If there is anyone on this site that is green as grass as far as gun building it is me. For my first gun I am going to build a full stock hawken as well. It will be a 54 caliber, however, it will be a percussion gun. I have done tons of studying and reading on the Hawken. One of my favorite articles I found here:
http://whitemuzzleloading.com/docs-ramblings . However, this is for the half stock. But it will lay out a lot of information for you on a traditional hawken in a short article.
There are several reasons that I chose the full stock, but one of the main reasons is the weight is reduced over the half stocks that I have researched. I have studied many original hawkens on the web. So many folks talk about authenticity, but in my research, these guns were built in a lot of different ways with many different characteristics. I personally feel that first and foremost the Hawken's were running a business. They appear to have used several different butt plates, trigger guards, barrels and locks. I think they used what was available to them on the market at the time. They may have built a lot of the parts in the beginning, but went to buying some parts that were pre-made (from where ever they found them).
Many of the full stock hawkens had stocks made of straight grained maple and cheek pieces were all flat. That is the way that they have been characterized to most of us moderns (as Doc puts it). But I recently came across an original full stock that was made of walnut and had the beaver tail cheek piece. The trigger guard was in the most common scroll style and the loop at the end was almost a perfect round shape like I have seen on the pre 1840 full stocks. It sold at auction for over $48,500.00. Personally, I don't know if it was original, but I would think that someone paying that kind of price for it must have done their homework.
To me that gun was really actractive. So my gun will be made of American black walnut and have the beaver tail cheek piece as well. What I am trying to decide on now is what type of barrel to use. In my readings I have learned that there were straight, tapered and "slightly" swamped barrels used on the hawkens. Straight barrels tend to be muzzle heavy, and the tappered barrels were really not that tapered. For example, the original Bridger hawken was 52 cal. The taper on the barrel was 1.175 at the breech and 1.125 at the muzzle. Carl Walker of GRRW said that kind of taper could be done with a file. Plus, I have read where tapered barrels (if too tapered) can make the muzzle too light and may wave around making it hard to hold on target. So since some had swamped barrels, then why not use one? The gun would be much better ballanced and would remove even more weight. Plus the flared end might be just enough weight to stop the waving.
One other thing that really drives me nuts is getting the lock inletted properly. I have seen tons of of hammers on original and temprorary guns bent over to fit the nipple. So it appears that even the Hawkens had trouble getting "lock geometry" figured out. Many of the full stocks that I have seen seem to line up much better. GRRW even said that the lock plate on the Bridger rifle was "bent" to fit the lock panel. Plus I get to learn how to make a ram rod channel inlet for future long rifles that I would like to build.
Like I said.... I am definitely not an expert at any of this. But I have done my reading and study on these guns. And I feel that you could use quite a few options and still be fairly historically correct. Just my opinion.
Jeff