Just curious to find out if anybody knows whether Cor-Bon develops their own powders or use commercially available powders in their "Factory Ammunition"?

I'm mainly interested in loads for the 460S&W...

Cor-Bon claim to achieve 2300+ fps using 8 3/8" barreled S&W 460 XVR firing Barnes 200 gr XPB ("Cor-Bon 200 XPB Spitzer")... Best I have achieved using this load and a very maximal charge of Winchester W296/Hodgdon H110 is 2150 fps.... Probably splitting hairs at this velocity but I was just curious... Would love to find a load that could match these claimed factory performances... especially considering factory 460 ammo is not practically "available" here

Most, but not all, factory ammo is done with non-cannister powders not normally available to the general reloading public!
H110 and WW296 are used in some of the factory magnum handgun loads in commercial ammo but this is more the exception than the rule - IMO.
Sometime handloaders can duplicate factory ammo but generally it is not the case.

This is a popular misconception and only true to a limited degree. Commercial grades of most propellants commonly available to the public are blends of two or more production batches of the powder. These batches are blended by the manufacturer to yield specific ballistic performance within a fairly narrow range. This allows the use of any lot of the propellant to be safely used with commercially available loading data. The majority of "Non-canister powders" are nothing more than the original production lot, without blending usually, which is useable by the factories which have a ballistic lab. They determine the performance level (velocity) they want and, if the lot of powder they are using can each the target velocity without exceeding their predetermined pressure limit they will proceed to load the lot of powder.

All "non-canister" means is the burning rate of the lot does not qualify it to be sold to the public packaged in "cannisters". It wouldn't necessarily produce higher pressures, but could just as well give sub-standard performance with "book" loads.

There are exceptions, but the vast majority of powder loaded by the factories is very similar, but not identical to, the same powder sold to reloaders. One of the major exceptions to this was/is a powder kwnon to the trade as "Bullseye 84". This was loaded by the factories (all of them in the U.S.) for many years in the modrate to high intensity cartridges for semi-automatic pistols. Examples are 9mm, 40 S&W, and everything in the same range. Several years ago Alliant decided to standardize this propellant as a canister grade powder and they put it on the market. It has become very popular with handloaders for the same class of cartridges. It is called "Power Pistol". It is, no doubt, still sold to the ammuniion manufacturers as the non-canister grade known as Bullseye 84. I would expect many of the recent introductions by Alliant have a similar history.

To sum it up, there is usually nothing special about propellants loaded by the factories. What is "special" is the ballistic testing equipment that allows them to load to specific parameters with propellant lots which are not sold to the public.

And, yes, contrary to popular myth, a careful, knowledgible, experienced hand loader can usually equal the performance of factory ammunition with similar components. Part of the problem is to know what the actual performance level of the specific load in question is. The vast majority DO NOT give velocity levels anywhere close to to published performance when used in real guns under normal circumstances.

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Gunsmithing since 1961