Severe Barrel Droop

dannyshoots · Nov 2, 2015

I have a Gamo spring gun I just put a new UTG scope on. It had the stock scope on it and I was wanting something better. After mounting the new scope I discovered I couldn't zero it because of barrel droop I hadn't noticed with the old setup. So, I went to Pyramid Airguns and found a compensating rail and mounted it. Still had droop to the extent that I was 5 mil dots low at 15 yards! I can adjust the scope to just barely zero but that runs it out to max and it wont hold zero. This gun shoots fairly well and I would hate to retire it for this reason. Does anyone have any ideas?

MOD EDIT: Moved to Springers section

ericgs · Nov 2, 2015

i have use some layers of photographic film on the rear scope mount below the scope, but sounds like this could be not enough, also not sure if adjustable scope mounts like the "fx no limit" will hold zero on a springer.

dannyshoots · Nov 2, 2015

ericgs,

I tried using a business card under the rear of the scope in the back ring yesterday and it barely changed the poi at all. It's really discouraging. I may wind up putting the Gamo scope back on the rifle. I don't know how it avoids this problem but it seemed to.

30cal · Nov 2, 2015

Hi Danny. Here is a recent discussion about this problem and some solutions: http://airgunnation.dev/topic/utg-3-9x40-scope-adj-problem-or-just-limitation/

dannyshoots · Nov 2, 2015

30cal,
Thanks! Chuck had the same problem with the exact same scope. I'm not sure what if anything I am ready to attempt with the breech face on my Gamo. But at least I know what is happening now. Thankfully, I also own a tack driving Daystate Wolverine. Squirrels shant be getting away while I work the Gamo's problems out.

30cal · Nov 2, 2015

Your welcome Danny! Have you read the article on bending the barrel? That's the easiest thing to do. The steel of air gun barrels is very soft.

WCT_Editor · Nov 2, 2015

Before doing anything to the air rifle, I'd rule out that the problem isn't with the scope. Especially, if you weren't noticing the same issue with the stock scope before replacing it with the new one.

dannyshoots · Nov 2, 2015

30cal,

Well, no I haven't read the article on barrel bending. I have goose bumps even as I type this just thinking about it. I will go look at it just to give it the benefit of a doubt.

Pauls Custom Targets · Nov 2, 2015

Hi guys I just wanted to add a good shim I use fairly often doing gunsmithing and now on the air rifles. I use one of those fake credit cards or the plastic look alike that you get from various companies with the scan codes on them. I cut them to fit and most times they are thick enough to be used without trying to build up film and the like. They are soft enough to mold to the scope with the tightening pressure and they stay there. I have used this on my Nikko scope and FalconT50 withj perfect results after I ran out of elevation room when I mounted these scope on two diff rifles.

Robonline · Nov 2, 2015

Please don't think that I am trying to insult you, but did you install the droop compensation the correct direction?
Rob.

Alan · Nov 2, 2015

I'm a bit reluctant to bring this up, for perhaps obvious reasons.

I own a Umarex Octane, and I am very sorry I bought the rifle. Barrel droop in one of several reasons. I "think" I have solved the screw-loose issues, along with the necessity of retightening the barrel cross bolt. But even then, every time I dig it out of the closet, it shoots a bit lower than the last time. I've gotten to the point that I turn the vertical scope adjustment about 4 to 6 clicks before I even cock it!

Over time, I've measured the straightness of the barrel using a short straight edge. I haven't noticed any deviation, until last Saturday. I'm guessing, but it appear that laying the straight edge on the back of the barrel, there is about a thousandth of an inch between the muzzle end, and the straight edge. To me, at least, this makes some sense. The reason is, the vertical displacement has always been worse than the horizontal displacement. Assuming that is true, it is easy to assume that barrel bending (drooping by any other name), is a fact of life.

The Octane requires almost more force to cock, than my 75 year old arms are capable of accomplishing. It is infact, heavy enough that the muzzle break loosened up its apparent epoxy sealant (I can now rotate it).

I'm not saying that all break barrel pellet rifles are bad. And, I'm not saying the Umarex is worse than others about barrel bending. But gosh, guys, when the barrel is metal, and the cocking force is 40 to 60 pounds, isn't it reasonable to assume, that barrel bending can, and perhaps is, an issue?

dannyshoots · Nov 3, 2015

Alright you guys. I took the UTG off last night and remounted the old scope that came on the Gamo. I was able to zero the gun with nothing but scope adjustment and it held that zero for ten shots. Then I ran the vertical adjustment out another 25 clicks just to be sure it wasn't maxed out. I took the drooper compensating rail off too. Just used a new set of rings and mounted the scope strait up. For me, that is plenty of proof the UTG doesn't have enough adjustment. I hope Pyramid Air will take the POS back. It was only a hundred bucks but the damn thing is worthless.

dannyshoots · Nov 3, 2015

Not insulted Rob. I wanted to make sure my eyes weren't fooling me so I pulled out a caliper and measured both ends of the rail to make sure I had the tall end to the rear. That UTG scope is the problem.

Pauls Custom Targets · Nov 3, 2015

New rings? Did you try the UTG in the new rings? The original rings may have been the issue. ??

dannyshoots · Nov 3, 2015

strikefast,

Yes, I used the new rings that came with the scope when I ordered it. They were the Weaver type and fit on the drooper compensating rail nicely.

peterdulux · Nov 4, 2015

Is the breech seal too proud?

dannyshoots · Nov 4, 2015

I don't think so, peterdulux. With the kind of droop the UTG scope was conveying, I would think you could see it in the offset. As I said, the old scope mounted back up with no droop compensation at all and has plenty of vertical adjustment to zero the rifle and it is holding that zero. I am convinced the UTG scope is junk.

22junkie · Nov 26, 2015

http://www.pyramydair.com/s/a/RWS_Lock_Down_1_Pc_Mount_w_1_Rings_11mm_Dovetail_Barrel_Droop_Compensation/2406

dannyshoots · Nov 30, 2015

22junkie,
Thanks for the link. I actually did buy that mount and used it to correct most of the issue. However, I was still having to run adjustment all the way off the tension spring to get to zero at 20 yds. Pyramid Air took the scope back and gave me credit without further question. They are absolutely GREAT to do business with. I have read other accounts from shooters who have experienced the exact same issue with UTG scopes. As I related earlier in this string, the Gamo scope that came with this spring gun works perfectly as far as adjustment goes. I put that scope back on the gun and left it there.

I have set the spring gun pretty much aside anyway, keeping it close to the front door for the occasional cottontail that wonders into the yard. My primary pea shooter is now the Daystate Wolverine B Hilite I recently purchased from AoA. I can silently drive tacks with that gun in the backyard...where it gets all of its use on the "parade of squirrels" generated by the old lady two doors down who feeds them. Youtube's Squirrel Hunter inspired me to set up my own feeder. Since I set it up, the tree rat population in the immediate area has diminished noticeably. I'm at 16 down in the last three weeks and they just keep coming.

dannyshoots · Nov 30, 2015

To all,
By the way, Ted turned me onto FX's adjustable rings in one of his videos. I haven't tried them, but I'm guessing they would give maximum correction for barrel droop. AoA sells them for about 75.00.

Severe Barrel Droop

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