Just happened to look one day

[amlevin]

Just happened to glance at the shellholder and bottom of sizing die in my RCBS RCII one day. Seemed strange that the shellholder didn't seem to touch the die all the way around it's top surface.

OK, now I'm curious. I screwed the die down some more and it still didn't touch fully on one corner.

Took some brake-kleen and a q-tip, cleaned the top of the ram and shell holder real well. Both looked like new. Still saw a gap.

I then removed the sizing die and installed an extra Dillon powder die I had lying around. Essentially just a threaded tube and lock ring when the caliber specific funnel is removed. Screwed it in until it contacted the top of the ram, without a shell holder in place. Wow, same amount of gap in the same place.

I then just inked up the top of the ram, ran it up against the bottom of the powder die body firmly but not banging at it. Repeated until there was a clear mark on the "ink", About 20 minutes with a flat diamond lap and I got full contact with the die bottom.

Put the shell holder back in place and checked for uneven clearance again - none found.

Has anyone else noticed this issue or was it just a case of my press being "dinged" some time in it's long past?

I always wondered why my case heads didn't seem to align perfectly around the end of a Wilson case gauge even though they indicated minimal runout. Maybe this was it??

 

[Area Man]

Thanks for posting this. I'm off to check mine.

 

[Outrider27]

Ditto.

 

[aj300mag]

That's what they make rubber o-rings for...

 

[stubbicatt]

aj300mag, O ring on your shell holder? :-\ Or is it on the sizing die, between the lock ring and the press?

 

[CatShooter]

I have no problem with that - my press weighs ~30 pounds - nothing "dings" it.

 

[aj300mag]

aj300mag, O ring on your shell holder? :-\ Or is it on the sizing die, between the lock ring and the press?

Between the die locking ring and the press.

 

[amlevin]

That's what they make rubber o-rings for...

To me, the O-Ring trick is like putting makeup on an ugly woman.

Only makes the problem a little less undesirable.

Why not fix the underlying problem and make the parts line up correct to begin with? Sized cases now don't have the earlier problem.

 

[gotcha]

Good observation Amlevin! Worth looking into on any single-stage press. Also might be interesting to check side play on ram at full extension? Ummmm?

 

[aj300mag]

That's what they make rubber o-rings for...

To me, the O-Ring trick is like putting makeup on an ugly woman.

Only makes the problem a little less undesirable.

Why not fix the underlying problem and make the parts line up correct to begin with? Sized cases now don't have the earlier problem.

So, you've inspected the contact surfaces of your shell holders to ensure they are parallel to each other within .0005" and you've machined the lock ring on your dies (after they've been adjusted and locked) so that the contact surface is square to the centerline of the die chamber to within .0005".

Cool!

 

[amlevin]

That's what they make rubber o-rings for...

To me, the O-Ring trick is like putting makeup on an ugly woman.

Only makes the problem a little less undesirable.

Why not fix the underlying problem and make the parts line up correct to begin with? Sized cases now don't have the earlier problem.

So, you've inspected the contact surfaces of your shell holders to ensure they are parallel to each other within .0005" and you've machined the lock ring on your dies (after they've been adjusted and locked) so that the contact surface is square to the centerline of the die chamber to within .0005".

Cool!

Let's just say that I have no more problem with cocked case heads. Nice and even across the top of the case gauge.

BTW, if you want to measure the parallel of your shell holders, just mount a dial indicator so it is indicating the top surface and turn it in the ram. Likewise for the surface that contacts the case head.

If you've ever used your press for swaging military crimps in primer pockets, you might want to check the top of the ram. The RCBS tool specifically requires some extra effort to remove the punch from the case and all of it us UP, against the top "lips" of the ram.

 

[jonbearman]

I wouldnt worry about the ram having movement as some benchrest guys have actually put the ram in a lathe and sand it to make more slop in the ram.

 

[queen_stick]

I wouldnt worry about the ram having movement as some benchrest guys have actually put the ram in a lathe and sand it to make more slop in the ram.

I put lapping compound on the ram, and worked the shit out of the press for an hour... much smoother operation, and it makes very straight ammo. I also 'stoned' the top of my shell holder to make even contact with the bottom of the dies.

Adding o-rings made my runout worse, but that's not always true. I think everyone should try it just to see how it compares to not using them...

 

[searcher]

I'm not sure how the "top" of the shellholder not being square with the press is an issue. I know the face portion that the shell sits on is an issue. I was once trying to figure out how to determine whether my shellholder was "true" with the press. I took a case, chopped it way down and trimmed it with a Wilson trimmer, put it in the shellholder which was in the press and raised to the bottom of a seating die while I held a small machine square between the die and the casing mouth just so the case mouth was joining a flat surface. This was a pretty crude test of a press and shell-holders but it was enough to show me I had some real problems. Use of a light all around the case mouth showed me that two of my shellholders were too far out to want to save. This was AFTER determining that my press was so far out it was a miracle my ammo came out as straight as it did and accounted for why I HAD to have my dies all sitting loose. I replaced the press and shellholders and life has been pleasant since. I since went to using the Redding Competition shellholders and they are great! I guess using hand dies is the best way to go for accuracy but sometimes we just need speed and acceptable accuracy - not necessarily absolute extreme accuracy. There are some really cheap presses out there that are really good and expensive ones that don't always measure up. For too long, I looked at everything except my press.

 

[amlevin]

I'm not sure how the "top" of the shellholder not being square with the press is an issue. I know the face portion that the shell sits on is an issue. I was once trying to figure out how to determine whether my shellholder was "true" with the press. I took a case, chopped it way down and trimmed it with a Wilson trimmer, put it in the shellholder which was in the press and raised to the bottom of a seating die while I held a small machine square between the die and the casing mouth just so the case mouth was joining a flat surface. This was a pretty crude test of a press and shell-holders but it was enough to show me I had some real problems. Use of a light all around the case mouth showed me that two of my shellholders were too far out to want to save. This was AFTER determining that my press was so far out it was a miracle my ammo came out as straight as it did and accounted for why I HAD to have my dies all sitting loose. I replaced the press and shellholders and life has been pleasant since. I since went to using the Redding Competition shellholders and they are great! I guess using hand dies is the best way to go for accuracy but sometimes we just need speed and acceptable accuracy - not necessarily absolute extreme accuracy. There are some really cheap presses out there that are really good and expensive ones that don't always measure up. For too long, I looked at everything except my press.

Get yourself one of these and measuring the surface that the case head sits on is easy.

Use a standard Dial Indicator holder and use this little gem to measure runout of any surface you can rotate. Also works great for measuring case runout as it doesn't stick up in the air above the case.

Not too expensive either

http://littlemachineshop.com/products/product_view.php?ProductID=1249

 

[searcher]

That is cool! I knew somebody had a REAL tool for the job.

 

[aj300mag]

I'm not sure how the "top" of the shellholder not being square with the press is an issue. I know the face portion that the shell sits on is an issue. I was once trying to figure out how to determine whether my shellholder was "true" with the press. I took a case, chopped it way down and trimmed it with a Wilson trimmer, put it in the shellholder which was in the press and raised to the bottom of a seating die while I held a small machine square between the die and the casing mouth just so the case mouth was joining a flat surface. This was a pretty crude test of a press and shell-holders but it was enough to show me I had some real problems. Use of a light all around the case mouth showed me that two of my shellholders were too far out to want to save. This was AFTER determining that my press was so far out it was a miracle my ammo came out as straight as it did and accounted for why I HAD to have my dies all sitting loose. I replaced the press and shellholders and life has been pleasant since. I since went to using the Redding Competition shellholders and they are great! I guess using hand dies is the best way to go for accuracy but sometimes we just need speed and acceptable accuracy - not necessarily absolute extreme accuracy. There are some really cheap presses out there that are really good and expensive ones that don't always measure up. For too long, I looked at everything except my press.

Get yourself one of these and measuring the surface that the case head sits on is easy.

Use a standard Dial Indicator holder and use this little gem to measure runout of any surface you can rotate. Also works great for measuring case runout as it doesn't stick up in the air above the case.

Not too expensive either

http://littlemachineshop.com/products/product_view.php?ProductID=1249

People actually buy those junk chicom indicators?

 

[letronshootit]

I have used an o-ring in place of the steel clip that holds my shell holder on top of the ram for years. It gives the case the ability to enter the die centered for all dies and wear that will happen eventually in a press.

 

[amlevin]

I'm not sure how the "top" of the shellholder not being square with the press is an issue. I know the face portion that the shell sits on is an issue. I was once trying to figure out how to determine whether my shellholder was "true" with the press. I took a case, chopped it way down and trimmed it with a Wilson trimmer, put it in the shellholder which was in the press and raised to the bottom of a seating die while I held a small machine square between the die and the casing mouth just so the case mouth was joining a flat surface. This was a pretty crude test of a press and shell-holders but it was enough to show me I had some real problems. Use of a light all around the case mouth showed me that two of my shellholders were too far out to want to save. This was AFTER determining that my press was so far out it was a miracle my ammo came out as straight as it did and accounted for why I HAD to have my dies all sitting loose. I replaced the press and shellholders and life has been pleasant since. I since went to using the Redding Competition shellholders and they are great! I guess using hand dies is the best way to go for accuracy but sometimes we just need speed and acceptable accuracy - not necessarily absolute extreme accuracy. There are some really cheap presses out there that are really good and expensive ones that don't always measure up. For too long, I looked at everything except my press.

Get yourself one of these and measuring the surface that the case head sits on is easy.

Use a standard Dial Indicator holder and use this little gem to measure runout of any surface you can rotate. Also works great for measuring case runout as it doesn't stick up in the air above the case.

Not too expensive either

http://littlemachineshop.com/products/product_view.php?ProductID=1249

People actually buy those junk chicom indicators?

Buy what you want. Pay 10X more for one if you wish. Unless you're working in a production shop they work just fine. The only thing they might lack is durability but if you're the only one using it, and don't use it 40 hrs per week, why not?

 

[aj300mag]

I'm not sure how the "top" of the shellholder not being square with the press is an issue. I know the face portion that the shell sits on is an issue. I was once trying to figure out how to determine whether my shellholder was "true" with the press. I took a case, chopped it way down and trimmed it with a Wilson trimmer, put it in the shellholder which was in the press and raised to the bottom of a seating die while I held a small machine square between the die and the casing mouth just so the case mouth was joining a flat surface. This was a pretty crude test of a press and shell-holders but it was enough to show me I had some real problems. Use of a light all around the case mouth showed me that two of my shellholders were too far out to want to save. This was AFTER determining that my press was so far out it was a miracle my ammo came out as straight as it did and accounted for why I HAD to have my dies all sitting loose. I replaced the press and shellholders and life has been pleasant since. I since went to using the Redding Competition shellholders and they are great! I guess using hand dies is the best way to go for accuracy but sometimes we just need speed and acceptable accuracy - not necessarily absolute extreme accuracy. There are some really cheap presses out there that are really good and expensive ones that don't always measure up. For too long, I looked at everything except my press.

Get yourself one of these and measuring the surface that the case head sits on is easy.

Use a standard Dial Indicator holder and use this little gem to measure runout of any surface you can rotate. Also works great for measuring case runout as it doesn't stick up in the air above the case.

Not too expensive either

http://littlemachineshop.com/products/product_view.php?ProductID=1249

People actually buy those junk chicom indicators?

Buy what you want. Pay 10X more for one if you wish. Unless you're working in a production shop they work just fine. The only thing they might lack is durability but if you're the only one using it, and don't use it 40 hrs per week, why not?

Why? Durability, reliability, repeat ability, the calibration is accurate through the complete range of travel...

I've got a handful of Interapids that have lasted me through 34 years (and counting) of use in precision machining including splitting tenths in a grinding room. I can't afford cheap test indicators.