OzFclass

BTW a preferred option to my dumb question could be .... Shut up Rob let's just get along well together.

For my part I'm planning to start some chat between us over here so this stuff that aint right gets talked about so we can avoid the inevitable tensions that will arise if we don't ! Regards Rob Kerridge.

Now how come my new F Open shooter's got vertical .... ??

Now how come my new F Open shooter's got vertical .... ??[/quote]

The reasons for vertical are varied and many .

I had unexplained vertical until I changed my position and installed ski rails ( open) on my forestock.
Shooting with a rock under the rear plate cannot be too good .

Also load that works at 900 yds can hit dynamic stability or dead speed zone and flop all over the target at 1000 yds

Signs of a load giving up its last spluttering of energy, just like a spinning top when it starts to wobble!

Now how come my new F Open shooter's got vertical .... ??[/quote]

Is your vertical at all ranges? Or only at the longs i.e. from 600 yds to 1000 yds? What caliber & which bullets?
Keith H.
Off topic, Alan perhaps move to Technical??

Back to the rear plate.
I have a rear plate made of 10mm aluminium with grip tape on top and 3 threaded holes for my adjustable spikes which I have used for years.
Fast forward to the FCWC and they are not permitted so most of us opted for a 12mm plate.
I glued some non slip rubber stuff top and bottom and simply placed it directly on the grassy mound with my seb bigfoot bag on top, this is by far the best system I have used!
The bag wouldn't move on the plate so it was a bit of a struggle to setup at times having to move the whole lot about.
There were NO elevation issues.
Only problem is more heavy stuff.

My rear plate is made of 3/4" (19mm) mild steel and has a chain as a carry handle. Its big enough for my bigfoot rear bag. I think it weighs nearly 10kg ,about the same as my rifle

No clump of grass has won an argument with it yet. It does not have spikes