Jon,
You will need to keep an eye on your headspace measurement when lapping the receiver face/barrel shoulder and especially the bolt lugs.
If done correctly, one can lap the same amount off the receiver/barrel as well as the bolt lugs so that headspace will stay consistant.
You can even slightly tighten your headspace up a bit with these proceedures but you can also increase your headspace if you do not know what your doing creating a dangerous situation.
Also remember that anytime you play with the receiver/shoulder length, your barrel is going to tighten down in a different location then original factory position so your barrel stamping will be off, how much depends on how much metal is removed during lapping.
Really, you should only be looking to take off 0.001" to 0.002" during lapping. If you need to take much more then this off to square things up, you whould really have things squared in a lathe by a smith.
Also, remember that your rifles headspace is set where it was tightened by the factory. Unfortunately, the factories use barrel tighening as a way to adjust headspace dimensions which is the poorest form of workmanship on a rifle.
But this is how it is and Rem can be as bad as any for this. So remember that if you do not get the barrel tightened back to its original point, your headspace may be loose to start with.
One other thing to remember when lapping your bolt lugs, make for **** sure you get all the lapping compound completely out of the bolt and reciever.
If you don't and fire the rifle, even with a minute amount of compound in the bolt or reciever, this compound will blow up into your chamber upon firing and give your chamber a frosted finish, then it will need to be repolished and that should be done on a lathe to do it accurately.
As far as hand tightening your rifle barrel, I would highly recommend you do not do this with a 300 RUM.
BR shooters can get away with this because they shoot small rounds with generally short light target bullets.
The 300 RUM creates enough torque as the bullet is driven down the bore to possibly cause some problems. Get it tight to at least 50 ft/lbs and I perfer 60 ft/lbs on a big game rifle in a round such as this.
The biggest thing is to know your limitations and if you are second guessing any of this work, take it to your accuracy minded smith and let them square up the rifle for you.
I get several rifles a year that have been home accurized and they need to be readjusted to proper headspace.
I am not saying that these things can not be done at home, only that you need to know what your doing to do it correctly and safely.
Good Shooting!!!
Kirby Allen(50)
