I agree . but it also depends .
While I like shumway’s book , which is what I learned the basics on many , many years ago , is IMO good , its often time lacking in details that are rather needed .
In this case WHY is the lock bolt canted . All he says is that its for architecture. But what is it that he is really talking about lets take a look at this original Derrick “thanks to the ALR virtual Museum “
Take note of the mortise. Notice how the top of the left hand mortise begins as as a line off of the top of the side flat . As such , both your bolt and side plate must set below that line . This is the architecture he is speaking of .
For the most part this common thought all the different makers . Sometimes you might see that line a little high but its not often .
Also if we look at the lock plate mortise , its also aligns with the top of the opposing side barrel flat
Again this is the architecture Shumway was speaking of in his suggestion on canting the angle of the bolt
Now as to the Depends part .
Shum way in his writings , as do most other writers , assumes you are building from a plank not a
Pre-carve . I know of no books being published about building from pre-carves . that’s Odd because frankly they have issues that are not covered in the books and thus folks struggle through or make very big mistakes . Basically the more you have done for you , the greater your issues can be concerning a pre-carve because in turn you reduce your options .
So in this case you are stuck with your lock inlet . It is where it is and you now have to deal with that .
vs. from a plank you can make planned adjustments like slightly canting the tail of the lock down to help position the rear bolt and help the front bolt clear the RR channel ..
So what to do ?
Well , if you have not noticed yet , most everything in building a rifle is about planning . it’s a game of chess . Not only are you looking at your next move but you also have to look at the effects of that move on everything else . IE everything is linked .
So set back an plan out your lock bolts placement. In doing so realize that the placement of the bolt is then going to effect your side plate and your Ram rod channel .
So the more info we have , the better of we will be .
So here is what I would do if it were me .
Remember back when shumway was talking about drilling the RR hole , he discussed drilling small holes in the bottom of the barrel channel so as to judge the position of the RR .
Drill two in the bottom of the barrel channel . One so that its even with where the front lock bolt will be and one just back of your entry thimble .
Now place the RR in the stock so that its all the way back . Insert a small piece of wire or what have you in the holes tell it touches the RR . that’s the top of your hole . Mark that position on both sides of your stock .
It should be just below your reference line for the bottom of the barrel channel .
Now remove the RR and again insert your wire tell it touches the bottom of your hole . Mark that location on both sides of your stock . Now take a strait edge and draw a line between the upper marks and one between the lower marks . Now you know where the RR channel is . you should have 3 lines on both sides of your stock
top line is the barrel channel . just below that the top of your RR Hole . Just below that , the bottom of the RR hole .
Now with your barrel placed in the stock and clamped so that its fully down in the barrel inlet we then look at the lock plate side of the stock .
Looking at the lock itself , there will be a thick section , back of the pan for you thread your rear lock bolt into. Make a mark in your inlet that corresponds with the position on the lock . Draw you a line all the way around your stock so that it corresponds with that mark in your lock inlet .
Now with your micrometer , measure from that point down to the existing belly “IE where the triggers will eventually set . Take that measurement and transfer it to the left side mortise. IE you now have a vertical line "the line you drew around your stock " and a horizontal line "the measurment to the bottm of the stock "
Double check your measurements.
Do the same thing with the front lock bolt position .
You now know where the lock bolts will come out if your drill strait .
Set back an look at what you have and ask yourself these questions .
A) will the placement place the rear lock bolt low enough to achieve the required architecture of the mortise. If not can the hole be angle slightly ?
Keep in mind that to much angle will then show up as the whole mortise must be at the resulting angle so that the bolt will be flat to the side plate OR the side plat must be brought to that angle . Myself i dont like angling the mortise itself. its just to easy to have to much .
OR can you lower the lock bolt position any at all where it threads into the lock .
DON’T GO TO LOW. You have to keep enough room for the threads to hold properly
B) does the position require the rear of the breach /tang support to be drilled through or notched . If so , make a not of it that .
C) will the front lock bolt go through the RR channel ?
If so where . Is it high low or center ?
It should clear or be high enough that you can file a notch around the bolt so as to clear the RR .
If its center then you might want to seriously consider only using the rear lock bolt . If you want the look of two bolts you can always turn the front bolt into a wood screw .
But it cannot run center through the RR hole .
So now you see the DEPENDS part of my comment . If angling the bolt slightly “within reason “achieves the desired results , then yes I would agree . But if it turns out that its not needed OR the required angle to be to great ,then I would not .
As you can see , by having someone else inlet your lock , it has now confined you to a given position . You no longer have the leeway of setting the lock a little low OR slightly canted so as to help with the bolt positions . . Simple fact maybe that no mater what you do , you may be stuck with the architecture of the mortise’s being a little high . Now some would disagree with me on this but. IMO its less of an issue to have the architeure alittle high then it is to have a majorly canted mortise .
