Bug Buster Killer

Three weeks ago I posted my first thread on AGN about accuracy problems with a RWS 34 .177. Eventually with suggestions from AGN members I tracked it down to a failed 3-9x UTG Bugbuster scope that was probably 15 years old or so. I sent the scope back to Leapers and they determined it was indeed faulty and offered me a credit on their site since that specific model/part number is out of production. Fair enough, I guess.

The old scope was vertically stringing. First few shots very low, next few a bit higher, next few a bit high, then a nice group at X. I'd set the rifle aside for a bit and the pattern would repeat when I picked it back up. It was very predictable. Made sure all fasteners were tight, etc. I also replaced the breech seal just as a precaution. A member here suggested that the elevation turret spring had failed. Leapers never told me what they found, only that they agreed it did not work properly. I suspect they duplicated my result and junked the scope without further analysis.

I like the features of the Bugbuster including parallax adjustment from 3 yards, lighted reticle and 3-9X. It is supposedly rated to handle airgun recoil and it did last 15 years of sporadic use of maybe 1000-1500 shots. I got a new model of the same scope from a mail order house and mounted it. I quickly found zero and since then used it for about 400 pellets, specifically 7.87 grain Diabolos that the gun seems to favor. I did not use a drop compensated mount so I had to raise the elevation significantly to match point of aim and impact, but I did not run out of elevation. I use a UTG Offset Airgun Mount for reduction of eye relief distance.. I'll add here that I store and carry the rifle in a padded hard case. I am the only user since the new scope and it has not been dropped or significantly jarred in any way.

Last night I had the rifle out for target practice and the vertical stringing suddenly reappeared. Same pattern. After 400 tightly grouped perfect shots the new scope failed exactly as the old one had. I had another shooter confirm the results last night and I shot it again this morning with the same pattern continuing. Although it was redundant, I pulled the scope and fired several groups with iron sights. No vertical stringing without the scope, same as last time.

What can I do to solve this problem? Is the infamous springer recoil somehow worse in my rifle? Does the UTG scope suck? Is the mount inappropriate? Something else?

Is there another scope that might be more durable that is similar? For my shooting needs It would have to be parallax free from about 5 yards at minimum. I could live without the lighted reticle if a had to, but I find it very useful for pest control in low light. Unfortunately my eyes are no longer good enough for consistent results with the iron sights. My rifle does not have the newer fiber optic sights. My preferred budget is around $150, same as the Bugbuster. I am willing to get a new mount on top of that if the mount is an issue.

I have found references to the Diana ZR mount, but it reviews are highly variable. AGN has a thread about modifying it to work effectively. I am reluctant to purchase something that I'd have to modify to begin with. I am no machinist.

I have looked around at scopes/mounts but the I'd like advice from real world users who have solved this problem already if possible. Any help would be much appreciated.
 
@rbeckey Great post. Thanks for sharing your experience with this scope on your RWS 34. I’ve read a few posts where guys were touting a certain scope or two as being tough and built to handle springer recoil. I’ll look around and edit my post with a link or two if I can locate those posts in a timely fashion. I’m sure others will chime in to help as well.
Here’s one, but it’s above your $120 price range. I’m posting this because I own one and can attest that they’re built solid! They’re a bit on the heavy side. I got a 10x fixed magnification scope for about $300. Mine is not mounted on a springer, but what’s stated in this thread is believable. https://www.airgunnation.com/threads/swfa-scopes-on-springers.1208441/#post-1208524

This link contains a lot of potential useful information for you. One member even discusses a scope for the RWS 34. I’ve also read a couple of posts that discuss mounts that help dampen recoil. It’s mentioned in the post below. It appears that the UTG scopes with etched glass reticles perform better. Did your Bug Buster have a wire reticle or etched glass? https://www.airgunnation.com/threads/diana-350-magnum-22.1156866/#post-1158988

I read reputable member (@Motorhead) state in another thread that the UTG SWAT was similar to the Bug Buster, but longer, I believe he said it has an etched glass reticle. Here’s a link to that thread https://www.airgunnation.com/threads/seeking-advice-budget-scope-for-springer.1235796/#post-1235828

Here’s one more thread to read through with a few good scope suggestions. https://www.airgunnation.com/threads/durable-scope-for-magnum-springers.953555/

I hope you find something contained in these threads useful.
 
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@rbeckey ,
This subject was just discussed recently in another blog. When you use too much up elevation in a scope to zero it, the erector tube spring is not as compressed and the mechanism starts floating during the vibration of a springer's shot cycle. This is typical in springers that have barrel droop compared to the receiver axis. The clue was where you said you used significant up elevation to accomplish your zero.

Sight down your rifle and compare the angle of the barrel to the angle of the powerplant cylinder. You'll probably see a big difference.

The solution is to shim under the rear of the scope so that you can zero the rifle with much less up elevation from the turret. I have done this with rectangles of material cut from aluminum or plastic soda bottles. It may take a couple of them, stacked up, placed between the curveed seat of the rear scope ring and the scope tube. This can also be accomplished using adjustable scope rings such as Sportsmatch or equal.

GL,
Feinwerk
 
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@rbeckey ,
This subject was just discussed recently in another blog. When you use too much up elevation in a scope to zero it, the erector tube spring is not as compressed and the mechanism starts floating during the vibration of a springer's shot cycle. This is typical in springers that have barrel droop compared to the receiver axis. The clue was where you said you used significant up elevation to accomplish your zero.

Sight down your rifle and compare the angle of the barrel to the angle of the powerplant cylinder. You'll probably see a big difference.

The solution is to shim under the rear of the scope so that you can zero the rifle with much less up elevation from the turret. I have done this with rectangles of material cut from aluminum or plastic soda bottles. It may take a couple of them, stacked up, placed between the curveed seat of the rear scope ring and the scope tube. This can also be accomplished using adjustable scope rings such as Sportsmatch or equal.

GL,
Feinwerk
I agree to this , but i do not like shims as a permanent solution , experiment with shims but watch how you tighten rings as your front ring will not be square flat , if this solves your issue buy adjustably scope rings
 
Three weeks ago I posted my first thread on AGN about accuracy problems with a RWS 34 .177. Eventually with suggestions from AGN members I tracked it down to a failed 3-9x UTG Bugbuster scope that was probably 15 years old or so. I sent the scope back to Leapers and they determined it was indeed faulty and offered me a credit on their site since that specific model/part number is out of production. Fair enough, I guess.

The old scope was vertically stringing. First few shots very low, next few a bit higher, next few a bit high, then a nice group at X. I'd set the rifle aside for a bit and the pattern would repeat when I picked it back up. It was very predictable. Made sure all fasteners were tight, etc. I also replaced the breech seal just as a precaution. A member here suggested that the elevation turret spring had failed. Leapers never told me what they found, only that they agreed it did not work properly. I suspect they duplicated my result and junked the scope without further analysis.

I like the features of the Bugbuster including parallax adjustment from 3 yards, lighted reticle and 3-9X. It is supposedly rated to handle airgun recoil and it did last 15 years of sporadic use of maybe 1000-1500 shots. I got a new model of the same scope from a mail order house and mounted it. I quickly found zero and since then used it for about 400 pellets, specifically 7.87 grain Diabolos that the gun seems to favor. I did not use a drop compensated mount so I had to raise the elevation significantly to match point of aim and impact, but I did not run out of elevation. I use a UTG Offset Airgun Mount for reduction of eye relief distance.. I'll add here that I store and carry the rifle in a padded hard case. I am the only user since the new scope and it has not been dropped or significantly jarred in any way.

Last night I had the rifle out for target practice and the vertical stringing suddenly reappeared. Same pattern. After 400 tightly grouped perfect shots the new scope failed exactly as the old one had. I had another shooter confirm the results last night and I shot it again this morning with the same pattern continuing. Although it was redundant, I pulled the scope and fired several groups with iron sights. No vertical stringing without the scope, same as last time.

What can I do to solve this problem? Is the infamous springer recoil somehow worse in my rifle? Does the UTG scope suck? Is the mount inappropriate? Something else?

Is there another scope that might be more durable that is similar? For my shooting needs It would have to be parallax free from about 5 yards at minimum. I could live without the lighted reticle if a had to, but I find it very useful for pest control in low light. Unfortunately my eyes are no longer good enough for consistent results with the iron sights. My rifle does not have the newer fiber optic sights. My preferred budget is around $150, same as the Bugbuster. I am willing to get a new mount on top of that if the mount is an issue.

I have found references to the Diana ZR mount, but it reviews are highly variable. AGN has a thread about modifying it to work effectively. I am reluctant to purchase something that I'd have to modify to begin with. I am no machinist.

I have looked around at scopes/mounts but the I'd like advice from real world users who have solved this problem already if possible. Any help would be much appreciated.
The Hawke Airmax line would seem to fit your needs. They do honor their warranty. However, my experience is they complain when your springer eats more than one scope, per year. (I should add, they were not nice about my second return In less than a year. In fact, they were downright mean. After that, I stopped buying Hawke scopes.)

 
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It is reasonable to believe that I caused the UTG scopes to fail by over adjusting elevation to compensate for rifle geometry. Many years ago when I got the first Bugbuster scope I initially got a UTG droop compensated mount for it. As I recall I changed to the offset mount for better eye relief with that scope. The compensated mount is marked +20.7. The question becomes, is that too much compensation? I reckon there is only one way to find out. After reviewing the information provided by AGN members I picked this scope to try:


Etched reticle, illuminated, 5m min. parallax, decent price point for my budget.

Should be here Sunday. I'll update when I have news.
 
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Interesting thread because I just installed a UTG 3-9 Bug Buster on my HW 95 Field Pro. The original scope that came with the rifle died after 5 and a half years. It was a very good scope and always held zero.

The Bug Buster zeroed in nicly. I did not have to make any excessive adjustments to the elivation. I zeroed it in off a bench. Shot it several times off hand since then and it still holds a zero. At least I'm still hitting tin cans out to 35 yards free hand. Yesterday I shot it on paper to check the zero and I was hitting one and a half inches higher than the last time I shot the rifle on paper. This was not vertical stinging. All shots stayed at the same point of impact. I shot about 25 pellets. The only thing I did different this time was my hold. When I first sighted in the rifle I shot it off the bench rested on sand bags. This time sitting on the ground I put my arm on a chair and had the forearm of the stock resting on my arm. The rest of the stock was not supported just up against my shoulder. So I'm guessing my change in hold caused the problem. Next time I shoot I'll check it again.
 
It is reasonable to believe that I caused the UTG scopes to fail by over adjusting elevation to compensate for rifle geometry. Many years ago when I got the first Bugbuster scope I initially got a UTG droop compensated mount for it. As I recall I changed to the offset mount for better eye relief with that scope. The compensated mount is marked +20.7. The question becomes, is that too much compensation? I reckon there is only one way to find out. After reviewing the information provided by AGN members I picked this scope to try:


Etched reticle, illuminated, 5m min. parallax, decent price point for my budget.

Should be here Sunday. I'll update when I have news.
I have that exact scope on my HW50. With the etched reticle you should be fine.
 
Thanks for the info on the bugbuster. New poster (and airgunner) here and I've been struggling to site in a scope on a springer. I actually had this vertical stringing happen to me the other day. I'll check now to see if I have the scope set excessively high to site it in.
I will be interested to hear if adjusting the elevation to a less extreme position makes the scope reliable again. I’d be concerned that there is some permanent damage.
 
Shimming is a bad idea, especially on a hard recoiling rifle. In saying that, I've shimmed scopes a few times with variable results, but absolutely WILL NOT on a side focus scope. They are much more sensitive to clamping pressures than our older objective parallax scopes.
There was a guy that wrote a simple research article on this very subject many years ago but I can't remember where it was published. In it, he tested a lot of scopes, including some higher end ones of the era. He made claims that the majority showed tracking errors when the mounts weren't trued. Shimming very much creates an untrued mount situation. His solution for this testing was to true up the mounts using epoxy. You can shim quite a bit of elevation with no side effects using his method. In his article, he tested the tracking carefully and with trued up mounts, found no tracking errors on even the cheapest and had several springers to test durability and had no failures. What this says is that mounting stresses, combined with recoil stresses, are causing the inaccuracies and failures.
You can use scope mount lapping, adjustable mounts , or something like this epoxy shim procedure , to create a stress free mount and hopefully help this kind of situation . Tim MacMurray had sets of Sportsmatch mounts that he milled for elevation and lapped available for a while, as a for instance .
I've personally only used adjustable or epoxy shimmed mounts since reading this article and can't recall any scope problems for certain. The procedure is to clean your mounts and install them on the rifle in the spacing you need and also wax the scope tube extremely well. Figure out how much shim you need and find a small piece of something that thick... like a 1/8" square piece of plastic maybe, and mix your epoxy and put the little shim in the rear mount (if trying for more elevation) and put enough epoxy on both mounts so you have a solid shim when done. Drop the scope in the mounts and lightly tighten the caps. You want to squeeze out the excess but not compress anything. When it's fully set but maybe before it's at full strength, take off the caps and lightly tap the scope tube to break it free. Clean up the edges and you're done... perfectly aligned mounts.
Some important points:
The mount spacing must ALWAYS be the same from that point on.
Protect your rifle from the epoxy, in case of drips.
I use a little cellophane tape to hold the epoxy in place while it sets but you could use putty instead . .. just have the put more cap pressure to make sure it squeezes the excess.
Hope this info helps someone...
Bob
 
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As I mentioned in my post... yes. It just requires more pressure and care to insure that it comes out right. Picture that the front mount will have very little... just enough to create the angle while the rear mount has the job of shimming to the angle needed. The epoxy should have no voids, ideally, so a lot of pressure is needed to squeeze out the excess for putty.
 
Baffled. 15 yards iron sights: 67F29CF0-BF50-41D6-8FE8-1D09D72A3DE8.jpeg

15 yards new Hawke scope:
E16B8342-1708-43CB-83FD-06DC941BE558.jpeg6A0C1E61-6CB2-4C3C-9A0B-020107A3010A.jpeg

I did not adjust the reticle. Other targets are similar. Groups that wander or no group.
 
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I also have bad experience on a Bug Buster, wouldn't hold zero on a Prod. But my main reason to comment is I have Hawke 25 moa shims on 4 of my 5 air rifles. They are plastic and expensive for little pieces of plastic but I think they are a reasonable alternative for those of us with airguns without a 20 moa scope rail. Because they are plastic I don't think they will hurt the scope (shims should deform first). I have not tried to dial up a zero beyond 40 yards yet but I think I have a much better chance to do it with the shims.
 
All fasteners were tight and periodically checked. I took out the pivot bolt and lubed it before shooting. It was still tight at the end. The mount was a UTG +20.7. UTG rings. If the scope was not locked down I couldn't tell.

The Hawke scope box was delivered in a larger box with no padding. I cannot help but wonder if it is was damaged in transit from halfway across the country. Is there a vendor that can be trusted to properly package optics? Trying to eliminate another variable.

I have arranged to borrow a known good pellet rifle/scope combination. I have permission to switch mounts and optics to find the issue.
 
Baffled. 15 yards iron sights:View attachment 279892

15 yards new Hawke scope:
View attachment 279893View attachment 279894

I did not adjust the reticle. Other targets are similar. Groups that wander or no group.
I had the same issue with my Remington Nitro, one day tight groups, next day stringing, also a Bug Buster but I've tried several scopes, solved SOME if the issue with a heavier pellet, but it still happens. I finally said enough and went with a PCP.
 
My Rifle:
Rifle 1: RWS 34 T05 circa 2005-2010
Mount 1: UTG +20.7
Scope 1: Hawke 2-7x

Borrowed Rifle:
Rifle 2: RWS 34 T06 marked 2017
Mount 2: UTG +10
Scope 2: UTG BB 3-9x

Rifle 2, the borrowed rifle was fired with the included scope and returned a nickel sized 10 shot group.
Rifle 1 results posted further up in the thread. No group.

Borrowed rifle (Rifle 2) was affixed with Mount 2 (+10) and Scope 1 (Hawke). 20 shot group:
IMG_2448.jpg

My rifle (Rifle 1) was affixed with Mount 2 (+10) and Scope 2 (Bugbuster). 20 shot group:
IMG_2451.jpg

After the first ten shots with my rifle I changed the breach seal for a new one provided by Vortek. No improvement for the last ten shots. I also fired the borrowed rifle with my mount and the Bugbuster and it returned a suitable group.. Since both scopes and both mounts returned suitable groups on the borrowed rifle then my rifle is malfunctioning. What is my next step?