Accuracy from push-button ejectors?

[Ray B]

Several years back, when the gun-writers were writing what the gun makers wanted, I recall an article that claimed a push-button ejector added to the potential accuracy of a rifle, compered to a fixed blade. the premise was that the button pushing on the topside of the cartridge base pushed the front of the case to the bottom of the chamber, and the cartridge was so placed for every shot, leading to increased consistency.

It seemed to me at the time that if a cartridge was properly sized and the bullet in a concentric position that it would be tight in the chamber and the bullet in a repeatable position without any need for a push from the ejector- but what do I know?

Thoughts? Was the author on to something. or just writing what the advertiser wanted?

 

[bruce moulds]

or did the author have his hand on it?
zero runout supposedly produces better accuracy.
the guy was actually inducing runout albeit in a similar direction.
however, very few rounds have zero runout within themselves, so some might have even more runout when pushed sideways by an ejector.
in my fclass rifle which is well put together and of good parts, i have tested 0.008" runout ammo vs nearly zero runout, and couls not detect enough difference to worry about.
other factors like bending light making the target appear in different places, unknown to the shooter, and wind deflection, and hold, even on a benchrest, can and will counter such fine variances for better or worse.
maybe an unlimited machine rest bench gun might show a difference.
for the average shooter/hunting rifle in the field, other factors will far outweigh any potential benefit here. (if there is one!)
bruce.

 

[Alistair]

I can sort of see how a push button ejector can be intrinsically more accurate, but I doubt it matters in any real world situation. Yes, the push ejector actively wedges the round into the chamber under slight spring tension, so the orienttion is perhaps more consistent, and also the firing cycle could potentially be a little more reliable and consistent too as the primer can't 'shuffle away' from the firing pin during firing and striker travel time and therefore lock time and ignition cycle could be better (in theory). The uninterupted bolt face is also slightly stronger and easier to machine to tight tolerances perhaps. That said though, with a chamber machined to equally tight target tolerances and with rounds which are meticulously sized and seated to achieve a slight crush fit into the chamber and maybe even into the lands? Meh. Nothing anyone could notice, especially not in the real world.

I rather suspect that the main reason that PRF actions win competitions and are possibly more accurate is a simpler one; they're simply more convenient for target shooting.

Push button ejector equipped actions are more accurate because they're use in competition. Therefore the top shelf PRF actions bought, used and tested in magazine articles by people who care about stuff like run out are designed to be 'F class' standard. CRF guns are designed to be 'hunting accurate'. A very different thing.

I don't know of many factory pillar bedded CRF guns for instance, or many chassis guns based around CRF, or many blueprinted CRF actions, or dedicated target triggers for mausers, or or or...

 

[bruce moulds]

added to which, to begin to see any difference, cases would need to be neckturnd, weighed, primer pocket uniformed, flashole uniformed, inside flash hole deburred, and more.
who wants to do this for a hunting rifle generally.
properly fls cases will not be pushed sideways by a plunger ejector, because the shoulder will be a nice fit in the chamber, holding things in line.
should your ammo be too slackarsed to do this you will never notice the difference.
should your barrel have been chambered and threaded in a 3 jaw chuck, you could never do this test meaningfully.
should you have a scope under 36x, you could never do the test.
how good would projectiles have to be to test properly, and those would be totally unsuited to hunting.
and so on ad infinitum.
sometimes gun writeres simply display sheer ignorance in their writing for all to see in full neon.
but people believe them because it is written in print.
this is how many urban myths begin.
bruce.