I cast for and reload most of the common (and uncommon) handgun calibers except for the 25 acp. About 7 years ago a friend gifted me a new RCBS 25 acp die set and shell holder he owned but decided to never us. I already had once fired 25 acp brass and was looking forward to the day when this project would come together. I bought and loaded some jacketed bullets but really wanted to load my own cast boolits in this caliber. Why? Just because.
My search for a suitable mold gave me frustration at the cost of these, both new and used. I even considered buying a used Lyman 257420 mold and having the base reduced in length to reduce the weight but even used these are fought for and pricey. This thought took me to a mold I already had - a Lyman Perfection 25 caliber mold. This is the nose-pour design with an adjustable stem that can be locked into any length for different weight boolits. My mold is old and pitted outside but clean inside, and functional. With a bit of adjustment I set the stem to drop boolits with a RF nose, driving band, loob groove and base band. As cast boolit weight came in at 45 grains and the bases are flat and smooth. With a bit of time I now have around 350 of these new boolits. Casting them was so much fun I couldn't stop. So far so good, but these dropped from the mold at .259" diameter. Now on to sizing and lubing.
I could not locate a .251" sizing die anywhere and had to consider other means. I started casting many years ago when I bought all of a caster's tools after he decided to get into swaging. Among these tools was a .244 sizing die that I had never used, and never would. This die was was the answer. I used a new 1/4" carbide drill to open up the sizing tunnel to just below the top set of lube vent holes. This was all the depth I needed for this project. Pin gauge (Vermont + set) measurements told the drill work resulted in a new tunnel measuring .248" diameter. Perfect. I used multiple wraps of fine sandpaper to polish this path until stopping at .252" diameter. Now I had a suitable sizer and was ready to reduce the as-cast boolits. Every time I pass a boolit through this die a feel 2 distinct bumps as the bands are reduced. Both bands exit the die round and smooth and the loob groove is even around the base. So far, so good.
My efforts to lube while sizing were not successful as my sizer is located in an unheated garage shop that stays cool this time of year. The lube simply would not flow into the die or boolit. I resolved to use the sizer only to reduce the diameter of these boolits and will make my first entry into tumble loobing. This will be another "first" for me and another learning experience.
Dummy round test time (brass and boolit, no primer or powder). I flared 3 pieces of brass and seated sized boolits in these with the top (driving) band barely visible above the case mouth. The COL of these rounds (.880") is shorter than factory FMJ loads (.900") but longer than is listed for the lighter HP loads (.860"). I gathered 2 of my favorite 25 acp pistols and charged the magazines with the dummies. Every time I drew the slides to the rear and released them the rounds fed up from the magazine, also exited the chamber without issue. Smooth feed-up and extraction are encouraging.
A bit of innovation and effort have brought me satisfaction in this project. Now I will be able to load this caliber ammo with my own boolits. All this reminds me of an old phrase - "Make it work. Wear it out. Make it do, or do without."