Gunsmithing question
 

If you have the lugs lapped on a bolt action, will the headspace change enough to have the barrel set back??

If not, will lapping the lugs have a noticeable effect on accuracy? Now shooting 1 1/2" groups at 100yds. This is acceptable but would like to tighten up by 50%.

Don't have the big $$$ to spend on a complete accuracy package, but would like to start somewhere and eventually get the action totally worked.

Just wondering if it will be money well spent.

Thanks

RE: Gunsmithing question
 

As always it depends. He might have to take upwards of .005" off. Any more than that and you wouldn't be shooting 1.5MOA. And also depends how close to min spec the shoulders are right now. If its near max spec, you bet ya, its going to have to be reheadspaced if he has to take off too much material. But probably, he won't and probably the headspace is in the middle of the range. He can tell you some of this before he starts work with go and no go gauges with spacers and might even be able to give a rough estimate of how even the lugs are now. Lapping the lugs from what I have seen (I haven't performed this myself) is usually polishing and getting that extra .001" of evenness.

RE: Gunsmithing question
 

If you haven't already done so, i'd work on the "bedding" first, starting with the bbl. chanell...

DM

RE: Gunsmithing question
 

Big Country,
Thanks for the reply. I have to call a gunsmith and go from there.

DM,

Thanks for the reply as well. It is a synthetic stock so I hope thats not an issue. I did bed the recoil lug.

I just want ring out more accuracy and think the gun should be capable of what I want (Winchester Model 70 SS).
30.06 with 180gr Nosler Partitions, WLP and 55.5grs of IMR4350

RE: Gunsmithing question
 

Lapping bolt lugs helps but it's usually one of the finishing touches on a rifle that's had a lot of work done on it. Any time I set a barrel back, re-chamber, or re-barrel, I lap the lugs, square up the receiver face, and center the receiver threads. It's a package deal and I would never just do one step.
Yes, it will change your headspace. If lapping removes .001" of lug and recess bearing surface, then your chamber just effectively got .001" deeper.
I agree with DM. Work on other areas first. Bed the receiver and float the barrel. I've never seen this not help. Have the trigger worked. Check the crown. If you're not already using them, switch to a quality scope like Leupold, and use one piece, steel base, with good steel rings.Steel Weaver type bases and rings are good.And of course make sure you're not the reason it's shooting 1.5". Have someone watch you shoot. Watch YOU, not the target. The target can't be coached. You can. 4 fundementals: Steady position, sight picture, breath control, trigger squeeze.And shoot other rifles for comparison.

RE: Gunsmithing question
 

Well you asked several questions, so I'll try my best to answer each one individually:

Q-->"If you have the lugs lapped on a bolt action, will the headspace change enough to have the barrel set back??"

A-->It depends. All you can do is lap the lugs sufficiently then check with go/no go gauges. If it removed enough material to all a the no go guage to close then Yes you will have to set the barrel back.

Q-->If not, will lapping the lugs have a noticeable effect on accuracy? Now shooting 1 1/2" groups at 100yds. This is acceptable but would like to tighten up by 50%."

A--> It depends on what you consider noticeable. 50%? NO! Itsmore ainstrument in an orchestra you have to have all the other instruments in tune as well.

"It is a synthetic stock so I hope thats not an issue. I did bed the recoil lug."

A---> Bedding the lug is insufficient in my mind. I like to pillar bed to relieveall stress. Then completelyglass the action and the first inch of the barrel. Free floating the rest of the barrel.

Also, as a side note the best money youcan spend for accuracy is a custom barrel. Even on an "untrued" action theaccuracy improvements are unbelievable. I've personally seen a gun that shot 1.5 moa go to .75 moa with amatch grade barrel. Now after that we trued the action, lapped the lugs, bedded, freefloated, addedJewel trigger.... Any guess what it shot then...... .5 Moa. Make your own conclussions.

Its kind of like the race car engine game. Getting 500 hp isn't too difficult or expensive. Going up from there gets harder and more expensive for each HP. Getting close to .5 moa is relatively easy and not terribly expensive.Going down from theregets increasingly more expensive and difficult.

RE: Gunsmithing question
 

before you even consider lapping the lugs... determine if they even need lapping... contact area and contact from lug to lug are teh reasons they are lapped....

aside from that... many factors come into play with "accuracy"... i find that most of the time you can significantly cut group size if you work on yourself before you work on the rifle...

My sequence of events on a "new" rifle is making sure everything is "correct" before shooting it, meaning bases and rings are properly installed and tightened and the stock to receiver interface is secure... so on and so forth.... then i generally take osme weight off of the trigger... and go from there...

if you are going to have work done to the rifle... there are a lot of things to do to make it all work together... just lapping lugs won't get you anywhere unless maybe one is touching and the others aren't...

RE: Gunsmithing question
 

Unless there is something obviously wrong with the gun that requires correcting, I would do an extensive amount of load development before I even considered any gunsmithing fixes. Normally, bedding and lapping the barrel would fall above lapping the lugs as a fix. Do you even know if the lugs are bearing unevenly? You might put some magic marker on each lug of the bolt and close the bolt on a case that has been fired in that rifle (not resized). Lugs may already be bearing evenly. Either way, for a hunting rifle I would try a lot of different load combinations before I started tinkering with the gun. Good luck. Roskoe

RE: Gunsmithing question
 

My feelings as well.The easiest way to improve accuracy is with proper load development,trying different powders,bullet stylesand bullet weights..

RE: Gunsmithing question
 

All,

Thanks for the replys. I will save up and have a gunsmith evaluate and go from there. I just feel the rifle should group better than that.

Scope is a Leupold VIII 3.5x10. I did do about 12 different loads varying the weight charges by .5 gr increments using IMR4350 and 4064 4831 using 180 partitions. 55.5 gr of IMR4350 was the best grouping I got. I like that bullet so I will stick with it.

Other rifles: Ruger mkII varmit .223 shoots .500 to .750 all day with handloads, my Ruger MkII .243 shoots around.750 to 1" as well as my 700 .22-250. So I know its not me

Thanks again for all the advice