Since I imagine a few guys will use Boyd's stocks, I figured I'd post a few pointers about them in general.
For starters, I have not ever had good luck with their rear hand guards. I typically burn them for firewood. Maybe you will have better luck with those, but I just get a good used GI one and refurbish it. The Boyd's ones are inlet too much under the knox form and don't give a snug fit, they tend to move side to side. They are too big on the outside dimensions, but that can be corrected by sanding. The biggest problem is virtually always they take too much wood off where the clip goes, so the clip does not push the handguard down firm enough on the barrel. To fix this, you would have to shim or bed the handguard clip, which is not an ideal fix. IMHO, get a GI rear hanguard, you can still get new-in-wrap ones on e-bay.
The front hand guards generally are OK in my experience, though I usually have to sand off a bit of the tongues on either end to get the HG to set fully into the barrel ferrule and to seat the front ferule cap fully. Sometimes I have to bend in the rear tabs on the spacer to get a tight fit as Boyd's sometimes inlets the tab area too deeply at the back of the handguard. I also use an old rusty front sheet metal ferule and an old rear ferrule as a guide and sand down the outside of the front handguard until it's just proud of the ferrules. Boyd's ships these left too bulky everywhere and it looks better if you put the HG on a diet.
The real art to fitting a Boyd's stock is all in the buttstock, so that's where I'll focus. ALWAYS fit the barrelled action first, THEN fit the trigger group, and lastly fit the front stock ferule. Always in this order.
First thing you'll notice is that if you can get your action legs to slide in (sometimes the inletting is too tight). If it is, it's usually obvious that there's a ridge or step that was machined a little off and you should flat file this flush with a medium bastard file.
Set the STRIPPED barrelled action in the stock and check to see if the barrel is lined up with the inletted "U-channel" up by the front tip of the stock. In all likelihood, it won't be centred. You will have to remove a small amount of material from opposite corners of the receiver leg inlet until the barrel is centred and aligned with the channel. For this operation, do not use files. You can't get a file into the tight corners where material has to be removed. Instead, use a SHARP good quality 1/4" woodworking chisel or an insetting scraper tool. On the example stock, I had to remove a little material (about 5 thou per corner) in these two locations to get my barrelled action centred and aligned in the stock.
Once the action is aligned longitudinally, you then have to make sure it's seating all the way down on the receiver ledge. I got lucky on this stock in that it was machined well enough I didn't have to adjust it, but most of the time, I have to tweak things. The very back shelf needs to be flatly contacting the receiver heel. Then there needs to be a small gap, enough to fit a business card into, between the rear shelf and the angled area of the stock machined at an angle to accommodate the operating rod shelf on the receiver.
While I'm working here, you'll notice that Boyd's machines the rearmost part of the receiver inlet with a ball cutter and leaves it round. It may clear your bolt, but almost certainly your firing pin will batter this part of the stock. I chisel the rounded profile at the bottom of the routed inlet back further until it totally clears the bolt in the rearward position. Insert your assembled bolt in the receiver and check the clearance. Keep chiseling back until you have clearance.
If you look at a GI stock, you will also see that rear of the operating rod shelf, the stock tapers inward. Boyd's doesn't machine this taper into their stocks, but I always file it in. It makes the stock look more GI and less bulky. You can make it out in the below pic at the bottom of the photo.
Now install your clip latch and check to see if it clears the clip latch inlet when the barrelled action is in the stock. It did not on this stock, it was binding at the front pard of the inlet. I used a small sanding wheel in a dremel tool (the only thing I ever use a dremel for on an M1 stock fitting job) to shape the inlet forward a little. It's not obvious, but it's now stretched a couple mm's and no longer binds. The pencil points at the relieved area.
At this stage, you may realize that your barrel is touching or getting close to touching the stock up at the tip (see where the pencil is pointing). Boyd's leaves this corner sharp. I always add a bevel with a sanding block on each side. The pencil points to that bevel. I recommend you add this relief. GI stocks all had it, and ones you properly fit the front stock ferule, your barrel may touch this area after the gun heats up while shooting. If it touches the stock here, accuracy will suffer.
Now we move to the trigger group. First thing you'll note is Boyd's only inlets for stamped trigger guards. GI stocks were interchangeable, so even if you had a stamped TG, the stocks were all inlet to accept the milled trigger guard. I ALWAYS add the dish cut for a milled trigger guard with a sharp chisel when I set up a Boyd's stock, just in case yo never want to swap in a milled guard. It looks like this.
Now set you stripped trigger housing with only the trigger guard installed into your stock. In all likelihood, you will see the rearmost part of the housing touching the wood here. You need to use a charm 45 degree cornering chisel to relieve the wood so that the trigger guard isn't pushing here. this could cause your stock to split under recoil. the receiver and trigger housing are monolithic when the gun is assembled and you only want the barrelled action to bear on the vertical shelfs that push on the rear legs of the receiver, not any place on the trigger guard.
The pencil points to where you remove wood.
Next, apply a little inletting black to the back side of the magazine baseplate on the trigger housing and on the parts of the trigger guard that are up inside the stock when assembled. Lock up the trigger group, then remove it again. You will probably see inletting black transferred to these two areas of the stock, and you need to carefully re-shape them back until you no longer see any contact.
Now you need to install the barrel ferule, gas cylinder, and the operating rod on the barrelled receiver. Put inletting black all along the bottom of the operating rod and place the the action in the wood. and lock up the trigger housing. Run the rod back and forth a little and disassemble. You will see that the operating rod is binding on the operating rod relief cut shelf, probably on two surfaces, and it may also be rubbing in the bottom of the stock channel. Use a file and draw-file the operating rod relief cut ledge and inner bevel until it no long rinds and transfers inletting black. These are the two surfaces where it will certainly be rubbing out of the box:
Next, try to install the ferule on the buttstock tip. It likely will sit too high. when fitted properly, it should be flush at the bottom of the inletting with the wooden channel. It should not be appreciably proud. It will be though, since Boyd's doesn't do a great job of machining the tongue in the right place.
I use chisels to remove a little wood at the top of the ears and bottom of the channel on the tongue to get the ferrule to seat low enough. On some stocks there's enough meat that the ferule will still grab when it's set down. On other stocks, I file the bottom of the tongue flat and epoxy on a small block of black walnut and re-shape the patched area to fit the ferrule such that it will snug up again. If you get it down flush, you SHOULD get adequate down pressure on the barrel ferrule from the tip of the stock. The stock, when the trigger group is latched in, should pull down on the barrel with about 3# (give or take) of source by virtue of the stock ferule pulling down inside the barrel ferrule.
If the semicircular lip on the front of the stock ferule is worn or undersized, you might still not get this downward pressure and the stock tip might sit too high in the barrel ferule. If this happens, you can carefully flare the topmost tips of the lip outward a little to increase the diameter of the lip. This should get the stock tip to push down as it's supposed to.
Now is the time to re-assemble and check everything with the tilt test. There are other tweaks that might become necessary or evident, but I find these are the most common ones. Hope that's helpful to some of you.
One other note, Boyd's leaves their stocks too fat, especially in the forward portion of the buttstock were it necks down to the stop ferule. I usually draw-sand this part of the stock with an 80 grit sanding block and then finish to 180 grit before oiling the wood. It helps to have a GI stock to copy, but the finished product is much better if you thin the stock out where needed to match a GI contour.