Re: S&B PMII 4-16
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamstur</div><div class="ubbcode-body">I currently have two USO SN3 3.2-17x and looking at the S&B 4-16x. I am drawn to the sleek look of the 42mm objective single-turn vs double-turns and the 50mm.</div></div>
The 0.1 MIL versions of the 4-16X42mm and the 4-16X50mm only come in ST (Single Turn). The .25 MOA versions only come in DT (Double Turn). This is because the Erector Assembly of the 4-16X only needs a ST Turret for the 0.1 MIL versions 13 MILs', but needs a DT (Double Turn) Turret to accomodate the 56 MOA of Elevation travel of the PMII 4-16X MOA versions'.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamstur</div><div class="ubbcode-body"> Does anybody have hands on experience with the different combos to share shortcomings with the 42mm ST besides low light performance compared to 50mm?</div></div>
Depending upon your age, you eyes may or may not be able to see the difference between the 42mm and 50mm versions. The older you get, the smaller the maximum diameter your pupils can dialate to, thus limiting the actual useable <span style="font-style: italic">exit pupil</span> diameter. If you are young your eyes may be able to make use of the 50mm's larger exit pupil <span style="font-style: italic">in low light</span>. In daylight it won't make any difference.
In terms of mounting the scope, as <span style="font-weight: bold"><span style="font-style: italic">Graham</span></span> alluded to, the 42mm versus 50mm difference typically won't make any difference in terms of lowest ring height that you can use. The lowest 34mm ring height easily found is .920" (measured from the top-of-the-base to the tube center). Seekins and TPS make this height, but there are others.
If you go with a 50mm the barrel diameter and the base cant <span style="font-style: italic">can</span> also have a slight influence on ring height selection. Clearance for scope caps such as Butler Creek Flip Opens can be minimal. The 42mm should have lots of room though.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamstur</div><div class="ubbcode-body">The intended rifle is already equipped with a BO 20MOA base. Thanks!</div></div>
PMIIs' are designed to be used with base cants that approximate 1/2 of the total Elevation travel. On a 13 MIL travel scope such as a ST PMII 4-16X the optimum base cant is 30 MOA. 23.4 MOA would be 1/2 of 13 MILs' and a 25 MOA base is pretty close, but the selection of a 30 MOA base will compensate some Elevation travel used while zeroing.
A 20 MOA base will work, but won't allow the scope to be dialed to maximum Elevation range. That may or may not be important to you. I like to be able to dial as much elevation as possible.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamstur</div><div class="ubbcode-body"><span style="font-style: italic">Disclaimer - I've read & briefly demoed to understand brand differences and want to thoroughly test USO v. PR v. S&B to make my own decisions. Not looking for a brand debate - strictly seeking S&B 4-16 option info.</span> </div></div>
I've owned a used a fully-loaded 35mm tube SN-3 3.2-17X 44mm ERGO Lo Profile with 0.1 MIL EREK and LH US#3 M40 Windage w/STOP, Green Illuminated GAP Reticle with ARD, A Premier Heritage 5-25X[56mm] 27 MIL MTC DT Gen 2 XR, and PMII 5-25X[56mm] LP DT 0.1 MIL Gen 2 XR CCW.
I traded my USO for the Premier, then sold the Heritage, the I sold the Heritage to help pay for a second PMII 5-25X[56mm] LP DT Gen 2 XR. IMHO, while the SN-3 was a very nice scope and the Heritage was also very nice and has the Illumination Control integrated into the Parallax Knob, overall the PMII is a better scope. The best way to describe it is that it just feels <span style="font-style: italic">"more refined"</span>. YMMV.
Keith
