Alpex 4k lite lrf question

[Dayrth]

I've been thinking about getting one of these for a while now. A couple of weeks ago I finally took the plunge. I must say I am glad I did. I went to the local range, spent a while zeroing on paper at what the lane told me was 30 meters, but the LRF said was 27. Then spent a good while trying to set up the ballistic calculator. I did figure it out in the end and it turned out to be a lot easier than it seemed at first, (probably should have read the manual ).

Once that was sorted I took it for a spin on the steel targets.
( .22 BSA R10 TH using JSB Exact Jumbo RS )

As you can see from the vid it's about spot on up to nearly 50 meters, but further than that it shoots a bit high. The last target at 53 meters, I have to drop my aim by half a mil-dot.

I know I need to increase the ballistic coefficient to account for this, but the question is by how much. The BC for these pellets is given as 0.026. Should I up it by a thousandth or two or does it need more?

I'm off to the range again on Saturday and can fiddle about with it, but I thought I'd ask in case I can take advantage of the immense amount of knowledge available on these forums and save a bit of time.

 

[Varminter]

I think it’ll just be trial and error as it will depend on your power level and zero distance. Personally I’d go in bigger steps and pull it back if it’s too much. But don’t forget to try it at short range too once you’ve made the adjustment.

 

[PhilmNW]

Thanks for sharing the footage. I had found similar, all be it the .177 JSB heavies dropping off a little lower over range. Assumed I would need to tweak the BC.
Really windy today so have left it where it is and will adjust on a still day.

 

[Lurker]

It's a tough thing to work out and can be very frustrating. My .177 shot QYS from my first set of data input spot on out to as far as I could shoot really.

Trying on a .22 I just can't get the numbers correct for certain pellets. Then shoot spot on but a bit high from 25m+. Then I change the BC and they shoot too low when I'm closer in.

Good luck. Let us know how you on.

 

[Squint1958]

I've been thinking about getting one of these for a while now. A couple of weeks ago I finally took the plunge. I must say I am glad I did. I went to the local range, spent a while zeroing on paper at what the lane told me was 30 meters, but the LRF said was 27. Then spent a good while trying to set up the ballistic calculator. I did figure it out in the end and it turned out to be a lot easier than it seemed at first, (probably should have read the manual ).

Once that was sorted I took it for a spin on the steel targets.
( .22 BSA R10 TH using JSB Exact Jumbo RS )

As you can see from the vid it's about spot on up to nearly 50 meters, but further than that it shoots a bit high. The last target at 53 meters, I have to drop my aim by half a mil-dot.

I know I need to increase the ballistic coefficient to account for this, but the question is by how much. The BC for these pellets is given as 0.026. Should I up it by a thousandth or two or does it need more?

I'm off to the range again on Saturday and can fiddle about with it, but I thought I'd ask in case I can take advantage of the immense amount of knowledge available on these forums and save a bit of time.

30 yards is 27.4 metres, so I would assume that is why you are getting that reading. Every range that I've been to uses yards and not metres.

 

[Lurker]

I forgot to say..

A. There is a feature to turn your lrf from yards to meters.

B. Mine also does not read distances completely accurately. It thinks they are a bit shorter than they are. I use meters personally. But always just go off the LRF system and try to forget it annoys me ! It doesn't really matter. Just make sure you remember if your switching guns at places you think you know well with your aplex!

 

[Dayrth]

30 yards is 27.4 metres, so I would assume that is why you are getting that reading. Every range that I've been to uses yards and not metres.

It was given as meters, but I think you are right and its actually yards.

I forgot to say..

A. There is a feature to turn your lrf from yards to meters.

B. Mine also does not read distances completely accurately. It thinks they are a bit shorter than they are. I use meters personally. But always just go off the LRF system and try to forget it annoys me ! It doesn't really matter. Just make sure you remember if your switching guns at places you think you know well with your aplex!

I always use meters. Not that it matters, as long as the thing calculates the ballistics correctly.

 

[Dayrth]

I am quite surprised by the outcome of my testing on Saturday. The BC for JSB Exact Jumbo RS is supposedly 0.026, although I have seen some people say it's 0.028. In order to keep the point of impact from climbing above the point of aim at distance I had to set it to 0.045. I'm pretty sure the muzzle velocity is correct. I've measured it with two different chronos now, and the poi at close range hasn't changed with the increase of BC.
Not that I mind. It's working as I wanted now and that's all that matters. Here how it went from 14m to 59m, which is well beyond the distance I would shoot at live quarry.