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Posted: 3/21/2011 5:20:28 PM EDT
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Yesterday, I made my first range trip with my PSL since I added a bipod. It is a Winchester bipod attached via a Harris adapter in the handguard slot.
I started at 25yds just to get warmed up and what-not. I was printing some decent groups just low and left of the bull. After everybody else had a go, I moved the target back to 100 yds. At 100 yds, I was not even on the paper, and I was unsuccessful in trying to "find" it by aiming around the target. I then retracted the legs on the bipod and began firing from the rest provided. First shot printed. I discovered that I needed to aim at the bottom of the outer circle (~8" in diameter?). As soon as I figured this out I was met with the one minute warning, so I swiftly and somewhat sloppily loaded and pounded out 5 rounds into a 4-5" "grouping." I am not sure how much of that was me or the rifle. I can consistently fire <.5" groups at 25 yds with 5.56mm. The only time I've really grouped at a longer range was also about 5", but it was with a high-end Remington 700 at 220 yds in 40+ mph winds. I really need some practice at longer ranges. 
Why was there such a discrepancy between the bipod and the rest? How do y'all think I go about zeroing a scope (Bushnell)? I have no idea what kind of trajectory the PSL fires. (I guess I should be asking what distance?) |
I've never fired it with irons because I don't have the tool to adjust the front and... well... that's what my Mosin Nagant is for.  (Yes, I know I need the same tool for it.  )
I'm using a Bushnell 6-18x50mm. I think it's a Banner. I just don't understand why there is such a big difference in POI. |
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there should not be a difference in point of impact off a bipod.
someone else here can explain better... probably way is being held as long as you fire the same off the sandbags. i have the homemade bipod adapter and biopd from wal mart (used to be rock river ridge but now is branded as winchester) and I never get the same groups off bipod as I do with supported sandbags on front and rear. psl is a hard rifle to shoot with short stock and no cheek weld (you use a chin weld) if you shoot with right eye. is actually meant to be shot with left eye and right cheek on stock. try shooting iron sights... my psl was already sighted in for irons. I have never adjusted the front site. |
A bipod mounted to a non-freefloated handguard on any rifle will pretty much always have a dramatic effect on your POI in comparison to shooting offhand or supported on a bag. Since there are no free-float options for PSL, I made a bipod mount that is attached to the receiver and extends forward, placing the bipod under the rear of the handguard. It looks similar to the bipod placement on the French service sniper rifles and it works well. I also added a cheek-weld extension to get consistent eye placement behind the scope. The old-fashioned design of the issue scope seems to cause big errors if the shooter doesn't consistently center up behind the lens. The combination of a non-barrel mounted bipod and improved cheekweld consistency dramatically improved my groups with the PSL.
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Quoted:
there should not be a difference in point of impact off a bipod. someone else here can explain better... probably way is being held as long as you fire the same off the sandbags. i have the homemade bipod adapter and biopd from wal mart (used to be rock river ridge but now is branded as winchester) and I never get the same groups off bipod as I do with supported sandbags on front and rear. psl is a hard rifle to shoot with short stock and no cheek weld (you use a chin weld) if you shoot with right eye. is actually meant to be shot with left eye and right cheek on stock. try shooting iron sights... my psl was already sighted in for irons. I have never adjusted the front site. I've never heard that. It doesn't make much sense, but I might give it a go sometime as I am actually one of those unlucky individuals that was born cross dominant (left eye, right hand). We're using the same bipod. 
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Quoted:
I've never fired it with irons because I don't have the tool to adjust the front and... well... that's what my Mosin Nagant is for. (Yes, I know I need the same tool for it. )
I'm using a Bushnell 6-18x50mm. I think it's a Banner. I just don't understand why there is such a big difference in POI. I should be more specific. I don't understand why the POI is so different at 100yds vs 25 yds. I have experienced this twice now. The last range trip, I zeroed it at 25 yds and moved the target back to 100 yds and hit nothing but air. I adjusted it until I was on the paper, but it was also one of those rushed short on time situations. This trip, I added the bipod and I was close to bull (at 25 yds) and made no adjustments. I was not on the paper at 100 yds until I retracted the bipod and fired from the bench. I am rather confused. |
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Quoted:
Quoted:
I've never fired it with irons because I don't have the tool to adjust the front and... well... that's what my Mosin Nagant is for. (Yes, I know I need the same tool for it. )
I'm using a Bushnell 6-18x50mm. I think it's a Banner. I just don't understand why there is such a big difference in POI. I should be more specific. I don't understand why the POI is so different at 100yds vs 25 yds. I have experienced this twice now. The last range trip, I zeroed it at 25 yds and moved the target back to 100 yds and hit nothing but air. I adjusted it until I was on the paper, but it was also one of those rushed short on time situations. This trip, I added the bipod and I was close to bull (at 25 yds) and made no adjustments. I was not on the paper at 100 yds until I retracted the bipod and fired from the bench. I am rather confused. First, the bipod on your handguard is putting tension on your barrel that will make big shifts in POI. Thats why precision rifles use free-floated barrels. Secondly, if you zero so that your trajectory coincides with your line-of-sight at 25 meters, your trajectory will be well off the POA when you move back to 100. As an example, think about the M16, the 25 meter zero has the same POA/POI impact at 25/300 (actually closer to 275) not at 100. If you are using the issued PSL scope, set the BDC to 100 and zero at 100 meters with a slight lateral offset to account for the scope offset. If you are using a commercial scope you'll need to figure out your own zero plan that matches up the trajectory with your intended use of the rifle. |
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