Brass Trouble (Help Please)

Zero- headspace from too many neck-sizing's.
Time to FL size it again.

It is so tight with zero headspace it is getting stuck in the chamber on closing the bolt.

Then 'pops' loose when the primary extraction cam pry's it out on opening.

rc

is this the, 'bumping the shoulder back' scenario I think I read about somewhere?

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Yes it is.

Jim

And is there some kind of rule of thumb?

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Nope, when the cases are getting tough to chamber, you either FL or bump the shoulder back...both achieve the same "improve case to chamber fit". Of course, one may be better than the other for your gun, and you'll have to figure that out by trying them.

Try bumping the shoulder back - .001" (with a FL die) everytime you resize. That'll keep your handloads uniform, and they'll always chamber.

There are no drawbacks to full length resizing, if it's done accurately.

A cartridge headspace gauge would be very handy here. Measure the case that is tight, measure the headspace, screw down the sizing die so that the shoulder is bumped back a few mils, recheck and record that number.

OR

Simply use a "too big" case and set the appropriate sizing die depth by trial and error and mark that spot with a magic marker on the die and locknut in relation to an index spot on your press.

For economy, if you want to also measure face to ogive lengths, get this set and just the .308 headspace gauge because you can't buy individual bullet comparators by themselves. No need to pay more for a bunch of headspace inserts you'll never use.

After buying these, I find a magic marker, a set of calipers and the guns themselves as the best gauges.

Keep it Simple ....

Kis2 ........

Just use a FL sizing die accurately, and it will resize the whole case in one operation (while fully supported). All you need to know is how much clearance your handloads have in YOUR particular chamber. Then set your die height to make perfect fitting handloads.


This gauge displays your exact shoulder clearance. It gets calibrated to one of your fired cases. Then, look at one of your handloads, and you'll see exactly how much to raise (or lower) your die height.

It works on ALL different calibers - without any special attachments or bushings.

This would work also:



It's called a Redding Instant Indicator. It measures case length, bullet length (base to ogive) and headspace and OAL.

Step 1: Measure the length of your difficult to chamber brass from base to datum on the shoulder using the gauge. Step 2: Use the FL or bump die to push the shoulder back a thou or two. Step 3: Use the gauge to see how much you're setting it back. Step 4: Check chamber fit. Step 5: Continue the loading process.

A $250 dial indicator set-up will certainly work.

However a simple L.E. Wilson case gage will work without Chinese Algebra.
Or a $1.49 Magic Marker or Dry Erase marker.
Or a .25 cent birthday cake candle.

Any will work as well, if not better.

1. Color or smoke the shoulder of a tight case.
2. Chamber it.
3. Where the marker ink or candle soot rubs off is tight.
4. Adjust the FL sizing die down to bump the shoulder back until it isn't tight.

IMO: I have never owned a rifle accurate enough to benefit from neck sizing only.
(If the FL sizing die is adjusted to fit the rifle chamber this way.)

rc

Ahem...

A $250 dial indicator set-up will certainly work.

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It's $120.99 RC.

Of course, bumping the shoulder until it fits is all that is necessary...and smoking the shoulder is more than adequate, but if you want to measure, you need a gauge. Same result, varying paths and prices to get there.

Best to remove the firing pin and spring from the bolt if you go old school for better feel when trying the cases in your rifle.

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Absolutely. On my benchrest gun, I remove the firing pin. Place a bumped case in the chamber and let the bolt handle fall on the case...if I did it right, it closes half to 3/4 of the way with a "crush fit" the last bit ensuring a perfect chamber fit.

Are you not losing case life by FL sizing over neck sizing? Or case volume? Or consistency? My rifle isn't a benchrest special 6mm, but it is all match graded.

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There is a wrong way and a right way to set up a FL die...unfortunately, both will let you chamber and shoot the cartridge. The wrong way overworks the brass because the die is set up incorrectly. The right way sizes it enough without overdoing it.

For my LR gun, I buy once fired brass. FL size it and shoot it in my gun. Plinking load or whatever I have surplus components for. Once it's formed to my gun, I neck, load, neck, load, etc. When the bolt gets difficult to close, I bump the shoulder using a Redding shoulder bump die, which I previously used a Redding Instant Indicator to set up for proper 1-2 thou bump, then load as usual......starting with a neck sizing die.

Other than a caliper, you need one thing and one thing only:
Hornady Headspace Gauge Set

You've already got some oversize (i.e, hard-to-chamber) cases, so....

1. Screw the sizing die to contact the shellholder and back off 1/4 turn.

2. Size a case and see if it will chamber without effort (we hope not)

3. Screw the sizing down another 1/16 turn and try again

4. And again 1/16 turn*** ... (sooner or later the bolt will close without significant feel and/or you will contact the shellholder)**

5. Use the Hornady guage to meaure the case's "headspace" dimension at that point and write it down. THAT is your target from now on... for any/all cases from whatever source, in that rifle.

NOTE: You may have to set up your sizing die slightly differently for different brass having different "springback" (See note below) -- but the headspace measure you established in Step 5 always stays the same.


** If you have to, go 1/16 turn beyond contact. I have to do that for my 30-06 Winchester brass. On the other hand, my Lapua brass requires shellholder contact only.

*** If you're really anal, go 1/32 turn.

guffey will be along soon with some feeler gauges to sort this out for you

Kis2 .....

As you can see there are a jillion different techniques for measuring chamber clearance. Some are a bit primative, and others are more refined. (I'm not sure which items cost as much as shown.)

The Digital Headspace Gauge can also measure the bullet jump to your rifling. Again, this tool requires no special attachments, and it works on ALL different calibers. Very simple to operate.

Are you not losing case life by FL sizing over neck sizing?

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Not enough to matter if your rifle works right!

Right??

IMO: Case life is meaningless to me.
New brass is cheaper then a new glass eye when an over the hill case lets go.

rc

size like rc said in post #12.

save one of the sized cases for next time, so you don't have to go through all that again. just put the case in the press, run the ram up to the top, screw the sizing die down to touch the case, and get to sizing. save that case again for the next time.

murf

New brass is cheaper then a new glass eye when an over the hill case lets go.

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Not to mention, vision is much better without the glass eye too.

After you accurately Measure your actual chamber clearance, then you can see how well other methods really work.

FWIW I'm going to neck size untill I have to FL. Then, I'm going to use a marker to mark that shoulder. Then, I'm gonna do it all over again. Because it is cheap, primitave, and fun. And I AM a cheap AND primative kinda guy! NEENER!