please define "pop loads".

A case full of 777 under a 240 grain pill is nothing to sniff at.

A very light, easy shooting load can be assembled with American Select, Green Dot, IMR PB or Unique and 200 grain bullets. At 600-650 fps they are a joy to shoot, and even young'uns will be able to safely and pleasantly shoot with you.

I once loaded 30gr by Vol. of Pyrofake RS under some 265gr jacketed bullets and tried them in my ruger 96/44. They were the true defanition of a "POP" load. A little pop and basically no recoil. I shot them offhand at 20 yards and if memory serves me correctly they grouped around 1.5" @ 20yds. but shot 5-6" higher than hunting loads. I used a .30 M1 case to compress the powder before seating the bullets.

Hope this helps.

Pure lead at that speed will be no problem at all.
777 should not be loaded with a filler according to the directions. True Holy Black can have all the filler you want. I would suggest corn meal as it's cheap, easy to use and find.

You will need to use soft lube (50/50 beeswax & olive oil works fine) in your bullets with real black powder or your fouling will be akin to concrete. NOTE: if you ask 10 black powder cartridge shooters what they use for lube, you will get 10 different answers. For what you are doing the above lube will work fine, you aren't trying to win 1000 yard matches.

You will also need to adjust your powder and cornmeal column under the bullet to give .06" to .2" of compression. No air space allowed under the bullet with Black Powder. Sart with 15 grains of FFg, then corn meal and bullet. add or subtract Black powder as desired and adjust the cornmeal too.

If dicking around with balck powder looks like too much work, and it can be a real PITA, look at the Alliant powder site under Cowboy loads for appropriate smokeless loads. (personally that's what I would do )

Thanks guy, Alliant has some good info, I'll try them first !