Very interested in this scope but have a query re IQ at high elevation/erector travel as 40 mils combined with wide fov HM glass truely sounds like an engineering feat.
So, how does the IQ fare when dialing in fm 30-40 mils ?
Thx for your time and help.
That is a very good question and the replies have been mainly correct. The IQ does degrade as you get to the adjustment extremes and this is exacerbated by the 25% great FOV. Let me quote from the March 5-42X56 HM WA manual, where on page 1 (definitely not hidden in the fine print at the end of appendix Z-99):
“
NOTE:
This riflescope has an internal adjustment range of 40MIL; 20 up, 20 down. In any riflescope the best image quality is at or near the center of the adjustments. Because of the very wide adjustment range of this riflescope, you may experience some image quality degradation as you near the limits of the adjustment range. This can occur because of the extreme refraction of the incoming light at the edges of the objective lens. This degradation will worsen as the magnification increases.
Therefore, we recommend using an appropriate canted rail if you plan to use this riflescope consistently near the limits of the adjustment range and at higher magnification. It can be utilised to gain additional elevation and to keep the scope optically centred as much as possible.
A 20MOA rail will shift the adjustment range by about 5.7MIL to 25.7MIL up and 14.3MIL down.
A 30MOA rail will shift the adjustment range by about 8.6MIL to 28.6MIL up and 11.4MIL down."
I don't know that you can be any more transparent and honest than this. Yes, there can and will be IQ degradation at the extremes. It's physics.
However, there are people who want this maximum adjustment for certain situations, and it's available to them. YOU DO NOT have to use that much adjustment if you don't want to, but it's there if you really need it.
Every time I look at a scope which somebody mounts on a rifle with 0 built-in cant, I can't (pardon the pun) help but think that they have surrendered about half the usable elevation right there. I totally get that the vast majority of shooters never go beyond 100 yards, because that's what the local range has, and that's absolutely fine with a 0 cant. But if your interest is longer range, you should have a 20MOA rail on your rifle or some form of external cant adjustment.
Let me address the carnival wheel comment. Yes, my Match F-TR rifle is topped with a March-X 10-60X56 HM riflescope, which is arguably the finest long range high magnification scope extant. I have a 3.5 inch wheel on my focus knob because I suffer from arthritis in my left hand and I find it difficult and painful to grasp a regular size focus knob. I also play with the focus quite a bit to view the mirage through my scope at various yard lines and I can pop back in forth in an instant with that "carnival wheel". It makes for superb adjustment. Again, if you don't want one on your scope, you don't have to get one. But if you do want one...
My superb March-X 10-60X56 HM is in a set of Burris XTR rings, on top of a 20MOA ramp. I have adjusted the scope so that it's near mechanical zero and 1000 yards, where I compete the vast majority of the time. I never shoot at less than 600 yards with this rifle. Initial load development is done shooting at 100 yards on a 48 inch tall thermometer target.
Since I need about 33 MOA from 100 yard zero, I would be at the end of the adjustment range all the time. That would be an utter waste of a fine riflescope. I mounted my scope so that I would get the best IQ possible from it at 1000 yards and let me tell you, it's glorious and I shoot at 50X virtually all the time, never less than 40X, because this riflescope can do it.
The March-FX 5-42X56 HM WA is one hell of a fine scope but if you're going to use it near its elevation extremes, do yourself a favor and get an appropriate canted ramp.
BTW, the business about looking through the center of the scope for best IQ at all times, is the motivation for the Genesis family of scopes from March. 114 MIL of elevation range (100 up, 14 down) and you're always looking throught the center of the scope with the maximum IQ.
