Sighting in a scope

Salmo_g

Well-Known Member
#1
I had been thinking off and on for the last 5 or 6 years about buying a pellet gun. After reading FSA's and Ive's recent threads on the topic, my interest grew even more. Knowing that Ive researches the hell out of everything before he makes a purchase, I decided this could be easy. So I just ordered the same Gamo air gun and Leaper's UTG scope that he did. I even ordered the same brand and type of pellet he did.

Here's the thing I think I need help with. I have never, ever before used a gun equipped with a scope. Only open iron sights. Growing up here in western WA, when I hunted the local blacktail deer, the longest shot I ever made was 30 yards with a Winchester model 94 30-30. That's partly what got me into bow hunting, close shots. But I digress.

Now I have an air gun that doesn't even come with iron sights, just a Gamo scope and the UTG which I installed based on all the advice that factory air gun scopes are pretty poor quality. Got it installed and have twice now tried to see if I can hit the broad side of a barn, or the target I have set up in my woodshed at 25 yards, which is similar to the distance (20 and 25 yd.) that I practice with my handguns with their open sights. Pretty consistently the point of impact (POI) is about 4" low and 7" to the right of my point of aim (POA) with the scope's crosshairs.

So today I removed the caps and turned the screws a couple clicks at a time because the manual says to make small adjustments. No change in POI, so I finally was making up to 4 and even 6 clicks per adjustment to move the POI. I guess I'm about 18 to 20 clicks of adjustment at this stage, and while my groups are nothing to write home about, they still average about the same 4" low and 7" to the right of my POA.

My conclusion is that the adjustment screw thingys are not really moving the reticule crosshairs at all. I'm probably doing something wrong, but I have no idea what. And the user's manual isn't very good at explaining any aspect of the scope, at least for me.

Any ideas?

Sg
 

Jim Ficklin

Genuine Montana Fossil
#3
Sg, Here is a summary of info I shared with Ive.

1

There are a host of air gun forums that can be a wealth of information. The Talon Airgun Forum (http://talonairgun.com/forum/index.php?sid=9e0cb8edc8b76652c2071afeb259b309) for example is one of them. There are also many airgun forums by airgun brand. I have never used this, but it lists a variety of options:
http://www.airgunarena.com/index.php/Forums_about_Airguns

In general, air gun care is characterized by subtle (and not so subtle) differences from conventional firearms:
1) NEVER use conventional cleaning solvents - these can & will damage seals. Only use airgun oil for lubrication & cleaning. IF you use felt cleaning pellets (I don't), back the felt pellet with a lead pellet - the felts don't provide sufficient resistance & over time repetitive use could damage the piston.
2) Airguns do not require frequent cleaning like powder burners; there are no corrosive products deposited in the bore; oil from the piston mechanism keeps a thin coat in rifle bore. Over time, you may see lead build-up (accuracy will drop off, but after many, many shots.). I only swab my bores when this occurs (I use a pull-through, coated cleaning cable ALWAYS from breech to muzzle or a similar pull-through device fashioned from heavy mono. IF the rifle muzzle features a barrel weight or shroud of some sort, a soda straw inserted through said device to the end of the rifled barrel will make dropping the cleaning cable into the barrel much easier.
3) If you swab the bore squeaky clean, you'll find that accuracy may be worse - some fouling is a good thing.
4) NEVER leave a spring piston ("springer") or gas piston air gun cocked for an extended period of time; it can & will weaken the spring.
5) I would caution against doing any main spring work; these springs are very stout & require the use of a spring compressor. Lots of folks have been injured trying to jury-rig a spring compressor.
6) DO NOT dry-fire; such practices can also damage the spring and/or piston/and firing mechanism.
7) To ensure best accuracy, avoid very light pellets. Endeavor to keep velocity under the speed of sound (~ 1100 fps in my neck of the woods); diabolo pellets become unstable at & above the speed of sound - touting "high velocity" is a marketing gimmick. Try a variety of pellets - I have had the best results with JSB products in my .22 & .25s; JSB & Crosman pellets work well in my .177s.

I have been involved with airguns for many years. I started with springers, but I only have one left - a delightful Beeman R-7 in .177 with which I will never part. I have 1 pistol - a single-cock, Baikal 10-meter target pistol (Starling & mouse insurance). The rest of my collection are incredibly accurate, pre-charged pneumatic rifles (1 in .22 & 2 in .25 caliber. .25 caliber mimics .22 LR standard velocity in performance.). The two .25s are easily the most accurate rifles I own, distance being relative. Both .25s will shoot 1-hole groups at 50-yards under calm conditions all day long when I do my part. I made a lot of mods to the Benjamin .22 myself - it is quiet, accurate, short & with it I "own" the area around my house.

You can make a very durable target frame by building a wooden box (mine is 12"x 10"x 5-1/2" backed with an 1/8" steel plate. the box is filled with duct seal, which lasts for 1,000s of shots. I removed a "ball" of lead from the center 1 time in 20 years & filled the void with fresh duct seal. Others have created similar arrangements using carpet scraps. My rifles are quiet when I shoot & there is no noise when the pellet hits the target (a boon in residential neighborhoods. Fortunately, you don't have that problem, lol.

If you opt to disassemble your current air rifle, search for videos or instructions in the various forums/You Tube. Take photos for reassembly reference before you disassemble anything complex (triggers for example.). Also, for years I have collected a variety of clear plastic bags in various sizes - I perform all first-time disassembly in one of these as well as any disassembly when "flying springs"/retainers/pins/ball-detents/etc. may be a possibility. I also use these when disassembling reels & the like. This beats crawling around on the floor searching for a wee part that took flight & ordering a replacement when you fail to find it.

2

Clean with air gun oil - air gun oil is synthetic & use oil sparingly in accordance with your owner's manual. Many conventional gun oils are petroleum-based formulations and such oils can deteriorate seals as well as some soft metal parts. There are lots of choices for air gun oil. I have always used Beeman Oil, but Gamo & other companies make similar products. And one thing air guns have in common with conventional firearms: NEVER lubricate trigger assemblies unless specified by the manufacturer (I have many guns - only ONE recommends a very light application of oil on the face of the sear (a "knee-jerk," stop-gap effort to resolve an inherent design flaw on an original 2-stage Bushmaster trigger, which I will replace with a proven Rock River trigger group one of these days.). When necessary, I ensure that a trigger group is clean - usually by "blowing it out" with canned or compressed air. When I do clean an air gun bore, I first pull a couple DRY patches through, then 1 patch with a bit of air gun oil applied followed by 1 dry patch. I DON'T want the patches coming-out clean like I do when cleaning the bore of a powder burner. I NEVER use a brush - brass OR nylon! The steel in the bores of air guns isn't as hard as that of conventional firearm bores; in the case of .177 rifles/handguns, shooting BB's will ruin the riflings (even though there are a few multi-pump air rifles that feature BB reservoirs (old Crosmans come to mind.).

When you are zeroing an air rifle, rest the fore end on a soft rest (I prefer a rolled-up bath towel - this seems to absorb vibration well.). Position the fore end so the rifle rests on the towel about 2" ahead of the front of the trigger guard - this is the approximate "sweet spot" for most air rifles. Do not hold the pistol grip of the stock in a death-grip - hold it lightly & consistent, good follow-through is imperative - due to the slower velocities, the pellet is in the bore for a longer duration. That is the same front support hold I use in the field - usually, I support the fore end ahead of the trigger guard on my finger tips when shooting off-hand, but I prefer using some type of solid rest whenever possible - steady rests make for accurate hits. Practice, practice, practice - results improve with trigger time, but most importantly be safe & have fun. Oh, and be aware that even though lead pellets are soft, they can & will bounce-back off of hard, perpendicular surfaces! Air rifles & .22s make old guys kids again
!

3

When I need to lube an o-ring, I use a very light coat of pure silicon grease, which is the recommendation. I use Dielectric Silicon Grease that I picked-up at NAPA & have never had a problem. If you use oil, buy some airgun oil - Beeman Metalophillic Compound # 5 is what I use, although I also have a similar product from Air Venturi (which I doubt you'll find in Spokane.). Gamo also makes a similar oil. I lube seals and everything else with air gun oil.

Pellets: Light pellets that allow velocities exceeding the speed of sound (~ 1100 feet per second here) are inherently inaccurate; Diabolo (wasp-waisted pellets) become unstable at speeds beyond that. Air gun manufacturer claims of super-high airgun velocities use that as a selling point; it is worthless hype. Find a pellet weight that allows you to maintain desired velocities. I shoot 7.9 grains in my .177s; 18 grainers in my .22; 25 grain pellets in my .25 caliber rifles (up to 40 grainers if I'm eliminating a problem Skunk or Raccoon.).

If you would like, send me your phone number & I'll call you to discuss scope mounting.

j.
 
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IveofIone

Active Member
#5
SG, I'm sorry to hear about your woes with the UTG scope. If Jim can't help you out then there is probably something so wrong with your scope that it needs to be exchanged. Unlikely but certainly possible.

I have been busy building and shooting a new Crosman pistol lately and hadn't shot my Gamo Swarm for a few weeks. Returning from squirrel patrol this week I thought I would try a few shots at my pistol target to see if it was staying sighted in. With 4 shots at the target all were in the bulls eye and touching each other. I figure that is close enough for an old guy and am impressed with the gun and scope as well as my own ability to shoot it. I'm sure that once you get sighted in you will love that new unit and certainly won't miss loading pellets one at a time between shots.

Let us know how this works out, now I feel complicit in your frustration!

Ive
 
#7
I bought one of the GAMO Air Rifles to deal with a rat problem. The scope it came with was a POS. Same problem as yours. The turrets would not move the reticle at all. Took it off and mounted a nice Vortex Strikefire II on it. Luckily I had the Strikefire laying around after putting a new scope on my wife's AR-15. Thankfully, the neighbor cleaned up the trash pile on his side of the fence, and our little GAMO dealt with any intruders to our side of the fence once the Strikefire was zeroed.
 

Jim Ficklin

Genuine Montana Fossil
#8
Be careful mounting conventional optics on spring-piston air rifles. Air rifle scopes are reinforced to endure the different recoil of a springer.
 

KerryS

Ignored Member
#9
I bought one of the GAMO Air Rifles to deal with a rat problem. The scope it came with was a POS. Same problem as yours. The turrets would not move the reticle at all. Took it off and mounted a nice Vortex Strikefire II on it. Luckily I had the Strikefire laying around after putting a new scope on my wife's AR-15. Thankfully, the neighbor cleaned up the trash pile on his side of the fence, and our little GAMO dealt with any intruders to our side of the fence once the Strikefire was zeroed.
I have a Gamo also. Good rifle but like yours the scope is a piece of shit. I need to replace it but for now I kinda play it as if it adds to the challenge of picking off rodents. When I get serious in eliminating fur and feathered annoyances I get the .410 out.
 

Salmo_g

Well-Known Member
#10
It was warm (63*) this afternoon and mostly dry, so I resumed my efforts at sighting in the Gamo Swarm with the UTG scope. Many clicks later aligned POA with POI, at least more generally. Looks like I'm a lousy shot. Still some scatter of pellet holes, but at least they are within a couple inches of the center of the target. That's so much better than when I began.

When I was young and had 20:20 vision and didn't need reading glasses, it was pretty easy to put holes in and near the center of the target. At least that's how I remember it - that's my story, and I'm sticking to it. It's possible that being a good shot just isn't in the cards any longer. My wife can pretty consistently shoot tighter groups with the handguns than I can, so there's that to consider.
 

Jim Ficklin

Genuine Montana Fossil
#11
Keep experimenting with pellets and fine-tune your shooting form. If your model scope has a diopter adjustment for the rear lens bell, dial that in/out (it will bring the reticle/crosshairs into sharp focus. I'd guess that some combination of the above is causing the "flyers" you're experiencing. Remember to rest the rifle ~ 2" ahead of the front of the trigger guard on a soft rest (like a rolled-up towel - this is the "sweet spot" on an air rifle.), no "death grip" on the rear of the stock, and follow-through consistently - don't let the rifle move following the shot. There are subtle differences between air rifle shooting mechanics and that of conventional rifles/"powder-burners." Keep practicing & you'll get there, Sg. I wish I lived closer to you.
 

freestoneangler

Not to be confused with Freestone
#12
Looks like I'm a lousy shot. Still some scatter of pellet holes, but at least they are within a couple inches of the center of the target. That's so much better than when I began.
Well, here's yet another thing we have in common... lousy shots, at least with air guns. The scope on my Ruger simply would not stay put. Jim recommended upgraded mounts, but I did not have time to complete that this summer, so I set about just tuning the fixed sights. During my last practice/sighting trip I was able to dial in my Winchester .22M lever action that has a scope. I was able to improve accuracy with the Ruger but not to the degree I did with the .22M, so I think it has to do with technique.

I used a sand bag support for the .22M at 100 yards and for the Ruger at about 30 yards. More or less unconstrained and really focused on breathing and trigger squeeze. I was still using the Crosman Premier hollow point , 7.9 gr, which Jim and others say have unstable flight. Next step is to repeat as currently sighted using the dome pellets.

Air rifles are a fun hobby... particularly like the price of ammunition.
 

zen leecher aka bill w

born to work, forced to fish
#13
I bought a Gamo switch barrel kit that also came with a scope. One thing I learned is the modern "reasonably priced" pellet rifles aren't all that accurate. Mine shot bigger groups at approximately 30 yards than my target .22 LR did at 100 yards.

It's still accurate enough to hold "minute of starling" groups at 30 yards.
 

alpinetrout

Banned or Parked
#14
Thankfully, the neighbor cleaned up the trash pile on his side of the fence
That must be nice...

I have neighbors on one side with all kinds of crap in their backyard, plus a couple of apple trees and a crabapple tree that they've let grow to at least 30 feet tall, so they litter fruit all over both their yard and mine. I clean up what drops on my side of the fence, but they can't be bothered. Almost all the fallen apples have chew marks on them, and they're not all from the squirrels. The bait station I put out seems to have helped considerably. The last rat I saw on my side was moving pretty slowly and got the backside of a splitting maul, center mass. That was pretty satisfying.
 

Upton O

Blind hog fisherman
#15
It was warm (63*) this afternoon and mostly dry, so I resumed my efforts at sighting in the Gamo Swarm with the UTG scope. Many clicks later aligned POA with POI, at least more generally. Looks like I'm a lousy shot. Still some scatter of pellet holes, but at least they are within a couple inches of the center of the target. That's so much better than when I began.

When I was young and had 20:20 vision and didn't need reading glasses, it was pretty easy to put holes in and near the center of the target. At least that's how I remember it - that's my story, and I'm sticking to it. It's possible that being a good shot just isn't in the cards any longer. My wife can pretty consistently shoot tighter groups with the handguns than I can, so there's that to consider.
I noticed that I have to remove my glasses when shooting through a scope, really makes a difference in clarity of the target.

What range were you sighting in? Bench rest? I have a Bog Pog shooting stick tripod that I set up in a specific location. It was really helpful sighting in at paper in the exact location where Ratus ratus met his/her end. I got hooked on shooting sticks for all of my rifle shooting, they are easily set up, very stable and really make a difference in my marksmanship.

https://www.amazon.com/BOG-POD-RLD-3-Shooting-Stick-Tripod/dp/B001G0MPKQ