Modding the Area 419 Zero Press for less flex

[MagnumW]

Using the Zero Press on bumping Large 40 degree shoulder Lapau AI brass I was seeing up to a .004 gap between the turret and the press (red arrow in pic below) as the turret flexed. Thats with 30lbs on the handle which is more than you will need for most cartridges and if you are just creeping up on the big stuff or not touching shellholder to die you can skip this.

But if you like a firm touch of shellholder to die (sized shellholders) this trick will help.

Use the back one or 2 threaded die holes and screw spare mandrel or bullet puller dies in there bottoming firmly on the press ( see green arrow) Reduces flex by 75%. Just takes a minute to loosen and turn turret. A light tap on the locking plate that says 419 also helps seat the turret.

When you are trying to control bump variation to .0005 this may help. Keeping the turret full of dies may also stiffen it.

For 30Br, .308 , 300wm you won’t need to bother with this.

As always modify at your own risk may void warranty……

 

[Dusty Stevens]

Its not supposed to flex. Zero

 

[STS]

There is a reason that most presses are made like a "O". It would be pretty hard for me to choke down paying that kind of money for a press, and then have to come up with a solution for a significant flaw in the design.

 

[MagnumW]

The turret or press could be redesigned for zero flex but it would add to cost. The turret could add stiifeners on top or the press could have C turret top supports in the front or a front clamp bolt. Easiest is to bolt a stiffener bar across the turret using two of the die holes.

But for bullet seating, neck sizing, and most cartridge sizing there is zero flex. Its only the few magnum cases with stiff shoulders that may see flex and even then its debatable whether it matters - .003 flex just screw die in .003 more. If flex is consistent so what.

 

[SKWERLZ]

Making mountains out of mole hills.

 

[SecondsCount]

The turret or press could be redesigned for zero flex but it would add to cost....

I didn't think you can pay more than what a A419 press goes for.

 

[MagnumW]

Making mountains out of mole hills.

Only when you are weighing to the kernal with an autotrickler, annealing everytime with an Amp, keeping bump to .0005 consistancy trying to shoot 4” five shot groups at 1000 with 300 gr bullets to little things like this matter to you. When loading for any typical competition cartridge you would notice zero flex.

 

[SKWERLZ]

Only when you are weighing to the kernal with an autotrickler, annealing everytime with an Amp, keeping bump to .0005 consistancy trying to shoot 4” five shot groups at 1000 with 300 gr bullets to little things like this matter to you. When loading for any typical competition cartridge you would notice zero flex.

I see guys winning National events not having to do that.

 

[MagnumW]

I see guys winning National events not having to do that.

They aren’t shooting my 12# lapua Ai with 300 bergers at 3000 fps.

 

[Area419Craig]

Based on email thread, I think between this and the idea of milling off the travel stops to allow you to create cam-over, you're looking for something to tweak on the press or an opportunity to make a thread.

The design you have is using a hardened tool steel center lug to secure the turret. Check out the cross-section here. You're either deflecting the aluminum portion of the turret, which means you've gone beyond any amount of needed pressure (the brass would form before you'd get shear deflection here) or you aren't tight with the pull-stud and wedge system. In overuse/failure testing we were able to create some small amount of deflection, which is the nature of using any materials (we could do it with cast o-press designs as well).

Could we make a press without a movable head that probably allows you to put an additional multiple of force into it with less deflection in the material itself? Maybe. But that's not the point of the unit. It's to be as functional, repeatable, and enjoyable to use as possibly for virtually all reasonable use cases.

 

[MagnumW]

Craig, thank you for some feedback! I researched all the FAQ and emailed questions to you before posting. In my rare case I noticed flex before my case was sized which lead my to this exploration. I can insert a .0015 feeler gage under the front of the turret with 15# on the handle. I am assuming this is normal? Perhaps my turret is not locking down as most do??? Its a brilliant press, just hoping to make the best ammo possible with it.

I measured the force required to bump the shoulder on a std Lapua brass .003 at 35lb on the middle of the handle knob. Less than this won’t bump it back enough. My Lapua AI requires a bit more.
With my mod it barely flexes sizing either.

 

[Evan]

Using the Zero Press on bumping Large 40 degree shoulder Lapau AI brass I was seeing up to a .004 gap between the turret and the press (red arrow in pic below) as the turret flexed. Thats with 30lbs on the handle which is more than you will need for most cartridges and if you are just creeping up on the big stuff or not touching shellholder to die you can skip this.

But if you like a firm touch of shellholder to die (sized shellholders) this trick will help.

Use the back one or 2 threaded die holes and screw spare mandrel or bullet puller dies in there bottoming firmly on the press ( see green arrow) Reduces flex by 75%. Just takes a minute to loosen and turn turret. A light tap on the locking plate that says 419 also helps seat the turret.

When you are trying to control bump variation to .0005 this may help. Keeping the turret full of dies may also stiffen it.

For 30Br, .308 , 300wm you won’t need to bother with this.

As always modify at your own risk may void warranty……

I'd like to suggest that perhaps it isn't your super tough brass creating this problem and that it is perhaps that your sizing die is to big to size the brass properly. Your picture shows full die/ram contact and I've never had luck getting any more sizing once my dies were in full contact with the ram. Have you considered having a custom sizer made based on your fired brass? My custom whidden dies size with noticeably less effort than off the shelf dies and the bottom of the die does not contact the ram when bumping the shoulder back 0.002".

 

[MagnumW]

Good point, but mine don’t contact the ram either except Im using a .010 thicker shellholder for consistent touch. I used a standard shellholder to test and it had a .010 gap to get a .003 bump. At that point I had 35# on the handle and about .003 flex on the turret. Sizing any large magnum round I expect you will notice some turret flex if you look close or measure with feeler gage. Not saying thats an issue as it should be fairly consistent. Use my mod mentioned to reduce it. It would be an easy redesign to eliminate it if mfg thought it was critical. Maybe they will now that they are aware of it - but their market of small competition cartridge users won’t notice any flex.

 

[JimSC]

Only when you are weighing to the kernal with an autotrickler, annealing everytime with an Amp, keeping bump to .0005 consistancy trying to shoot 4” five shot groups at 1000 with 300 gr bullets to little things like this matter to you. When loading for any typical competition cartridge you would notice zero flex.

how much flex is in the die when the cartridge is being full length sized ? How much play is in the shell holder ?

 

[MagnumW]

The die (turret) goes up about .003. The shellholder has zero vertical play. Plenty of radial play. I’m not sold on rigid dies being better than floating dies. I’ve had good luck with oring under lock ring to float die at times. Im trying to minimize flex with this press to find out how to exceed my rockchucker results which were good.

If you setup ram to just touch the die at the top of stroke without brass you need to turn it in another third of a turn to compensate for press flex when sizing large brass. The “zero flex” isn’t there to the degree I expected.

 

[big5ifty]

This brings to mind the excitement people got caught up in sticking straws in the Chargemaster.

Nobody seemed to think that spending that kind of money on a piece of equipment, and then having to insert a McDonalds straw into it to make it work properly, was any kind of problem.

 

[SeabeeKen]

Does the problem go away on an O press?

 

[JimSC]

The die (turret) goes up about .003. The shellholder has zero vertical play. Plenty of radial play. I’m not sold on rigid dies being better than floating dies. I’ve had good luck with oring under lock ring to float die at times.

what I was referring to with the die is when the ram is at top dead center and the case is inserted into the die, how much play is present. The answer is effectively zero, you are in a Class V press fit situation, or as a friend described it doing a cold extrusion. When the forming of the case is taking place the only "play" between the case and the die would be a few molecules of lubricant. Before that case emerges from the die it is as concentric as the bore of your die. Considering that dies are made using a through reamer, that would be as close to perfect as it gets.

Just my theory here but I think the necks are bent out of concentric during the downstroke when the expander ball passes through the neck and the sides of the neck. The brass is unsupported by the walls of the die at that point and logically that is the only time it can happen

In regard to the shellholder having zero vertical clearance, that is false. If it did you would have a heck of a time getting that case in and out of the shellholder without some sort of mechanical assistance. The best you could hope for there is a Class IV transitional fit and the normal RCBS shellholder would be a Class I loose fit

The bottom line is that the purpose of a press is simply to allow you to do a press fit into the die and mechanical aid you to remove the case from the dies. The die is where all the forming of the case takes place whether you use a press or a hammer to get it in.

 

[MagnumW]

This brings to mind the excitement people got caught up in sticking straws in the Chargemaster.

Nobody seemed to think that spending that kind of money on a piece of equipment, and then having to insert a McDonalds straw into it to make it work properly, was any kind of problem.

Or buying $15 set of 3D printed washers from a guys kid to make the $600 autotrickler work consistently…….

 

[big5ifty]

Does the problem go away on an O press?

I haven't got the tools to measure. It would be interesting to know if even the aluminium Lee Challenger has any measurable flex. I doubt it has.