Rifle Scopes Anyone understand how a S&B PMII works?

[Bloodstriker]

I noticed that when I resetting zero on my 5-25x56, I still had .5 mils below and 2 full turns minus .5 up. Every scope I've used in the past would only allow what's left. I know that this is normal and very awesome, but I'm wondering if anybody knows how the scope achieves this?

 

[lizzardking308]

I believe what you are referring to is the zero stop.

 

[Bloodstriker]

I believe what you are referring to is the zero stop.

No. What I'm referring to is how resetting the zero still allows full usage of all of the travel.

 

[Captain Kirk]

It has .5 mils below your zero, and if your mount/rifle combo will allow it will give you the full 26 mils in the second rev. I have a 5-25 on a 20 MOA base and it runs out of elevation at 19 mils, I would need another 20 MOA (around 6 mils) to get near the top of the second rev. It sounds like your getting near all of the availavle elevation with your setup, the .5 mils under zero is normal.

 

[One-Eyed Jack]

I noticed that when I resetting zero on my 5-25x56, I still had .5 mils below and 2 full turns minus .5 up. Every scope I've used in the past would only allow what's left. I know that this is normal and very awesome, but I'm wondering if anybody knows how the scope achieves this?

Your turret knob may turn two full turns, but is the erector actually moving? Look through the scope while cranking the knob and you can see whether the erector has stopped although the turret knob turns to the end.

 

[Kiba]

The 5-25 has a little more internal elevation travel (usually around 29 mils) in the erector mechanism than the mechanical 2 turn / 26 mil limit of the DT elevation knob.

Depending on the cant of your base and where your zero falls there are two possibilties:

1. You have an aggressively canted base in which case you will have 26 mils up elevation available. The turret will stop rotating at 26 mils (2 turns) when the zero stop & 2nd turn "flipper" mechanism inside elevation knob hits the pin inside the scope. The scope may still have some erector travel left (they usually have about 29 mils or so) but the zero stop & "flipper" mechanism stops the knob from going up any higher than 26 mils.

2. You have a less aggressive canted base in which case the elevation knob will stop before the zero stop & 2nd turn "flipper" mechanism encounters the 26 mil/2 turn limit because the erector runs out of travel.

Summary: on a ~40MOA base you'll have the full 26 mils of up elevation available. The scope will still have a little erector travel left but 26 mils is the hard limit of the DT knob. On a ~20MOA base you'll probably only have around 19 mils up from zero as the erector runs out of travel and stops the knob.

As mentioned, the zero stop is located slightly below zero so you can "dial under" if needed. My PMII's stop at 0.6 mils below 0.

 

[Bloodstriker]

The 5-25 has a little more internal elevation travel (usually around 29 mils) in the erector mechanism than the mechanical 2 turn / 26 mil limit of the DT elevation knob.

Depending on the cant of your base and where your zero falls there are two possibilties:

1. You have an aggressively canted base in which case you will have 26 mils up elevation available. The turret will stop rotating at 26 mils (2 turns) when the zero stop & 2nd turn "flipper" mechanism inside elevation knob hits the pin inside the scope. The scope may still have some erector travel left (they usually have about 29 mils or so) but the zero stop & "flipper" mechanism stops the knob from going up any higher than 26 mils.

2. You have a less aggressive canted base in which case the elevation knob will stop before the zero stop & 2nd turn "flipper" mechanism encounters the 26 mil/2 turn limit because the erector runs out of travel.

Summary: on a ~40MOA base you'll have the full 26 mils of up elevation available. The scope will still have a little erector travel left but 26 mils is the hard limit of the DT knob. On a ~20MOA base you'll probably only have around 19 mils up from zero as the erector runs out of travel and stops the knob.

As mentioned, the zero stop is located slightly below zero so you can "dial under" if needed. My PMII's stop at 0.6 mils below 0.

That's exactly what I'm looking for. Thank you.

 

[JayCarver]

Basically they have more erector travel than turret travel, this is even more true in the 12-50 PMII's.