Gunsmithing Just have one of those days

[Rhys]

everything was going totaly smooth. Barrel dialed in to less than .00025 in just a couple minutes, chamber cut beautifully, shank and threads going good and clean. Checked the fit, just a bit snug one more pas on the threads of about .002 should take care of it. Missed the cog on the half nut and took the tops of the thread right off. Oh well, still have enough barrel shank to redo it thankfully just have to reposition it prior to cutting the new set of threads.

If you don't screw something up once in a while yer not doing anything.

 

[300sniper]

Re: Just have one of those days

you cut your chamber before the threads? what is your reason for that?

 

[Rhys]

Re: Just have one of those days

Something I've been doing for a while. I figure the sooner I cut the chamber after getting the bore indicated in the less chance for something to get out of alignment. Also I can cut the chamber just slightly deep, measure that depth, and make cleanup cut to bring the face of the barrel to that exact point. Then I can cut the tennon exactly where it needs to be and end up with headspace right at minimum without having to check and adjust until the chamber is within tollerance.

I also cut my threads going away from the headstock by turning the tool over and running in reverse. This allows me to cut threads at a much higher without any concern of crashing into the chuck. The higher speed gives a better surface finish. I've done probably the past 20 this way and the results have been great. This is the first one I've screwed the threads up on doing it this way. I'll probably back the speed off to the 900 RPM range to avoid it again. I've been cutting them at about 1300.

 

[x ring accuracy]

Re: Just have one of those days

Many good smiths cut chambers first. Anyway, sorry for your tough luck, thats why I thread first for disasters like yours : (. I am usually comfy chambering, but the dreaded threading crash is my worst nightmare. Did you back off the thread cutter too far? I have seen that done where they back the bit off .100 and wind up hitting the previous thread? Just a thought. Good luck.

 

[300sniper]

Re: Just have one of those days

i like the idea of threading first and timing the shoulder so the muzzle high spot is facing up, then cutting the chamber. i'm still learning so i like to ask why people do what they do.

 

[Rhys]

Re: Just have one of those days

I've tried the idea of timing it so the muzzle was going straight up, and took that same barrel and indexed it over another 90 degrees. I didn't realy see any difference. Still shot centered for windage so I don't worry to much about it now. By cutting the chamber first I'm not trying to chase that last .005-.010. I take it just a bit deep, and then bring everything else to match. Gives a known repeatable point, and actualy saves me time as I'm working with only one set of calculations.

 

[Rhys]

Re: Just have one of those days

Keydiver,

The problem came in that I finaly missed the exact engagement of the halfnut so the cutter wasn't in the exact same tool path. It doesn't take much to ruin the threads. No issue with crashing into anything using my method, just need to go back to threading at about 900 rather than 1300, and won't have the issues. I just got a bit to comfortable with my method and it finaly bit me because I was pushing it to much.

 

[Hateca]

Re: Just have one of those days

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rhys</div><div class="ubbcode-body">I've tried the idea of timing it so the muzzle was going straight up, and took that same barrel and indexed it over another 90 degrees. I didn't realy see any difference. Still shot centered for windage so I don't worry to much about it now. By cutting the chamber first I'm not trying to chase that last .005-.010. I take it just a bit deep, and then bring everything else to match. Gives a known repeatable point, and actualy saves me time as I'm working with only one set of calculations. </div></div>

That's great for that one barrel, but all barrels are not the same. You can have bore run-out that if not timed to the action the run-out can and will cause you issues with running out of scope adjustment, or the barrel not running down the stock barrel channel straight making the barrel look crooked, not to mention timing barrel fluting.

I to have seen barrels with very little run-out and not had to worry about barrel timing but those were far and in-between.

Are you indicating just the chamber end (or the end you are working on) before cutting or are you indicated both ends true before cutting?

I to cut chambers last, but there's more then one way to skin a cat and if you are comfortable with it and your customers are happy then you have no problems.

 

[Rhys]

Re: Just have one of those days

Supprisingly maybe 5% of the barrels I do are fluted. I indicate in the first couple inches of the end I'm working on. When I goet one that is way out I can time it up, but most of the barrels I've been using have at worst .015 out from one end to the other. I have hit a couple tht were .030+ and those were timed. When said the shots still went to center the shots were going within 2 minutes on windage. If that amount of wind determines if the scope is going to run out of adjustment the equipment is being pushed well beyond where the system as a whole was intended to work.

 

[Hateca]

Re: Just have one of those days

2" at 100 yards = 20" at 1000 yards, but like I said if what works for someone and they are happy then all is good.