Bumping the shoulder question...

[mbohuntr]

I'm still learning the tricks, so this might be a silly question... If I have several rounds thru some brass, and it has probably stretched and started to get hard to close the bolt.

Can I anneal it, measure it's overall length with calipers, and full length size it checking the overall length until it shrinks a couple of thousandths? I would check the overall length and trim if necessary afterwards...

Thanks!

[Texas10]

Cartridge OAL and base to shoulder are not the same. OAL is important because you don't want the mouth of the cartridge to jam in the throat of the chamber. This can cause a pinched bullet and possible chamber rupture upon firing. Base to shoulder dimension is important for chamber fit, and brass life/growth, and a too loose fit will cause misfires. You DON'T want to stretch your brass a whole lot every time you cycle it, it'll soon split. I recommend you buy the gages and learn to set up your dies properly for good fit, function, and case life. Sorry, but anything else is just a waste of your time and money, IMOP.

[Robinhood]

Good advice there. Annealing is part of the quest for consistent accuracy.

[Stumpkiller]

I never bother to anneal. But I do outside trim necks. It depends on your cartridge shoulder angle, load intensity, and maybe even your individual chamber.

If your cases don't requite trimming to length after 15 reloads then annealing probably isn't worth the bother.

I find my primer pockets get loose and I disguard cases before annealing would have been worthwhile.

[Robinhood]

I never bother to anneal. But I do outside trim necks. It depends on your cartridge shoulder angle, load intensity, and maybe even your individual chamber.

If your cases don't requite trimming to length after 15 reloads then annealing probably isn't worth the bother.

I find my primer pockets get loose and I disguard cases before annealing would have been worthwhile.

You do realize brass work hardens right? Neck tension and all that....Nevermind, you can't teach an old dog new tricks anyway!

[mbohuntr]

Cartridge OAL and base to shoulder are not the same. OAL is important because you don't want the mouth of the cartridge to jam in the throat of the chamber. This can cause a pinched bullet and possible chamber rupture upon firing. Base to shoulder dimension is important for chamber fit, and brass life/growth, and a too loose fit will cause misfires. You DON'T want to stretch your brass a whole lot every time you cycle it, it'll soon split. I recommend you buy the gages and learn to set up your dies properly for good fit, function, and case life. Sorry, but anything else is just a waste of your time and money, IMOP.

I think I didn't explain it right.. I was thinking of using the OAL measurement to measure shoulder bump since I don't have a way to measure that accurately. I just read that neck sizing DOES bump the shoulder. Maybe I should look into a set of gauges to see what's going on. I always check OAL as part of a case prep check, and trim as necessary.

[LoneWolf]

You need to purchase a bump gauge. You can’t measure the shoulder based off OAL.


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[Stumpkiller]

You do realize brass work hardens right? Neck tension and all that....Nevermind, you can't teach an old dog new tricks anyway!

Oh yes. I had heard. Just as important as having a sharp flint in the lock and a dry frizzen.

I know it is a viable method. Especially if you are resizing from another cartridge and the neck is set back (I used lead immersion as a "younger dog" when forming .22 Jet cases). Not without problems, though. Softer brass flows and stretches easier and requires trimming more often, and can cause neck thinness. Then you're right back to inconsistent neck tension. Too soft and the neck will collapse when seating the bullet. Done right it makes more consistent pressures. Done wrong it may do more harm than good.

[yobuck]

Good advice there. Annealing is part of the quest for consistent accuracy.

Notice he said (quest) lol.
As for a case not chambering after its been fired a few times, its due to case stretch which is a normal thing, and annealing wont help that.
Full length resizing helps in that area, but even if you use that system of loading it can eventually happen.
You might not be able to bump the shoulder back enough by full length resizing after it takes place.
Easiest fix is to go to a place like Sinclairs and get a set of (competition shell holders).
Just follow the directions included, which will have you changing the shell holder on your press till you get to the one allowing the bolt to close.
Its just that simple, and there really isn't any need to dig any further than that.
If you change brass, go back to your standard shell holder till the problem pops up again.

[mbohuntr]

I think I'll look into that, Thanks all!

[ssgairborne187]

Your case has stretched, to set your shoulder get a set of automotive feller gauges use a .004, turn your die down until the gauge has some resistance with the ram fully extended that sets your shoulder, full length size and trim to spec. your ready to go until it stretches again our the cases usefull life has ended.

[geargrinder]

You don't need anything fancy to check shoulder bump. Just head over to your tool box and grab a socket that fits over the neck but not the shoulder. Use it as a bump gauge. Put it over the neck and measure from the end of the socket to the end of the case. Adjust your dies to get the amount of bump desired, verified with your new bump gauge.

I'd also add annealing into your reloading routine.

[GaCop]

You don't need anything fancy to check shoulder bump. Just head over to your tool box and grab a socket that fits over the neck but not the shoulder. Use it as a bump gauge. Put it over the neck and measure from the end of the socket to the end of the case. Adjust your dies to get the amount of bump desired, verified with your new bump gauge.

I'd also add annealing into your reloading routine.

+1......

[OLEJOE]

When you first start full length sizing, your cases may actually get longer to the datum on the shoulder from the sides of the case being reduced in diameter. I back the die off and slowly move it back down in small increments until I where I want it to be .

[bigedp51]

Below minimum shoulder bump would be .001 to .002 below the red dotted line for a bolt action rifle.



Below measuring a "FIRED" Lake City 5.56 case from my AR15, and then adjust the die for .003 shoulder bump. I used Redding competition shell holders to control the amount of shoulder setback.

If i had used a standard shell holder and adjusted the die per the instructions, meaning hard contact with the shell holder with press cam over the shoulder would have been pushed back .007.

Bottom line, by measuring a fired case with a Hornady type gauge and adjusting the die for minimum shoulder bump you will extend case life.

[mbohuntr]

LOTS of good ideas here... THANKS!

[Stumpkiller]

Now picture the prior illustration but with a set of various shell holders that hold the cartridge head 0.002", 0.004", 0.006", 0.008" or 0.010" lower than the "regular" one (while still bottoming out the die for consistency) so you can still get the tapered case resized mostly to the base and yet just set the shoulder back 0.002" from the fire-formed dimension. (Redding Competition die set - $50 +/-)

[mnbogboy2]

Here is a quick & effective method that I use for using a full length die to bump.
Tools;
1) fired brass
2) scissors
3) scotch tape (.002 thick)
4) the rifle
5) press, die & lube
Step 1) Place one thickness of tape on the head of a piece of fired brass that needs to be bumped. Try to close the bolt. It should not close. Remove the tape.
Step 2) Set up full length die per mfg instructions and then back it off approx 1/3 turn (2 hexs if it is a hex lock nut).
Step 3) Size the first piece of brass (piece 1) at that setting and try in the chamber. Back the die out more if it closes and start again with another piece of fired brass.
If it did not close turn the die in approx 1/36 of a turn at a time, resize and try in chamber (1/36 turn is approx .002).
Step 4) As soon as the brass closes in the chamber, discard that piece and size another (piece 2), try to close the bolt on this second piece.
If it closes then put a piece of tape on the head of it. If it closes but very "snug" you are where you want to be. If it closes easily with tape on it you have gone too far and should back off the die a little and now start with another piece of fired brass(piece 3).
If (piece 2) did not close with tape on the head you are very close but maybe need just a smidge more (1/40th to 1/60th of a turn).
Step 5) Lock down that setting and try a couple more. Check with and without tape.
Side note: older brass that has not been annealed has varying amount of springback and consistency will vary. Older I mean 10-20 firings. Usually a person has to bump long before that.
If you get my drift here and are fairly good running a pair of scissors it only takes 5 or 10 minutes to get the bump set. It has worked well for me and the best part is that is pretty much fool proof.
My .02,
Randy

[Muddly]

I used the highly advanced socket method to adjust my full length dies. Pure genius. I set for .002, I hope it will take care of the odd flyers. I checked what the dies were bumping before and got .006. Not good...

[yobuck]

I used the highly advanced socket method to adjust my full length dies. Pure genius. I set for .002, I hope it will take care of the odd flyers. I checked what the dies were bumping before and got .006. Not good...

Well i lived in SE PA for 64 years, (Bucks Co.), and i know for a fact not all that live (lived) there are pure genious. lol
For this non genious, just changing the shell holder seems easier.

[Muddly]

I know what you mean. I'm in Lehigh county, and being an upstate New York transplant (x40 years) I still meet people who make me wonder who tied their shoes...