neck tension in .313 neck.

[gilmillan1]

Hello,

i have a question. I have a 284 rifle that shoots absolutely phenomenal. However, I have noticed that in the second reload of my brass, the neck tension has gotten high. I turned my brass. My fired rounds measure .311 at the neck. I was using a .309 bushing for my neck sizer. However, i really think i need less neck tension. I can tell that it takes much pressure to seat the bullets because I am using a hydro bullet seater. What kind of tension are you guys using? I just ordered a .310 neck bushing to see if this solves the problem.

 

[mikecr]

Your post seems abstract to assemble.
Did you turn necks before or after the problem and what thickness did you turn to?
Are you pre-expanding necks before bullet seating, or are you using bullets as your expander?
Did you do anything to the carbon film in your necks(affect friction)?
What do your sized necks measure?

 

[Ringostar]

Why would you use a 313 chamber? A 315 is considered a tight neck for a 284. I use a 317 with a slight neck turn, then a 310 bushing.

 

[Terry]

The bushing is only part of the story. If you anneal the brass seating will be easier.

 

[JHardy]

In addressing the .313 chamber neck, my experience with the .284 based long range rounds is that a .313 chamber neck is perfect. The 284, Shehane and etc. shoot best with .004 neck clearance. It takes a neck turn of .0125 to clean up a Lapua 6.4x284 case that has been necked up.

A neck turn of .0125 + .0125 + .284 = .309 loaded round which is a perfect dim. for this case and gives you .004 neck clearance. In that regard, it is wise to have neck bushings of .308, .307 and .306 so that you can address neck tension -- and bullet pull -- from .001 to .003 -- I like what my rifle tells me which is .003 usually. BTW, true carbide neck bushings will last a lifetime and are ground round. Many commercial bushings are not round, and you will go nuts trying find out what has happened to your loaded round concentricity.

Necks that have a perfect chamfer and internal polish work nicely, and a consistent annealing program also helps you find consistent neck tension = consistent bullet release = low ES = less long range vertical.

There is certainly nothing wrong with a no turn chamber. But the above is one reason that a .313 chamber neck is perfect if you neck turn. A tip when using a hydro seating press: you will get much better consistency in your bullet seating if you speed up the seating stroke somewhat. Slow is NOT as consistent with the numbers which kinda screws up the entire reason for spending the bucks.

I hope this helps some.

Regards,
Jim Hardy

Hardy Custom Bullets, Inc.
Passion + Precision = Perfection

Shop: 770-886-1997
Cell: 770-855-8960

 

[mikecr]

He didn't say he had a .313 chamber neck, or that he turns, or anything about annealing.

 

[jonbearman]

Mike reread the name of the thread.

 

[JHardy]

Mike, your are correct to a point. There was a questioning about the .313 neck. I also gave some additional information I thought might help someone. Maybe the original poster. I tend to give information to folks if it might help. The original poster was running a tight clearance between his loaded rounds and the chamber neck. This was explored long ago by Jerry Tierney and he shared his info with me. He was correct and I just passed it on.

The original poster was having problems with his neck tension and i believe I have given information that should help him. The poster I responded to seemed to (maybe) put some blame on the .313 neck when the problem, in part, was not enough neck turning for the .313 neck.

On the other hand, I don't understand where your dog is in the issue beyond a somewhat rude comment. If you were offended by my additional information, I am sorry about that. I agree that I certainly strayed from the issue -- but gave what I know to be good information.

I have read many of your posts on this board and I believe Bench Rest Central. You tend to be very helpful yourself, and you possess a lot of good knowledge and tips. The written word can be a dangerous thing in that if you try to help with your experience you can come across as a know-it-all. Or, you can sit on issues when you have experienced the same thing and have arrived at a proven solution(s) that might help another.

I will be more careful in the future as you really don't know how someone will take what you say. I appreciate (kinda) your comments and lesson learned on this end. Respectfully, you have no idea whatsoever why I feel so compelled to help other shooters or what drives me in that direction. It is enough to say that it is my passion.

Keep up your good work on this board and BRC as you have a lot to offer to those that will listen. I will do a better job on my end.

God bless,
Jim Hardy

 

[Ringostar]

Most of us are shooters, not writers. Sometimes what we're trying to say, doesn't come across clearly. I stated what myself, and fellow F class shooters use for chambers. I was never saying that a 313 doesn't work, only asking why he went with that size. I'm always willing to learn about other things to try. Jim gave great info for his set up. I only do a slight clean up of .014, giving a .312 loaded round with .005 total clearance. I guess what we should be asking the op, is "What thickness have you turned your necks to?" That would be a better way to help figure out a proper bushing size.

 

[bsumoba]

annealing will help, a slightly larger bushing will help, and using a dry tumbler versus wet tumbling (i have no clue which you are using, but wet tumbling will leave the inside of the necks almost too clean).

 

[expiper]

your fired round give a good idea of what your neck dia really is ,,,but most important of all is the loaded dia,,,,the bushing should be .002-.003" smaller than that,,,remember that Redding bushings are rarely what they are marked to be,,,measure a sized neck and see what it is,,,Roger

 

[gilmillan1]

thank you for the lengthy response. I appreciate when someone shares their experience. As far as my problem goes, i do anneal, turn necks to .012-.0125. I had no issues loading new brass. However, once I tried to reload the brass, the tension spiked. I can think of only two things. Either my SS tumbler is cleaning brass too much or my brass is getting more resistant when i anneal. I am still trying to solve the problem. I already prepped some brass that was not tumbled at all. I only cleaned the neck and the primer pocket. I did anneal them. I will see if this makes any difference.

 

[Ringostar]

Are you using Win brass or necked up 6.5x284 brass. You might also want to check for internal doughnuts in the necks. That will increase your seating pressure, if your seating bullets down to them.

 

[mikecr]

I was prodding earlier to get actual information, still missing some. But you're suspicions here are plausible.

Either my SS tumbler is cleaning brass too much or my brass is getting more resistant when i anneal. I am still trying to solve the problem. I already prepped some brass that was not tumbled at all. I only cleaned the neck and the primer pocket. I did anneal them. I will see if this makes any difference.