Thoughts and experience with expander dies to set bullet tension.

[odoylerules]

I use FL bushing dies and sometimes turn necks to achieve best results. I have a good friend that swears by using the Sinclair expander dies to set the bullet grip. I'm considering trying it but wanted to hear from others about their experiences. Thanks

 

[Dave Tooley]

In the past some have thought that you get better uniformity in regards to neck tension. Size the neck a bit smaller than necessary and then run an expander mandrel through it. It may sound good but in 40 years of competition I've never been tempted to try it. Good brass, good dies, good chamber, good bullet, good load are 98% of it. I've never seen any difference on the target with minor variations in neck tension. I couldn't sort out the other 2% if I wanted to let alone see the difference on the target.

 

[Deputy819]

I like to use the "21st Century" expander mandrels/dies to "set" neck tension on my rifles that I expect a higher degree of accuracy from (.280AI, .243 Win). I feel like it's just another piece of the accuracy puzzle in my loading regimen for them.

 

[ShtrRdy]

In the past some have thought that you get better uniformity in regards to neck tension. Size the neck a bit smaller than necessary and then run an expander mandrel through it. It may sound good but in 40 years of competition I've never been tempted to try it. Good brass, good dies, good chamber, good bullet, good load are 98% of it. I've never seen any difference on the target with minor variations in neck tension. I couldn't sort out the other 2% if I wanted to let alone see the difference on the target.

Thanks for sharing your experiences Dave. Do you use a bushing die? Do you use the expander that's on the decapping rod in the die? Do you turn necks?

Thanks -- Todd

 

[Dave Tooley]

Thanks for sharing your experiences Dave. Do you use a bushing die? Do you use the expander that's on the decapping rod in the die? Do you turn necks?

Thanks -- Todd

I do turn necks in my target rifles. Obviously that helps. I don't anymore in my hunting rifles. I've got better things to do. I use bushing dies for some and standard dies for some. That means I drag the expander ball back through. Many of the dies I lapped the neck area to decrease the amount of sizing on the neck.
Something else to consider. You are working your brass more which then requires annealing. If neck tension is important to you then you just changed it by annealing. Also the very real chance of the neck being misaligned. In a good bushing die the case is as straight as it's going to get when it comes out of the die.

 

[65WSM]

I have a several calibers of Sinclair expanders and their die holder. I find myself using the K&M expanders to get 1.5 thousandths below bullet diameter. Their holder has a window, so I can see how deep the expander is going into the case. All new cases, usually 4 thousands below bullet diameter, get expanded. Fired or not fired, I usually prefer 1.5 thousandths of neck tension. I am using Wilson seating dies with VLD stems and some of the tipped bullets with thinned jackets will dimple with 2 thou of neck tension. I load 18 cartridges from .17 Fireball to 7mm Remington Mag with less than two thousandths. I like a little more tension with the .35 Whelen and .375 H&H Ackley which are crimped so the bullets don't grow in the magazine.

 

[J E Custom]

If you get the proper fit almost any method will work, but some will decrease brass life. I prefer to turn the necks to the same diameter and then size them with a bushing die with the expander remove to get the most consistent bullet grip. (One defeats the purpose of the other). Expanders of any type double the work hardening of the brass and shorten the life unless you Anneal.

I used to turn down expanders to get proper fit in some cases but then they were wrong for other brand cases of the same cartridge. Turning the necks solved this and selection of the correct bushing was all that was necessary to get the proper fit. In my opinion, if you are not turning the necks, a decapping die expander or an independent expander does a good job of sizing the neck ID but does nothing for concentricity.

J E CUSTOM

 

[Greyfox]

I also use and expander with new brass to bring the neck ID cluster to .0015-.002" of neck tension. Whether I use it during the ongoing reloads depends on my run-outs and consistency of the seating pressure. I have loads that provide better runout with some and some without the use of an expander. Lapua and Norma neck wall thickness has generally proven to be very consistent negating the need of neck turning.

 

[65WSM]

I have a question for J E Custom. How are you "turning necks to the same diameter" with factory brass? I would like to do this but I have to expand the factory necks to get the neck turning (I have Sinclair and K&M hand tools) to fit. Often shooting the brass once before turning is necessary to get the clearance to slide the case necks over the mandrel. The expanders are too tight still for the turning mandrel.

 

[J E Custom]

I have a question for J E Custom. How are you "turning necks to the same diameter" with factory brass? I would like to do this but I have to expand the factory necks to get the neck turning (I have Sinclair and K&M hand tools) to fit. Often shooting the brass once before turning is necessary to get the clearance to slide the case necks over the mandrel. The expanders are too tight still for the turning mandrel.

The Sinclair neck turning Kit has two mandrels, one fits the sizing die in the kit for sizing the ID of the neck .001 thousandth larger than the turning mandrel for the best fit, so first I use the sizing mandrel in the furnished die body and then use the appropriate turning turning mandrel to turn the OD of the neck. expander mandrels are only .001 thousandths larger than the turning mandrel, so if the right pair of mandrels are used, there should be no problems.

The reason I turn the necks before I fire them is to avoid offsetting the neck bore due to thickness variations.

J E CUSTOM

 

[ronstone09]

If you get the proper fit almost any method will work, but some will decrease brass life. I prefer to turn the necks to the same diameter and then size them with a bushing die with the expander remove to get the most consistent bullet grip. (One defeats the purpose of the other). Expanders of any type double the work hardening of the brass and shorten the life unless you Anneal.

I used to turn down expanders to get proper fit in some cases but then they were wrong for other brand cases of the same cartridge. Turning the necks solved this and selection of the correct bushing was all that was necessary to get the proper fit. In my opinion, if you are not turning the necks, a decapping die expander or an independent expander does a good job of sizing the neck ID but does nothing for concentricity.

J E CUSTOM

i like to neck turn also but i use pins to set my neck tension on my target gun

 

[antelopedundee]

I also use and expander with new brass to bring the neck ID cluster to .0015-.002" of neck tension. Whether I use it during the ongoing reloads depends on my run-outs and consistency of the seating pressure. I have loads that provide better runout with some and some without the use of an expander. Lapua and Norma neck wall thickness has generally proven to be very consistent negating the need of neck turning.

+1 about the Norma brass. Took some new .25-06 cases and expanded using the .256 Sinclair mandrel. Turning using the .255 mandrel was a snug fit. The same was seen for new Nosler brass. OTOH I had some new Quality Cartridge 6.5-06 brass and some new and once fired PPU brass that were something of a joy to turn. The PPU necks seem to be thinner than other brands I've tried.

 

[antelopedundee]

I have a question for J E Custom. How are you "turning necks to the same diameter" with factory brass? I would like to do this but I have to expand the factory necks to get the neck turning (I have Sinclair and K&M hand tools) to fit. Often shooting the brass once before turning is necessary to get the clearance to slide the case necks over the mandrel. The expanders are too tight still for the turning mandrel.

New brass is usually intended to be loaded as received so the neck diameter will be smaller than bullet diameter. So to neck turn new brass just run them over the appropriate expander. For once or more fired cases one sizes them without an expander and then expands them up using the Sinclair die and mandrel as described by J E Custom.

 

[antelopedundee]

I use FL bushing dies and sometimes turn necks to achieve best results. I have a good friend that swears by using the Sinclair expander dies to set the bullet grip. I'm considering trying it but wanted to hear from others about their experiences. Thanks

The Sinclairs usually limit you to 2 choices for neck expansion say for .257 they offer .256 and .255 mandrels. Depending upon the bullet you could size with no expander and seat the bullet letting it be the expander or somewhere in between. Redding advises against a lot of neck tension when using their competition dies.
For the Redding bushing dies I assume I could use the same die, but different bushings for all .30-06 based cases.