Donation

Support Equipment For PCP/HPA/CO2 and springers ,rams > Optics, Range estimation & related subjects

barrel droop.....does it even exist?

<< < (2/4) > >>

Joey:

--- Quote from: wolverine on September 19, 2020, 02:04:07 PM ---i thought pellets and bullets rose from the from the muzzle to an apex and then began to drop, making the trajectory an arc and giving 2 poa/poi.

--- End quote ---

Pellets fall from the second they exit the barrel.  You have to point the barrel up ( or point the scope down) to get that trajectory in line with the POA. 

I do think that barrels can bend over time, but I shot 30,000 plus rounds through a Diana 34 and didn't notice any appreciable droop from day one. 

If it would be a "fault" of manufacturing, why would it always be droop and not upsweep or a side-to-side error? 

Think about it.  The higher above the bore the scope or sight is, the more the scope has to be adjusted.  High 30mm rings and 50mm objectives cause the scope to have to be adjusted down a LOT to get the pellet up to the POA. 

Yogi:
AR-15's droop alot!
If the rear sight is mounted on the barrel, a break barrel rifle, it make no difference.
Of all the things to worry about, barrel droop is one of the easiest to fix.
No big deal!!!! :D

-Y

Hoosier Daddy:

--- Quote from: Bentong on September 19, 2020, 01:24:36 PM ---yup...we all tend to droop over time. Compensation is the key.

--- End quote ---

Ain't that the truth... over a half century of abuse, old "Hodgy" has it's "droops".  ::) :P

nced:

--- Quote from: Joey on September 19, 2020, 10:26:52 AM ---Why would several excellent companies, making quality spring piston rifles all have "problems" with barrel droop.  If you can make a rifle capable of one hole groups out to 25 yards or so, why would barrel droop be a problem?

I've been thinking about this for years and I think I have an answer.  A well made rifle puts the centerline of the rifle bore and the centerline of the scope( when the scope is adjusted at the center of it's range) pretty much parralel.  If that's true, the rifle would NEVER shoot to point of aim.  The bullet starts dropping from it's centerline as soon as it leaves the muzzle.  With an airgun, that drop amounts to several inches at , say 50 yards.  Well, the pellet starts out about 1 1/2" below the centerline of the scope and at 50 yards could be maybe 6" low.  That's a LOT for a scope adjustment to make up.  Back when iron sights were more popular, they could be built to copensate for that easier because they were closer to the centerline of the bore.  Building a rear sight a bit higher and with more adjustment is a piece of cake for a good gun maker. 

A fast, centerfire rifle bullet drops WAY less than a pellet, and is normally sighted in at much longer distances.  This next bit is all nominal for explanation purposes.  A 1 degree adjustment in the scope elevation would put the POA and POI at the same point because of the flatter trajectory of the faster rifle.   Comparitively, a pellet has a rainbow trajectory that needs a LOT of adjustment to tilt the ever-falling pellet up to get to the POA. 

A pretty, computer designed picture here would certainly help me explain my concept.  Not in my skill set.



--- End quote ---
Perhaps "barrel droop" isn't an issue for the majority of airgunners outside the USA that use "iron sights". I've read that some makers (such as Diana) "design in" droop to accommodate the tall front sights with the interchangeable inserts (however I don't know if I completely believe this story). If the droop issue was only related to "manufacturing tolerances" then there would be Dianas with both "snoop and droop". Since droop is the "common issue" I do tend to believe that droop is "designed in" for whatever reason..........

I've never handles a Diana "fixed barrel" but I just finished looking a a lot of RWS54 pics and it certainly seems that the barrels are "drooping" relative to the receiver.

Anywhoo....I do know that "droop" is a reality for guns such as the RWS34 that I looked at decades ago at an airgun show. The droop with the brand new RWS34 was so pronounced that it was easily seen by eye without the need for a straight edge as a reference. Rather than "fix a droop issue" RWS offers the "Lock Down mount" with .025" elevation compensates for barrel droop...........
https://www.pyramydair.com/product/rws-lock-down-1-pc-mount-w-1-rings-11mm-dovetail-barrel-droop?a=2406

LOL......I bought one of these mounts and used it on my HW95 resulting a poi 4" above the poa at only 18 yards!

   

lefteyeshot:
That's why they make droop mounts.

Navigation

[0] Message Index

[#] Next page

[*] Previous page