I'll give you the information, Larry, but I think you'll agree that it isn't
something you want to tackle in your garage workshop.  The following is taken
(and slightly paraphrased for brevity) from Roy F. Dunlap's _Gunsmithing_,
(Small Arms Technical Publishing Co., 1950):

After suitably preparing the metal parts by sand blasting or other suitable
preparation, the parts are boiled in the parkerizing solution from two to four
hours, watching for the exact color desired.  After boiling, they are rinsed in
cold water, then in hot water, then dried in sawdust, after which they are
heated dry to a temperature at which water dropped on is immediately thrown
off, then dipped in lindseed oil.  The oil is drained off and parts heated
again slightly to dry the oil.

The original Parkerizing process formula is as follows:

     Phosphoric Acid, density 1.5          365 grains
     Manganese Dioxide                22 grains
     Water, add to above to make 1 quart.

Iron filings can be substituted for the manganese dioxide.

The bore should not be exposed to the solution for any reason.  Dunlap
recommends neopreme bore plugs driven in the bore tightly.

Parkerizing should only be applied to _external_ parts and should be kept away
from internal working parts such as springs, screws, bores, etc.

Your best bet would be to have a good gunsmith do the job for you.  Second best
would be to take the prepared parts to a commercial plating shop and let them
do the actual parkerizing.  If you decide to do it yourself, _BE CAREFUL_!
