Just curious, what are you rechambering to 357 Maximum?
I have a CVA Scout rechambered to Max, as well as an MGM 13" Barrel for my G1 Contenders.
I have worked with 1680, LilGun, AA#9, 300MP, and H110 in the 357 Maximum with 180 XTP's. In a G1 Contender you will probably hurt the frame with a very steady diet of loads much over 1900 fps with 180 XTP's. I got to 2000 fps with H110 walking my loads up 1/2 grain at a time. I backed my load back down to 1850 fps. I had three reasons, ONE recoil above 1850 would be a little more than the wife would enjoy. TWO I am pretty sure that 1850 fps loads of H110 will not hurt my G1 Contender frame. THREE would be Brass Life. My 1850 fps load does not loosen up primer pockets or cause any other brass failures with multiple reloadings.
My hunting bullet mold is an NOE 360-180 WFN-GC. This bullet mold has 2 crimp grooves like the 180 XTP. I seated them long just like the 180 XTP to maximize case capacity. I have not worked with them a lot so far. My notes say that I started at 20.0 grains of 300MP for 1790 fps up to 23.0 that averaged 1968. No mention of cratered primers or sticky extraction. This work was done with my MGM barrel, which I believe has a .358 bore. It did not like my lead bullets very well. I got a larger bullet sized die but I have not loaded any of the larger diameter bullets for the MGM so far.
I shot up the remaining cast bullet loads in my Scout with a .357 bore, and it liked them just fine. No idea what I had them loaded with however. I am using White Label "Carnauba Red" in the Lube Grooves, and then Tumble Lubing with Bens Formula Tumble Lube (The Recipe can be found on the Cast Bullet Forum).
I really need to build another Fackler Water Box to test some bullets in. I would be tempted to build one that would use 1 Gallon freezer bags, and do my shooting at 100 yards to get the Impact Speed adjusted for an average deer shot. Using 1 Gallon Bags will give some latitude on alignment at distance. I have the multiplier to convert Water to Ballistic Jell results. It would be good to know just how far bullets penetrate, and what the bullets look like when it ends it's journey.
See You At The Range