16 Jan 2005 19:52:11
E Willson
Reason for barrel droop

I have mounted scopes on two underlever guns recently. On each gun the
barrel pointed downhill relative to the receiver. The muzzle was typically
about 1/4 inch lower than the breech. I could understand how this can happen
on a breakbarrel gun but cannot see why underlevers have this "feature".
When the scope is set to its lowest adjustment both guns shoot about three
inches low at 25 ft.

One gun scribe recommends bending the barrel to correct this situation. This
seems to me to be a rather drastic solution.

I have two questions. Why are the guns built this way? and what can be done
to correct the situation so that the scope can be zeroed?

TIA,
Ernie




16 Jan 2005 21:39:36
Les
Re: Reason for barrel droop

Contact Mac-1 airguns and have them send you a drooped scope mount. They
remachine the mount so the scope points downhill a bit when set to zero.
Works just great.

Les

E Willson wrote:
> I have mounted scopes on two underlever guns recently. On each gun the
> barrel pointed downhill relative to the receiver. The muzzle was typically
> about 1/4 inch lower than the breech. I could understand how this can happen
> on a breakbarrel gun but cannot see why underlevers have this "feature".
> When the scope is set to its lowest adjustment both guns shoot about three
> inches low at 25 ft.
>
> One gun scribe recommends bending the barrel to correct this situation. This
> seems to me to be a rather drastic solution.
>
> I have two questions. Why are the guns built this way? and what can be done
> to correct the situation so that the scope can be zeroed?
>
> TIA,
> Ernie
>
>


16 Jan 2005 23:17:13
Mike Nelson
Re: Reason for barrel droop

E Willson wrote:
> I have mounted scopes on two underlever guns recently. On each gun the
> barrel pointed downhill relative to the receiver. The muzzle was typically
> about 1/4 inch lower than the breech. I could understand how this can happen
> on a breakbarrel gun but cannot see why underlevers have this "feature".
> When the scope is set to its lowest adjustment both guns shoot about three
> inches low at 25 ft.
>
> One gun scribe recommends bending the barrel to correct this situation. This
> seems to me to be a rather drastic solution.
>
> I have two questions. Why are the guns built this way? and what can be done
> to correct the situation so that the scope can be zeroed?
>
> TIA,
> Ernie
>
>

I read somewhere why they have it, but I can't recall the particulars.
There are a number of mounts available that can compensate for droop.
Mac-1 seems to get the most press. I copied some comments from

http://www.funsupply.com/airguns/scopeinfo.htm

> Jack: there are several ways to handle droop.
> Mounts bored to compensate (drooper mts. from Mac-1).
> One of a few adjustable mounts out there. Examples are: BSquare AA mounts, Tasco 810L, Hakko AirGunPro, BSquare #17011 elevation only adjustable, and the RWS C mounts. All theses are considered one piece mounts and offer considerably more grip than two piece mounts. I have all the mounts above. I can endorse the BSquare 17011 and the Hakko as being top notch adjustable. The 810L is very easy to use and is the cheapest. The RWS C and the BSquare AA are more complex.
> Last reset= shimming under the rear of the scope. I recommend trying the Drooper or the adjustable before shimming. RB

I've also seen Beeman, Gamo, and a couple others listed. BSquare makes
a couple different adjustable styles.

Mike


17 Jan 2005 14:36:18
E Willson
Re: Reason for barrel droop

I just want to thank Mike and Les for their comments. I put a 0.020" (1/2
mm) shim between the top of the bottom part of the rear mount and the scope.
It solved the problem.

Thanks
Ernie


"E Willson" <ewillson@patmedia.net > wrote in message
news:41eb093b$0$27445$9a6e19ea@news.newshosting.com...
> I have mounted scopes on two underlever guns recently. On each gun the
> barrel pointed downhill relative to the receiver. The muzzle was typically
> about 1/4 inch lower than the breech. I could understand how this can
happen
> on a breakbarrel gun but cannot see why underlevers have this "feature".
> When the scope is set to its lowest adjustment both guns shoot about
three
> inches low at 25 ft.
>
> One gun scribe recommends bending the barrel to correct this situation.
This
> seems to me to be a rather drastic solution.
>
> I have two questions. Why are the guns built this way? and what can be
done
> to correct the situation so that the scope can be zeroed?
>
> TIA,
> Ernie
>
>




17 Jan 2005 16:41:48
Les
Re: Reason for barrel droop

Careful - you can kink the scope tube this way as the mounts are no
longer concentric. It's like having the rear mount higher than the front
mount.

Les



E Willson wrote:
> I just want to thank Mike and Les for their comments. I put a 0.020" (1/2
> mm) shim between the top of the bottom part of the rear mount and the scope.
> It solved the problem.
>
> Thanks
> Ernie
>
>
> "E Willson" <ewillson@patmedia.net> wrote in message
> news:41eb093b$0$27445$9a6e19ea@news.newshosting.com...
>
>>I have mounted scopes on two underlever guns recently. On each gun the
>>barrel pointed downhill relative to the receiver. The muzzle was typically
>>about 1/4 inch lower than the breech. I could understand how this can
>
> happen
>
>>on a breakbarrel gun but cannot see why underlevers have this "feature".
>>When the scope is set to its lowest adjustment both guns shoot about
>
> three
>
>>inches low at 25 ft.
>>
>>One gun scribe recommends bending the barrel to correct this situation.
>
> This
>
>>seems to me to be a rather drastic solution.
>>
>>I have two questions. Why are the guns built this way? and what can be
>
> done
>
>>to correct the situation so that the scope can be zeroed?
>>
>>TIA,
>>Ernie
>>
>>
>
>
>


17 Jan 2005 17:51:57
Mike Nelson
Re: Reason for barrel droop

Les wrote:
> Careful - you can kink the scope tube this way as the mounts are no
> longer concentric. It's like having the rear mount higher than the front
> mount.
>
> Les
>
>
>
> E Willson wrote:
>
>> I just want to thank Mike and Les for their comments. I put a 0.020"
>> (1/2
>> mm) shim between the top of the bottom part of the rear mount and the
>> scope.
>> It solved the problem.
>>
>> Thanks
>> Ernie
>>
>>

You're welcome. I'll second Les's concern. With spring guns, you need
to have the scope snugged up pretty good to keep it from sliding around.
Snugging up mounts with a shim on the scope might bend the tube and if
that happens it might cause some internal problems.

"Might" being the operative word here. Keep an eye on things as you
shoot and if the tube starts sliding, you might want to try another
solution.

Another possibility besides the adjustable mounts is epoxy bedding the
scope. I've personally never tried it so I can't vouch for it. Others
seem to like it.

http://www.varminthunters.com/tech/scopebedding.html

http://www.blueline-studios.com/kuengairguns.com/workshop.html#custom_mount

Regards

Mike


18 Jan 2005 17:33:57
BTMO
Re: Reason for barrel droop

> Re: Reason for barrel droop

Beer?

;-)




18 Jan 2005 13:24:15
Mike Paulson
Re: Reason for barrel droop

Here's some info I found at http://www.straightshooters.comin the forum
section.

Europeans like the taller (than the stock, rear, open blade) diopter or
aperture sight, and to accomodate them without having the front post grow
too tall, they angle down, or "droop" the barrel in the gun's manufacture.

Bending a barrel to correct for excessive droop is a common airgunsmith
technique. It isn't all that difficult an operation and many a shade tree
airgun smith will do it using only a vise and muscle power. I believe
airgunsmith Russ Best <http://www.airgunshow.net/Bestunes.htmcolor=#0000FF> >, being a
little more sophisticted, uses a press. Still, it's a very doable,
relatively simple adjustment.



08 Apr 2005 12:43:43
SimonSX
Re: Reason for barrel droop

I have heard that if shimming, film roll is the right thinkness to use as
shim


"E Willson" <ewillson@patmedia.net > wrote in message
news:41ec10b1$0$27391$9a6e19ea@news.newshosting.com...
>I just want to thank Mike and Les for their comments. I put a 0.020" (1/2
> mm) shim between the top of the bottom part of the rear mount and the
> scope.
> It solved the problem.
>
> Thanks
> Ernie
>
>
> "E Willson" <ewillson@patmedia.net> wrote in message
> news:41eb093b$0$27445$9a6e19ea@news.newshosting.com...
>> I have mounted scopes on two underlever guns recently. On each gun the
>> barrel pointed downhill relative to the receiver. The muzzle was
>> typically
>> about 1/4 inch lower than the breech. I could understand how this can
> happen
>> on a breakbarrel gun but cannot see why underlevers have this "feature".
>> When the scope is set to its lowest adjustment both guns shoot about
> three
>> inches low at 25 ft.
>>
>> One gun scribe recommends bending the barrel to correct this situation.
> This
>> seems to me to be a rather drastic solution.
>>
>> I have two questions. Why are the guns built this way? and what can be
> done
>> to correct the situation so that the scope can be zeroed?
>>
>> TIA,
>> Ernie
>>
>>
>
>