Author Topic: neck tension? (Read 273 times)

tootalloutdoors · « **on:** February 28, 2006, 02:22:01 AM »

How do I adjust the neck tension with my die? I'm using rcbs for a 220 swift. Not getting the consistency in accuracy that I want and am wanting to experiment with the tension. Mine are extremely tight. Could this be a factor? thanks

Catfish · « **Reply #1 on:** February 28, 2006, 03:16:50 AM »

Neck tension determans hold hard the bullet is to pull, or push from the case. The tighter the it is hald the higher the presure nessary to push it from the case and the faster you get a spike in the presue curve. This will have a small effect on the velosity that you will be able to get, but from my experance almost none on accuracy as long as the tension from round to round is consistant. To obtain the most consistancy you turn the necks of your brass so that they are all of the same thickness. HOWEVER, unless you have a tight neck chamber you will only get 1 or 2 loads from your brass and with a factory chamber it will not help you accuracy much anyway. You will have a better chance of improveing your accuracy by playing with the seating depth of your bullets. As long as you have some jump to the lands you can`t run into trouble, but if you jam into the lands you will get a big jump in presure.

victorcharlie · « **Reply #2 on:** February 28, 2006, 07:16:28 AM »

You can adjust the die to size more of the neck, but the sizing is really done with the expander ball being pulled back out of the case. I usually adjust the die to where the bullet will slip a little, but you can't really do this if you shoot anything other than single shot......

Try taking a case fired from you gun as see if a bullet will pass into the case before resizing it. If the bullet is tight then the case neck has thickened to the point that it needs to be turned or reamed. Most die makers offer different sized expander balls to change the "fit".

If you have a good powder, bullet, and primer combination, then have you tried adjusting the over all length by seating the bullet farther out?

Also, a good bullet seating die, like a wilson does a lot to prevent runout.

I personally have never loaded for the swift, maybe one of the guys who load the cartridge can clue you into what works for them.

skb2706 · « **Reply #3 on:** February 28, 2006, 10:58:38 AM »

My personal opinion would be that it is very doubtful that neck tension is your issue. Although it does take a certain amount of pressure to push the bullet free from the neck.....to the lands, that thin wall brass tube, roughly .015" wall offers little resistance when applying over 25 tons per square inch of energy to the bullet. I would focus on other possible problems........but thats just me.