I thought I might start a thread related to issues we face in the shop with M14s.
I'll do a new quick reply whenever I have the chance update.
"Timing"
Timing and point of impact are one of the major considerations for M14 rifles. The timing is critical. Often, a perfectly timed rifle will not shoot point of aim when the front and rear sights are at mechanical zero.
If timing is a few degrees off and you have a unitized gas cylinder, that front band is not going to mate up perfectly with the stock ferrule.
That is why it is critical to not unitize a gas cylinder before you build and test fire.
Barrel timing has many variables. The splines, gas port, shoulder, tenon length, and threads. Here is a tough question to answer though; what is being used in timing as the point of origin "zero origin" Many use the rear sight pocket, and some time off the bottom of the receiver. I have found the internal cylindrical portion of the rear sight ears has the greatest correlation to getting timing right the first time around. A hardened rod is inserted through the rear sight and a v-block machinist level is placed upon the rod. Although the base of the rear sight pocket intuitively seems like the best location for determining alignment, it's the rear sight ear's cylindrical portion that determines how the rear sight lines up.
I'll do a new quick reply whenever I have the chance update.
"Timing"
Timing and point of impact are one of the major considerations for M14 rifles. The timing is critical. Often, a perfectly timed rifle will not shoot point of aim when the front and rear sights are at mechanical zero.
If timing is a few degrees off and you have a unitized gas cylinder, that front band is not going to mate up perfectly with the stock ferrule.
That is why it is critical to not unitize a gas cylinder before you build and test fire.
Barrel timing has many variables. The splines, gas port, shoulder, tenon length, and threads. Here is a tough question to answer though; what is being used in timing as the point of origin "zero origin" Many use the rear sight pocket, and some time off the bottom of the receiver. I have found the internal cylindrical portion of the rear sight ears has the greatest correlation to getting timing right the first time around. A hardened rod is inserted through the rear sight and a v-block machinist level is placed upon the rod. Although the base of the rear sight pocket intuitively seems like the best location for determining alignment, it's the rear sight ear's cylindrical portion that determines how the rear sight lines up.