AK Sponsor
Posted: 9/9/2011 1:17:05 PM EDT
| Which is the proper way to zero the PSO 4x scope on a psl? Ive read it both ways now. Do i zero it for 100 yards on the "0" mark ,,, Or on the "1" mark. I want to be able to move out to 200, 300, 400 and so on, and be able to adjust the scope to the proper number and be hitting close. Like i said, ive seen it both ways now. one way says the 0 setting is for 100 yards, 1 for 200, 2 for 300, and so on and so on.. Another way has it set at 1 for 100, 2 for 200, 3 for 300, and so on and so on. Currently i have it on "1" at 100 yards. thanks for any help |
|
The fact is it doesn't really matter where you set the turret prior to zeroing (although it's easiest if you start at "1" when zeroing at 100 yds/metes.) This is because once you zero it at 100 yds, you will reset the turret to the "1" position. It can also be zeroed at 25 yds, afterwhich you would set the turret to "3." HTH |
|
Quoted:
1 = 100 You'll get better results at long ranges if you offset your POI to match the lateral offset of your scope too. The Soviet zero protocol with the 91/30 Mosin Nagant and PE or PU scopes was to zero at 100m with the scope set to 300m using a 17cm offset. In other words the rounds were supposed to impact 17 cm above the point of aim - although Soviet doctrine also dictated hold points that were a bit low, effectively keeping the targeted POI slightly above the really thick post reticle in the PU scope, which accounts for the excessive vertical offset. The barrel lengths and velocoities are a bit different but the same approach works with the PSL Personally, given the ballistics of the load I use, with a 300m zero, the POI is 5.5" above the POA at 100m. Consequently, I zero at a range of 100m with the elevation set at 300m and then adjust the scope to get the POI to be 5.5" above the POA and then adjust the ring to center up the 300m mark. Then when I get the chance, I confirm the zero at 300m. This approach is preferrable to just zeroing at 100m with the scope set to 100m as it reduces the potential 4-5 times magification of any zeroing error that could otherwise occur at the relatively short range of 100m and would then be problematic at the much longer ranges of 400-500m. Even worse is assuming that a 25m zero will be ballpark close to the 300m zero. In reality you may encounter a .5" difference at 25m that then becomes significant at 300m. This approach works, but it is a "zero" only in the respect of getting you on the paper at 300m and consequently requires you to confirm the zero at 300m where you may find 2-3 clicks of elevation or windage may be needed to properly zero the rifle. For the average grunt who can't shoot, a 25m zero with a non precision battle rifle is fine, but if you want maximum accuracy out of a DMR like the PSL, you'll want a real zero. More importantly, the actual trajectory of the ammo you shoot will most likely not be 100% compliant with the range marks on the elevation ring (1 at 100m or 3 at 25m). If you zero at 100m and are not shooting a load that is very closely matched to the scope, the deviation between the POA and POI can get significant at 300-500m, and of course the error is greatly magnified if you used a 25m zero. In contrast, if you zero at the same 100m but use a calculated vertical offset for your round, you will at worst only be an inch or so off the actual mid range trajectory at any range less than 300m and will have much less error at ranges of 400-500m. Again with the 91/30 equipped with a PU scope, it was common to set the scope up so that the extended line of the vertical post passed through the axis of the bore. This meant the rifle was slightly canted when the horizontal element of the reticle was level, but it ensured the line of sight was directly above the bore, effectively compensating and correcting for the offset scope. The rifle does not care if it is tilted, what matters is that the line of sight is directly above the center line of the bore/line of departure. With the scopes used on the PSL this is not possible as the scope does not rotate in a set of rings. In this case, it makes sense to to offset the POI the same horizontal distance and in the same direction that the center line of the scope is offset from the centerline of the bore so that the line of sight and line of departure are parrallel rather than at converging/diverging angles. Practically speaking, the scopes used on the PSL "corrected" the potential of the PU scope to "drift" if the infinitely adjustable and very easy to move windage and elevation knobs were bumped, but it also means that the adjustment are now fairly large "click" adjustments so the choice for adjusting windage is often either right on the money, or correctly offset to the left - or alternatively too far to the left. So go with either of the first two options if one or the other is available and avoid the third option. |
|
that wasnt confusing or anything......
Reason i ask is because of this.. http://www.ar15.com/content/manuals/pos1.pdf It states that "0" is 100 . "1" is 200. right now i have mine set for 1=100. point of impact is roughly about 2" high of point of aim. (3" groups) But when i click it up to 2, its not even on paper at 200. (paper plate targets) so just wondering what i can do to make it a little closer i reckon. |
|
If you don't have an LPS scope then it probably is confusing...
The PSL normally has a 4x LPS scope. It uses the same basic 1.7m (5'7") military range finding reticle, but the turrets are different than on the POSP 4x and 8x scopes. For example on mine there is no "1.5" setting, just 0, 1, 2, 3, 3.5, 4, 4.5 etc out to "10" and more importantly, the intervals are non linear so it functions like a BDC on a PSL with 7.62x54R light ball. So the 4x PSOP / PSO-1 info is not quite an apples to apples comparison to the LPS. While not exactly original the POSP 8x42 SVD scopes are also found on a PSL as they are fairly inexpensive but offer great optics, more magnification, better light gathering ability and a nice illuminated reticle that does not rely on tritium like the LPS scope. The POSP 8x42s also use a 1.5 m (5'0") reticle, so it is more suited to hunting 4 legged elk sized game than 2 legged targets. The 8x42 POSPs come in a couple versions - the basic model that, like the LPS, has the standard military 3.6 MOA windage increments (with half clicks between the numbers allowing 1.8MOA windage adjustments) and the pro models with .5 MOA clicks. However the 8x42s have 20 hash mark turrets with half clicks and equal intervals so they do not function like the BDC found on the LPS. In this case, the table 2 (for 0-20 marked turrets in the link you referenced) and the 1.5 zero setting at 100m it references would be applicable, and when zeroed that way it will for all practical purposes act like a BDC out to 550m. However, with that said, a 4x PSOP / PSO-1 with a 0-10 scale elevation knob doesn't seem to have any strong correlation between ranges and numbers, so you'll need to memorize them, remark the turret or tape a card to the stock. |
|
Since a picture is worth a thousand words: http://www.dragunov.net/lps_scope.html |
AK Sponsor