Reloading presses relating to concentricity?

[in2deep]

As far as critical precision loading for long range shooting goes does anybody feel that any loading press can have a detrimental effect on concentricity with sizing or seating?
I know the thinking with the Forster Co-Axial is it's supposed to limit run-out by intentionally being sloppy and letting the case move around under the die somewhat thus allowing the die to align the bullet or case instead of the press being the limiting factor and this got me wondering if a traditional fixed press can by design or construction or flaw be out of true enough to affect the above parameters and if any types tend to be better than others or if there is really much difference generally.

 

[HolyMeekrob]

I can't speak to the 'trueness' of traditional presses and the individual brands, but I have read that placing a rubber o-ring under your die lock ring will allow for the same sort of 'slop' as the forster.

 

[BoydAllen]

The most important issue, as far as runout is concerned, is to have a FL die that is a close match to your chamber, and a seater that holds the bullet and the case coaxial during seating. if you don't have these, no press is going to make up for it. What equipment are you currently using? (BTW, the O ring thing works.)

 

[Larryh128]

+1 on the o-ring. I have loaded some very concentric ammo on my 1st loader that was a cheapie Lee. I think that good ammo can be loaded on any decent commercial press as long as the dies are concentric & you use good loading techniques. One thing that I have done over the years to improve bullet run out is to seat the bullet about 1/2 depth, rotate the case 45 degrees & finish seating. The will really help true up a bullet started less than perfectly straight.

 

[in2deep]

I have a Co-axial and a Harrell's and was just trying to decide which to keep. And generally after working with the co-axial it seems that my idea of a precision press is out the window as the co-axial has lots of "slop" by design and is supposed to make good ammo and and like you guys say if you buy an expensive press anyways the first thing you do is add slop with a rubber o-ring.
Guess I can leave this to rest now and move on.

 

[brian427cobra]

I think the term "Sloppy" used in referenced to a Co-Ax press is incorrect, my RCBS Partner Press has a considerable amount of slop in the ram and handle, my Co-Ax has no such movement that I can detect, things are allowed to float in the Co-Ax which aids in concentricity, adding a Oring to a die in another brand of press is basically doing the samething, but the repeatability is not there, also no other press has the mechanical advantage the Co-Ax has, that is no big deal in small rounds, FL sizing 300 winmags it comes in handy, I would keep both presses, one should never get rid of tools.

 

[in2deep]

What I meant by the co-ax being sloppy was meant to be a positive and it's not that the ram is sloppy but the play is designed into the unit by allowing the shell holder to slide back and forth under light spring pressure and also play is designed into the shell holder and it is allowed to move front to back so they call it co-axial since it has movement intentionally in both directions and they say this dual motion allows the shell to be guided into the die squarely by nature of the concentricity of the die itself and not the possible inconsistencies of the press ram alignment.
I had this idea from reading where some folks actually like to buy old worn RCBS presses that are loosey goosey from wear for the same reason to allow the brass some slop to allow the dies to do the alignment instead of relying on the squareness of the presses. Some even grind the shell holder open a little for added movement. Not sure if in theory there is repeatability in slop but it seems like there should be and that the rams in a co-ax only allow the force upwards and does not affect the angle or concentricity of the case and this is what got me thinking about what makes a press more precise than another if the co-ax allows the shell and die to actually move around.
This is probably all theoretical but does help me to understand what makes for a good press and try to eliminate another variable.

 

[flashhole]

larry128 made a good comment when he asserted using good loading techniques. When I set up my sizer dies I like to run a lubed case up into the die before locking it down. In my opinion this technique goes a long way to ensure concentric brass during the sizing step. I've noticed the Lee Classic Turret allows some movement that emulates the "slop" benefit. Simply paying attention to detail pays big dividends.

 

[FroggyOne2]

On my Hornady Pacifica press, I removed the retainer ring that holds in the shell holder and trued the top of the press. The last time I was about to check runout, it was at .001