Pressure Signs for Mechanical Ejectors

[Marksman_92]

When working up a load to discover max charge weight in your rifle, how does one look for pressure signs in an action that uses mechanical ejectors? Such as the American Rifle Company Mausingfield and the Kelbly Atlas Tactical? Does the brass still flow like your standard plunger ejector or are there different signs to look for?

 

[spife7980]

You just have to watch the primers that much more closely and then look for swipe that occurs when the brass is forced again the face tight enough that the rotation to unlock marrs the brass. Then you can feel for the heavy bolt lift of click at the top. You can measure your case head diameters. Excessive velocities.

 

[steve123]

^^^^^
And if you do a ladder test, most of the time the rifle will shoot best in a node at normal pressures. In my experience with Mausingfield it takes a ton of pressure to get to the sticky bolt indication. Using a chrono, and common load data, if you've exceeded max by a lot you can assume it's over pressure.

 

[Sheldon N]

I have a TL3 and will start to see ejector marks when I get towards the upper end of pressure. Ejector marks look different though, they are a horizontal line where the groove for the mechanical ejector goes. Sort of like a stripe on the case head. Pressure for me usually is light ejector marks, then heavy bolt lift which creeps in slowly as pressure increases.

 

[PinesAndProjectiles]

I've got 116 rounds through my Nucleus with a 6.5 Criterion right now and so far, every different charge weight has some primer catering. I'm shooting Lapua SRP brass with CCI 450s.

Even the factory Hornady 140g Match ammo had some catering.

But no flat primers, no ejector marks and no stiff bolt lift. Today I loaded up 43g of H4350 under 142 SMKs and I get the same results. The cratering on this stout load seemed to be worse than the rest so I'm backing off as it has to be getting hot.