Please Help, Trying to narrow down an accuracy problem.

[SubaruEJ25]

Hello everyone, I am new to the forum but a long time shooter.  I recently went back to air rifle shooting because I'm about to buy a house and get married, so I needed to save some money by cutting out range fees and ammo cost.  I am having a serious problem with accuracy and I need some help.  To start out I have a Gamo Varmint Hunter (Basic S1K) it's about 3 years old, not too many rounds through it.  Before getting back into shooting it, I gave it a good cleaning and made sure all components were in proper order.  The seal had a few wear marks in it but nothing more than normal use.  I also ditched the standard 4x32 scope and replaced it with a Leapers 3-9x40 illuminated mil-dot and swapped triggers for a GTR III.
     To put it simply my groups are horrible, 2.5" - 3" @ 20 yrds.  The patterns are random, 1 shot high and left, 1 shot low and right, one in the bull; you get the picture.  I know I'm getting scope creep, up to .3615" at that point it knocked the scope stop off.  I then cleaned the mount and rings w/ alcohol and loctite'd all points but I'm still getting creep.  I have an Accushot one piece mount on its way, hopefully that will solve the problem.  Is there anyother explanation beyond scope creep???  I've been shooting for 20 yrs now and I know I can hold a much tighter groups with irons, I would try this but my Gamo does not have iron sights.  I have tried various bench methods to remove shooter error from using a pillow to a vice.  The only other things i could attribute would be a bad scope or worn seal, I will know better once my 1 piece mount arrives.  I have had good luck w/ Leapers in the past but I know every so often they make a few bad ones.  Could it be time for a new seal as well??  Thank you very much in advance for your help.

[SubaruEJ25]

[RCnMo]

If you have creep, you will have accuracy problems. I haven't shot the Varmint Hunter, but I have pulled all but one hair out of my head trying to figure out what's wrong with my Crosman Quest. Proper lubes are a must in air rifles and the lube master as well as springs and seals is Jim Maccari. The one piece mount should help considerably because it will have much more surface area for clamping. If it is grouping well with iron sights, check for barrel lock up problems. I have a few rifles that are hold sensitive and one that if it isn't held exactly the same way for every shot with proper follow through, you'd swear you were shooting a 12gauge at the target. There are many brilliant guys and gals on this forum that will probably chime in on this and get you fixed up. You can check your crown with a q-tip by giving it a light twirl and see if it is grabbing bits of cotton. If it is, you can try the brass screw and toothpaste/mild abrasive trick. I don't know what hold you are using on your rifle, but I have found the best luck on most of mine with just resting the forearm where the rifle balances on your hand and barely shouldering the buttstock with very little cheek pressure. Let the rifle recoil on it's own and see if your groups shrink. This doesn't work with all my rifles. I have to sand bag my B3's buttstock and rest the forearm on my hand to get it to group. My B30 took a nose dive after I scoped it (added weight?) and I have to give it heavy cheek pressure and barely shoulder it to get it to group. When I get it right, it will stack pellets in a dime sized group at 30 yards. Good Luck and welcome to a great place...........I think I finally beat BigBill to it!

[longislandhunter]

Hi Scott and welcome to the forums,,,, it's great to have you with us  !!  

The problem could of course be any number of things but if you're having that much of a problem with scope creep I'll betcha that could be the culprit.  Once you get that Accushot 1 piece mount clean the rifle receiver and dove tail grooves again thoroughly with denatured alcohol,,, then clean the new scope mount with the alcohol also.  Clean every part of the mount,,,,, take the mounting screws out and clean them,,, clean the screw holes as best as you can and of course clean the clamping shoes of the mount as well.  Clean EVERYTHING....

When you install the mount and scope make sure you use some blue loc-tite on the screws,,,, you can also put some in the dove tail grooves although I don't always do that.  Let the loc-tite dry and cure for at least 24 hours, 48 hrs is better, before you shoot the rifle.   That procedure, if followed religiously, should end your scope creep problems forever...  

The other thing I noticed is that you didn't mention what kind of pellets you're using.  If you haven't tried an assortment of pellets then the problem could also be a simple case of feeding the gun a pellet she really doesn't like.  Try an assortment of pellets until you find one that the gun groups the best.  Straightshooters.com has a nice pellet assortment packet, well worth the money.....

I'm sure some of the others will chime in here soon with their advice so I'll finish by welcoming you again to GTA and saying that I'll be looking forward to your future posts...  BTW,,,, congrats on the upcoming marriage and new home ownership  

Jeff

[SubaruEJ25]

Sorry, forgot to post what pellets I'm using.  Crosman 7.9gr Premier Hollow Points & Pointed, also RWS Superpoint 8.2 gr.  I find that the mid-weight pellets perform better than anything too heavy or too light.

The crown is perfect too, no q-tip fibers left behind.

[longislandhunter]

I've never had much luck with pointed pellets, I do have a gun or 2 that will shoot them OK but most of my shooters hate em..  The CPH's are a good pellet and I use them quite a bit also.  MId weight pellets are surely the way to go but I'd still get a couple more varieties of pellets and do some grouping tests.  I would suggest CPL's, superdomes, JSB's, GAMO tomahawks and perhaps some GAMO hunters.  Beeman FTS are also an excellent pellet.  

Let us know how you make out.....

Jeff

[RCnMo]

The Crosman 7.9g Premiers have been the main staple of most of my rifles. The 10.5g heavies shoot the best out of my POS Quest. The RWS superpoints stack on top of each other out of my B3 at 15yards and they tumble out of my B30. Gamo hunters and Crosman premiers shoot great out of my .22 TF89. My CFX puts the CPL's wherever the trigger breaks, lots of dead grasshoppers, Japanese beetles and tomato worms with these. My father swears by RWS Meisterkulgens in his B25. Lot's of pellets out there to choose from and like the earlier post said. You might try a sampler to save yourself $$ and half empty tins of pellets. Also, a lot of members agree that heavy pellets in springers shorten the life of the spring, me included. I just couldn't find anything that my quest will digest without puking all over the target. Let us all know what you find out.

[vinceb]

Try other pellets - I suggest Crosman Premier domed (7.9gr, in the brown box) or Benjamin Diablo (basically the same pellet). May shooters report that pointed pellets don't seem to do as well, and I suspect that quality control on the Hollow Points is hit-or-miss (it sure is for that pellet in .22 caliber!).

Springer guns tend to be more sensitive to hold than firearms... they should be held lightly (and consistently so). However, the Shadow isn't as sensitive as some other guns, it should be fairly easy to shoot it reasonably well.

Also, don't assume that your cartridge rifle bench-resting techniques will work on this gun. Many shooters find that the best bench results happen when they lay the forearm in the open palm of the hand, and then lay the back of their hand on the rest.

It's a shame that you don't have open sights to try... but you may be able to retrofit them if your gun has a solid steel barrel. I believe that both the front and the rear are available as service parts from Gamo.

In any event, I'd kinda doubt that it's a spring or seal that's the problem. If you were getting wild velocity variations, low power or a lot of noise while cocking then an internal problem might be indicated. May I assume that your barrel lockup is nice and tight?

[fnash]

The problems you are having sounds the same as I am  having with a Gamo Hunter Sport. And like you said without iron sights it is hard to find the problem, rifle or scope.
I finally fixed it where the scope would not creep. Still had problems but not as bad. I gave it a lube tune to make sure that it was lubed correctly and that there was nothing to make it diesel as I suspected that there might be a slight  diesel action that was hard to detect.
After that it was better but not what I cared for.. So, apart it came and installed a shorter spring to detune it a bit as I thought it was just slamming to hard. The Hunter don't have much weight to hold it down.
It is much better now and am still getting in the 800's and the shotgun effect is gone.  It likes RWS pellets, the MK Match Rifle and Super Dome. They are 8.2 and 8.3 gr  so am thinking it likes pellets in this weight.
I tried about 12 different pellets and these are the best performing...  If I try the others I quickly go back to these two...
I know this is not all good news, but this thing has given me fits..   Frank

Noticed a mention of pointed pellets. I get the best pointed pellet results from the RWS Super Point 8.2 gr, but not in this rifle. For me it is the best pointed pellet performer.

[SubaruEJ25]

I want to order a box of CP domed, but at $30 shipped I want to work out some of the kinks in my Gamo 1st, atleast to a managable 1" or less.  If this rifle turns out to be a turd, there would be no use polishing it and having it dollar me to death.  As i said I have alot of bills coming up so I was trying to do this fairly economically.  The scope, trigger and mount can all be reused, but I really like the ergonomics of this rifle.  Thanks for all the advice.

[Big_Bill]

Welcome to the GTA Forums Scott,

You have found a GREAT PLACE TO BE !

You have been give a wealth of GREAT information ! And the only thing left out, and probably not the problem, would be to check all your screws, you may have a loose stock screw or two ? or as I have found, a loose scope mount screw, some times when you tighten one side, the other side will become loose. I check these three or four times when I mount a scope, as ounce burned, twice shy.

You didn't say if you had better groups with the 4X32 scope ? or what lubes you used when you reassembled your rifle ? and if it shot well before you disassembled it ?

But now that your a member of our airgun addicted forum, I hope to see you here often ! Let us all know how you are making out !!

And YES Ralph, your the MAN ! You welcomed Scott first, Thanks for your Help !

Bill

[davee1]

Like everyone else, I see your scope creep as a major player in your inaccuracy probs. Fix that and I think your consistency/accuracy will go way up, provided that your holding tecknique is good.

Then theres the pointed pellets. No pointed pellet shoots well in any of my guns except a Predator Pellet.

The breech seal is easily checked for major problems by blowing into the muzzle, ***with the rifle UNCOCKED, UNLOADED,*** and fully locked up. If it wont hold your mouth pressure back, it sure will leak when its actually fired. You can look at the breech seal to see if its chewed up, and if it is, you can buy a set of 4 new seals for 10 bucks on the Gamo site. You can also play around with shimming the breech seal to see if that has any effect, but I would do that after the creep issue is fixed. Also, the breech mating surface (opposite the seal)must be flat and even...no flecks of glue, manufacturing blobs, or crud of any kind. I like to lube up my breech seals with silicone grease, so that the sealup is "tighter than a bull's ass in a beeswarm".

[SubaruEJ25]

I shot about quarter sized groups with my 4x32 out to 35 yards.  All screws on the stock are tight.  After I put everything back together I cleaned the barrel with solvent making sure not to get any in the breech, i then used i light coat of Remoil after the solvent then swabbed it out dry again to remove everything I could.  I used a very small amount of silicone grease on the O-ring, trigger and sprind still had adequate amounts of lubrication.  I have a feeling that the light 4x32 did not cause the amount of creep the heavier 3-9x40 does.

[Big_Bill]

Scott,

Check if there is any play, up and down, or side to side between the barrel and the receiver. If side to side, you need to tighten the receiver bolt. if up and down it is the barrel locking mechanism, and I do not know how to fix it, an air gunsmith or return to the factory my be required.

And you didn't mention if the Leapers scope you have is airgun rated ! If not the scope also may be the problem, they are not made to resist the forward and rearward recoil

Bill

[arathol]

"The breech seal is easily checked for major problems by blowing into the muzzle"

Whoa, hold on. Thats past being crazy and is just plain stupid. NEVER EVER for any reason should you point the gun at your head, let alone put in your mouth. To test the breech seal, just put a piece ot tissue paper over the breechblock andshoot the gun normally. If its leaking, it'll be quite obvious, the paper will be blown off the gun.