adjustable hi rib question

[ips]

I cant get my head around the geometry (if that's the correct term)

I have a mid bead on me new fangled adjustable rib. If I set the comb at a given height and stack the beads and for argument sake lets say we have fifty fifty poi, then if a lower or lift the comb and re adjust the rib to stack the beads will poi remain the same ??

I know we all love a poi thread NOT but this is a serious mathematical question. Off you go .....

 

[V8 90]

If you lower the front of the rib then lift the comb slightly you'll maintain the bead stack & lift the pattern  :wink:  

 

[ips]

so having beads stacked does not equate to pattern remaining the same then, its dependant on comb height is that what your saying. I am not convinced I am thinking pattern remains same if beads are stacked regardles of comb / rib height.

ps

I reckon 6 .. At least ?

 

[Mutley]

If the rib pivots down at the front, its nearer the barrel, so if you keep your sight picture the same you have raised poi, or if you raise the front and adjust for same sight picture you have lowered poi.

Get a roll of wallpaper, lay the gun on it, and trace the rib and comb position, then rule a line out from the centre of the barrel, then lower your rib, place it back on your marks, adjust the comb to match, draw another set of lines from the barrel, it will be higher than the previous...

 

[ips]

andy

so mid bead alignment is irrelevant once you start fiddling. ??

 

[Mutley]

No, you get the sight picture you want, i.e how much rib you like, then bugger about moving the rib and resetting the stock to alter poi, I had a customer I sold an MX10 to, he never touched the stock once set, just the rib,

We patterned the gun with the rib fully up and set it for sporting height, the pivoted fully the other for when he shot DTL, worked fine, its a bugger about on a plate with it for a bit and get it where you are happy,  if you set the comb up as you would with a fixed rib, (with the rib in centre or top setting), then without adjusting the stock alter rib to bottom at the front and pattern it again, you will see a big jump in pattern placement...  Its a way to beat the boredom in the hotel room mid shoot,  a fiddlers delight,   just keep notes of what where how etc....

 

[ips]

cheers Andy gonna pattern it wed eve on a locked off straight dtl target, that'll do the trick. I have set comb height for comfort so I am hoping a few clicks at the muzzle end and job done

 

[DolphinCTC]

I predict you will be booking into the Betty Ford Clinic within 3 months!!

 

[ips]

oh ye of little faith

 

[MJJ]

One could always use a few sheets of paper to prove or diss-prove any theories. After all its only geometry - Triangles or oblongs.

 

[Les53]

I predict you will be booking into the Betty Ford Clinic within 3 months!!

It could have been worse....he could have bought a gun with independently adjustable POI on both tubes! Then all of us would have been heading for Betty Fords place!

 

[Les53]

No, you get the sight picture you want, i.e how much rib you like, then bugger about moving the rib and resetting the stock to alter poi, I had a customer I sold an MX10 to, he never touched the stock once set, just the rib,

We patterned the gun with the rib fully up and set it for sporting height, the pivoted fully the other for when he shot DTL, worked fine, its a bugger about on a plate with it for a bit and get it where you are happy,  if you set the comb up as you would with a fixed rib, (with the rib in centre or top setting), then without adjusting the stock alter rib to bottom at the front and pattern it again, you will see a big jump in pattern placement...  Its a way to beat the boredom in the hotel room mid shoot,  a fiddlers delight,   just keep notes of what where how etc....

Oh come on mate! Now you have suggested notes he will be producing endless lists about his fiddlings :smile: !

 

[Dog Tyred]

I thought mid-beads were just for inexperienced shooters to confirm they were mounting the gun properly

DT

 

[maddmatt]

Ian, think you need this...

 

[Les53]

I thought mid-beads were just for inexperienced shooters to confirm they were mounting the gun properly

DT

Flippin Eck Greg.....has his new toy got a mid bead then? We could be in for some fun if it has!

 

[ips]

it has but only cos I had no choice otherwise it would not. Neither would it have multi doo dahs but what can you do but embrace the modern age

 

[ExSCA]

Ian, think you need this...

View attachment 5765

Blimey - the Neville Algorithm.... long time since I've worked on polynomial interpolation. 

 

[ips]

that is EXACTLY what I thought, really brings back memories of happy times spent in math lessons, I knew that algorithmic thing would come in handy one day

 

[Dog Tyred]

 but what can you do but embrace the modern age

Cough !!

Did I really just read that?

DT