dangun
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I love the smell of burnt gun powder.
Posts: 517
Location: SW Florida
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Post by dangun on Nov 16, 2014 23:02:52 GMT -5
Chuck,
Nice job. I have to ask, How much grip are you putting on the bullets? I think maybe the grip or neck tension isn't consistent from round to round. While those are decent group sizes, I think there is room for improvement. Of course if it doesn't need to be better than that then lock it down.
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7mmmountaineer
Member
Time to face it I am a workaholic............
Posts: 521 
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Post by 7mmmountaineer on Nov 16, 2014 23:09:14 GMT -5
Dan I have never measured grip ever so I have no idea. I use what RCBS calls their custom competition dies. I know that compared to my Lee Collet dies their is a lot more grip. My collet dies even after sizing I can start a bullet enough that I will stay in the case. Were as with the dies I used today I can't. For what he is going to be doing with it what I have for him is good enough if he decides to use one of them.
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bob
Member
I'm too old to be nice but never too old to learn!
Posts: 1,457
Location: Northern California
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Post by bob on Nov 17, 2014 1:21:34 GMT -5
Dan, You asked how much grip is Chuck or me for that matter applying to the bullet. How do you measure the grip? I realize that grip will affect interior ballistics and then of course have an effect on exterior ballistics. The only way I know to control grip for bottle neck cartridges is to neck turn,trim and anneal the brass then size all of the bullets which I believe you do for competition. Is there some other way?
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7mmmountaineer
Member
Time to face it I am a workaholic............
Posts: 521
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Post by 7mmmountaineer on Nov 17, 2014 13:59:38 GMT -5
Chuck, Nice job. I have to ask, How much grip are you putting on the bullets? I think maybe the grip or neck tension isn't consistent from round to round. While those are decent group sizes, I think there is room for improvement. Of course if it doesn't need to be better than that then lock it down. Dan I think that a big part of his problem was the fact that he never annealed his brass. Add to that I ran a FL sizer die that increased neck tension and it helped. Room to improve on it sure their is always room to improve. Am I going to do it for him no. The fact that I have the number rounds under my belt with this caliber that I do was a plus. Do I think if he had changed rifles back in say August or September when he would have had more time to work with help sure it would have. He tried to be slick then got pissed when things didn't work out right off the bat. I have done all I can he will either take what I have found or he won't its his choice. |
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dangun
Member
I love the smell of burnt gun powder.
Posts: 517
Location: SW Florida
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Post by dangun on Nov 17, 2014 23:05:41 GMT -5
Bob Bullet grip is another term for neck tension. It is basically a measurement of the interference fit between the small inside neck die and the bullet dia. Here is a good article on Neck Tension. |
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bob
Member
I'm too old to be nice but never too old to learn!
Posts: 1,457
Location: Northern California
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Post by bob on Nov 17, 2014 23:40:30 GMT -5
Good article Dan, thanks very much. Over the years I have measured the before and after dimensions of the neck but not affixing a value to it,I think we had a discussion about this in our past life.
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dangun
Member
I love the smell of burnt gun powder.
Posts: 517
Location: SW Florida
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Post by dangun on Nov 18, 2014 7:48:07 GMT -5
Bob, Yes I can remember this coming up in discussion at least 2 previous times. For me it is always fun to go back and revisit some of these topics because opinions do change or methods to control these variables sometimes improve. More often than not this is one variable that most reloaders don't look at much or give much thought, nor do they really need to in everyday use. The neck tension or bullet grip needs to be much tighter in everyday or hunting ammo than in competition ammo. Off the shelf standard sizing dies have no adjustment for this and the amount of tension is determined only by the neck wall thickness. This is why most competitive shooters use neck bushing dies. This is by far the best method I have found to TRY to control at least one more variable. In my 22BR, 22PPC, 6PPC, 6BR, 7BR, and 30BR ammo, the neck tension is usually between .002" and .003". That is barely enough to keep you from pulling the bullet by hand. With that light of a tension an un-fired round cannot be extracted in one piece. The bullet will almost always be left in the chamber. This is partly due to the fact that all of my benchrest rounds are jammed into the lands when chambered. However the throat is usually tight enough to cause the same thing. I did some experimenting and found that I had to have at least a .006" tension to extract and un-fired round. If you think about it this is another reason to keep your brass annealed. If not the brass will not springback when a bullet is seated. Most of us have been at the bench loading away and then find a round or 2 rounds that the bullet is very loose. Either that case didn't get sized or it has become so hard that it has no springback and will not maintain neck tension. Just one more variable for you guys to fuss over!  |
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My daughter came from Missouri, my son and grand son, my wife and I had a nice dinner of grilled "porter house" pork chops, corn on the cobb, my son, G'son and I share 10/5. G'son is 4 minutes early though @ 10/4.
Pooh I hope you find to right house . 
