What exactly is done when an action is trued? What is the difference between lapping the lugs and "truing" the action? What are the benefits of a "trued" action? How does it improve the rifle? Smoother operation? Increased accuracy? Is it worth the expense on a hunting rifle?
[This message has been edited by jack2 (edited 01-07-2002).]
I saw a tool on midway.com that you actually apply compounds to and was spring loaded. You rotate the face of the bolt into it. Making your case sit perfectly against the bolt. I could be mistaken, But that is how I interpret it....
SCOUT>
Posts: 2 | Location: Florida | Registered: 08 March 2003
quote:Originally posted by jack2: What exactly is done when an action is trued? What is the difference between lapping the lugs and "truing" the action? What are the benefits of a "trued" action? How does it improve the rifle? Smoother operation? Increased accuracy? Is it worth the expense on a hunting rifle?
[This message has been edited by jack2 (edited 01-07-2002).]
Jack2/ It is like "blueprinting" a motor...you square everything that is supposed to be square...lugs to lug-recess,front of action,threads in action,bottom bedding area in most actions,and the top mounting surfaces on some that need it.....the lugs are fitted and then the face of the bolt is cut to be exactly 90 degrees to bore and the barrel is recut if necessary with threads to mate tightly to the new threads cut/cleaned up in the receiver and chamber is checked for fit and alignment to squared action...some of these aren't necessary for every action and unless you are just after every last hundredth of inch in grouping or shooting 600-1000yd I don't think it is worth doing to a hunting rifle unless the gun has a very bad problem in one area and that one problem can be fixed without doing the total job at a greatly reduced price...but somethings require the other surfaces to be trued to make the one out of spec item align and work well....this is from reading and talking to my gunsmith who farms out this detailed work to smiths set up to do this for match/BR actions as some of the setup is very time consumming and special jigs save a bunch of time and setup.....good luck and good shooting!!!
Posts: 687 | Location: Jackson/Tenn/Madison | Registered: 07 March 2001
Truing or blue printing is a method of truing the threads to the centerline of the receiver. Squaring the lug area and face of the receiver to the centerline of the action. Most of this is done on a lathe. Mansonreamers makes a kit that will allow you to blue print an action. These things are done buy well practiced gunsmiths. Lapping is done after truing. You need 100% contact, between the bolt lugs and receiver. The spring loaded device is used to put pressure on the bolt face. Lapping compound is placed behind the bolt lugs the bolt is slid into place and worked in. If you would like to see this done their is a gunsmith/hobbyist named Steve Acker who has a video you can watch. This will give you an idea of what a gunsmith has to do and why it costs so much. I hope I didn't put you to sleep.
Never have quite understood how lapping the bolt lugs would result in 100% contact with the receiver. I always thought that removal of more material would result in less contact.
Reminds me of my Dad doing renovations on our house when I was growing up...."*#!?#*@ it, I've cut this blasted thing three times and its still too short!!!"
Canuck
Posts: 7121 | Location: The Rock (southern V.I.) | Registered: 27 February 2001
Canuck, The idea is that by lapping you remove the high spots of contact so that eventually the entire lug contacts it's seat. Headspace is necessarily increased but usually not by much. In reality there is probably no difference from a performance standpoint between full contact and 75%. Actions that have been trued to BR specs will have the seats and lugs cut so close to perfect that lapping is probably unnecessary. I usually finish up with just a few cycles using JB as the cutting agent and contact is full. Every gunsmith who purports to build BR level rifle knows or should know how to get the most out of a Remington action. They should, they've had 45 years to figure it out! Apart from slight differences in methodology all do essentially the same things. All other actions may be treated in much the same way allowing for the idiosyncrasies of the particular action. Everything that is done is really a simple matter of using common machine shop practices to accomplish an end. Regards, Bill.
One other thing to consider...you spend a good deal of effort to make reloads that have very little runout and then fire them in an action that isn't "straight" wasted effort.
The big thing is to shoot your rifle first and if it fulfils your expectations you're in good shape...if not, time to spend some money.
Posts: 4360 | Location: Sunny Southern California | Registered: 22 May 2002
Canuck