Chad, by no means have you offended anyone. Simply suggesting there are other meathods to achive results. I have come up with this method, I'm sure others use it, and it is not lapping the bolt in with the cocking piece and sear assembled. I'm kinda suprised you seem to be getting a little testy when someone dosn't completely agree with you.
Now as far as the sear dropping and all the tension goes away. Go dry fire your remi then push down on the rear of the bolt, there is still tension on the bolt pushing it upwards. It's not much but it is there.
Sooo just as the trigger starts to move the bolt is pushed up, both of my lugs contact.
Just a nano second after the sear drops the bolt is still being pushed up, both of my lugs contact.
A nano second after that pressure builds and both of my lugs are still in contact.
All I'm doing is eliminating a possible vibration induced by the bolt being forced to center in the raceway as the top lug slams into the top lug abutment.
Now if your still up on your Trig you can figure out how out of square my bolt face will be with the base of my brass cartrige when in battery. Its less than the distance your top lug is going to have to move to contact the lug abutment.
jmason, I have checked the lug engagement on my rifles with blue dye. If they needed it, I lapped them until I got at least 75% engagement on both lugs. Then spent a lot of time cleaning the compound out until I couldn't see any of it anywhere and had no gritty feeling anywhere on the bolt travel or lockup. I honestly don't know if they needed it or not, but it made me feel better about the safety and accuracy of the rifle. Be sure and have the headspace checked if you do lap them.
Nesikachad said that he does it to satisfy customers and had done it as a quality control measure. This discussion got too complicated for me, but I would definitely be one of those customers who would want it done.
Good thread, both opinions well stated. Tom
Texas State Rifle Association Life Member
NRA Endowment Life Member
A big fast bullet will beat a little fast bullet every time
Just to throw in my two cents and thats about all its worth
I personaly don't see a benifit in going through the effort in lapping the lugs without squaring the bolt face unless one lug is making no contact at all. I just can't get my head around going through all the effort of making a perfect chamber dead strait with the bore then going through all the bells and wistles doing case prep and loading strait ammo then firing it with a bolt face that not holding it square..
I have disscussed this at length with a smith who builds and shoots guns that hold world records. When he builds a factory action he simply cleans out the factory threads with a tap , then lightly laps the lugs with 80 grit compound and thats it !!! he laps the lug by applying pressure on the bolt face with the firing pin assembly removed. This smith builds some damn accurate rifles and swears that the accuracy is in the barrel and chamber and that you could set it off with a hammer and as long as the chamber is strait and the barrel is good then it'll be accurate. Again I just can't get my head around doing a job like that and expecting it to shoot as well as possible.
If I'm the gun plumber doing the job and I'm installing a good barrel I'm gonna make sure that the action is trued to the bolt race way and the bolt lugs (front and back) and the bolt face are true to the bolt body this way everything is making solid contact. Now the only way I can see making both bolt lugs make full contact is to have the bolt body fitting solidly in the rear bridge and the only way to do that is by having a bolt that has full contact top and bottom and this achieved via the "bump" system like Jim Borden is known for and I have never done that so I guess that my rifles are in the group that only has one lug making contact.
I'm not sure that anybodys way is better than anothers but I feel that as long as all possible varibles are eliminated then the chances of the gun shooting are far better
James, I hear ya, I have some customers who see no need for putting money in trueing an action. Some of those guns flat out shoot. I suspect a good barrel and quality fitting go a long way in and of itself. I have seen mauser shoot amazingly well with no other work then a skim cut on the reciever face, go figure.
When someone wants a "blueprinted" action and bolt, and after all surfaces are single point recut, I lap the lugs the way I do knowing that when there lapped in that way the bolt is up in the rear and both lugs contact. If there is .003 bolt clearance at the back reciever ring, that means The bolt is pushed up .0015" from it's true center. When you do the trig for a triangle that is roughly 4" long and raised .0015" and then transfer that angle to a bolt face that is aproxiamatly a 1/2" you end up with a bolt face that is out of square by about .0002" (in a perfect world)
I don't know anyone who is measuring there loaded cartrige runout to the ten thousandths of an inch.
Now spread that angle out to the tips of the lugs, as if they were lapped in to be square with the center of the bolt raceway. With the bolt pushed up in the rear you now have close to a .0004 gap between the top lug and top lug abutment. AND your bolt face is still out by .0002".
I'm just lapping out the .0004" gap between the lug and abutment, Hopfully eliminating one more variable.