Canadian Airgun Forum

I shoot a scoped springer (Diana 240 with 3-9X 42" UTG scope) from about 10 metres. I often shoot the targets with a whole series of small targets that cover the page like this [url] http://www.mytargets.com/target22%20circles%20x20.pdf [url]. I am noticing that my accuracy seems to change depending on where the target is on the page. As a I aim towards the edges of the page, I need to aim off centre to actually hit the centre of the target - usually down and to the left a bit.

Is this hold related or is there something else at play?

Where you are aiming at on a piece of paper ought to have no bearing in the point of impact. Are you shooting off hand or from a rest? Are you using the "artillery hold"? Are you allowing the rifle to recoil the same way for each shot?

Parallax, maybe?

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SR1911 .45ACP
Smith & Wesson M&P 9mm
Savage Mk II BTVS / Nikon 3-9x40 BDC150
Canuck 12 Ga O/U
Webley Alecto .22
Webley Tempest .22
Crosman 2240 .22
Crosman 1322 .22
Beretta PX4 .177
Member of NFA, CSSA & IPSC

Yeah, I'd suspect parallax. Do you know approximately what distance for which the scope's objective lens is focused? I just recently found out one can actually adjust this, tried it on a cheap Simmons (Bushnell, re-branded for some reason) 4x scope and was very relieved when bringing the centre of parallax compensation in from 50 yards to about 24 metres made it almost not a factor for my usual range. I shoot anywhere from 7 metres to about 50 metres. Parking the focus in the middle of that means there's very little parallax error if my eye isn't exactly on centre of the ocular lens anywhere in that range, none at all at 24 metres.

But failing adjusting the front lens focus, the main thing you can do is try to keep your eye exactly centred. Bob your head up and down, side to side, and use the shadows appearing at the edges to judge where the middle of the range is. Then just try to stay there. Easier to adjust it though. You could also make a card to fill most of the rear lens, with a hole about the size of a dime to look through. That should eliminate most errors.

There's some psychology at play too. I don't like shooting near the edge of my target holder and tend to pull towards the middle. You may also be getting a 'cleaner' view of the targets away from the edge. If the paper is much whiter than the background and the zoom on your scope is such that you see an even amount of white around the central targets, but part white, part background for those near the edge it will likely influence your aim. This effect is very pronounced with peep and open sights. There are good reasons for competitions to be shot on single targets with fixed position.

We have a guy in our shooting club that we call "Ping Pong Harry". He shoots ping pong balls at 300 meters with a 338 Lapua. First shot from a cold barrel. Most would say it's impossible. Not for Harry.
Old school too. He shows up with 200 lbs of sandbags. Takes him about 15 minutes to get everything set up. Even with very high end equipment, Harry's head bobs around like it's loose just before every shot. Up, down, left, right just like Gerard says. Then silence, no movement, then boom.
Harry was a top benchrest shooter in the 70's. I doubt anyone would recognize the manufacturers of his handloading tools. I made a few loading tools on my lathe for Harry (based on his measurements) that he uses to compliment his other tools.

When Harry shoots, the whole line watches and goes quiet.

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12 springers and a couple of pumpers.
2 lathes and lots of scrap metal.

I'm not multitasking. I'm doing something else until I remember what I was doing.

Off a bag rest. My hand is on the bag and the rifle rests loosely on my hand. I am trying to use the "artillery hold" but am still learning

The scope will go down to 5yrds and is currently set for just beyond 10 yrds. Looking through the scope, the image and writing on the page are clear. I mounted the scope and used a plumb line to line it up and I use the reticle to try and ensure that I am holding the rifle level when shooting.

It could very well be the position of my head, (and way I am holding the rifle). I noticed last night that I can get a better result if I tuck the rifle into my shoulder, set up then finish the last bit of aiming using my shoulder.

I am fairly new to this and am trying to learn and improve. Thanks for your suggestions.

Thanks.

Elevation presumably does have a predictable affect on point of impact (although I haven't managed to work out what it is). Windage shouldn't (other than the minuscule increase in distance to target), but given springers are amazingly hold sensitive it's possible that body position/relationship to the bag rest is having an effect. Have you tried shifting your entire shooting position left and right for the off-centre targets, so that you're not angling to one side or the other but still shooting parallel to the original centre-line? That could also play into the shift in eye position that can cause parallax errors.

NB parallax is different to focus - you can have the target in focus but out of parallax adjustment by an inappropriate adjustment of the eye piece. You set the objective lens for parallax error by deliberately shifting your eye around and checking for minimal relative movement between the crosshairs and the target. If necessary you adjust the focus with the eyepiece. People have a tendency to set the eyepiece by concentrating on the focus of the cross hairs, and then set the objective by focussing the target. This is inaccurate and likely to cause parallax errors (unless you really know what you're doing, have a top quality scope and have it correctly set up ahead of time - before all you sidewheel twiddling FT'ers take me apart).

Just so we're clear, I'm not referring to the regular focus feature of your scope. Rather the objective lens focus. In the case of my cheap scope it's supposedly a fixed focus model. But by gently loosening the stuck front retaining ring (used an old steel compass adjusted to fit the two tiny slots in the ring, with a wooden wedge between the compass legs to keep them spread while twisting carefully - it's very easy to slip and maybe scratch the lens) I was able to turn out out a couple of times to adjust parallax. Did a lot of head bobbing with the gun on a bag while doing this until the target at 24 metres didn't budge no matter where my eye was. Of course if your scope has an adjustment knob for parallax that's a lot simpler.

I spent a bit of time last night shooting and trying different hand positions, raising the bag, shooting with the rifle on the bag without my hand between etc. I can't say that the scope is 100% zeroed in as good as it can get but I am fairly certain that I am the weak link in the chain.

I did try moving my head up and down and back and forth while looking through the scope and, to the degree that I could still see through the scope, the target vs. the reticle wasn't bouncing around.

I do think that moving my head around while settling in did help me be more consistent with my aim. It just seems so tough to keep the rifle still - even my heartbeat moves the aim point around

Yeah, that's a drawback of shooting through a scope. Or even with open sights once you get to a certain level. Heartbeat/shot timing is an art one cultivates. You can do something about breathing at least, taking a couple of long, slow breaths and firing midway through the slow exhale of the second breath. That's a fairly standard practice for 10 metre air pistol competitors anyway, and I find it helpful when shooting a scoped rifle.

I am going to try out some of these tricks as I have noted the same problem with my Daisy 953 stock scope and could not figure out the why.

I have loosened the ring at the front of the scope before so perhaps it needs readjusting.

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Crosman 1377C - 760X - Vigilante - 2240
Daisy PoweLine 953
Diana Panther 21
Beeman P-17
Hatsan Mod 25
Umarex Beretta PX-4

Had an opportunity to try the "bob" move while firing my Daisy 953.

Initially it was not clear in my mind what exactly I was expecting to see in the scope. After several shots it became evident that my head placement was not consistent. Once corrected, shots at the top and bottom of the target remained at the same level. Accuracy issues were a result of my movement.

Nevertheless, once I got the idea, the next two targets were some of the most accurate to date. Including a dead bullseye (unheard of for me)!

Cheers.

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Crosman 1377C - 760X - Vigilante - 2240
Daisy PoweLine 953
Diana Panther 21
Beeman P-17
Hatsan Mod 25
Umarex Beretta PX-4

Finding centre is critical to making consistent scoped shots. To do that requires either bobbing your head around every time to find that optical centre, or more practically (speedily) it can be done by memorizing the placement of your face on the stock. If you rehearse it enough, getting the right 'cheek weld' every single time can save you a lot of missed shots and a lot of time spent hunting around for optical centre. If it takes modifying your stock or even buying a different stock so be it. Among air pistol competitors grip carving is pretty much a requirement. Getting the grip tuned to a point where sight alignment is automatic is a crucial element, so there's no twisting of the wrist to force the sights into line. It's the same with rifle shooting and getting the eye in the right relationship to the scope. And yet strangely it seems very few air rifle shooters seem interested in removing or adding stock material.