PA 1-6x ACSS [Formerly: Let's talk magnifiers and mounts...]

[essjay]

Installed the PA 1-6x today on an ADM Recon-X mount, so I'd be able to shoot with my nose closer to the charging handle. This was my first time mounting something that needed to be leveled, and I didn't have a really legit setup to do so, but this should be alright, right? The reticule definitely looks straight to my eye, but those cheap levels don't really lend to my confidence...

[essjay]

Well... those levels definitely didn't do the trick. Went to zero it with a friend out at Sunnyvale Rod & Gun yesterday, using Federal Independence M193I, and couldn't do any better than about 5moa, despite using front and rear bags. I don't expect the PA 1-6x to turn milsurp ammo into match ammo... but, considering that I can get groups less than half that size using the same with irons and the Aimpoint, I figured something was up, particularly since, despite boresighting the rifle 1.5" high at 10 yards, my rounds initially were over 15" low.

So, I went home, gave the rifle a real thorough cleaning, and then checked the mount (American Defense Recon-X) and sight. Turns out that I was able to squeeze two more turns out of the nuts for the mount's QDs after shooting it, so maybe it loosened a bit under recoil. Then I borrowed a much more legit level from a friend, and placing it on the upper below the eyepiece, on the handguard, and on the turret with the cap removed, found it was pretty off. Spent way too much time trying to get it perfect, because I only had one level and sandbags holding it in place rather a vice, but it's definitely on there straight now. Boresighted it again 1.5" high at 10 yards, and put it away.



So... took it back out today to LARG. To make sure that it was on paper in generally the right spot, I started off by putting five rounds of the same Federal milsurp through it at 50 yards - came out as a 1.25" group about an inch low. Then I moved over to the 100 yard lanes to zero it in, which went very smoothly this time around. That being said, I had a very hard time keeping the Federal ammo in a relatively good group - I typically would get a group that would be 2.5moa on one axis, and string out to 4.0moa on the other.



Ended the day shooting at the target below with the following: 20 rounds of 5.56mm Federal Independence M193I 55gr FMJ at the center target, 10 rounds of 5.56mm PMC X-Tac 55gr FMJ at each of the lower targets, and 4 rounds at the center of the upper right target (all but one landed off the paper, high), 6 rounds at the right corner of the center diamond, and 10 rounds at the bottom corner of the upper left target, all with .223 Fiocchi Exacta 77gr HPBT (Sierra MatchKings).

Aside from the very high second-shot flier (jerked the trigger, and called it), the PMC X-Tac was very consistent with sub-3moa groups through 40 39 rounds. The Federal Independence on the other hand... not sure what's going on there, but I'm not super pleased.

The Fiocchi grouped at 1.23moa (6-round group) and 2.54moa (10-round group), with the former being about 1.5" high and the latter being about 2.75" high. Based on my observations of the 4-round group, I think I my have lollipopped my reticle below my perceived POA on the 6-round group, which resulted in a tighter group than the 10-round group, in which I attempted to center my reticle on the bottom point of the diamond, rather than lollipopping it.



As for the sight itself, it's great. It's very clear, and I have no problem shooting it with two eyes open up to 4x or so. It's definitely not as fast as the Aimpoint, but, since I'm not competing with it or engaging in CQC against zombies/pirates/ninjas/etc., it's not really a big deal. I'm sure that I'll get faster with it as I get used to have my cheekweld a few inches further back than I did with the Aimpoint, anyway.

Probably will end up leaving it at 2x or 3x for the most part. My only real complaint about it is that, unless I'm missing something, there's no way to lock down the focus ring so that it won't rotate with the rear lens cap if it takes a knock. Also, the illumination isn't really daylight bright, but I expected that and it doesn't really bother me.

So, to end this way too long post... a pair of questions for Primary Arms, or anyone else who can answer:

1. Being a SFP sight, if the center dot of the reticle is 1moa at 6x and 6moa at 1x, is it 3moa or 2moa at 3x? Not really a big deal obviously, but i was curious if the change in reticle size is linear or on a curve.

2. I plan on re-zeroing this later with Magtech/CBC's Mk262 Mod 1 clone (5.56mm with 77gr Sierra Matchkings), but still using 55gr for plinking. My understanding is that I should zero an inch high at 100 yards for the BDC to be accurate using this ammunition. Assuming that the POI will be similar (if not higher) than the Fiocchi Exacta, how far off would this knock the BDC for typical milspec 55gr or 62gr ammunition?

[PrimaryArms]

PA 1-6x ACSS [Formerly: Let's talk magnifiers and mounts...]

Question 1 yes its a sfp so the reticle will get bigger as power down.
Question 2 each load will give a different harmonic signature and different point of impact. Also look at Hornady 75gr TAP its far superior to 77sml in both external and terminal ballistics.

[Junkie]

The CBC 77gr stuff is very reasonably priced at around $.60 so that's probably why he's going with it.

Regarding whether or not it's level, that shouldn't influence your groups. It will influence BDC farther out, but group size should be the same.

[PrimaryArms]

The CBC 77gr stuff is very reasonably priced at around $.60 so that's probably why he's going with it.

Regarding whether or not it's level, that shouldn't influence your groups. It will influence BDC farther out, but group size should be the same.

No it wouldn't.. Higher BC= less drift and smaller groups at .395 the 75gr hndy is far superior.
-Dimitri

[essjay]

The CBC 77gr stuff is very reasonably priced at around $.60 so that's probably why he's going with it.

Yep, that's exactly why. I plan on shooting mostly M193, but use the CBC 77gr for longer range applications (hence why I want to zero with it). If I ever find the time (and space) to start reloading, I'll be sure to give the Hornady a try.

[Whatisthis?]

No it wouldn't.. Higher BC= less drift and smaller groups at .395 the 75gr hndy is far superior.
-Dimitri

Trying to learn here. I understand that would apply at longer ranges when there are more variables uncorrected for, but how does that work at 100 yards on a static range where most variables are either accounted for or almost negligible? Wouldn't smaller groups have to do with consistency as opposed to BC? Just because a bullet has a high BC, does not mean the ammo will be consistent. I'm not arguing about the consistency of the 75gr TAP ammo, though.