Neck tension too light?

[marchx]

1 I. either FL size my brass oruse a Forster bushing bump die.
2. after that I run a standard 21st century carbide mandrel throught the necks (graphite lube applied before)

I noticed that after 3rd firing my neck tension becomes light to the extent that when using Hornady comparator to measure the CBTO I can push the bullet inside if I push against the comparator a little harder ( 0.005-0.01). should I prevent this or is it ok?

I am considering using smaller bushing before running the mandrel. What do you think?

 

[jepp2]

I can push the bullet inside if I push against the comparator a little harder ( 0.005-0.01). should I prevent this or is it ok?

More questions than answers. But if using your comparator you can push the bullet inside the cartridge further, that is a problem.

What cartridge are you loading for?
How much neck tension do you want?
What is your loaded neck OD, fired neck OD, sized neck OD, and neck OD after expanding?
What diameter mandrel are you using?
What is your bullet seating depth (the length of the shank in contact with the case neck, if BT that length doesn't count)?
Answers to those questions might define you need to anneal, might need to use a smaller mandrel, might need to use a smaller bushing, and the possibilities go on.

 

[swd]

Annealing will keep your neck tension much more consistent and also your shoulder bump.

 

[Big Mc]

1 I. either FL size my brass oruse a Forster bushing bump die.
2. after that I run a standard 21st century carbide mandrel throught the necks (graphite lube applied before)

I noticed that after 3rd firing my neck tension becomes light to the extent that when using Hornady comparator to measure the CBTO I can push the bullet inside if I push against the comparator a little harder ( 0.005-0.01). should I prevent this or is it ok?

I am considering using smaller bushing before running the mandrel. What do you think?

What swd said. Tommy Mc

 

[Coyotefurharvester]

Smaller bushing, same mandrel probably won't increase interference fit. Find the answers to jepps questions and you should be able to fix/find consistency.

 

[Clancy]

Just to solidify what the others have said, because it’s such great advice….. running .001 tension requires springy brass, and you get that with annealing.

Just for kicks though, verify the diameter measurement on your mandrel at several points, and keep it clean. Brush your case necks out before running the mandrel.

When you’re playing with ten tenths, you don’t have room for error.

 

[gme]

as the brass hardens (by firing and resizing) the necks will become loser (because the work hardened brass springs back) annealing is the fix

 

[marchx]

@jepp2

1.What cartridge are you loading for?
I am referring now to 6.5 CM
2. How much neck tension do you want?
Good question. I was thinking 1 thau is ok, but it seems maybe to light. I am not sure, advice on this would be welcomed here.
3.What is your loaded neck OD, fired neck OD, sized neck OD, and neck OD after expanding?
fired neck OD- 297
Loaded neck OD- 290

Sized neck OD using Forster FL die- 286
Sized neck OD using Redding neck die- 289 (does it makes sense to run a mandrel here at all?)


4. What diameter mandrel are you using?
262
5. What is your bullet seating depth (the length of the shank in contact with the case neck, if BT that length doesn't count)?
320

 

[JMayo]

Stop using the mandrel. Nk bushing only.....

 

[JFrank]

@jepp2

1.What cartridge are you loading for?
I am referring now to 6.5 CM
2. How much neck tension do you want?
Good question. I was thinking 1 thau is ok, but it seems maybe too light. I am not sure, advice on this would be welcomed here. -testing is the key, my set up like a bushing .003 under a loaded round
3.What is your loaded neck OD, fired neck OD, sized neck OD, and neck OD after expanding?
fired neck OD- 297
Loaded neck OD- 290—-I would start here

Sized neck OD using Forster FL die- 286– and here
Sized neck OD using Redding neck die- 289 (does it - makes sense to run a mandrel here at all?) - I don’t think so


4. What diameter mandrel are you using?
262- stop this
5. What is your bullet seating depth (the length of the shank in contact with the case neck, if BT that length doesn't count)?
320

If you’re annealing, I would suggest setting a few rounds aside and let the brass firm up a bit more and test no annealing. You may be surprised at the results.

 

[marchx]

Stop using the mandrel. Nk bushing only.....

I am using it only because the committee of wise men adopted the position stating that using a mandrel is mandatory if you want to win matches.

 

[marchx]

If you’re annealing, I would suggest setting a few rounds aside and let the brass firm up a bit more and test no annealing. You may be surprised at the results.

I don't anneal. I used to but I quit because as Loud Murdica said- either use AMP or don't anneal at all.

 

[JFrank]

I am using it only because the committee of wise men adopted the position stating that using a mandrel is mandatory if you want to win matches.

How’s that working out ? Seriously just test a few bushing sizes and let the target tell you what the rifle prefers

 

[marchx]

How’s that working out ?

Well, when I win Southwest Nationals, I'll let you know.

 

[BoydAllen]

For me, one of the main points of having bushing dies is to also have a selection of bushings to try, to see what works best. I have noticed that this option may not be exercised by many who use these dies. I would expect the same to be true of expander mandrels. I have found that some powders have definite "preferences" for neck tension. Like most other things, I have made this determination by doing my own experiments, which I encourage others to do. Over the years I have been privileged to have interviewed, pursuant to writing articles, a number of match winners. One thing that they all seem to have in common is that they do their own testing of literally everything they think might influence accuracy.

 

[swd]

I am using it only because the committee of wise men adopted the position stating that using a mandrel is mandatory if you want to win matches.

Both ways work, bushing or mandrel only. I’ve won individual days at state championships using both methods. But the one thing that always gives more consistency is annealing.

My experience is the same as yours, the 3rd firing is when cases get noticeably harder and inconsistent.

I get it, the price of admission for an Amp is painful. Next to my AD scale and auto trickler it’s the best thing I’ve bought in the last 20 years for reloading.

 

[marchx]

@swd what is your recommendation for addressing the issue I mentioned?

 

[swd]

@swd what is your recommendation for addressing the issue I mentioned?

If your not going to anneal, skim turn and try smaller bushings and keep using the mandrel. Or bite the bullet and anneal. Personally I think flame annealing is better than not annealing but comparing flame and the Amp, the Amp is even more consistent.

 

[whatsupdoc]

@jepp2

1.What cartridge are you loading for?
I am referring now to 6.5 CM
2. How much neck tension do you want?
Good question. I was thinking 1 thau is ok, but it seems maybe to light. I am not sure, advice on this would be welcomed here.
3.What is your loaded neck OD, fired neck OD, sized neck OD, and neck OD after expanding?
fired neck OD- 297
Loaded neck OD- 290

Sized neck OD using Forster FL die- 286
Sized neck OD using Redding neck die- 289 (does it makes sense to run a mandrel here at all?)


4. What diameter mandrel are you using?
262
5. What is your bullet seating depth (the length of the shank in contact with the case neck, if BT that length doesn't count)?
320

Something is not right here, .286 bushing and .262 mandrel should provide adequate neck tension for a 6.5 Creed case.

Loaded over 9k of 6.5 creed using a .262 mandrel with various brands of brass.

What Brass?

Try loading two cases without using the graphite inside the neck, use
whatever you use to lube the outside just make sure you clean it off the inside of the neck.

 

[marchx]

Something is not right here, .286 bushing and .262 mandrel should provide adequate neck tension for a 6.5 Creed case.

Loaded over 9k of 6.5 creed using a .262 mandrel with various brands of brass.

What Brass?

Try loading two cases without using the graphite inside the neck, use
whatever you use to lube the outside just make sure you clean it off the inside of the neck.
@whatsupdoc

I didn't say I use .286 bushing. I use only Lapua brass. I'll skip the graphite next time.