vanilla,
Sorry it took awhile....but to answer your question in regards to hard LaserCast bullets working okay in your guns.
With revolvers, just take the bullets, and with the gun cylinder open, try and push them through the chambers backwards. They should push in with steady, not hard, thumb pressure. It shouldn't have to take a lot of pushing, or hammering to get them through.
If they push through with slight, or moderate resistance, then they are a good fit for your gun(s).
In semi auto pistols, you'll have to slug your barrel for the proper sizing.
With very hard bullets like you stated, it's far more important to have them properly sized than anything else.
Hook,
Odd .... I load 158 grain MagTech SJSP and the cannelure has a finite width. I can load the round from 1.575 all the way to 1.590, without any problem ... and I do, depending upon the load manual I'm choosing to follow (Alliant shows 1.575", Lyman shows 1.590". I imagine other manuals show other O.A.L. data.
How do you decide ?
The .575-.590 differential will have little affect on the pressure of the load. Some, possibly, but nothing near dangerous unless you were going to run full maximum loads. Small pressure signs might show if you're running on the edge already.
Where you see major differences is when a guy is crimping in the standard crimp groove, then changes to crimping over the front driving band without reducing the load.
Crimped over the front driving band, the bullet is seated far deeper (far more than .015"), and whichever way you desire to crimp, this should be decided upon before building a load around it.
One of the reasons why you probably didn't see a COL/OAL recommendation in this thread is because most cast bullets hinging around the 2400 topic, have a designated crimping groove in them. So, crimping at that point is kind of a given.
Since you mentioned jacketed bullets and OAL decisions with them, my suggestion would be to compare your bullets to any other bullet on the market that has a similar configuration. Take a look at Speer, Hornady, etc.
If your bullet shape has a rounded ogive (radius/profile), then compare it to one that is similar. If you want to go further, you can get your hands on one of those bullets and measure up from the bottom of the bullet base to the bottom of the cannelure. You can also measure the approx. width of the cannelure to see if your crimp point fall's within that distance, but it really shouldn't be all that critical.
The main thing is that if you're running at "maximum", I'd back it down until you can get a decided OAL set to your liking, just to be on the safe side. Once you get a position you like, then if you want to work back up......that'd be fine.
Sierra has a "stepped", or ledged type ogive, and it enters the forcing cone/rifling more abruptly, than a rounded bullet.
If you can find that "similar bullet", use their OAL and try seating one and see where it comes on your bullet's cannalure.
Many of the OAL numbers that you see in manuals (and the variations between bullet manufacturer's) are due to their specific bullet "fitting" in various guns as a priority first, then the loads are built around that. In other words, the OAL length is decided primarily on fitment reasons with their bullet...........then they build the loads for their manual.
I make my own jacketed bullets (when I need one), and I have my own canneluring tool. When I want to build a load using a particular custom bullet, I can either set the round (brass and bullet/OAL) to seat a bullet out near the rifling, or to fit a magazine, etc., then I build the load starting at minimum powder listings for bullets in that weight, or close to it.
I've always heard that a minimum seating depth for a bullet was "as deep, as it's diameter", meaning that your bullet should be seated as deep as .357 as a minimum rule of thumb. I've never checked this because, as like you, I've always used published OAL figures, or made my own with custom bullets. But, it sounds like it'd make sense I guess.
The process of building a proper load all stems around safety if the rules are followed. Anytime you plan to alter any part of the equasion, back it down.
Hope this helps somewhat....
Take care,
Bob