I have a PST (not used any more) and a Razor (not used for ELR).
I stopped using my PST because at anything past roughly 1k, I started getting eye strain. Since I want to be able to shoot past 1k with everything I've got, the scope now is sitting atop a friend's hunting rifle.
The Razor is a marked improvement over the PST. You will immediately notice the difference. However...
- It still is below other scopes that are maybe 1/2 a price class above it in terms of optical quality. If you can spend up here, spend up.
- While I love the EBR reticles on the Vortex scopes for closer-in work, I do not like a xmas tree reticle for mile+ stuff as the lines can partially obscure splash on low misses, making it harder to self-spot for correction.
- Internal elevation max = 28.5 mil
So... let's talk all things in:
- If you're talking about really stretching things, you want to have as much internal travel on the scope as possible - definitely north of 30 mil. That rules out things like the Razor (and my much beloved Steiner) without having to get some form of external adjustment.
- If you get something like a 300 PRC, you'd need somewhere in the neighborhood of 34+ mils at 2400 yards, and while someone with a 338 LM can give you specifics, you're not too far below that - this is why I shake my head somewhat at people who want to get a 338 LM for ELR. The slower muzzle velocity means it slightly underperforms against big 300s at medium ranges, and performs only marginally better farther out - and it's much more expensive to load/shoot. And I don't get too many ugly looks when I take my 300 to a local range for zeroing, trigger work, etc. but my friend sure does with his 338. You pick up some ability to spot splash, and some wind benefits, but I don't consider those worth the negatives. This is why 338 has never been a consideration for me - go one of the magnum .30 cals, or go bigger - 338 AI (at the minimum), 33XC, any number of 375s - talk about expense! Now I'll duck out of the way as all the 338 LM owners come to their caliber's defense
- At 34ish mils, even the higher end scopes with more travel (Atacr, ZCO), you're right on the edge without having to hold over, which means you're looking well off center of the glass. This impacts clarity. AND you need to match rail/mount elevation to get the max. A 20 moa rail is roughly 6 mil. If you pair it with a 9 mil Spuhr, you're still only at 15 mil total, so you're leaving 2.5 mils on the table. With a 13 mil Spuhr, you'd be unable to zero at 100 (barely).
- This is why people get adjustable mounts (like the Eratac or Ivey) or an optical adjuster like a Charlie Tarac (there's that expense thing again).
So, what scope:
If I had to pick one scope for my 300, it would the NF Atacr 5-25 with the Mil C reticle. 35 mils internal elevation, 5-25 is perfect for a 30 (and more), clean, floating dot reticle, good hold over, very good optical quality, expensive, but it won't break the bank. Note that the 7-35 Atacr has only 29 mils. No need pair it with an Ivey or Eratac adjustable mount if I wanted to go past ~2200 yards because it's a good hold over reticle - easy choice.
For my new 37XC build, I decided on a March Genesis. I haven't mounted it yet, though tempted to put it on my 300 as I wait for all my 37XC parts. We'll see how that plays out.