.001 neck tension for .308 F-TR load?

[skiutah02]

I test religiously, and am always happy to share what I have learned. I keep no secrets. When newish shooters set or tie national records after helping them out (this has already happened) I feel like part of the team, and when they stomp me the next time we meet (which has also happened) it takes a little of the sting out of the drubbing.

 

[dcali]

The idea that there are any secrets is sort of amusing. It's really a matter of discovering the whys, which then lead you to the whats. There is no secret recipe - only the understanding and process that lead you to good results.

 

[Alex Wheeler]

What I can say about most shooter's "secrets" is that all they are, are things that most people wouldnt think to try that ended up working really well.

 

[cw308]

In 99.9% of the time everyone in the shooting spot are willing to share , I just bumped into that 1%er.I was taken back for a second though . Only a second . Sorry for changing the subject of the post .

 

[270WinDude]

Neck tension is a weird area of reloading where people like to come up with theories on what should work and why, then stick with it. While in other areas like powder charge, we all just test it until you find the right place. I recommend treating neck tension the same way.

From all I've gathered it depends on the cartridge. The Litz related testing I've read he tested for velocity spread and what was interesting to me was that in the 308win and 223 he didn't record any differences yet in the 243 he did. So until someone produces a cartridge specific test for the particular one I am shooting I'll continue to operate under the assumption that I have to test all these variables. The best group I've shot so far was some rounds I should have pulled because the bullet was so loose I could pull it out with my hand if I needed to and a more jump then normal. Having said that, I do realize how hard that would be to make that into a consistent thing, so I do what's repeatable.

 

[270WinDude]

I might try seating some 7mm bullets in some 6.5-284 brass. Necking up is for suckers.

ah yes the good ole 284-6.5-284win jam right?

 

[Richard Coody]

Is the force needed to push the bullet out of the case neck the same 5 days (weeks?) after seating the bullet as it is after 5 minutes?

If not, what's the difference?

i have no idea but my experience with my benchrest rifle has told me it likes freshly loaded ammo. just my experience that i get high 2's with week old ammo and 1's and low 2's loaded the night before. I know others have different experiences. whatever works for you.

 

[cw308]

Could it be bonding of the neck an bullet ? That's why I started using dry neck lube to the bullet . It working out well so far for me .

 

[Richard Coody]

Could it be bonding of the neck an bullet ? That's why I started using dry neck lube to the bullet . It working out well so far for me .

i leave the carbon in the necks undisturbed except for a light brushing before charging. use the imperial dry neck lube on new brass.

i use the 21st century shooting hydro press and have found if i size several days before seating bullets seating effort goes up a lot. something is happening with the brass during that period of time. now i use an expander mandrel sized for .001 neck tension right before charging and seating. works very well for seating effort consistency.

 

[Bart B.]

Could it be bonding of the neck an bullet ? That's why I started using dry neck lube to the bullet . It working out well so far for me .

If you're referring to dissimilar metal bonding by electrolysis, that is possible. Especially if both bullet and case surfaces are very clean.

Some years ago at a match, someone used very old reloads 'cause he "wanted to use them up." One round was so much over pressure it froze the bolt as the rifle recoiled much more than normal. Finally was able to open the bolt then extract the 30-06 case. Its neck was torn off at the shoulder and went downrange with the bullet.

This is one reason military ammo has that sealant between bullet and case neck. Bullet release force stays more consistent a long time.

 

[riflewoman]

For a “50,000 foot” background:

https://en.m.wikipedia.org/wiki/Cold_welding

 

[Dusty Stevens]

I know last weekend i pulled some bullets that had been loaded over a perfect carbon layer you guys like for 2 yrs and i had to seat them deeper to break the seal and it pegged my hydraulic press out to the max and they broke loose with a loud pop. When they were seated they had around 15psi

 

[Bart B.]

Some people on military teams used a Lyman 310 tong tool seating 7.62 NATO M118 match ammo bullets .010" deeper breaking that sealant to cut velocity spread and vertical shot stringing at long range in half. Bullet extraction force spec was 20 pounds minimum. Some lots had a 5 to 10 pound spread about a 25 to 30 pound average.

 

[Drop Port]

I know last weekend i pulled some bullets that had been loaded over a perfect carbon layer you guys like for 2 yrs and i had to seat them deeper to break the seal and it pegged my hydraulic press out to the max and they broke loose with a loud pop. When they were seated they had around 15psi

In the past when i had more time, got out more and was more neurotic, if I loaded in advance for a match or anticipating a day of shooting, I seated a bullet half stroke and quickly ran them through the seater the day of or night before shooting.

 

[cw308]

Bart B
Knowing bullet extraction point is far above my pay grade . I can't imagine the amount of gages an tools you all have to test . Just to make that one hole five shot group . Easier to carry a dull #2 pencil , think of how much powder an bullets you could save making your target looking good .

Chris

 

[Martin52]

......

• Open neck back up minimally with correct size mandrel pin referenced above.
• 

Just on this, opening up minimally would not pass the yield point ?

 

[Dusty Stevens]

Just on this, opening up minimally would not pass the yield point ?

Sometimes you have to run a +.003 mandrel to get +.001 in the end according to brass hardness

 

[Martin52]

Sometimes you have to run a +.003 mandrel to get +.001 in the end according to brass hardness

I don't disagree but if the neck brass is annealed I am not sure whether minimal 0.001 expansion up (that may not break the yield) is better that say 0.004 that may break the yield but run out gets worse (my experience).

 

[Dusty Stevens]

I don't disagree but if the neck brass is annealed I am not sure whether minimal 0.001 expansion up (that may not break the yield) is better that say 0.004 that may break the yield but run out gets worse (my experience).

Get a porter precision mandrel die. You can set it in half thou increments or even finer if you get into the plus/minus pins. No matter what annealed state its in you can move seating pressure in lb increments if you like to get that fine with it

 

[Richard Coody]

only one way i know of to know how consistent your neck tension is and that is an arbor press with some sort of seating force indicator gauge. otherwise you are just guessing. i got the 21st century shooting hydro press. Quite an enlightening experience for me.