Mandrel die came in today and I tried it

[6pakzak]

Got my Sinclair mandrel die in with .223 size mandrel, loaded up some ammo for AR-15 using lake city brass I had around. I body sized with Redding die, neck sized with LCD, and then put through mandrel die, made 25 rounds, worst runout out of whole batch was .0015, almost all the others were .001 or under, about 10 under .0005, these are definitely the best numbers I got out of this brass, I was happy to keep this brass under .002 before which is right around we're it was. I also checked the neck runout after LCD and noticed it improved after mandrel die which explains the better numbers, so far looks like money well spent, got the idea from you guys, this place will help you get better.

 

[6pakzak]

Well since I posted last post I loaded up another 20 rounds with PMC brass I had saved, still runout .001 for most but about 7 breaking .0005 and no surprises with big runout, starting to feel like I can't make a bad bullet.

 

[atkins0331]

Nice. Always to learn a new trick

 

[6pakzak]

My goal is to make the best ammo I can without neck turning since I have no customs, this 223 round has been a challenge to keep them straight, much easier with 6.5 but now they are staying straight consistently

 

[6pakzak]

People say runout doesn't matter and I strongly disagree, every gun I got shoots better with less runout, way better.

 

[MagnumManiac]

People say runout doesn't matter and I strongly disagree, every gun I got shoots better with less runout, way better.

Depends where the runout is, seating bullets can induce runout in variable places on the neck, the bullet heel or the bullet tip. This ruins what you just achieved with the mandrel. Have seen it enough not to bother measuring runout anymore.
The groups will tell you at distance what neck tension the rifle likes, even if there is runout present.

Cheers.

 

[6pakzak]

Yes the seating die can increase runout, that's why you buy a good seating die, a good die will not increase runout and that's all you can ask for, started using mandrel and runout decreased but I should attribute it to something else that has not changed, and yes neck tension is important, so is how straight your ammo is, so is your powder, so is your seating, so is your shoulder bump, so is your brass condition, so is your bullet, so is your primer depth and primer, plus other ****, but keeping your ammo straight means a lot and if it didn't why would there be such expensive dies and presses and brass, primers, bullets if it didn't matter, just don't think about it makes it not matter, ok.