So 21st century is probably a good choice cause you can get different sizes? Looking at 21st web site, so I would get .223 and .263, if I was to get a couple more mandrels in each caliber what would you go with, free shipping if I'm over 150.00, also thinking die with window would be good or do you think unnecessary?
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Sinclair mandrels
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SealT5
Well-Known Member
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Get the die with the window and a .223, .222, .263, and .262. You'll have plenty to experiment with. Do some course testing and if needed you can get the in between sizes. I've yet to have a barrel that doesn't shoot with .002" of neck tension aka interference
QuietTexan
Well-Known Member
Yes, exactly. You can match mandrels and bushings to minimally work the necks, but in a very consistent and repeatable way.
I agree with ^^^, I would get .222 and .262, so you'd have -0.001 and -0.002 mandrels.
Most of my mandrel dies have the window, I think the Sinclair is the only one that doesn't. I like having it, not a deal breaker to not have it, but if it's an option I get it.
I have both Sinclair and PMA mandrel dies. Both are interchangeable with either mandrel.
I've been using Sinclair carbide expander mandrels for setting neck tension. They are .001" under caliber. With springback the necks end up about .0015" under caliber. I also have their turning mandrels which are .002" under caliber.
I also have Century 21's steel mandrels in .0005" sizes from caliber to .002" under.
I found better SD/ES and group sizes generally better using the expander mandrels (.001" under caliber).
I use graphite lube on every case whether using carbide or steel. The carbide does collect less brass on the neck. However, I've had a number of the Sinclair carbide mandrels collect brass that ends up scratching in the inside of the necks. After spending time removing the brass with Montana Extreme I can see little scratches that are collecting the brass. I can polish these on the lathe but it's a PITA because it doesn't take long to start collecting brass again.
I just received PMA carbide mandrels late last week. I've not had time to use them but PMA mentioned theirs are more highly polished that Sinclair so I'm going to try them.
Incidentally, after watching Cortina's recent youtube interview with Orkan (Primal Rights) I heard him mention using graphite-infused bronze to make mandrels. I made a 6mm out of that bronze and it is pretty slick. Erik said they wear out but he just makes another. I'm going to try that the next time I've got a bunch to do.
Note, with Imperial or wet lube I don't get any scratches. However, I don't want to tumble brass again after using the mandrels especially when I load large batches on the Dillon.
I've been using Sinclair carbide expander mandrels for setting neck tension. They are .001" under caliber. With springback the necks end up about .0015" under caliber. I also have their turning mandrels which are .002" under caliber.
I also have Century 21's steel mandrels in .0005" sizes from caliber to .002" under.
I found better SD/ES and group sizes generally better using the expander mandrels (.001" under caliber).
I use graphite lube on every case whether using carbide or steel. The carbide does collect less brass on the neck. However, I've had a number of the Sinclair carbide mandrels collect brass that ends up scratching in the inside of the necks. After spending time removing the brass with Montana Extreme I can see little scratches that are collecting the brass. I can polish these on the lathe but it's a PITA because it doesn't take long to start collecting brass again.
I just received PMA carbide mandrels late last week. I've not had time to use them but PMA mentioned theirs are more highly polished that Sinclair so I'm going to try them.
Incidentally, after watching Cortina's recent youtube interview with Orkan (Primal Rights) I heard him mention using graphite-infused bronze to make mandrels. I made a 6mm out of that bronze and it is pretty slick. Erik said they wear out but he just makes another. I'm going to try that the next time I've got a bunch to do.
Note, with Imperial or wet lube I don't get any scratches. However, I don't want to tumble brass again after using the mandrels especially when I load large batches on the Dillon.
QuietTexan
Well-Known Member
One of the reasons I bought the full-caliber sets from 21st Century is that they also include 0.000", +0.0005 and +0.001 mandrels to straighten necks back some before sizing if you ding one. I will probably only rarely use them, but they're there in the toolbox when the day comes.
I didn't know that PMA would make custom carbide mandrels until I looked just now. If I was using a mandrel in a progressive press that would probably be worth the cost to get.
FLShooter293
Well-Known Member
I use the 21C mandrels. I took all my expander rods out and I get much better results. I lube the mandrel with Imperial dry neck lube then lube each neck with it which has the added benefit of lubing the neck for bullet seating.
ntsqd
Well-Known Member
What I posted a while back about mandrel dies:
What I like about the Porter Precision system is that they use common off the shelf gauge pins. Can buy those online from lots of places in .001 increments or even smaller if you really think that you need to. Not too hard to add the lead-in taper by hand with a fine wheel on a bench grinder.
A qwik search of MSC Direct shows a .224" and a .264" Class ZZ gauge pin from Vermont Gage for $6.62 each. Class ZZ pins are within .0002″ of their etched size and round within .0001″, with a surface finish of 10 micro-inch Ra
Can get tighter tolerance pins, in Class X the pins are within .00004″ of etched size, round within .00002″, & have a finish of 4 micro-inch Ra
What I don't like about the Sinclair, 21C, etc. mandrels is that I don't know and they don't (to the best of my knowledge) publish what tolerances their mandrels are made to. The general rule in desinging tooling is the the tolerance of the tool has to be 10X smaller than the desired result in the product. So if I want the case necks to be round within .0005" the mandrel or pin that I'm using needs to be made to a roundness tolerance of .00005"
What I like about the Porter Precision system is that they use common off the shelf gauge pins. Can buy those online from lots of places in .001 increments or even smaller if you really think that you need to. Not too hard to add the lead-in taper by hand with a fine wheel on a bench grinder.
A qwik search of MSC Direct shows a .224" and a .264" Class ZZ gauge pin from Vermont Gage for $6.62 each. Class ZZ pins are within .0002″ of their etched size and round within .0001″, with a surface finish of 10 micro-inch Ra
Can get tighter tolerance pins, in Class X the pins are within .00004″ of etched size, round within .00002″, & have a finish of 4 micro-inch Ra
What I don't like about the Sinclair, 21C, etc. mandrels is that I don't know and they don't (to the best of my knowledge) publish what tolerances their mandrels are made to. The general rule in desinging tooling is the the tolerance of the tool has to be 10X smaller than the desired result in the product. So if I want the case necks to be round within .0005" the mandrel or pin that I'm using needs to be made to a roundness tolerance of .00005"
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Becareful when using mandrels. I have found some to be mismarked. I mike them all the time when I get them. Admittedly, 5 tenths is hard to mike, but some are a thou off what was stamped. But then again, the same hold true for bushings...
Mikecr
Well-Known Member
Neck tension is spring back force(hoop tension) applied to an area of seated bullet bearing.
This sets up pounds per square inch of gripping force (PSI).
Neck spring back is around ~1/2thou. After that, brass yields.
If you were to downsize necks 1thou under cal(after outward spring back) and mandrel expand at cal, the necks would spring back (inward) from this to ~1/2thou interference. At this, the neck would not be further upsized with bullet seating. It would expand to cal of course, but there would be no further yielding (sizing).
This is a baseline condition, and I think most would find this works very well.
Adjusting tension then is accomplished through LENGTH of neck sizing. This, adjusting the area of gripping force.
So with partial neck length sizing, no more than seated bullet bearing, setting interference beyond natural brass spring back (~1/2thou under) is merely adding energy that will be countered(with more energy) by the upsizing of bullet seating.
With this and an excess neck clearance trend, it's no wonder so many people are finding benefit in constant annealing..
I suspect they're overworking necks.
For analogy, consider when you've tightened a bolt to the point of yielding. It's an awful feeling where further turning of the wrench no longer tightens the connection. And you just know, or learn to know, that going further is adding bad energy.
Brass is little different than steel. When you cause yielding, you're breaking up it's grain structure, and rational management of this is in order.
Regardless of expansion I would never FL size necks.
It brings donut area into tension, and there is nothing 'good' in that. Only bad.
This sets up pounds per square inch of gripping force (PSI).
Neck spring back is around ~1/2thou. After that, brass yields.
If you were to downsize necks 1thou under cal(after outward spring back) and mandrel expand at cal, the necks would spring back (inward) from this to ~1/2thou interference. At this, the neck would not be further upsized with bullet seating. It would expand to cal of course, but there would be no further yielding (sizing).
This is a baseline condition, and I think most would find this works very well.
Adjusting tension then is accomplished through LENGTH of neck sizing. This, adjusting the area of gripping force.
So with partial neck length sizing, no more than seated bullet bearing, setting interference beyond natural brass spring back (~1/2thou under) is merely adding energy that will be countered(with more energy) by the upsizing of bullet seating.
With this and an excess neck clearance trend, it's no wonder so many people are finding benefit in constant annealing..
I suspect they're overworking necks.
For analogy, consider when you've tightened a bolt to the point of yielding. It's an awful feeling where further turning of the wrench no longer tightens the connection. And you just know, or learn to know, that going further is adding bad energy.
Brass is little different than steel. When you cause yielding, you're breaking up it's grain structure, and rational management of this is in order.
Regardless of expansion I would never FL size necks.
It brings donut area into tension, and there is nothing 'good' in that. Only bad.
IHFarmer07
Well-Known Member
Bingo…..I started with Sinclair die and mandrels and quickly switched to Porters die system that was built for f-class shooters. With pins gages, the measurements are infinite and are built with tool steel!
