RIFLE CANT

[Blackbaronfish]

Side levels are great when on hilly terrain as it’s hard to get a true horizontal position, and can be used as a reference.
I have one on my 223 and shooting out at 300 meters

BBF

[John814ce]

Ye they great but you must get the side/rifle level set perfectly centred to correspond when the ret is true to the earth using a plumb line. And if you take that scope off that rifle you've got to plump it again so that's why i use a scope level bubble once its done its done i can remove my scope if need be any time as long as i leave the scope level on the tube its always true. Cheers, and good shooting

[tonyc]

I think your mistaken, you can hold your rifle how you like and how it fits your position and then adjustment to be made to the ret to correspond with the plumb line then set the scope level..... think about it how does the gun know it level when the barrel muzzel is round.

What a load of rubbish!

The line of sight intersects the barrel axis when the reticle vertical aligns with the barrel axis. If the reticle is set to vertical the centre must be directly above barrel otherwise you introduce a horizontal error which increases with range. I'll keep it simple as you clearly don't understand trigonometry.

Take a 11.5ft lb .177 with a near zero of 15 metres. The line of sight crosses the barrel axis at near enough 10 metres. With the scope centre at 50mm above the barrel axis the line of sight converges on the barrel axis by 50mm in 10m, that's 5mm in every metre. Now turn the rifle through 90 degrees anticlockwise (looking down the barrel). The line of sight now crosses the barrel axis from left to right, intersecting at 10m but continuing to diverge by 5mm in every metre. At 50m (i.e., 40 meters past the intersection) the line of sight is 5x40 = 200mm (8") to the right of the barrel axis. So the POI will be 8" to the left of the line of sight (reticle centre). This is an extreme example of the effect of cant with the scope set correctly.

Now let's look at the extreme example of not setting the scope vertical with the rifle level.
If we leave the rifle turned at 90 degrees, set the reticle vertical to a plumb line, and re-zero at 15m, the barrel axis and line of sight now cross at 15m but continue to diverge at 50mm every 15m, that's 3.3mm every metre. At 50m the line of sight is 3.3x35 = 120mm (5") to the right of the barrel axis. So the POI will be 5" to the left of the reticle vertical.

[TenMetrePeter]

Thats the point I made earlier. There would need to be some windage adjustment with distance. It’s just another table. For someone with a physical disability it may be doable.
But at 10 degrees the effect would be much smaller and reasonably consistent if the cross hairs were plumb.

[tonyc]

Thats the point I made earlier. There would need to be some windage adjustment with distance. It’s just another table. For someone with a physical disability it may be doable.
But at 10 degrees the effect would be much smaller and reasonably consistent if the cross hairs were plumb.

Yes, with windage adjustment according to range. I've done all the trig calculations while investigating a particularly troubling scope/barrel misalignment and I came to the conclusion even a 5 degree error needs windage adjustment at long range.

[TenMetrePeter]

As a right handed shooter with poor right eye I have looked at various left eye options if I went back to FT.

[FPoole]

Cant can also effect the elevation as well. I've found this out the hard way, as in, missing shots at a FT match.

[John814ce]

Ok tonyc you seem to what your talking about? Richard uttings know nothing. The trouble with this site is its the few who seem to know there stuff..........NOT, When if fact they didn't even know that a bolt fed aa system doesnt even seat the pellet in to the rifling, and shit scared to take the barrel off. Didn't even know the the s510 tdr silencer slips over the barrel end and threads into the centering insert. And Still useing the 2 piece ventrui screws instead of 1 single screw. The fact is you dont know as much as you think.

[Blackbaronfish]

The way I understood what was being said was that the barel can be rotated by canting the rifle, and then if you re alighn the scope to a true horizontal it will shoot as normal......which it would.
Am I missing something.
Debate is all about being challenged with out getting hot headed. Please play nicely.

BBF

[John814ce]

Ok sorry tonyc, look go on youtube look and listen to richard uttings he knows his shit, he owns half of the guns and scopes in the uk he is a very clever man i bought my tier one mounts and my delta Stryker 5x50x56 sfp on his recommendations and vortex scope level... total cost £1565.00. It seems on hear you can't say a thing without someone jumping down your throat. I know my shit, i know my gun is absolutely perfect in every way. Im now getting 40 sweetspot shots with a 6fps spread and a exactly measured 60 yard group within a 50 pence piece and pellet on pellet at my zero at 27 yrds. ive told you guys things I've done to my gun which you lot never even dreamed of doing to your guns, may be thats it...maybe im more knowledgeable when it comes to aa than some of you lot? and its hit a nerve and some of you dont like the new kid in town!