Perfect,  thank you Shadow!

I've inherited a few boxes of Precision Cast Co. .40 cal cast bullets I'd like to use up.  They weigh in at 148gr, 159gr, 179gr and diameter average .4005.  These will be for plinking bowling pins at a casual club fun shoot from my Colt DE (mild to medium loads are fine).  I'm having trouble finding load data for cast in the 150/160 weights.  Can anyone point me to a reference guide for 10mm cast?
I have not slugged my barrel and want to avoid leading.  Some diameters measured .3995, is this a problem?
I have a variety of powders: Blue dot, Power Pistol, Unique, CFE, but hoped to use Long Shot perhaps.

Anyway, if anyone could recommend where I could go to look for cast data for those lighter weight bullets would be appreciated. (cowboy data??)

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?

Thank you for the website.  I have seen that before but was reluctant as I can't find publish dates.  The 10mm I did see on Amazon was from 2004.  A lot of new components since then...  I emailed the company asking where to find published dates, and will report back here when they respond.

Thank you.  My angle is to not simply accept a manuals recipe, but understand the principals behind it.  It seems the 10mm has such a wide variety of uses, bullet weights, velocities, that the options (compared to other cartridges) are a bit overwhelming.  If I can get a baseline of principals, I will be more confident on load development. 

In reference to my other thread about the Delta's chamber, I am leaning towards a heavier bullet and a slower powder for a more stable and controllable pressure.  Would there be any validity to that?

I'm deciding on a powder for a load work up for 10mm.  I have on hand 135gr Nosler and 155gr Speer JHP.  I have a  large variety of powders to choose from and wondering about a correlation between the light weight bullets and the burn rate of various powders.  Is there a connection as far as rule of thumb? 
When I move to loading 180/200gr, would a slower powder be an advantage?

...Like building a piece of art!

In reference to the Speer data comparison.  For the 180gr Blue Dot data, the DE came in about 4% lower on the start charge and 3% lower on the max charge.  FPS were 5.5% and 9% respectively.  The new data did not have 800X to compare. (per the Speer website)

I see you posted the 180/200gr.  Did they publish any DE data for lighter projectiles?  I have a couple boxes each of  135gr Nosler JHP and 155gr Speer JHP.

Certainly.  And when I looked up those old emails to reply to Shadow, I noticed that each email I sent them he responded inside of an hour.  Gave me some projectile suggestions and more.  I'm glad to see that company grow. 

Thank you for digging that up Shadow! 

I find that interesting and had an email thread back and forth with Underwood back in 2016 about that special Delta loading. 
"The ramp on the barrel was a weak point and brass would bulge excessively at that point. We had a special "Delta Elite" line of 10mm ammunition for people with these ramped barrels. We have since re-engineered all of our 10mm cartridges to be compatible with all 10mm firearms, so this is no longer an issue at all. We still offer that specific loading because a handful of guys just fell in love with that cartridge."
"Luckily we have found a way to fix that and all it took was a little homework on powders and testing."

I will find it interesting as well to compare this data you posted to new current data and see what % down they thought satisfactory for loads.  --Which sort of goes back to my op...are they looking at case pressure or post case/primer condition?

What parameters are suggested for load development in my DE? (circa 2015)  With the stock barrel should I be selecting loads by pressure rating?  This is my first unsupported barrel, and wondering what parameters are chosen as the limitations on this. 
I will not be loading to SwampFox/Underwood velocities, but I would like to get something more than 40SW from it.

I've been reading up on this for quite some time and did tryout some med Blue Dot loads successfully.  I also have on hand Longshot, 800x, and a plethora of other powders.  I'd like to do this in a responsible manner and plan ahead instead of just "case inspection" after the fact.  (I have a chrono and also downloaded the Gordon's Reloading app)