Neck Tension

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Poconolg

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I neck size my brass. I am using Redding Comp Bushing dies for my 22-250. Do you get better accuracy with more or less neck tension? Thanks for the help.
 
I think you get more pressure with more tension, I think consistency is the biggest issue for accuracy

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Went down that road with my 308, started with neck sizing only, then partial neck sizing, read about neck tension. Ordered the Redding S type bushing dies Full & Neck die. Did my measuring, ordered bushings with tensions of 1&2 thousands. Some benchrest shooters soft seat with little tension , seat the bullet long, when chambering the bullet seats it self into the rifling. I found .002 neck tension to work best. I feel bushing dies as designed for custom bench rest barrels with neck turning your brass. For accuracy I found the standard full length die with .001 headspace worked best, gave me .002 neck tension with .001 and better runout. Runout for me was a problem with bushing dies. Do you jump or jam your rounds?
 
I use the standard Lee dies and sometime need to make the expanding ball smaller . I remove the decapping rod and put it in my drill and sand the Expanding ball a little .
 
And then there is that story about the firing pin; the firing pin strikes the primer and then 'the whole thing', the case, bullet, powder and primer takes off for the shoulder of the chamber. Except on my rifles, I use killer firing pins; my firing pins crush the primer before the case, powder and bullet know their little buddy the primer has been crushed.

And then there is that story about firing pins crushing the case as in shortening the case between the shoulder of the case and case head before anything happens. There is nothing I shoot and or load that goes in slow motion.

I am the fan of the bullet jump; I want my bullets to have that running start and I want bullet hold, I want all the bullet hold I can get. BUT! When seating bullets I want that operation to go smooth, I am the fan of alignment between the neck of the case and bullet.

F. Guffey
 
cw308, OP poster was asking question about bushing neck die. The Redding neck die gives option that you don't use expander so only runout difference should be neck thickness. If your fired dia is more than 0.008-0.010" bushing size your going to have runout that will effect accuracy.

I shoot few tight neck rifle and some custom builds like OP and I don't turn necks and I can shoot some pretty small groups.
 
old roper, l used the bushing dies. They worked fine, shot good, my runout was worse with the bushing dies. Found F/L sizing with the RCBS F//L sizing die gave me the best of two worlds. My loaded 308 neck measurement is .338 used the .336 bushing for .002 neck tension,on a FC neck thickness measured at 12, 3,6 & 9 o'clock at .015 used the expander ball on both standard & bushing dies. Found neck sizing only runout was average .003
 
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For 223 and 308 semi's/bolts am not expanding the case neck (unless I need to trim them) then using Redding comp seater dies. And yes you can get too much tension.
 
I'm cheap, I use the Lee collet die to acquire my neck tension. I go down half way, spin my case a bit and finish the other half to eliminate that ridging of the collet. The key to consistency is the use of a light grease on die parts so they glide easy and not mar internal die surfaces and keep the same internal frictions. I use shooters grease w/ a cotten swab. Any light grease that stays put will suffice. I have great concentricity afterwards and the tension is consistent. One of the keys for that is consistent cases w/ bumps/lengths being consistent as well. Separate out your brass by manufacture and weight, etc before you get into the manipulation of the brass. Let your rifle tell you the needed tension as they may be slightly different on FB vs BT bullets. Somewhere between .001 and .002 neck tension seem to fit most of my rounds. On AR's be careful, no, be really really careful! The Redding page listed annealing. You will find comments all over the grid. I finally settled on using a machine for consistent heating. I used temp sticks (750 for neck, 450 for just below the shoulder) and set the torch and spin speed so they melted at the same time (aprox 5.5 seconds). To keep the temp stick material on the surface, use a sacrifical brass and scrape the neck and case area w/ the edge of a file to the rough surface will collect the temp stick material. Each case lot will need that sacrificial piece as different manufactures cases are not all the same mixture of materials and wall thicknesses. Once you get that done, you can use the Harbor Freight temp laser to check accordingly. The temp sticks are more accurate than the $20 on sale laser. But the laser is consistent. You can read the inside of the neck and see the 750 degrees. That 750 number is not majic. It was offered by various case manufactures and so I went with it. It seems to work well for me and eliminates my guess on the hue of color. None of my brass turns red or orange and does develop that blue tinge down just over the shoulder. I'm not disagreeing w/ others who do it differently because it works for them. It is just where I settled and works for me. You pick your choices.
 
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