With all the versatility of the 10mm, I like to experiment with various loads and bullet weights. My Delta has the standard fixed blade rear sight, and I'd like to replace this with an adjustable one. Anyone have any suggestions of what will fit the cut and slide of my DE?
You may want to check with BoMar
As far as I know, this is the only adjustable rear sight on the market for a GI sight cut:
https://www.sightsinc.com/product/combat-carry-adjustable-rear-sight/
It is drift adjustable for windage and twist adjustable for elevation.
To be honest, I was surprised with a google search returned this option as I have never seen anything for the GI cut. It is just accepted, it seems, that you will have your slide milled for a different cut.
You didn't ask, but I am offering my opinion here as well. I would not invest in an adjustable sight. Three reasons.
1. I have not experienced enough change in POA/POI in my shooting for the difference to matter, practically.
2. When testing a load I am more concerned with group size than point of impact. Aim at the same spot, don't care if the group is on that spot or not.
3. In all honesty, I have never adjusted my adjustable sight pistols. And I am pretty confident in milk jug hits out to 100 yards if I have a rest.
Lots of guys swear by them and there is obviously a huge market. I am not saying what should work for you, only what I have found true for me. I certainly would suggest you don't make a decision unless/until you actually have a load that doesn't shoot acceptably to POA.