Reloading question. Switching to bushing dies.

[richhymas]

I have a question about brass prep when using bushing dies. I started out using Forster press and dies, but have switched to Redding bushing style dies. I am sitting down to prep some new 300 win mag Norma brass and I realized that because they are a bit undersized, the resizing process is kind of a waste. The shoulder doesn't need bumped and the bushing is essentially doing nothing to the neck because it has nothing been fired yet. I fear that there may still be some neck tension variability from the factory. What do you bushing resizer guys do to account for this with new brass?

 

[BoomFlop]

I would recommend running an mandrel in the neck to make perfectly round and set your neck tension initially. I do not use bushing dies, however, I remove the stem and set neck tension with mandrels.

 

[MagnumManiac]

I use a mandrel to set my neck tension on all brass, if this means running them through a neck die or bushing, then I run .001" SMALLER than the mandrel size.
I don't use bushings, I use honed neck bump dies, mostly Forster, but have RCBS and Redding dies that I have honed. I also use modified expanders. I find all new brass to have a neck IF that I do not want, regardless of brand...even Lapua.
I run all new brass through a neck/bump die of my dimensions first.

Cheers.

 

[Joefrazell]

Get a lee neck sizing die. It has a mandrel. Or just shoot them. They won't be a great fit in you chamber till fired anyway. I wouldn't over think/complicate things.

 

[richhymas]

One other complicating factor is that my browning x-bolt 300 WM doesn't feed fired and resized brass well. The shoulder is too far forward for the lightly shoulder bumped brass. Poor design on browning part that uses the same mag for 7 mag and 300 WM. They feed well with new brass, but I would have to bump thst shoulder almost .010 to get it to feed well, which will wear my brass out very quickly, is for hunting rounds where reliable mag feed is critical I develop a load using new brass. I have a slightly modified load for fired brass for the range where I simply hand feed. Stupid work around I know but talk to browning about this well known problem that is specific to the 300 WM.

 

[L.Sherm]

Make sure and "float" your bushing, you should hear just a slight rattle inside when you shake your die. Make sure you chamfer the outside and inside of your cases. I suggest you get a whidden expander mandrel for your die there's definitely a difference in expander mandrels. You can change your neck tension- interference with whiddens expander mandrels sets if you choose to get them. Over working necks when sizing is the biggest culprit to runout on bushing dies along with not floating the bushing

 

[richhymas]

Make sure and "float" your bushing, you should hear just a slight rattle inside when you shake your die. Make sure you chamfer the outside and inside of your cases. I suggest you get a whidden expander mandrel for your die there's definitely a difference in expander mandrels. You can change your neck tension- interference with whiddens expander mandrels sets if you choose to get them. Over working necks when sizing is the biggest culprit to runout on bushing dies along with not floating the bushing

Thanks. I do "float my bushings. Back of 1/4 turn and shake to confirm it's loose in there. I need to get a mandrel set. I have 1 30 cal mandrel from Sinclair but nothing to mount it in. I use whidden gunworks dies. I'll have to get their mandrel set as well.

 

[JCow14]

On all my new brass, I run a mandrel to open them up a bit, they will contract back and still give you neck tension for the first firing- on a 7mm neck I would use a 7mm mandrel. I like the 21st century ones . Lapua Brass is bad about being very tight necked from the factory. Some re-loaders will use the mandrel before the bushing die and vice versa to get the desired neck tension they want when resizing.

https://21stcenturyinnovation.com/buy-online/ols/products/titanium-nitride-expander-mandrel

https://forum.accurateshooter.com/threads/bushing-size-for-mandrel.4009591/

 

[QuietTexan]

Whidden makes expander kits for their dies with five sizes, but they're still pulled up through the neck. 21st Century makes mandrel kits in 0.005" increments that push down. Same concept, different directs, some people have strong opinions on pulling buttons out of the neck depending on how the neck of the die is honed/ bushing size.

Expander Ball Kits - Whidden Gunworks

We also offer single Expander Balls in the most recommended size for the caliber of your choice. *Our expander ball kit is designed to work with the Whidden Gunworks decap assembly.

www.whiddengunworks.com

Caliber Specific Expander Mandrel Kits

Our caliber specific expander mandrels are available in .0005” increments in calibers 22 to 338 and will range from .001” above bullet diameter to at least .003” below bullet diameter depending on caliber. This will allow the reloader to find proper neck tension to fine-tune their loads. The...

21stcenturyinnovation.com

 

[Mikecr]

I'm not concerned with neck tension/variance, or any other dimension until the brass is fire formed.
Unfired brass just doesn't matter to me, as what I use in the field is always what I've reloaded.

 

[nksmfamjp]

I love my new Whidden sizer. I bought the expander kit so I can neck size to just below the expander size and expand back to ideal!
After fireforming, I'll be able to confirm runout. I would guess it is close to what my Forster die is giving me which is 0.0015" max.

 

[vancewalker007]

Thanks. I do "float my bushings. Back of 1/4 turn and shake to confirm it's loose in there. I need to get a mandrel set. I have 1 30 cal mandrel from Sinclair but nothing to mount it in. I use whidden gunworks dies. I'll have to get their mandrel set as well.

Another little tip, since your new to bushings, put the bushing in stamped side down. The mechanical operation of making the stamped number can make that side of the bushing slightly less square. When you run a case up into it the bushing pushes up against the top of the bushing chamber so the non-stamped side will square slightly better against the top of the bushing chamber.

 

[L.Sherm]

While this is true on Redding bushings, Whiddens have an arrow on the side pointing down.

 

[Greyfox]

Like others, I use an expander to bring the neck of new brass to the the same neck diameter of my finished loads. I will fire-form the brass to my chamber then use my Redding S-Die(FL) with a bushing about .004"-.005" smaller then my fired brass neck dimension. I adjust the bushing for a faint rattle when shook, and lightly lube my case/neck with RCBS case lube. ES is use usually <12FPS using this process.