UPS & DOWNS

I've been having some issues with my Gamo shadow 1000 .177cal. I have fired about 1200rds thru it. It has been lubed tuned only and new GTX trigger installed. I have a Leapers 3-9x40AO mounted. I shoot alot in my basement @ 20-23yds. I shoot CPL and Beeman crowmags. The problem is the rifle will shoot a very tight groups but at 1.5" high from aim point. After shooting about 20rds the point of impact will change to hit the aim point. I have no left and rights and very tight groups. I have tried to adjust the AO of the scope and have checked all mount screws. It does this constantly. It is like I'm looking thru the scope differently @ times. I have noticed some build up in my barrel about 1" from the breech. I have tried to clean it. It seems like the rifle is very hold sensitive. I'm wanting to squirrel hunt with it but I never know if i'm going to hit anything. Any suggestions?   Thanks, John.

[Gene_SC]

John, I am sure some more of us will give you some ideas. I also have a Shadow 1000 and had it tuned and a GTX trigger installed by CharlieDaTuna. Very powerful and consistant velocities after the tune. Yes, the shadow is very touch sensitive and it seems more so than my Gamo CFX's which have been tuned and GTX triggers. When I shoot the shadow I only have my finger on the trigger and thumb on the stock. My shadow is not as accurate as my CFX's are but more power. The shadow is lighter and that makes some difference.

If you have found your sweet spot and it consistantly moves off target, I would check your stock mount bolts. Make a mark somewhere on your barrel where the scope mount is with a pencil. Then shoot some and see if your mount is not moving back. That was happining to me and it took me a while to figuer it out. Also if you have another scope, change scopes and re sight and then see how it works..

At that distance you are shooting, you should be right on every time.

I use RWS Superdomes exclusivly with my CFX, Shadow, 1250 and 440, They work good in my guns. But remember that not all Shadows will like the same pellet. It is different from gun to gun.

I am sure the other more experienced members may have a solution for you..

Good Luck
Gene

Thanks for the info, I'll recheck everything again. How do you hold the frt of the stock? I noticed if I hold the rifle loosely it flies everywhere and my groups get bigger than if I hold it tight and tight against the shoulder. I'm getting 1/4" or smaller groups at this distance but need to figure out this problem. I have shot several different pellets thru this rifle and these 2 shoot the best. Hopefully I figure it out before squirrel season.

[CharlieDaTuna]

I would be concerned about what it is in the barrel near the muzzle. What ever it is should be cleaned out so that it is smooth. I suggest using a pull through and GooGone to clean it.

I would also be interested in knowing just what you used to"Lube Tune" it and where as that can be critical to the guns performance, especially if the seal has any damage to it. A damaged seal often occurs during assembly is not uncommon.

                                 PLUS...ASSUMING ALL ELSE IS A-1


Take a look in the library under "Shooting Guide's" You will probably find something in some of those articles that will help you determine where your problem lies or help you to resolve your issue's. More often than not, it's like Gene said, finding the sweet spot and being consistent when you find what works best.

[Gene_SC]

I shoot from a table with rifle forward stock resting on a good solid sand bag. I never hold the front of stock or even touch it. While sitting down I rest the rifle on the bag with butt against my shoulder. I only have my forefinger and thumb touching the rifle. Thumb rests on top of stock and forefinger squeezes trigger.. I do not grip top of stock with my thumb. It just sits there...
That how I get the best consistancy..

When I sight in my scope, I start at 10 to 15 yards and work out from there. If I do not get consistant groups at 10 to 15 yards I start looking for loose bolts and possible a loose mount, stop or scope.

Gene

[-=ed]

< s i g h >, Gene, that would take some of the fun out it somehow. For me, at least.

I like to hold the gun.

But I suppose in the drive to get better, I'll be trying it out.        

Oh, well, I guess smaller groups are worth it

         

John:

What did you do for this lube tune?  How long ago did you do it?

Does it do the same thing with heavier pellets? Do you happen to have any CPH or Kodiaks around?

I would think that if it was dieseling, you'd know about it, as the report would be noticible and particualrly so in a confined space, but that kind of sounds like a mildish deisling condition, either from the wrong lube getting in the wrong place when you had it apart, or from a smallish cut in the piston seal when you reassembled it.

I'm just grapsing at straws here....

Another possiblity is that the erector mechanism in your scope is shot but I wouldn't expect it to print twenty shots high and the remaining right on if that were the case.

The reason why I am asking if you've got heavier pellets is that shooting them will kind of add more "backpressure" during compression, and thus cause more heat to be generated, and thus possibly force the seal to do it's thing and simultaneously help burn up any excess lube forward of the piston seal.  Might help you troubleshoot the problem without tearing down the gun to do it........  Though if the seal is bad, you'll be tearing it down anyhow to fix it.

On another note.........

Sometimes I feel like an alien from another planet, because most folks who've shot Shadows tend to think they are really "hold sensitive" while the Shadows that I've shot have impressed me as being among the least worst offenders in that regard.

I've got an article on spring-piston shooting technique in the Photo Essay section of Uplandhunter.net that you might find helpful.  I'm shooting my .177 R-9 in the photos but I shot my Shadow the same way, and shoot my wife's that way, and I got and still get very satisfactory results. It might work for you, too.

Oh, and as for cleaning.  Everyone has their favorite bore cleaner for airguns it seems.  Mine is Simple Green.  The stuff works like a champ.

Blessings and Tight Groups,
-JP
http://www.uplandhunter.net

[Gene_SC]

LOL Ed... I hold my Co2 and PCP whith both hands and squeeze da trigger... It is just that I find that when I hold the front stock with my left hand with fingers wrapped around stock my shot are awful when shooting any springers. I tried it shooting from table with resting my elbow on table and resting the stock in my palm. That is some what better but I shake alot and can not hold on target very well.

I am sure those out there who do not shake like myself could do this without a problem... All springers are somewhat hold sensitive. Some worse than others. Like my Hunter 1250 Royal .22.. NO WAY can I just hold it and shoot... Absolutly have to have it on a rest of some kind or a near by tree to rest it against before I shoot. I have never taken the 1250 hunting because the chance of me hitting something with it would be 100 n 1 shot..

Gene

[vinceb]

An inconsistent breach lockup will cause up-and-down scattering with a scope (my Quest loves to do that).

I agree about the Shadow's lack of hold sensitivity - mine seems to shoot well no matter what.

[CharlieDaTuna]

I agree with JP regarding the hold sensitivity in the Gamo in most cases as not being overly excessive, especially if properly tuned. If tuned properly, a great majority of the torque is reduced eliminating the "twist" as the spring unwinds as well as the excessive vibration and recoil. If not lubed properly with the correct lubes, the hold sensitivity can actually be increased considerably.

I would be careful about using heavy pellet though. Dieseling can help in ridding the chamber of excessive lube  but you also need to be careful about detonation. Detonation (explosion in the compression chamber) can cause damage  to springs quite easily.

I also agree with Vince about poor breech lockup , especially in some of the Chinese manufactured guns like the B-18/19's, the older B-20's, Quest and the Legacy and some others, but it is a very uncommon issue with Gamo's.

[-=ed]

I shake a bit too, side effect of my meds.

I can't shoot offhand anymore, I'd be dangerous.  

With the .177 S1k, animals would be safe. For me, it is incredibly hold sensitive, or I have a bad scope [which I'm checking out tomorrow.]  The .22 Supreme would be a different story. I don't know why.

I hold to a tree or fence when I'm not at a bench. I would like to be able to shoot away from the bench, so I try to get more of my hand into the game to be able to do this impromptu shooting. I don't shoot animals [except maybe for the chipmunks that destroy my expensive japanese maples, and I usually just shoot to scare them], I just shoot at litter for the fun of it. It's not easy anymore.

I'm giving serious consideration to a .177 RWS54, to hopefully redeem myself.  

I thought life choices would get easier as I got older...  

     

     

[Gene_SC]

LOL Ed, seems we are in the same boat... What counts is we are enjoying what we love most. It is fun and healthy. Keeps our minds working and alert.

I am sure that every one who shoots air guns has there own ways of shooting. I always remember that not all of us are are the same and niether are our airguns... lol  

I just keep shooting and havin fun with it. I learn something new every week.


Gene

THANKS GUYS,
  I'll check these things and get back with you. I know for a fact that it is not dieseling too much I just smell a hint of dieseling. As for as a heavier pellet it seems not to like them as well.

Ok Guys,
  I checked all my mount screws and a few other things. What I noticed was if I would move my power of my Leapers scope to 7 instead of 9, it seemed to cure the problem. Does this make sense?

[-=ed]

To some, I'm sure...