What is the best to use to get consistent neck tension and the desired neck tension? I suppose some have a couple of mandrels/M Dies for each caliber.

I use a pair of Long and Short M dies. Expanders I have are not caliber specific, but instead mine are in numerous sizes for everything from .223" through .512" size.

Marlene wrote on Jan 1^st, 2018 at 4:51pm:


Agree, but I don't have them.

SO, I make my expanders to fit the L.E.Wilson expander 7/8-14 die and turn them to two diameters and a flair with a positive stop.  (first smaller diameter gives the majority of the neck-tension, larger diameter for 1/10" allows slip-fit and slight flair keeps from shaving lead.  Positive stop (shoulder) makes the end of the case the depth stop.  THEN I use/make the sizing die to just barely size down the neck.

I think a mandrel can expand the neck, but you may want some form of a flare to start a lead bullet. The M-die forms a particular type of flair. If you decide to form a flare on the case mouth and decide not to 'crimp', you may want to check if it chambers the way you want it to.

If concentricity is your goal, you could pick that type of gauge and just measure it. I don't think just running a bullet in a sizing die can ensure concentricity. 

If you like the way that your brass is fire formed to your chamber, neck sizing only might be all you need to set the bullet tension that you want. A different size neck bushing will size to a different amount. I think the die that was mentioned above may full length size or size the shoulder along with having a changable neck sizing bushing.

An expander won't necessarily give you the neck tension that you want unless is sized for the bullet diameter you want to seat. Best of luck with it.

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I always used a mix of Lyman M dies and Lee expanders.  Size the fired case with a F/L die open it back up to desired size and neck tension with the expander.  Want a flare for cast run the expander a bit deeper & Catch the plugs shoulder. M being the best, Lee’s work ok too, but often need polishing. Other companies make expanders too.

Lately I am using more CH 4 D neck sizers.  Die itself  is not cartridge specific, 3 different body’s depending on the shells length. Sizer is a bushing that drops in the top of the die and brings the neck size back to any possable desired dimension.  I find they give me more,consistent control over the bullet pull, as long as the brass is consistent. It’s sizing from the outside so neck wall thickness  comes into play. Not a problem same lot of brass carefully measured and possibly neck turned.  Mixed brass better set the dimension from the inside with a plug. 45 acp mixed brass often left on the range when match rules don’t allow picking up brass, expander is the way to go.  Both cast bullets different situations.    

Added plus for the neck sizer is home made bushings are easy to make. Bit easier than home made M die plugs.  Of course both easier to adjust  size using a factory Plug/Bushing and opening up or cutting down to desired. Good number of mine have been “tweaked”

Boats

Again opinion. If I had your rifle and loading smokeless I would use the bullet as cast no sizing alloy 1/25. Use a neck sizer to bring the case down enough to give a light bullet pull. Test would be thumb pressure resistance to movement.

If black powder I would not size the bullet at first however a bit smaller bullet could be better. Sizing down .002 worth a try, shoots good then order a bullet to drop desired dim without sizing.  You could slip fit, I would neck size for a very little bit of neck pull.

Watch that aneling, if the case needs it aneal, the Brass will tell you when it gets work hardened. If it works easy don’t mess with it.  I used a 500 case lot of 38/55, 140 sized to 32/40, rest shot as 38/55 for almost 20 years before they needed aneling 

Boats

When seating a slip fit bullet with smokeless powder, will it work to expand the case neck down to the point where the base of the bullet should stop/incur restriction? 
And can one use the expanding mandrel as a compression tool. Then slip fit the bullet until the base hits the restriction? 
Or is all of the above standard stuff?