I just picked up the CPA Stevens in .40-65. I realize true silhouette shooters usually cast their own bullets and use blackpowder, I am not a true sil. shooter and I plan on using it for fun sil shooting and plugging a pig or deer or two. Any advice on commercially available bullets and any favorite smokeless loads would be appreciated. I see that leadhead bullets does not cast a .40 caliber so that favorite source is out.

Congratulations on your new rifle. I've never owned a CPA 44 1/2 but shot a scheutzen model in 38-55 a couple times. Beautiful well made rifle.
For casual silhouette shooting you can get very good cast (or swedged), pre-lubed bullets from Buffalo arms, Midway, Cabellas, and probably other places as well. They are not cheap...about $20.00 per 50. If your barrel is .410 (some are .408) you can shoot .41 mag pistol bullets (jacketed or cast) in it. They shot ok in my 40-65 but there is no load data anywhere I know of so you have to "wing it". I used light loads of Unique. Also, sometimes you can find the factory jacketed 265g flatnose 40-65 bullet but they are scarce. Have'nt owned a 40-65 for quite a while. Maybe other owners will have current info.

Like Jon alluded to, the biggest challenge is going to be finding out what your barrel mikes out at... I know of a couple of different projectiles that may work for you. One is the NEI 411-275, that has shot very well out of my Pedersoli 40-65. (Unfortunately, I don't remember the load, and it is kind of late this evening to go look...)
The second is the RCBS 40-400 BPS. Out of 1:20 alloy it mikes out at just a bit over .410, which fits the Green Mountain barrel just fine pan lubed. I have shot it with 52 grains of FFF and it shot to 1-1/2" with aperture sights.

I have also been told that the Lyman Snover bullet cast 1:20 shoots very well with 52 grains of Goex Cartridge black.

I have moulds for the first two, and a bunch of the Snovers that were cast up and came with the rifle. If you would like to try some of these before you go spend money on the mould(s), send me a PM. I will send you enough to play with. Then if you like what you see, we can talk. (I am not a commercial caster, but I have been hand casting for a bit over 20 years, and I do good work...)

Lyman sells a cast bullet that weighs about 400 grains called the Snoover. The Lyman bullet is too soft to go very fast, but it come with printed data for about 7 or 8 powders. It is so late I don't have good sense and I just got off a plane but if you will send me a PM tomorrow I will dig out the data.

The 40-65 as now used in BPCR silhouette rifles is a little different than the original round. The original twist is listed in the "Cartridges of the World" at 20 to 26 inches. The twist is now much faster--- usually about at one turn in 16 inches. This makes it capable of shooting the heavier bullets. The original bullets were about .406 diameter. Now they are .408 to .410.
If you look for cast bullets on the web search for .408 and .410 diameters.

Midway has a few bullets from Montana Precision Swaging if you can stand the price.
Meister Bullets has some.
Cast Performance makes both plain base and gas check bullets in .410 diameter for the 41 Magnum. They are lighter weights.
Cabela's also has 2 bullets.
Buffalo Arms
Track of the Wolf

Ireload and all:

Thanks for the advice, I'll check it out. I think (subject to delivery) I found a relatively cheap source of loaded rounds, they probably won't be all that accurate but for close in fun practice they should work well. I'll post the source when I get mine.

If you have the supplements to Pet Loads by Waters, he has an article and data for the 40/65. I shoot the 400gr Lyman out of my Italian Sharps and see no need for anything else. Of course casting has become an all consuming hobby in itsself. I like it!!

Hey Fcat,
Don't do dat. I knew I should not have listed Track of the Wolf.

PMC 40-65.

Unless you specified different or supplied your own barrel to CPA, barrels they use will be nominally .408 (individual barrels may slug a bit bigger). Most .40 barrels are now except for Shilen which for some reason uses the now-obsolete .403. A wide range of appropriate dismete bullets are available from Buffalo Arms. If you desire to shoot jacketed bullets, I believe BA also has something in .408. Hawk makes soft-jacketed bullets in .408. At this point in time in seems saccreligious but when I first got my Shiloh .40-65 and was itching to shoot it, I shot some .410 Remington 210 gr hollowpoints. The charge was, IIRC, 22 gr of 4759. Accuracy from a bench at 100 yds. was on the order of 2 moa with the buckhorn sight.
I now shoot the RCBS 400CSA bullet (over 55 - 57 gr of FFg) but an thinking of giving their 300CSA a try.