and see what happens.

DSC gun works does a lot of them. He is fast and affordable too. https://dscgunworks.com/

I did some load work ups with Hornady 68 gr. BTHP in my 18 inch 223 Wylde. So using a similar but not the same bullet. This bullet wasn't anything special for accuracy in my rifle so I didn't buy more when I ran out. If you are looking for a spherical powder, I got good velocity (up to 3000 fps) with Ramshot Tac. Accurate 2200 (spherical, meters well) and Varget (stick) both worked up to 2800 fps.

You can use a single Dillon powder measure for all three calibers. It's fairly easy to adjust and quick to move over to a different tool head. They work very well with spherical type powders.

I have more fun shooting rimfire. It's also the only venue to compete with my .22s.

10-8 performance makes an improved national match rear sight that will fit the military dovetail. For the front sights you can use paint or nail polish to make it more visible. To change front sights you'll need either a wide or narrow tenon replacement depending on which style they used. There is a square hole in the top of the slide, the front sights drops in and then it gets opened in place.

I think Insufficient tension on the disconnector / sear spring can cause hammer follow ?

Try IA Coatings in Houston and let them know what you want to do. They were pretty affordable when I had a pistol refinished.

Before one of my moves I asked a friend who is an explosive ordinance disposal officer about transporting reloading components. His only advice other than the precautions you have already taken (storing in a container that doesn't allow pressure to build if it does burn) was to not let the powder get excessively hot as it becomes more reactive at higher Temps. Probably not a major consideration except in summer.

I'm using the boss hanger with a safariland QLS so I can click in any holster with safariland pattern screws. I have one boss hanger with the safariland adapter and one without. You get more adjustability with the adapter but also more offset. but the QLS plate does work without one.

Try esstac https://esstac.com/shop-all/magazine-pouches/pistols/2011/