Super dupper drooper.........

[Yogi]

It is not just the D34 that is a drooper.  One of my rifles shoots 6 inches low at 10 yards with the scope turned ALL the way UP(Yicks, not good for your scope).  This is mounted in a Sportsmatch one piece mount.  Are they directional?
For all you gifted Math Geeks, how many degrees of correction will I need so my gun shoots 2 inches high at 10 yards, with the scope the same way?
TIA,
Yogi

[Novagun]

I think i could do that at school. Isoceles triangle and all that  may be even at boy scouts pioneering badge but time dulls . And after a night cap or two I just don't care.
Sleep well .

[Robert 5mm]

I think this answers your question of the number of degrees the barrel must point up

Tangent = Rise / Run
Rise of 6 + 2 inches = .667 feet
Run of 10 yards = 30 feet

Arc Tangent of .667/30 = 1.27 degree

[tjk]

Without a scope mount or rings that are adjustable, your only real option is to shim the rear ring of the scope to get it (the scope) closer to the same plane as your rifles barrel. I am not sure if your articular scope mount is directional, but sportsmatch does indeed sell a mount that is adjustable vertically as well as horizontaly. PA used to sell a mount specifically for Diana's with a few degrees of droop incorporated into the mount itself. They also offered the same mount without droop compensation. HTH's

[SpiralGroove]

Hey Yogi,
- Center your scope.
- Bend the barrel upwards in small increments until you get within 1" of the bull or better.

That's it ..... -> no reason to overthink it .

[Roadworthy]

Check to see if the barrel has a downward bend to it.  If so you'll need to bend the barrel.  If not see if when closed the barrel is parallel with the top of the compression tube.  If not it may not be closing completely due to a too thick breech seal or something mechanical.  Confirm the rear face of the breech is perfectly perpendicular to the top line of the barrel.  They are not always and can bind when closing the gun.  Too tight pivot screws can also prevent complete closure of the barrel.  Of course if your scope is not quite mounted properly this can have an effect, as can using a droop mount backward.  These may give you some starting points, though.

[PasadenaMike]

Why not just adjustable scope rings ?

[nced]

Hey Yogi,
- Center your scope.
- Bend the barrel upwards in small increments until you get within 1" of the bull or better.

That's it ..... -> no reason to overthink it .

Yep, good call! Years ago I bought a RWS drooper mount and fitted it to my Beeman R9 which didn't have any noticeable droop and needed to bend the barrel down to lower the poi 4" in only 18 yards. After bending the barrel so the poi was about 1/8" low at 18 yards with my optically centered scope the barrel bend wasn't even visible!

I didn't like that RWS mount so it was removed and the barrel was re-bent to achieve the original poi with no problems. Here is my home made "barrel tweaker"  disclaimer: I'm sure you've seen this in multiple posts but this if for those who haven't...........
The RWS Lock Down Mount with .025" Elevation Compensation for Barrel Droop.........


Barrel tweaker made from construction 2x4s and various hardware.........



 

[lefteyeshot]

I don't mind bending a barrel if it needs it. But before that and shimming, sounds like a UTG Drooper Rail from Pyramyd, part # PY-A-4191, $17.97 would fix that.

[Yogi]

Hey Yogi,
- Center your scope.
- Bend the barrel upwards in small increments until you get within 1" of the bull or better.

That's it ..... -> no reason to overthink it .

Kirk,
That is Plan C.  I need to exhaust Plans A & B first.
Still perplexed what happened.  They were shooting just fine, then I change stocks and other things and now WAY off.  I guess I should check the new breech seals.  I installed new Aussie breech seals.  Nice blue color.
Can you bend a barrel by thousands of cocking cycles.  Not a gorilla, but cock them firmly.  As you know the compound linkage of the HW 50 shortens the stroke but increases the effort.
The one rifle that has not changed, has a sleeved barrel.

-Y

[Yogi]

Check to see if the barrel has a downward bend to it.  If so you'll need to bend the barrel.  If not see if when closed the barrel is parallel with the top of the compression tube.  If not it may not be closing completely due to a too thick breech seal or something mechanical.  Confirm the rear face of the breech is perfectly perpendicular to the top line of the barrel.  They are not always and can bind when closing the gun.  Too tight pivot screws can also prevent complete closure of the barrel.  Of course if your scope is not quite mounted properly this can have an effect, as can using a droop mount backward.  These may give you some starting points, though.

Will check.

-Y

[nced]

Hey Yogi,
- Center your scope.
- Bend the barrel upwards in small increments until you get within 1" of the bull or better.

That's it ..... -> no reason to overthink it .

Kirk,
That is Plan C.  I need to exhaust Plans A & B first.
Still perplexed what happened.  They were shooting just fine, then I change stocks and other things and now WAY off.  I guess I should check the new breech seals.  I installed new Aussie breech seals.  Nice blue color.
Can you bend a barrel by thousands of cocking cycles.  Not a gorilla, but cock them firmly.  As you know the compound linkage of the HW 50 shortens the stroke but increases the effort.
The one rifle that has not changed, has a sleeved barrel.

-Y

"I installed new Aussie breech seals. "
Hummm........perhaps this is a clue to the "low poi". If the breech seal is too thick or firm that will affect the barrel latch-up position.

As a side note, I've only replaced one factory breech seal which deteriorated with age (a couple decades) so I tried a couple different aftermarket breech seals with my R9 and ended going back to the factory HW breech seals. The factory HW breech seals have been very long lasting and my HW95 has never needed a new breech seal after several years of use. The damaged R9 seal along with a couple new HW seals...........

[Petey]

Hey Yogi,
- Center your scope.
- Bend the barrel upwards in small increments until you get within 1" of the bull or better.

That's it ..... -> no reason to overthink it .

BINGO!!

[Yogi]

Why not just adjustable scope rings ?

Because they will not hold on a springer.  They are PCP only...

-Y

[PasadenaMike]

Why not just adjustable scope rings ?

Because they will not hold on a springer.  They are PCP only...

-Y

Ahha makes sense

[SpiralGroove]

Hey Yogi,
- Center your scope.
- Bend the barrel upwards in small increments until you get within 1" of the bull or better.

That's it ..... -> no reason to overthink it .

BINGO!!

Yeah, I even have no problem bending the barrels on my $2K RAW's to correct POI- nothing like manually indexing the barrel too . 
Just be careful ......

No need to add more gadgets to get the gun zeroed - just spending more $$ to line "marketer"s" pockets.
However, fix any action/barrel lock-up issue first.

[cjtamu]

Why not just adjustable scope rings ?

Because they will not hold on a springer.  They are PCP only...

-Y

Sportsmatch makes a one piece adjustable. No problem with it staying put. It’s only in High though so you have to live with that.

[Yogi]

To make matters worse, my scope's spec say 36 moa of vertical adjustment.  Not sure if this is 36 total or 36 in each direction.  Either way, not much.

-Y

[nced]

To make matters worse, my scope's spec say 36 moa of vertical adjustment.  Not sure if this is 36 total or 36 in each direction.  Either way, not much.

-Y

Humm, not much of an issue if you simply bend the barrel. I know that I was able to do a 4" adjustment at only 18 yards (trying the RWS LockDown mount on my R9 which had no droop) and the bend wasn't even noticeable by eye.

Anywhoo, relative to scope clicks (just for grins)..........
Formulas
(Distance to target in yards) / (100) = inches per MOA at that distance.

*(Number of inches of adjustment needed) / (inches per MOA at that distance) = MOA adjustment

*(Number of clicks per 1 MOA on scope) x (MOA adjustment) = adjustment in clicks on scope

*Note, if you insist on using 1.047″ per 100 yards instead of 1″ per 100 yards, you must multiply the (inches per MOA at that distance) by 1.047.

[HectorMedina]

Kirk,
That is Plan C.  I need to exhaust Plans A & B first.
Still perplexed what happened.  They were shooting just fine, then I change stocks and other things and now WAY off.  I guess I should check the new breech seals.  I installed new Aussie breech seals.  Nice blue color.
Can you bend a barrel by thousands of cocking cycles.  Not a gorilla, but cock them firmly.  As you know the compound linkage of the HW 50 shortens the stroke but increases the effort.
The one rifle that has not changed, has a sleeved barrel.

-Y

If the seal is "proud", it is too large, and yes, it will "invite" excessive droop.

Get the seal out and sand the REAR section of the seal (the one that goes INTO the gland), then test.

Breech seals in break-barrels do NOT seal by compression, but by expansion of the seal into the gland by the first puff of air blown into the cavity by the piston.
Some breech seals in some break barrels even benefit from getting a small "V" notch cut into them on the INSIDE circumference, to allow a quicker action.

Start with getting the breech seal to the point where it is NOT noticeably proud of the breech block's face.

HTH, keep well and shoot straight!



HM