Neck Tension, how loose is too loose?

[tonedaddy]

On my 6.5 Grendel single shot pistol if I turn the bullet really hard in a case it will rotate, is this not enough neck tension?

 

[nonliberal]

Since its a single shot it won't hurt anything as long as you feel like your gentle enough that your not effecting seating depth. If they are all a little different accuracy will suffer.

 

[LHSmith]

Some old time Benchrest shooters used "fitted" necks...essentially zero neck tension and claim to have shot amazingly well. It also depends if your bullet is into the rifling at all. However, once loaded it was not a good idea to attempt to extract a loaded round unless one enjoys cleaning powder kernals from the action and perhaps the trigger....and dislodging a bullet from the barrel . If these light neck tension rounds shoot that much better than those with heavier neck tension, and you can live with the fact that once they're loaded, they must be fired ... they are not too loose. Also be aware that seating depth (i.e COL) will probably change just from handling.

 

[243winxb]

When the primer fires, the bullet may move if not jammed into the rifling. Slow burn rates of powders can not start burning correctly with bullet movement. I would guess more neck tension may be better?? At least with a single shot, no feeding problems. As said above, some use brass spring back/tight neck chambers, to hold the bullets. Testing, only way to know for sure.

 

[gotcha]

The concept of min. nk. tension goes all the way back to the original BPCR rifles shooting cast bullets. They would place a bullet firmly against the lands & then chamber a loaded case that contained a filler to prevent the powder from escaping. ( a simplified explanation) All the caveats listed above would certainly hold true...... I have a rifle that shoots exceptionally well w/ min. nk tension, bullets seated long & using gentle caming of bolt to seat bullet against lands & further into case. Though w/ this particular rifle I've seen no ADVANTAGE in accuracy compared to cases w/ .002" nk tension & bullets seated to touch lands.