Neck Tension - Bolt Guns

[rcw3]

Bolt gun cartridge neck tension - how much is too much & how little is too little & what is just right?

Robert

 

[tenring]

You will only know when you experiment with different bushings. Generally .002 - .003 tension is common.

 

[TrapperT]

Robert:

I have experimented with neck tension over the years and I have found that .001-.002 works very well in a number of chamberings. I actually feel that .001-.0015 is perfect for what I do. Going too high can increase pressure and can cause erratic groupings. Found this out when shooting a .243 I had. A higher neck tension (.003) may be good for people who are loading a magazine (tactical rifle) but I still feel .002" is adequate even in this situation. Obviously you are no stranger to neck tension and I would be interested in what you have observed over the years.

Tony

 

[gme]

When I soft seat I run about .001, if i'm jumping I'll run a little tighter, about .002
Gary Eliseo

 

[Tom Bear]

I'm happy to have a consistent .002 for my reloads.

 

[hoverp]

nice annealed brass and a true .0025 is perfect for my Hbn coated bullets for single round feed and also for rapids

 

[Bob3700]

I set my brass up for .0005" difference between the bullet diameter and the inside neck diameter. The wt of the press handle will generally seat the bullet. The bullet is held in the case with sufficient tension that you cannot spin the bullet by hand.

Those bullets are seated .020" long and the bolt and bbl will seat the bullets for me. That way, bullet seating is the same each time and I don't have to chase the throat as it wears.

Works across the board on my three rifles, 6mm BRX, 308W Palma Rifle, and 6.5x284 .

Bob

 

[LHSmith]

If the OP is asking what is the optimum neck tension for accuracy purposes, then I would say it's dependent on the burn characteristics of the powder used. Consider that is common in BR to change loads, including powder type, from one match event to another in respect to the conditions that are present ...... in some cases, the powder type is changed between the AM and PM matches. If one is using N133, a high neck tension is universally used because that is what works, if using certain lots of H322, or 8208, a lighter neck tension usually produces the best results. There is decades of empirical data that prove this point.

 

[FroggyOne2]

I know that in my 223's, if using Varget or RL15, they seem to like 1 thou'd of tension, but when I started testing 2200MR, that that powder likes .002 tension.

 

[1shot]

Robert,
I'm with Bob Beckett (Bob3700) on this one. I do exactly the same thing with both my Palma rifle and my 1K cartridge. Careful neck turning is the key to success for me.
I hope this helps,
Lloyd

 

[rcw3]

Thanks guys - great info here. When I used to shoot moly bullets, neck tension was not such a big deal for bullet release because the lubrication seemed to make it so an easy consistent bullet release could happen even with uneven neck tension or high neck tension. With naked bullets in a wildcat cartridge I am working with (with a make do jury rig die set I put together for testing purposes) I have a bushing that gives me about .001" neck tension and another that gives about .0022 neck tension. I like the .001" neck tension feel when I seat the bullets although it's rather light, but I don't like the feel with the .0022" neck tension because I feel a firm push back through the press handle when I go to seat the bullets. What I was really looking for is some confirmation that the .001" neck tension was not out of the ordinary or "crazy stupid" and there is enough solid good advice here from well heeled experienced shooters to confirm that .001" may be just fine (especially since I will be loading bullets in the lands .015" or so). I'll give it a go and see how things wind up.

Thanks again.

Robert

 

[GSPV]

Let the target tell you what works...