21st century lathe setup question

[Jefferson]

you may want to full length resize the cases first,

then neck them back down to a measurement that the mandrel will fit,

then run the mandrel into the case for a snug fit, to test that it works to hold the brass,

then and only then can you start the cutting process

maybe a machinist or a better gunsmith can chime in this was for 6ppc turned to .0005 with lapua brass

Jeff

 

[geraldgee]

It would seem to me that if the cutter was chipped or something loose, it would mark the entire case 360 degrees as it turned on the mandrel into the cutter until it stopped on the shoulder of the mandrel. I am wondering if it isnt related to sizing or lack thereof.

Good luck on getting it solved.

 

[ljmontano]

I see the same thing when necking up 6.5-264, i just load and shoot.

 

[Colnagotex]

I agree with just adjusting enough to kiss the shoulder. I find very few new cases that are perfectly concentric in the shoulder-neck junction and I'm using Palma brass as well. I use a paste lube inside and out and run my drill pretty quick. As you can see I get the same results but it doesn't impact performance and after your first firing will go away.

 

[TerryH]

I get some cases that look like that as well. I'm turning new Lapua cases only. I've checked and double checked everything that has been suggested here. I don't find that that variation on the neck to shoulder cut is any issue. Seem to shoot just fine.

 

[Linko]

Can you wiggle it in the slot by hand?

Yes

 

[Linko]

Is the case locked into the turner and spinning consentrically ?

Case is locked in the holder and the holder pin w/o-ring feels like it seated in the primer pocket.

 

[Linko]

you may want to full length resize the cases first,
Yes i did

then neck them back down to a measurement that the mandrel will fit,
Yes did this also

then run the mandrel into the case for a snug fit, to test that it works to hold the brass,
Ditto did this

then and only then can you start the cutting process

maybe a machinist or a better gunsmith can chime in this was for 6ppc turned to .0005 with lapua brass

Jeff

 

[Linko]

I get some cases that look like that as well. I'm turning new Lapua cases only. I've checked and double checked everything that has been suggested here. I don't find that that variation on the neck to shoulder cut is any issue. Seem to shoot just fine.

Terry, I am also using new Lapua brass.

I may be expecting something that doesn't happen

How much are you cutting off the neck? I am taking .001

 

[dminn1]

Try turning after fire forming.

 

[ranger3]

Also I find that a light oil works best for me, I always fire form and resize before I turn necks. Just how I do it. If the cases are snug, I'd look closely at your cutter.

 

[rocketron]

Take a ready to turn case and place it on the mandrel. Now spin it by hand. Does the case run true or does it wobble? I've had some cases with the wobble and got the bad shoulder cut. It seems as if the neck is not square to the shoulder.

 

[TerryH]

Terry, I am also using new Lapua brass.

I may be expecting something that doesn't happen

How much are you cutting off the neck? I am taking .001

I am turning them to .0135. As stated above, I feel like some of the cases turning out like that is nothing but tiny differences in the shoulder angle on some of the cases and not an issue.

 

[R.Morehouse]

Looks like the brass is a bit crooked. I don't use Cen. 21.....I use the Benchrite and hold the cutter in my hand so it can "float" with the ones the are not strait from the factory. All i use for the most part is Lapua. Shooting them before turning may work with a no turn neck and just doing a clean up pass but it isn't an option for mine. I always go up and back twice with the 2nd being pretty much a tool pressure clean up, they come out much nicer. There is a slight learning curve to it but once you got it, you got it......

Best Regards
Rick

 

[DOGCAPPER]

The amount of mandrel shoulder exposed regulates the shoulder cut by stopping the case mouth.

 

[Petros284]

Linko

Shoot John from 21st an email at john@21stcenturyshooting.com. He will be able to figure out what is going on and get you set up right.

Thanks

 

[Bob L.]

Linko

Shoot John from 21st an email at john@21stcenturyshooting.com. He will be able to figure out what is going on and get you set up right.

Thanks

Could John's reply be posted here as well?

 

[Fotheringill]

Just another potential issue- You are using a power screwdriver and going as slow as you can go. That might be too slow and too slow going from the mouth to the shoulder. You are going to get 100 different maybe's here.

Call 21st Century, ask for tech and stay on the line with them going step by step to analyse the problem and find a solution.

 

[Linko]

Linko

Shoot John from 21st an email at john@21stcenturyshooting.com. He will be able to figure out what is going on and get you set up right.

Thanks

I sent a couple of e-mails but have not had a response from John. I figure he must be busy. I am being patient. I will try calling again. They might have been closed for awhile.

 

[michaeljp65]

I sent a couple of e-mails but have not had a response from John. I figure he must be busy. I am being patient. I will try calling again. They might have been closed for awhile.

They just got back from holidays, probably has a thousand emails to get through.