Bushing dies and expanding mandrel

I currently have bushing dies for sizing and have recently pulled the expanding ball out of them as I started using mandrels for expanding.
Curious on others thoughts. Is it over kill having both? Would future reloading dies be worth the extra money for bushings if using the expander mandrel for neck tension? Right now I kinda feel having the best of both worlds is working good and helps me sleep at night. Just wondered what others thoughts were on this as there are some good non bushing sizing dies out there. Thanks!

I've been using Redding Type S bushing dies for a long time. This year I bought a set of Century 21 mandrels to see if there was anything to the hype. What I noticed was that seating pressure, from one case to another, is more consistent after using a mandrel. I noticed that my CBTO is also more consistent.

I use the Century 21 moly/ceramic beads before inserting the mandrel. This leaves traces of moly in the neck, which would also contribute to more consistent seating.

With a bushing you can adjust both downsizing and length of that sizing, so you're not stuck with FL sizing of necks (something NOBODY should do today). Pre-seating expansion is useful to consistently finalize desired interference. Doing this with a mandrel reduces loaded runout over pulling 'most' buttons.

The worst thing you can do is a bunch of neck upsizing with bullets. That's not what they're made for.

I do not use bushing dies at all, for brass needing to be turned, bushings push irregularities to the inside, for turning, you want irregularities on the outside.
I discovered a long time ago that Forster BR NON-BUSHING dies with honed necks and custom sized expanders that are highly polished produce the straightest, most consistent brass you can use.
Runout is virtually unmeasurable.
2 reasons for this with these dies, expander shape and position and the honed necks, less brass movement and HOW it is controlled is key.
Redding dies are great, .002" brass movement is very good, but their expanders need a lot of work to be GREAT. Polishing, sizing correctly and shape can all be better. I like tapered expanders for coarse sizing, it's smoother and nicer to the brass. Then finish with a mandrel.
I lube my necks with graphite powder before each of these steps, it is not removed, it makes bullet seating more consistent.

Cheers.

A couple years ago on the advice of a of another competitor who said it decreased his SD and ES, I tried a mandrel. He was absolutely correct. I saw my SD and ES both decrease and the feel was also improved. I have switched to this method for all my bolt rifles.

I have mostly bushing dies and conventional dies. Expander balls are removed in everything but .223 (for junk shooting, were to I load for bolt .233 accuracy, I would start using a mandrel there as well.)

Honestly, you CAN get phenomenal accuracy with all sorts of approaches. Just some are more repeatable over the long run. Working the brass less, combined with occasional annealing seems to be a great discovery. That being said, newly annealed brass behaves differently. Best to have relatively large lots of brass (I like 200 now) and produce a good number of identical (to the best of one's ability) brass; Then shoot a quick couple groups around your former sweet spot and see if its still good.

I think a standard die and expander ball is great for a reloader that want's say 2 moa from an autoloader. And with some guns you will do far better. But the expander ball elongates the cartridge as it pulls the neck to size. A mandrel does the oposite. Chambering issues do not emerge as often.

Hey, if ya sleep better and your process is showing solid results then rock on! I switched over years ago from RCBS dies to Forester and use the 21st century mandrels with the moly/ceramic like Varmint Hunter, I will never go back. Best of luck and happy shooting. Jason

I use both Forester and Redding bushing dies, my experience has been;

Forster sizing dies with their expander adjusted correctly can produce incredibly straight sized brass with no runout at the neck. The issue for me has been that the expander adjustment is a bit finicky to keep adjusted correctly. I now remove the epander and use a mandrel, this works great.

With the Redding bushing dies, there is always a bit of play with the bushing inside the die. The bushing sometimes seems to tilt, ever so slightly, going down on the brass neck and the result can be a slight bit of runout at the neck. I have also quit using the redding expander button and use a mandrel.

In the end, I believe a standard full length non bushing sizing die followed by a mandrel with the inside the neck lubed with graphite is the way to go.

Icing on the cake would be doing as @MagnumManiac suggested and having Forester hone the inside of the sizing die to work your brass less (getting the same result as a bushing die) then using a mandrel, would be the perfect setup. Forster explains how to get a die honed on their website.

I'm trying to learn about mandrels vs. bushing dies. I have the RCBS matchmaster die and have the expander ball left in. I've read somewhere that I should remove the expander ball.

What is the difference between a mandrel and bushing die? Why is one better than the other? I called RCBS and the man I spoke with said he leaves his expander ball on his bushing die, because he doesn't neck-turn.

Help, please.
Thanks

tylerthorson95 said:

I'm trying to learn about mandrels vs. bushing dies. I have the RCBS matchmaster die and have the expander ball left in. I've read somewhere that I should remove the expander ball.

What is the difference between a mandrel and bushing die? Why is one better than the other? I called RCBS and the man I spoke with said he leaves his expander ball on his bushing die, because he doesn't neck-turn.

Help, please.
Thanks

Click to expand...

A bushing die can be set up with whichever size bushing you deem necessary to size the neck down to the desired size. A mandrel is a sized shaft that fits into a mandrel die to size the neck from the inside.


Utube can be your friend in learning much of this and provides visual reference

I use mandrels with some of my standard FL sizing dies and no expander at all with my bushing dies. It takes a bit of experimentation to get the right bushing, and at $20 each, it isn't for everyone but if set up correctly, you don't need anything going on the inside of the necks when using a bushing die.

The danger is as MM pointed out. Any defect in the neck is going to be pushed to the inside of the neck when using a bushing die. If extreme accuracy is your aim, then that is less than desirable. I have been able to produce ammo that provides me with more than sufficient accuracy using the methods I use, so I am good.

MagnumManiac said:

I do not use bushing dies at all, for brass needing to be turned, bushings push irregularities to the inside, for turning, you want irregularities on the outside.
I discovered a long time ago that Forster BR NON-BUSHING dies with honed necks and custom sized expanders that are highly polished produce the straightest, most consistent brass you can use.
Runout is virtually unmeasurable.
2 reasons for this with these dies, expander shape and position and the honed necks, less brass movement and HOW it is controlled is key.
Redding dies are great, .002" brass movement is very good, but their expanders need a lot of work to be GREAT. Polishing, sizing correctly and shape can all be better. I like tapered expanders for coarse sizing, it's smoother and nicer to the brass. Then finish with a mandrel.
I lube my necks with graphite powder before each of these steps, it is not removed, it makes bullet seating more consistent.

Cheers.

Click to expand...

Could you give an example of one of your cartridges including case measurements and how you decided on the measurements of the die and expander? I assume your using the expander in the die to help move inconsistencies out but wouldn't the mandrill do that on its own?

The mandrel is the last step, and so it should be.
I measure brass, mostly Norma, Lapua or RWS, if I can get it.
The first case I ever did this with was 6.5x55 Swede. I took Norma cases, measured them, then had a reamer made for both the rifle and sizing die.
No measurement, except the neck, moves the brass more than .002", with springback, it's actually .0015". The neck has .003" clearance in the chamber, the necks in the dies, both FL & Neck, are honed to the tenth, the expanders are custom tapered, polished and sized exactly to be .0015" under bullet spec, then a mandrel that is .002", or whatever, it used last.
I turn after the initial pass through the die, normally takes me .001"-.002" to clean up my brass to give me neck clearance. I turn 80% of the neck and size the same amount/length.
I do not do this on my hunting rifles, but I do still use dies that move the brass a minimum amount. I don't size all of my neck length either.
My custom 264WM is picky about this, first time I have ever encountered this, so had to experiment with mandrel size a little more than usual. It likes double the interference I normally use.

Cheers.