I have had a Delta Gold Cup since the mid 80s and purchased a DW Razorback a few months back. Recently, I completed a "FrankenColt" build. It is an older DE frame, late model DE slide and Kart Para/Clark ramped barrel. Needless to say, I have a newfound interest in 10mm reloading, both for velocity and accuracy.

I am looking for an "Inherently" accurate cast bullet in 10mm. I cast my own and would like some input on favorite molds for accuracy. Seems that .38 Specials and .45 ACPs have 1 or 2 bullets that are inherently accurate, but I don't find that much info on 10mm bullets that show great accuracy when target shooting. As of now, I am only casting Lyman 155gr SWC, but feel sure that there are more accurate cast bullets around.

For those that "cast their own" I would appreciate any advice on weight, style and molds for the most accurate bullets.

Thanks,
Bill

Hello Bill and Welcome to the forum!  I started casting for 10mm early 1990 with the RCBS 175 grain TC SWC and it was very accurate and the ever so slight SWC portion cut clean holes in paper.  From my S&W 1006 these would shoot to 4" and under at 100+ yards (I was younger and eyes of a bird of prey back then).  Since then I purchased the Lyman 175 grain TC and and obsolete Lyman 156 grain Devastator hollow point mold as well as the RCBS 200 grain TC SWC for the heavy hitter.

As a caster you understand the most important thing is bullet fit, I size my 10mm bullets to 0.4015" and currently using While Label Lube's Carnuba Red (RATED AT 2700 FPS) which has shown good properties for my pistols too.  I used to use Rooster Labs Red Zambini lube but that was discontinued sometime back.

Here are my cast bullets...

I appreciate the comments. The 80s Delta Cup slugs out at .4022. The DW slugs at .4015. I have yet to slug the Kart barrel, I had to re-cut the feed ramp to 29 degrees to make for a decent feeding of the Lyman 155 gr. Seems the Kart barrel had a steeper ramp than the DW, so cutting was necessary to feed bullets with wider meplats. I do like the nose shape of your bullets. They all seem to have a slight radius at the edge of the meplat. This should make for good feeding. Looks like your RCBS molds have a, somewhat, SWC nose shape. Do they fly as well as the true truncated nose bullets? I have been eyeballing a couple of Tom's 180gr molds at Accurate Molds. One is a true truncated nose the other has a slight swc shape.

I like White Label Red lube and Randy Rat's TAC X. Being from the south, slightly harder lubes are somewhat necessary, especially in the summer months.

Thanks again,

QuoteThe 80s Delta Cup slugs out at .4022. The DW slugs at .4015.

That's some large bore's for 10mm, and that would make leading an issue with the blow by, and not stabilizing the smaller diameter bullets.   I would have thought that they would have been at 0.4000" even, and I thought I read of some 1911's 10mm barrels being even tighter @ 0.3990".

The slight SWC do fly straight and as I mentioned they help cut a cleaner holes in the paper targets.  That was important with those  who shoot competitions and scoring.  Yes those rounded MEPLATs help prevent feeding issues.

Best shooting bullet out of my 10's are the Lee 175 grain TL.  For bores the size of yours I would not size them at all, and might over "lee-ment" the mold a bit to get some .403" bullets.

That said, I haven't really tested the accuracy of my NOE 200 grain WFN's.  They are plenty accurate for defensive use.

Evidently, the Colt Delta Gold Cup was manufactured during on of those time periods when Colt was having "Issues". I have found quite a few barrel problems in Colt 1911s manufactured in the mid 80s. The DW accuracy is decent, 2-1/2" at 50 yards, when sized to .402 using Lyman #2 alloy. I just figured a heavier bullet may fly a tad better than the 155gr.

The heavier bullet is usually longer having wider bans and as such may stabilize better overall.

I had good results with the Lee 145 SWC and TL175 SWC in both 10mm and 40S&W.

I sold my 175 grain mold because I wanted to conserve lead. Paper doesn't care about power factor.