Neck tension question

[CPC280]

My micrometer is not what I would call a quality, precision instrument. I do not have a ball micrometer but I do have a nice set of Mitutoyo calipers.

My question is, can I measure the thickness of my case neck using my calipers, factor in the bullet diameter to quantify my OD and accurately set my neck tension from that?

Such as the Peterson brass for my .280 has been no thinner than .015 so:

.015 + .015 + .284 = .314

Based on that I should be able to use a .312 neck bushing and achieve .002 neck tension.

Will this work?

Bought a set of Neck tension gauges from ballistictools.com wouldn't be without them now.

 

[CPC280]

Bought a set of Neck tension gauges from ballistictools.com wouldn't be without them now.

 

[Dragoon300]

Everyone has pretty well covered it, as stated above it mostly depends on your needs. I have decided to use the bushing die, then a mandrel as the last step in case prep. It is easier for the case shoulder to support a mandrel being pushed in, than an expander ball pulling out. (especially if not properly lubed) you will see spring back regardless of which method you use. The more spring back you have, the more "tension" will be there, if wall thickness is the same. Annealing addresses this issue, the only way. The goal is to have a consistent release of the bullet. Another thing that happens is when very clean brass necks have new copper bullets pressed into them without graphite to keep them from bonding to each-other. (cold weld) Carbon build up on fired brass usually keeps this from happening, but it does happen, and to varying degrees that really messes up consistency so use graphite when seating bullets.

 

[Bullwhacker]

Tune your neck tension like a powder charge. Your rifle will typically shoot much better with one than the others. I test 3 bushings with groups at 500 yards or further. 0.002", 0.004" and 0.006" will tell you what your rifle likes. It's a big variable that is often left out. Usually a hunting barrel prefers more tension in my experience and the difference will be noticeable.

 

[7stw]

Tune your neck tension like a powder charge. Your rifle will typically shoot much better with one than the others. I test 3 bushings with groups at 500 yards or further. 0.002", 0.004" and 0.006" will tell you what your rifle likes. It's a big variable that is often left out. Usually a hunting barrel prefers more tension in my experience and the difference will be noticeable.

I agree. My .245 bushing shoots better the the. 246. Neck tension is very lite with
246, much better with 245. The Peterson brass is very sensitive to the .001 difference.

 

[Whitesheep]

Who offers inside mandrels of different diameter for the same caliber? I use Sinclair mandrels, but these come in stated calibers only.

 

[7stw]

Who offers inside mandrels of different diameter for the same caliber? I use Sinclair mandrels, but these come in stated calibers only.

Short Action. That's the begging of the name of the company. I believe they carry them.
Speedy may have some too!

 

[BBean70]

Who offers inside mandrels of different diameter for the same caliber? I use Sinclair mandrels, but these come in stated calibers only.

Porters Precision Products in Lake Jackson, Tx makes them also https://portersprecisionproducts.com/

 

[dfanonymous]

Why would I bother, you just told him…

…cause you've bothered before, on the last neck tension thread. The mere colloquial term has never bothered me.

 

[Dragoon300]

Expand Mandrel Prebuilt Kits - All NEW

Prebuilt kits for expanding the case neck so the brass will spring back to size for seating bullets. | .17 - .50 cal | Start, Range & Full Kits

kmshooting.com

I get mine here.

 

[MontanaJack]

After years of wrestling with neck tension by using bushing sizer dies, neck turning, I invested in 21st Century mandrels and graphite to achieve consistent neck tension as a final sizing step. I have multiple undersize mandrels for every caliber that I load. The 1000 yard hunting ammo I load for my hunting partners will produce subminuite accuracy to that distance. That said, I bagged hundreds of animals over the years just using standard RCBS, Redding, Pacific, Lyman, Herters, or Hornady dies. Rarely shot beyond 300 yards. Now I shoot long range comfortably by using more precise methods. Making an eithical shot beyond 400 yards requires more and more skill and experience as the distance increases. Few weekend warriors achieve the skill level to perform those shots consistently enough to attempt them. I've met many guides over the years that tell horror stories about hunters that show up with equipment that don't know how to operate and leave hunting camp empty handed with dead animals in the woods they wounded but never found to tag. Hopefully, our group understand the need to punch a lot of paper before attempting to bag game long distance.

 

[Csbc4fun]

After years of wrestling with neck tension by using bushing sizer dies, neck turning, I invested in 21st Century mandrels and graphite to achieve consistent neck tension as a final sizing step. That said, I bagged hundreds of animals over the years just using standard RCBS, Lyman, Herters, or Hornady dies. Rarely shot beyond 300 yards. Now I shoot long range comfortably by using more precise methods.

Amen Brother! I do the same and all groups at 100 yards are 0.250 or less. No reason to buy more tools and measure, measure, measure…. I spend the time shooting.

 

[Shootin4fun]

I now anneal after every firing and guess what- no discernable difference in velocity between cases fired 4 times and those fired 10 times. (Lapua, 6.5cm 270 win 243 win). I still track batches though. But it means i can acually span 2 batches of different "generations" while testing loads and know that any differences are from changes in the load, not the fact that they were shot from different batches. I suffix batches with a letter, starting with A and progressing alphabetically. My M cases produce the same velocity as G cases with the same loads.

No turning, no expander ball, full size only, bushing die. (Abandoned neck sizing). Though for my BAR I do use the expander because necks sometimes get dented/deformed. When using an expander ball i lube the inside of the neck, then remove the lube with an isopropyl dampened cotton swab. The cases get beat up by automatic ejection process before primer pockets ever give way.

As most of us do, i seek single digit SDs, and get them on all rifles, even the BAR (270).

 

[Shootin4fun]

After years of wrestling with neck tension by using bushing sizer dies, neck turning, I invested in 21st Century mandrels and graphite to achieve consistent neck tension as a final sizing step. I have multiple undersize mandrels for every caliber that I load. The 1000 yard hunting ammo I load for my hunting partners will produce subminuite accuracy to that distance. That said, I bagged hundreds of animals over the years just using standard RCBS, Redding, Pacific, Lyman, Herters, or Hornady dies. Rarely shot beyond 300 yards. Now I shoot long range comfortably by using more precise methods. Making an eithical shot beyond 400 yards requires more and more skill and experience as the distance increases. Few weekend warriors achieve the skill level to perform those shots consistently enough to attempt them. I've met many guides over the years that tell horror stories about hunters that show up with equipment that don't know how to operate and leave hunting camp empty handed with dead animals in the woods they wounded but never found to tag. Hopefully, our group understand the need to punch a lot of paper before attempting to bag game long distance.

I keep thinking i should learn about mandrels but ive been using standatd dies for over 50 years, and my SDs are in single digits, somtimes under 5, so im not sure if i would benefit from a whole changeover. If my stats are what i said, do you think i would gain any significant improvement by switching over? I don't plan to hnt over 600 -700 yards at this point but i do ring steel out to 1k.