I bought my first and only air rifle a couple years ago (a Gamo Bone Collector Bull Whisper .177 cal air rifle), and this is a rifle I wish I had never purchased. I've tried several types of ammo before I found one that works decently. With almost all ammo, I'd be lucky to have 2 or 3 out of 10 shots in a target the size of a dinner plate - almost all were strays in all different directions. The new ammo (Gamo Rocket Pellets) do much better with 10-15% strays - I still think this is too high, but it's much better than what it was. I had hoped moving away from the scope that came with the gun might help the situation, so I purchased a Hammers 3-9x40 AO Magnum Spring Air Gun Rifle Scope, and it looks really solid and seem to mount well. I was excited to use this combo hoping I'd *finally* have a working rifle, but even with the scope adjusted all the way up, it's still shooting around 10" low at 30 yards. I know I can shim the front mount, but I was hoping someone might be able to provide some insight into this problem. Maybe there is a problem or other adjustment I can make? Maybe toss this and get another air gun? Thanks for any assistance.
Problem with scope - shooting too low
- Thread starter baskervi
- Start date
Is there a weight difference between the pellets? If so that's the answer. Another one is that the spring in your rifle has worn out and needs to be replaced. You can actually upgrade to a gas piston which is better and last longer. Don't quote me on if you can install a piston in that particular rifle. I'm almost positive,but not 100% positive.
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Well you wouldn't shim the front ring, instead shim the rear. As far as your erratic shot group goes(sounds more like a shot pattern) you should try the artillery hold to tighten your group. In case you are not familiar with it you can find an explanation here. http://thegodfatherofairguns.com/basics/the-artillery-hold/
You could try turning the one piece scope mount around 180 incase it has a bit of anti droop built in...assuming you are still using the same mount that came with the gun.
You could try turning the one piece scope mount around 180 incase it has a bit of anti droop built in...assuming you are still using the same mount that came with the gun.
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Thanks for the responses.
Topcat, the new scope doesn't shoot high enough for any pellet, regardless of weight. The new pellets (9.6 grains) do shoot a few inches lower than some other pellets I've tried (7.9 grains), but even the lighter pellets can't reach the center of the target. This particular gun comes factory with a gas piston.
Chachoze, I use a lead sled with two lead bags on a heavy wooden bench when sighting in, even for this air rifle. I should say especially for this air rifle because of the constant problems. I did contact Gamo about the poor grouping, and they didn't seem too surprised by the erratic shot group. They said this particular gun was very dependent on the ammo type, and I'd have to try various types to find the right one. I actually was trying to send it in to the factory to have them check it out, because even the ammo that came with the gun didn't shoot worth a flip. I'm no longer using the same mount that came with the gun - the mount that came with the new scope is significantly larger and has more screws to tighten everything down, plus it has an integrated scope stop. It's a really solid mount. This scope says in place. The old mount would tend to drift back, and I couldn't stop it - I almost purchased a scope stop to use with the original rings, but I got the new scope instead. I read a lot of complaints about the old scope and mounts for this gun, and many others complained about their scopes drifting back. I'll try rotating the scope and see if this helps.
Topcat, the new scope doesn't shoot high enough for any pellet, regardless of weight. The new pellets (9.6 grains) do shoot a few inches lower than some other pellets I've tried (7.9 grains), but even the lighter pellets can't reach the center of the target. This particular gun comes factory with a gas piston.
Chachoze, I use a lead sled with two lead bags on a heavy wooden bench when sighting in, even for this air rifle. I should say especially for this air rifle because of the constant problems. I did contact Gamo about the poor grouping, and they didn't seem too surprised by the erratic shot group. They said this particular gun was very dependent on the ammo type, and I'd have to try various types to find the right one. I actually was trying to send it in to the factory to have them check it out, because even the ammo that came with the gun didn't shoot worth a flip. I'm no longer using the same mount that came with the gun - the mount that came with the new scope is significantly larger and has more screws to tighten everything down, plus it has an integrated scope stop. It's a really solid mount. This scope says in place. The old mount would tend to drift back, and I couldn't stop it - I almost purchased a scope stop to use with the original rings, but I got the new scope instead. I read a lot of complaints about the old scope and mounts for this gun, and many others complained about their scopes drifting back. I'll try rotating the scope and see if this helps.
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Well the lead sled is the source of your grouping problems, nearly all spring/gas piston gun don't work well with most shooting platforms or gun vises that's why I recommend the artillery old. I once had a variant of the Gamo Whisper that I tried to shoot accurately with a similar gun platform and would have a hard time hitting the broad side of a barn until i started using the artillery hold then things started shaping up nicely. Keep in mind you still wont have hole in hole accuracy at 30yrds with that gun but I think you should be able to do better than a dinner plate grouping.
If the old scope and rings/mount didn't have the issue with your point of impact reaching your point of aim and then you switched out the scope and rings/mount at the same time with new ones and now you are shooting low then I surmise that the old mount had a bit of anti droop built into it and your new one doesn't, that is likely why you are hitting lower than your point of aim. A fairly easy test would be to put the old mount/rings back on the way they were exactly along with the new scope and take a few shots, if the shots begin to meet where you aimed then you know what the problem is and that you should be able to correct it with shims in the rear ring(closest to you). Just be certain not to go overboard with the shims or you could damage the tube.
If the old scope and rings/mount didn't have the issue with your point of impact reaching your point of aim and then you switched out the scope and rings/mount at the same time with new ones and now you are shooting low then I surmise that the old mount had a bit of anti droop built into it and your new one doesn't, that is likely why you are hitting lower than your point of aim. A fairly easy test would be to put the old mount/rings back on the way they were exactly along with the new scope and take a few shots, if the shots begin to meet where you aimed then you know what the problem is and that you should be able to correct it with shims in the rear ring(closest to you). Just be certain not to go overboard with the shims or you could damage the tube.
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I've got a gamo whisper fusion also. It has terrible barrel droop. I put a dnto6 droop compensating mount, which gives 10" droop compensation at 30 yds. It was still too low so I put on a dn034 compensating mount which gives a 19 " droop compensation. I had to grind the front stop down to get it to fit, but it solved my problem. It shoots within an in at 25 yds now with jsb 15.89 gr. seeming to be the best. It is a .22.
Your scope may be adjusted up so high your scope won't hold center, The spring loses tension on the scope tube when adjusted too high. Adjust your scope close to center with your mounts then use the scope adjustments for fine tuning. The artillery hold helps. I shoot off the palm of my hand.
I hope this helps some. Good Luck
Your scope may be adjusted up so high your scope won't hold center, The spring loses tension on the scope tube when adjusted too high. Adjust your scope close to center with your mounts then use the scope adjustments for fine tuning. The artillery hold helps. I shoot off the palm of my hand.
I hope this helps some. Good Luck
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Thanks for all the valuable information. I'm checking out the mount and rings now.
Jimbo1947, I know you are right, and I'm not sure if this makes sense - as I was approaching the very end of the spring (trying to move the sight up), the cross hairs actually dropped slightly.
I have a plan now, and I appreciate the feedback.
Jimbo1947, I know you are right, and I'm not sure if this makes sense - as I was approaching the very end of the spring (trying to move the sight up), the cross hairs actually dropped slightly.
I have a plan now, and I appreciate the feedback.
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If the mounts you are using are parallel and of equal height I would get a base to compensate for barrel droop. Then remounting the scope and rings. The FX no limits are another great idea in that you can tweak the elevation of the rear scope mount to compensate and bring your POI into the bull.
As to the scattering problem ditch the lead sled. A springer needs movement to shoot well, locking it down tight will ruin accuracy. Like a chick with large breasts you got to let them bounce.
As to the scattering problem ditch the lead sled. A springer needs movement to shoot well, locking it down tight will ruin accuracy. Like a chick with large breasts you got to let them bounce.
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