I am bumping the shoulder on 22-250 cases, I would like to move them .003". All my fired cases measure 1.519" so that puts me at 1.516, correct? I am using Redding competition dies with the separate body die for this procedure and the cases are lubed with Imperial sizing wax. The shell holder Lyman, is the thinest one I have for that case. So even with the die cranked down all the way to where it makes contact with the shell holder all the bump I can muster is .002" to .0025" and it differs with each case, not consistant. Where am I going wrong ? It seams so straight forward. I am using the Hornady comparator and shoulder bump gauge set to make my measurements.
Shoulder bump confusion
- Thread starter rr2030
- Start date
XTR
F-TR obssessed shooting junkie
I have had a short chamber that I had to lap the top of a shell holder to get enough bump on a particular rifle. That's not been an issue since I got my own reamers and spec my chambers with the smith.
As to consistent bump, ±.0005 is plenty for me, your mileage may vary.
edit: oh yea, anneal. If I don't anneal I get shoulder bumps all over the place.
As to consistent bump, ±.0005 is plenty for me, your mileage may vary.
edit: oh yea, anneal. If I don't anneal I get shoulder bumps all over the place.
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DngBat7
Silver $$ Contributor
If you mean the hornady headspace gauges?, those are crap and I returned mine. Big and clumsy. I never got the same reading twice on the same piece of brass. Check this one out. It gave me way more accurate results
https://www.whiddengunworks.com/product/shoulder-bump-gauge/
Much smaller and well made
Dusty Stevens
Shiner
Try more lube and keep the press at the top longer. Are they chambering ok? Put a feeler gage under the case the additional amount you need. Id back off and use a .010 thick blade
IME it's hard to position these tools and the cases in precisely the same position each time. While I find it remarkable that ALL your fired cases measured EXACTLY 1.519", let's run with that. Apparently, your tools aren't crap after all 
Anyhow, I personally got more consistent results using the Hornady Anvil Base Kit piece that helps ensure the base of the case is flat against the "caliper". If nothing else it made me feel better, quicker lol.
I'd probably leave things alone at 0.0020-0.0025 and declare victory, but shaving your shell holder or the base of the die a tad could get you an extra thou or so.
Anyhow, I personally got more consistent results using the Hornady Anvil Base Kit piece that helps ensure the base of the case is flat against the "caliper". If nothing else it made me feel better, quicker lol.
I'd probably leave things alone at 0.0020-0.0025 and declare victory, but shaving your shell holder or the base of the die a tad could get you an extra thou or so.
How did you arrive at this number? Do they fail to chamber? For me, if the cases chamber (which most of mine do do) I'm not 'bumping' anything.
Your head to datum measurement is no where close to the SAAMI spec of 1.578"
I know its just for comparison, but seem like it should measure closer, with the proper diameter bushing?
Hornady headspace bushing B .350" for the 22-250
As stated use enough lube not too much consistency on press stroke each time and annealed brass so that it is consistently the same throughout. Did I say consistency?
Some like to shim, I would rather take a flat piece of steel, put a piece of 600-1000 wet dry on it and a drop of oil and lightly ease the surface of your shell holder or bottom of your die.
Some like to shim, I would rather take a flat piece of steel, put a piece of 600-1000 wet dry on it and a drop of oil and lightly ease the surface of your shell holder or bottom of your die.
Well from reading stuff here, .0015 for the bench rest guys .003 for gas guys. Im running a factory stock Rem 700, I figured .003 would be good to go with. No ? The cases all chamber nicely. And yes they all measure exactly the same after firing.
The Butler Creek comparator size is 28, purchased prior to Hornady taking over. A brand new never fired Federal Premium 55HPBT measures 1.514"
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rr2030
As stated above if you pause at the top of the ram stroke for 4 or 5 seconds it reduces brass spring back. And this gives you more uniform shoulder readings, especially if you do not anneal your case necks.
I buy bulk once fired Lake City 5,56 and 7.62 brass fired in a multitude of chambers. And the first thing I do is size the cases in a standard die and pause as above.
If the case does not fit in my JP Enterprise case gauge I break out the small base die. The JP Enterprise gauge is cut with a finish chamber reamer and is smaller in diameter than other case gauges. I give the case the plop test in the JP Enterprise gauge then measure case headspace length.
I have the Hornady cartridge case headspace gauge and I prefer it to the RCBS gauge below. And the reason for this is I have a digital vernier caliper with "BIG NUMBERS" for my chronologically gifted eyesight.
Below a fired LC 7.62 case in a Dillon case gauge.
Below the same case in the JP Enterprise gauge, the case does not drop in as far because the gauge is smaller in diameter and cut to minimum SAAMI dimensions.
Bottom line, I'm sizing these once fired cases with a standard sizing die and pausing and they drop right in the JP Enterprise gauge.
As stated above if you pause at the top of the ram stroke for 4 or 5 seconds it reduces brass spring back. And this gives you more uniform shoulder readings, especially if you do not anneal your case necks.
I buy bulk once fired Lake City 5,56 and 7.62 brass fired in a multitude of chambers. And the first thing I do is size the cases in a standard die and pause as above.
If the case does not fit in my JP Enterprise case gauge I break out the small base die. The JP Enterprise gauge is cut with a finish chamber reamer and is smaller in diameter than other case gauges. I give the case the plop test in the JP Enterprise gauge then measure case headspace length.
I have the Hornady cartridge case headspace gauge and I prefer it to the RCBS gauge below. And the reason for this is I have a digital vernier caliper with "BIG NUMBERS" for my chronologically gifted eyesight.
Below a fired LC 7.62 case in a Dillon case gauge.
Below the same case in the JP Enterprise gauge, the case does not drop in as far because the gauge is smaller in diameter and cut to minimum SAAMI dimensions.
Bottom line, I'm sizing these once fired cases with a standard sizing die and pausing and they drop right in the JP Enterprise gauge.
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Let your chamber tell you how much to bump. If you can strip your bolt(Rem 700 and clones are easy), run a case thru the body die and chamber. Inadequate bump and bolt will not close. Re lube, adjust die down a bit and repeat until bolt closes with just a little resistance. You can use bump gauges to take readings during this but bolt closure tells you case is resized. I use custom dies now but when I used Reddings, I had to get my press to " cam over" to get adequate bump.
What I am doing now and I am not comfortable with it.
^^^^+1k%
C. Nichols
Gold $$ Contributor
RR2030, there nothing wrong with your method or measuring devices. It’s your die. I’ve seen this numerous times. Dies are no different than anything else man made. The tooling gets worn or the reamer or CNC may cut it a tic too deep. Just find you a friend with a lathe and a carbide insert and turn about .020 off the bottom, slick it back up and go for it. Just my experience.
I should say the die is a tic too deep for your chamber, or your chamber is a tic shorter than your die. Nevertheless it can be fixed. Hope this helps
I should say the die is a tic too deep for your chamber, or your chamber is a tic shorter than your die. Nevertheless it can be fixed. Hope this helps
Adding additional lube and giving a 5 count at the top of the ram travel has worked a little better. A fired not sized case easily chambers in my rifle near un noticeable difference than the sized case. As a note, performing the sizing operation exactly the same every time yield .001" to .0015" difference in length. if I didn't know better I would say Hillary is messing with me.
I think I am making this difficult. Going to set the die as I have for 15 years and pretend I never heard of shoulder bump.
I think I am making this difficult. Going to set the die as I have for 15 years and pretend I never heard of shoulder bump.
That's not going to work. When it touches the dimension is as short as its ever going to be without removing metal from the shell holder or the die.
After your cases have been fired 2 or 3 times without bumping the shoulder measure.them to see what your chamber is . Then set your die to bump .002-.003. if you need to face off the shellholder in a lathe .002 to get the bump.you need. If .002 isn't enough take .002 more off shell holder.
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