21st century expander mandrel diameters?

[Sniper338]

anyone know the exact diameters the 21st century stainless steel expender mandrels are cut to?

I want to order thousandth specific expander mandrels, but need a starting point. I've used the E20 to E33 to set neck tensions before, some are still too tight.

I could measure on calipers, but Im not at home, and would rather have their exact numbers they cut to just to negate any half thou possible hickup...

 

[rwj]

Try this link... http://www.xxicsi.com/caliber-specific-expander-mandrels.html

 

[Petros284]

The standard expander mandrels are turned to .001 below bullet diameter. Thanks!

 

[Sandstorm]

Sniper...are you annealing your brass every firing, and how many X fired are your casse's ?

 

[Ned Ludd]

The 21st Century mandrels are cut in .0005" increments as you will see if you visit the link rwj posted. I have quite a few, and they are spot on to .0005". If you want even thousandth mandrel diameters, that's fine. You can order mandrels of diameter 0.xxx0". However, they may not give you exactly what you're looking for. If you wish to use a mandrel after a bushing die as the final step for neck sizing, you'll need to account for spring-back of the brass. When opening necks up with a mandrel, spring-back will work in the opposite direction than it does when sizing them down with a bushing. For example, if you wish to generate very close to .002" neck tension/interference fit, you need to open the necks up with a mandrel that is only .0015" under bullet diameter because brass spring-back adds the extra .0005" neck tension. Using a mandrel that is .0020" under bullet diameter in this case will give you something more like .0025" neck tension. No worries. You can also order mandrels from 21st Century of diameter 0.xxx5".

 

[Sniper338]

Try this link... http://www.xxicsi.com/caliber-specific-expander-mandrels.html

Yep, that where I'll buy them. Thats not what I asked though.

 

[Sniper338]

Sniper...are you annealing your brass every firing, and how many X fired are your casse's ?

Yes, propane torch. Every batch of brass for every gun is different. I have an amp anealer now though, had it for 2 years haven't used it yet though, just getting back to where I can get into it all again. Had a 2 year delima due to my job. I just know what issues I had when I left off, back to buying things now and been wanting to start using expanders as a last step in sizing.

 

[ppaul]

Have a 21st mandrel marked .263, I get .2626. My mic and my hands.

 

[Sniper338]

I just measured my expander mandrels tonight with my new high end mic I forgot I bought. It ended up dead nuts on with the sizes they make for every caliber so I just ordered 2 expanders each a half thou larger for each caliber. That will get me started. Dropped $1300 tonight with 21st century... expander mandrels, power lathe, concentricity Guage, and drop tube powder funnel with each caliber head... buy once cry once, but they make good shit. I have alot of their products.