Mandrel as last step?

[Mikecr]

The records are meant to be broken, prove us wrong.

It seems absurd to nurture a notion that record shooting came down to any single item (among so many).
That is not how anything in particular is proven.

What primer was a last record shot with? Should everybody now be using that primer, for that reason?
What wind flag, or sizing lube, or scope? Was there shooting skill involved?

Can YOU prove any particular thing caused a record group.
If you can that's great. Bring the understanding that is predictable and passes all tests.
That is how things are proved.

 

[Alex Wheeler]

Mike,
The point I am trying to make is that there are different ways to achieve the goal. You say that you should mandrel and not seat with more interference fit than the yield of the neck. You can do that, and if your rifle likes that you will have good results. But I can also point to many group aggregate records where no mandrel was used and a lot of neck tension was use. Because thats how those rifles shot best. Not single targets, year long aggs. These are the most accurate rifles in the world, grouping far better than a hunting rifle. So you can see the difference. Again, not to say that you cant anneal, mandrel, lube, and run light neck tension with success. Some of my customers do. But you cant say any of those things are the best or correct way to do it.

 

[Mike Matteson]

Finding the primers for part of the component is part of developing a load. I realize the some primers work better than others. Two different rifles could be two different primers. "There more than one-way to skin a cat" That the fun part of reloading. Is to develop a load that's accurate, does the job you want it too. Explore or read about what other people are doing and trying if you want too. See how it works in with your personal style of reloading, or upgrading your equipment to match what really works.
"THE RABBIT HOLE"
It's beginning to sounds like religion. Mine is better than your's.
I have the greatest amount of respect for both of you, Alex, Mikecr and several others here.

 

[DoneNOut]

I've just introduced mandrels to my program. I'm not telling anybody what to do, this is just what I am testing. There is some info in this thread I got to process.

Annealed brass (I used to think that was ok until Alex just gave me a stroke about it)

1. Universal decapper
2. A series Redding or RCBS FL die with decapper removed.
3. Expand necks with mandrel to desired fit/size

I discovered the mandrel needs to move the brass by .003" to hold to mandrel shape. Trying to tickle a case neck to just .001 larger didn't stick and spring back overcame.

Having recently delved into controlling my "neck tension" I now know what Lee was doing with their collet dies I had in the early 2000s. I always thought their 'interference fit" was way too loose. I would order the smaller rod, or reduce it with emery cloth. Well, Lee was putting their necks at .0015-.002" fit. All other dies would give ,003-.005 interference. My mandrels have me at that Lee tension now. LOL. Student to the grave!

 

[Mikecr]

Mike,
The point I am trying to make is that there are different ways to achieve the goal.

That IS NOT what you implied. You said "The records are meant to be broken, prove us wrong".
This, implying that you aren't going to assign credit for anything, from anyone, without this prerequisite qualifier. Right?

Have you ever overtightened a bolt, felt it go plastic, and knew right there that you were screwed?
Well, let me pose this to your method of understanding: have any of your BR heroes ever done that?
That's what you're doing with sizing necks ~6thou.
You are not producing any 'more tension' with that, than continuing to turn that bolt would. Right?
What do you think the elastic range of cartridge brass is?

 

[Alex Wheeler]

That IS NOT what you implied. You said "The records are meant to be broken, prove us wrong".
This, implying that you aren't going to assign credit for anything, from anyone, without this prerequisite qualifier. Right?

Have you ever overtightened a bolt, felt it go plastic, and knew right there that you were screwed?
Well, let me pose this to your method of understanding: have any of your BR heroes ever done that?
That's what you're doing with sizing necks ~6thou.
You are not producing any 'more tension' with that, than continuing to turn that bolt would. Right?
What do you think the elastic range of cartridge brass is?

Mike, go back to post 27. I only made mention of the non mandrel and heavy neck tension records to say that it works as well. I have no heros and was a mechanic for 14 years. We all know the necks yield when you seat bullets. It does not matter. What matters is the accuracy of the rifle changes. Why, I dont know. But there will be a difference in group size with all the different neck bushings. We test the hell out of this on paper at 1k with rifles that shoot the difference. The difference between .004 and .005 nt is usually obvious. But it should not matter because its way past the yield point right? But it does. Im not sure how many thousands of 1kyd test targets I have seen and shot but I am not making this up. You are wrong and the only reason I waste my time on forums like this is to stear guys in the right direction.

 

[Mike Matteson]

Interesting on the back and fore on tension. I am just barely getting into this neck tension. I just used whatever the sizing die provided for most of my life. It's just been over a year I have changed to using bushing dies, and setting neck tension. So school is just beginning for me on sitting neck tension.
I still dropping back and changing things. I am adding a rifle with two shorten barrels to fireform my cases. before going to my rifles. I have just started that. In setting up to have a 257/280AI rifle, I made the move to have a second action to use to fireform cases. I looking foreward to getting behind my 6mm/280AI rilfe that is done and begin to shoot it.
My time here in Montana is running out again. Having to go back to Mexico-North again for awhile.
It's been interesting as I go along in life, how the twists and turns come about. I wanted to spend as much of a winter here in Montana to see if my wife would like it. Grand kids are here. So she loves it.

 

[Mikecr]

If only we could measure neck tension..

 

[M1A1ABRAMS]

If only we could measure neck tension..

I may be way off here but when you measure the amount of force it takes to seat a bullet doesn't that give you some indication of your neck tension ? That is on a non compressed load. I am real new to reloading. But I thought that was the point of doing such. Am I wrong ? Please explain it in a simplistic way as best you can.

 

[Dragoon300]

I may be way off here but when you measure the amount of force it takes to seat a bullet doesn't that give you some indication of your neck tension ? That is on a non compressed load. I am real new to reloading. But I thought that was the point of doing such. Am I wrong ? Please explain it in a simplistic way as best you can.

There is a product on the market.

From AMP, same people making the induction anealing machine, pricey but worth it.

 

[DoneNOut]

If only we could measure neck tension..

and get people to specify "cartridge" and not "caliber" used to imply cartridge...

 

[M1A1ABRAMS]

There is a product on the market.

From AMP, same people making the induction anealing machine, pricey but worth it.

Yes I saw Eric Cortina use it. Comparing the flame to the amp machine.

 

[Mikecr]

I may be way off here but when you measure the amount of force it takes to seat a bullet doesn't that give you some indication of your neck tension ?

Not a direct indication.
A prior thread about this: https://forum.accurateshooter.com/threads/seating-force-measurement.3985487/

Seating force is mostly frictional, which plays no internal ballistic role.
So we can only correlate seating force with 'relative' tension (roughly) -at carefully controlled/normalized friction.

True neck tension, amounts to hoop tension, provided by brass spring back force, against a bearing area (PSI).
It is possible to measure this force but there is currently nothing available for it on the market.
Given this, instead of trying to set force (which you can't measure right now), it's easier and more precise to adjust sizing LENGTH, which spring back force would apply to. It's also easier, and logical, to do this in a pre-seating operation, so that you can match it before seating bullets.

 

[Dragoon300]

I do believe that frictional force, or the psi required to move the bullet directly affects internal ballistics, and that actual neck tension (squeeze) creates more or less friction. I also believe that consistency is the end goal, regardless how much friction is present. Loads can be tailored to suit. If the friction is consistent, that part of internal ballistic deviation is removed. Hence, neck tension can be high or low so long as it remains consistent, the friction stays the same. It would seem then that if you measured seating force and kept it consistent things should be good, unless the bullet and case bond after sitting as in "cold weld" creating a pressure spike. I do think the AMP anealer and press would be very helpful tools. Maybe next on my list.