How to judge when a press is "worn"?

[fguffey]

And then there should be a question that goes something like; “It is possible to reduce the inside diameter of a worn press if the ram is not worn?”


The bore can only ware in the form of an hour glass meaning it is not likely to ware in the middle. Again because of the linkage getting tangled up on the Rock Chucker before it has a chance to cam over the bore would ware in the front top and rear bottom.


Then there are shell holders that fit, my Herter shell holders fit, my favorite shell holder is the RCBS but it only fits where it touches.


F. Guffey

 

[BoydAllen]

The purpose of a press is to shove a case into a die to make straight ammunition. If it does that IMO it does not need fixing. I have a friend with a lathe that has done some work to make his RCBS shell holders have more clearance, and has recut the slot in the top of his rockchuckers' rams to more of a keyhole shape to create some needed clearance toward the rear. He raises the ram until he feels the case lightly touch, and then reverses it slightly before raising it again to size the case. All of his work has resulted in measurably straighter brass. Whether the difference is enough to show up on the target is another matter, but he has the time, interest and tools, so he did.

 

[trental]

That is exactly what I do. Raise the ram until the case enters, then slightly let off pressure and let the case find center and position itself in the shell holder. Then resize with a full stroke. Seems to be working.

 

[savagedasher]

My feelings about miss alignment of ram to sizeing dies . Whenever you size a case and the ram and the die are close together Any missed alignment changes the case face . The case will show straight but the face that meets the bolt is now crooked . Larry

 

[bheadboy]

I had two RCBS A2's I used for making br bullets, using B&A and Deitsch dies, 224 and 6mm

the result bullets were very very good, the rams on both presses rattled a little if shaken,

let the object self align with the dies,

my 35 year old RCBS ammo master progressive loader ram is well worn in after 100k+ loads and the ammo comes out very true using rotational dial indicators, and hornady base to oj, measuring

FWIW
Bob

 

[fguffey]

My feelings about miss alignment of ram to sizeing dies . Whenever you size a case and the ram and the die are close together Any missed alignment changes the case face . The case will show straight but the face that meets the bolt is now crooked .

I made a tool that measured that problem, problem: I did not make the gage to measure cases. Then there is the alignment between the press, case and die. My cases align the die with the shell holder in the top of the ram. I do not remove the detent spring in the shell holder, I did purchase a small bag of 5 retainers just in case I came across a few shell holders that did not have one.

F. Guffey

 

[savagedasher]

I made a tool that measured that problem, problem: I did not make the gage to measure cases. Then there is the alignment between the press, case and die. My cases align the die with the shell holder in the top of the ram. I do not remove the detent spring in the shell holder, I did purchase a small bag of 5 retainers just in case I came across a few shell holders that did not have one.

F. Guffey

The best answer is use a press without a ram and float the die . Or custom the press and dies for perfect alignment. That is why I use a custom seater And a arbor press

 

[BoydAllen]

A little story: I have several presses. They all seem to work for sizing with few if any problems. What I have noticed is that my straightest sized cases come from one piece dies that have the correct neck ID. For example, I have a stock Hornady die that has a neck ID that is about .258, and the runout of sized brass from that die (with no expander) runs about a third of a thousandth at the end of the neck of a 6PPC case, and in my opinion that is plenty good for any application, no matter how demanding.

Years ago, I helped a friend with a project. We ordered a chambering reamer for a match spec. tight neck .223 chamber, that was designed to work perfectly with a stock, one piece, RCBS FL die, so that sized brass (no expander), of the correct thickness to give the loaded round neck clearance that he wanted, would have the correct neck tension. That rifle shot like a true benchrest rifle even though it was only a varmint rifle based on a Shilen barrel and a single shot Savage action. The brass and loaded ammo was exceptionally straight. All of his sizing was done on a stock Rockchucker.