First rechamber. Critiques needed. 10 Jan update

[mram10]

Finally used a real barrel. I had a 300rum takeoff I decided to cut and rechamber to a 300wsm.
1. Dialed in the muzzle od in the spider on the left side of the headstock.
2. Dialed in the chamber in the 4 jaw
3. Cut 1.5” off the chamber with a parting tool
4. Cut the shank 1” long x 1.065 to fit the recoil lug. Iscar carbide insert @ 1100rpm.
5. Touched up shoulder and trimmed face to make it .950 and made 45deg chamfer on face
6. MISTAKE: Threaded with cheap insert @ 180rpm. Had to sand threads down to 1.058 to fit the action because I forgot to cut the shank to 1.060 for threading
7. Cut bolt recess with a boring bar. Turned out .706 x .150.
8. Didn’t chamber since I don’t have a go gauge yet. I’ll do that and post pics later.

Forgot my phone while in the shop, so here are just the finished pics.

 

[carlsbad]

If you didn't chamber it yet, why is it not still in the lathe?

 

[mram10]

I won’t have my go gauge for a week and want to practice more.

 

[Cloudrepair]

View attachment 1031292 View attachment 1031288 View attachment 1031290 View attachment 1031291 Finally used a real barrel. I had a 300rum takeoff I decided to cut and rechamber to a 300wsm.
1. Dialed in the muzzle od in the spider on the left side of the headstock.
2. Dialed in the chamber in the 4 jaw
3. Cut 1.5” off the chamber with a parting tool
4. Cut the shank 1” long x 1.065 to fit the recoil lug. Iscar carbide insert @ 1100rpm.
5. Touched up shoulder and trimmed face to make it .950 and made 45deg chamfer on face
6. MISTAKE: Threaded with cheap insert @ 180rpm. Had to sand threads down to 1.058 to fit the action because I forgot to cut the shank to 1.060 for threading
7. Cut bolt recess with a boring bar. Turned out .706 x 1.50.
8. Didn’t chamber since I don’t have a go gauge yet. I’ll do that and post pics later.

Forgot my phone while in the shop, so here are just the finished pics.

How are you dialing in your breach end? Ok I missed that.
Or what method are you using to dial in barrel, throat and muzzle, throat and ahead of throat a couple inches,
In any case I wouldn't dial in off the outside of the muzzle it will not be concentric to the bore.

 

[mram10]

Dialed in muzzle with od. Not best, but don’t have a setup that reaches the rifling. Dialed in the breach with a 1” test indicator(.0005) pushed in the existing chamber.

 

[Dusty Stevens]

keep workin at it you'll get there. try to thread without that relief cut.

 

[Eddie Harren]

Are you sure that bolt recess is ".706 x 1.50"?

 

[mram10]

Thanks Dusty.
Ed, typo. .150 is what it measures. My tolerances aren’t great, but I can’t hold and inch

 

[carlsbad]

So you've been threading with a relief cut, not you've stopped and you have an uneven gouge caused by stopping your feed at various places. This is very hard on your cutting tip and will break carbide inserts. Unless you can disengage at the same point every time, I recommend you go back to the relief cut.

 

[paperpuncher]

Might be the picture but the threads dont look right to me. Looks like they arent 60*in the pic and the root of the thread looks wrong as well. My 2 cents is step back slow down and get the basics down before moving forward. The threads you showed at the end of the other thread looked better put the pointy end of your fishtail in the thread and look closely at the angle.

 

[hogpatrol]

If the breech end is tight and you are moving the muzzle in a spider, all you are doing is bending the barrel. The threads indicate incorrect tool geometry or slop in your machine.

 

[ab_bentley]

If the breech end is tight and you are moving the muzzle in a spider, all you are doing is bending the barrel. The threads indicate incorrect tool geometry or slop in your machine.

To expound, use a pivot point to allow the barrel to move. Give and take on the chuck is still necessary. Even with a pivot point, if you're forcing either end to move, you're running the possibility of inducing flex.

 

[GenePoole]

Looks like there's too much radius on your cutter. Probably not a problem for R700 actions, as they tend to have a lot of flat on the crest of the internal thread, but you'll eventually want to re-cut your action threads as part of a truing job so best to start now. You shouldn't have that problem with inserts at all.

Learn to make a thread without a relief. You can't always count on having room for one. This carries over to internal threads as well. Get a travel dial. Can be as simple as a C-Clamp with an indicator attached. This will allow you to watch the dial for the time for proper pull out with your cutter.

I noticed you say it was cheap inserts. Are you using full or partial profile? Still looks like gummy cuts. is that a SS or CM barrel? CM in my experience will cut gummy looking threads until you get down to the last few tenths on your spring cuts where it will clean up and shine.

 

[Cloudrepair]

Being a new lathe and your using threading inserts it looks like the gibs may need to be tightened up on the compound and cross slide

 

[paperpuncher]

Being a new lathe and your using threading inserts it looks like the gibs may need to be tightened up on the compound and cross slide

Ive been watching this and the other thread and I think something in the setup is not kosher.
Gibb adjustment on the saddle, crosslide or compound
Chuck to backplate bolts secured
Camlock pins adjusted correctly backplate to spindle nose fit correctly
Toolpost properly secured to the compound
Tools securely clamped in toolholder
Check tool height I run mine a hair below center
Just a few random thoughts

 

[Stan Taylor]

A great educational these post are I have been doing my chambers wrong all these years.LOL

 

[hogpatrol]

ACK!!!! A turret lathe!! With a steady rest no less!! Blasphemy. I bet none of those barrels ever shot any good either, right?

 

[hogpatrol]

Ask twenty machinists how to do a job. You'll get twenty different answers and every one is the "best" way.

 

[Haasvf8]

A great educational these post are I have been doing my chambers wrong all these years.LOLView attachment 1031331

What model lathe you running there Stan ?

 

[shortgrass]

Everyone knows you can't chamber on a turret lathe! Doesn't look big enough (the turret) to be #3, but too big to be a #1