Help with Rear lock bolt issue

[JLayne]

I am working on my second kit build. It's a Chambers Early York Rifle Kit in .40 caliber (my first was a Kibler Colonial kit and everything went smoothly and I had fun, so I decided to step up one more notch on the difficulty scale). Well, today, I used a center to center drilling guide from RE Davis and drilled for the lock bolts and everything appears to have gone smoothly with the drilling and tapping. However, when drilling for the rear lock bolt, I notice that it did not pass through the square bolster at the back of the breech plug. The instructions said the breech plug bolster would need to be notched, but the drill passed through easily, leading me to believe I must have passed just behind the plug bolster. Is this something that will have a negative effect on the rifle's safety and/or accuracy?

Thanks in advance.
Jay

[Eric Krewson]

It is best to drill through the wood first to the lock bolster. I already have a hole in the lock bolster and drill on a drilling spike to make sure I hit my mark, your setup will work just fine.

I have never missed the lug on the breech plug but if you do it is not a problem. You don't want the barrel lug to touch the rear bolt because the repeated recoil from the barrel may cause the bolt to crack the stock, give the bolt plenty of clearance.

A couple of guns ago I had a senior moment and tried to drill through the wood and breechplug at the same time, naturally my drill bit altered its course going through the very  rear of the lug and I didn't come close to my intended target. I patched the hole and did it right the second time marking the lug with my drill bit,removing the barrel and completing the hole in my drill press.

On my last lock bolt I just hit the back of the barrel lug and made a cutout to give the bolt a lot of clearance.

 

[JLayne]

Thank you for the reply. I tried mostly to follow the instructions on Jim Turpin's video, minus using a handheld drill, which I was convinced would lead me to mess up the job. After inletting the lock plate and the side plate, I center punched and drilled #29 holes in the two dimpled positions marked on the side plate while it was off the stock. Then I replaced the side plate, and using a small square, I drew lines from the center of those holes up and over the barrel and down the other side of the lock and lock inlet to mark the front-to back position of the corresponding holes for the lock plate bolts to pass through on the other side. Using calipers, I also measured the thickness of the barrel along this line at the forward lock both, and marked the lock plate accordingly so that I would miss the bottom of the barrel (and hopefully, the ramrod channel) when drilling through the stock.  I then drilled the marked lock plate holes off the stock. After that, with both plates clamped in place, I marked the wood inside the pre-drilled lock and sideplate holes with an awl. I then removed the plates, and used the marks from the awl to drill toward the center of the stock from each side using the center-to-center guide on a drill press. I just got worried when the #29 bit seemed to pass through for the rear bolt holelike butter, because I was expecting the rear bolt to pass through the breech plug bolster. So, I decided to seek a more experienced opinion to see if I had made a serious mistake.

Thanks again for your help.
Jay

[smallpatch]

I assume the barrel is completely inlet, including plug bolster?
Another concern would be touch hole clearing font of the breech plug.

[Daryl Pelfrey]

I do not know that much but in my novice thinking i would be more concerned about liner location than lock bolt going through
 Lug of plug. I read another thread about this and the thoughts of more advanced builders was that the rear lock bolt did not need to go through the lug and actually needed a little clearance from the steel lug to prevent reciil damage. Thats my  .5cent.lol

[JLayne]

Thanks guys. The barrel, plug and tang have all been fully inlet and the barrel pins and tang bolt installed. Using the ramrod to measure, it appears that the scribed line marking the face of the breech plug falls just ever so slightly forward of the center of the pan, so it looks like I will have to file a notch in the breech plug face to channel the powder to the inside of the touch hole. I will be installing a Chambers 1/4-32 white lightning liner.

[frogwalking]

  Warning  Amateur Ahead. 

I assembled one of these kits in .45 some years ago.  I assumed the barrel inlet and lock inlet had been coordinated by the stock carver.  Once the detail inletting was completed, the lock fell a little far to the rear to clear the breech face.  I first widened the recess in the lock pan to try to make the flash hole liner fit.  It was not enough.  I direct drilled a 1/16 inch flash hole.  The resulting ignition was slow and unreliable.  Using a no 50 or 51 drill, I opened the flash hole a little with no appreciable improvement.  I later made a reamer and outside coned the flash hole, then found a more aggressive reamer and still had unacceptable ignition.  I finally drilled, tapped and installed the White Lightnin liner, trimmed the inside of the liner, as part was in the breechplug overlapped it.  Filed a notch in the breechplug face.  The rifle now exhibits fast reliable ignition, and has proven to be an accurate shooter.  The pan is also further to the rear, and thus more authentic than I normally build them.

Go ahead and install the liner and skip a lot of wasted effort.  Look into the breech and trim the liner as required.  I gave the rifle to my son-in-law, who has since killed (killt?) a deer with it with one clean shot.

[Jeff Durnell]

I just got done getting the barrel in place on my Chambers Haines precarve. First thing, laid everything out and found that the barrel needed to go back 1/8 - 3/16" so the touch hole, centered in the pan, would clear the breech plug face. Now it's good, and it also appears the rear lock bolt will be just within the lug of breech plug.

I need to try to think 4 or 5 steps ahead on this thing... usually I'm only good for 2 or 3