Shoulder Bump

[semomike]

Annealed 6.5cm Hornady 1 fired brass, Redding UltraMag, Redding SMALL BASE die

Guys, I'm reloading for a POF gas gun and trying to achieve a consistent .003 shoulder bump.

I'm getting at least a a variance of .003 measured with a Mitutoyo caliper and Hornady case bump gage .375 without moving the die. I'm verifying that all case are approximately 1.5620 before sizing, and getting some wild changes. Sometimes even as small as 1.535. The press is camming over, and am using a very small amount of unique on my rubber gloves prior to sizing. Sometimes I will achieve the desired 1.5950 I'm shooting for.

What the heck am I doing wrong? I'm assuming it's spring back, but I thought annealing was supposed to help with this!

Yes, I meant 1,5535, and I flame anneal. I usually shut out the lights when I anneal, putting the inside flame almost touching the shoulder, and setting my time till the brass just starts glowing red

 

[semomike]

I have a set of burst fire inside neck diameter “pin gauges” and use the .291 (I think, I’m not at my bench) neck bushing (special order Small base type s Redding die) to try to achieve about 3 thou in neck tension. I’ve struggled getting neck tension to be consistent when don’t use an expander ball. My process is measure case length with .375 Hornady gauge, bump the shoulder with the press, check neck tension with the pin gauge, measure the shoulder bump achieved. I use different pieces of brass to zero in. As soon as I achieve my results (usually 3-4 pieces of brass) I will just run with it checking periodically with the pin gauge and bump gauge.

Maybe I’m under lubed (always a problem!!!!!). I usually put a very small amount of unique on my gloves and give the brass a quick spin in my hands n the way to the press.

I also try to remove expander ball and see what kind of results I get this time on neck tension and shoulder bump.

 

[Link]

I make my adjustments with "THESE" ... it solves that for me. Trying to get it right without adjusting the shell-holder, can be really hard sometimes.

No other good way to do it, if you want to bump camover.

 

[One Eye Pete]

Another quick tip. If you want to get away with using a minimal amount of case lube try polishing the inside of the sizing die. I do this with almost all of my sizing dies and it makes a huge difference especially on a small base die where you are squeezing down even more. It’s a simple procedure, I use a piece of paper towel wrapped around a wooden dowel until it fits snugly into the die. I coat the paper towel with either Flitz or White Diamond metal polish and work it around inside the die until it has a mirror like finish. It takes about 20 minutes but makes a bid difference in the force required and amount of lube needed for sizing. No it doesn’t affect the die dimensions as you are only removing the roughness of the metal surface.

 

[ELR LVR]

When I push the brass up into the die I always pause 4-5 seconds. This will help with springback and you'll get more consistency. As others have said, watch for lube on the shoulders a make sure you're not getting lube buildup inside the die. Die might need to be cleaned.

Good tip I sometimes forget to do
Takes a second for brass flow

 

[DJSBRS]

When you anneal make sure you have enough heat on the shoulder and not just the neck itself. If you are flame annealing and the flame in only hitting the neck the shoulder may not be getting hot enough and giving you some spring back. I like to point the flame at the shoulder just slightly behind the neck shoulder junction.
The other thing is check your press. I don’t let my press cam over, I use a hard stop. You can also do this by using Redding competition shell holders and always have the shell holder touch the bottom of the die when sizing. This helps minimize inconsistency with the press. Also as mentioned above no lube on the shoulder. Also as mentioned above I never use an expander ball just a good bushing die or a standard die and then a mandrel.

Exactly!

DJ

 

[foxguy]

When you anneal make sure you have enough heat on the shoulder and not just the neck itself. If you are flame annealing and the flame in only hitting the neck the shoulder may not be getting hot enough and giving you some spring back. I like to point the flame at the shoulder just slightly behind the neck shoulder junction.
The other thing is check your press. I don’t let my press cam over, I use a hard stop. You can also do this by using Redding competition shell holders and always have the shell holder touch the bottom of the die when sizing. This helps minimize inconsistency with the press. Also as mentioned above no lube on the shoulder. Also as mentioned above I never use an expander ball just a good bushing die or a standard die and then a mandrel.

I saw that this was mentioned a couple of times, Is the lube adding like +,- .0005 to shoulder bump (onto the already .001) adding to inconsistency? I have never seen no lube on the shoulders. I have been lubing the neck, shoulder, and the case body lightly.

I have been targeting .002 of shoulder bump +/- .0005. getting .002 +/-.001 sometimes.
How consistent of a shoulder bump are you typically getting, .XXX +/- .0005?

I need to start Annealing regularly.

Thanks for sharing your experience.

 

[quest450]

I recently sized 200 7X fired AMP annealed after each firing brass and I get .0005" variation with my custom Warner die.

 

[charlie b]

I saw that this was mentioned a couple of times, Is the lube adding like +,- .0005 to shoulder bump (onto the already .001) adding to inconsistency? I have never seen no lube on the shoulders. I have been lubing the neck, shoulder, and the case body lightly.

I have been targeting .002 of shoulder bump +/- .005. getting 002 +/-.001 sometimes.
How consistent of a shoulder bump are you typically getting, .XXX +/- .0005?

I need to start Annealing regularly.

Thanks for sharing your experience.

Decades ago the lubes could be a bit 'waxier' and it was easy to put the lube on unevenly. You could get 'dents' in the shoulder when the lube was built up in one area. I suspect you could also get more of a shoulder setback that way as well.

 

[Kracken McGraw]

I don’t see how one could not get dented necks by putting lube on the shoulder, I could get them if I barely put any on the neck. I dip my necks in 21st Century moly beads and wipe the outside off and then just sparingly lube the body with wax.

 

[charlie b]

I've sprayed on lube for quite a while now (Hornady) and not had any issues with the shoulders. The lube 'dries' pretty fast, leaving a very thin layer of something.

 

[Webster]

Annealed 6.5cm Hornady 1 fired brass, Redding UltraMag, Redding SMALL BASE die

Guys, I'm reloading for a POF gas gun and trying to achieve a consistent .003 shoulder bump.

I'm getting at least a a variance of .003 measured with a Mitutoyo caliper and Hornady case bump gage .375 without moving the die. I'm verifying that all case are approximately 1.5620 before sizing, and getting some wild changes. Sometimes even as small as 1.535. The press is camming over, and am using a very small amount of unique on my rubber gloves prior to sizing. Sometimes I will achieve the desired 1.5950 I'm shooting for.

What the heck am I doing wrong? I'm assuming it's spring back, but I thought annealing was supposed to help with this!

You never mentioned how you are annealing. Some guys still think you can anneal at 750F, you need 1050-1100F to flash anneal. The neck and a little of the shoulder should turn red for 1-2 seconds. I use a handheld propane torch. The necks get red in about 9 seconds. I don't have the tip of the flame away from the neck like all the videos show. I push the flame into the neck so it wraps around rhe neck for more uniform heating. A lot of the videos on annealing show 1 side of the neck getting red before the far side. I hold the cases in a turner case holder in an electric drill.

 

[Chris Edmondson]

Just to rule out metrology issues, try measuring the same piece several times in a row. A caliper and attached gage, even with a flat base, can yield inconsistent readings; there's a bit of technique required to achieve consistency. Cleanliness of the caliper jaws and the gage is important as well, it's amazing how the tiniest pieces of grunge can throw off readings.

 

[JFrank]

Annealed 6.5cm Hornady 1 fired brass,

1 time fired brass is rarely consistent and this would be my guess as to the variations you are seeing.
Report back after the brass has been fired 3 times or so.

 

[Ilmo]

“Lube inside neck. Expander ball pulling the soft (annealed) shoulder up. If you Graphite on a small mop, you won't need clean it out. Helps in bullet seating with the soft necks”

What he said

 

[7stwwsm]

Annealed 6.5cm Hornady 1 fired brass, Redding UltraMag, Redding SMALL BASE die

Guys, I'm reloading for a POF gas gun and trying to achieve a consistent .003 shoulder bump.

I'm getting at least a a variance of .003 measured with a Mitutoyo caliper and Hornady case bump gage .375 without moving the die. I'm verifying that all case are approximately 1.5620 before sizing, and getting some wild changes. Sometimes even as small as 1.535. The press is camming over, and am using a very small amount of unique on my rubber gloves prior to sizing. Sometimes I will achieve the desired 1.5950 I'm shooting for.

What the heck am I doing wrong? I'm assuming it's spring back, but I thought annealing was supposed to help with this!

need to stop using hornady brass and it needs two firings before you get to consistent reloading

 

[Maximus1840]

After a few decades of reloading I tried the competition shell holders. WoW! Made my life so much easier

 

[danny]

Why the small base die?

That's a very good question..

Danny