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General Discussion To Gateway To Airguns => Gamo Gate => : October 06, 2006, 10:34:43 AM

: Which CDT tune to get?
: October 06, 2006, 10:34:43 AM
Ok so ive been trying with this rifle for the past few days now. (shadow sport) and it seems like anyhting I try it never works. I get it sighted in dead on one time. Then the next string of shots are like 2 inches lower and to the left. Then they move around again. Ive tryed 3 different airgun scopes and it hasnt made a differance. So Im wondering if a tune could help this out. There is a conciderable amount of recoil and I think what you guys call spring twang. You can defenatly hear it when the shot lets loose.

So based on your oppinions which tune should I got for the super (115) or the turbo (149) id also be picking up a trigger at the same time.

but lets get some oppinions  :)

Edit : Ive also tryed a few different types of ammo. I have rws pointed, rws superdomes, some beeman crow mags (which are all gone) and crossman wadcutters. All had the same unpredictable results.
: Re: Which CDT tune to get?
: Gene_SC October 06, 2006, 11:40:17 AM
A tune won't help that problem with the sighting. I would bet it is a mount or scope moving on you. Also you may want to check the screws that hold the stock to the barrel. When they loosen up I have had same problem. Don't trust a Gamo stop to keep your mount in place. Use a one piece mount on that particular rifle. Also get a mount that has a stop pin hole in the bottom of one of the rings.

But a good tune on a Gamo after you have put a few hundred pellets through it would not hurt.. In fact you will love it afterwords.

Personally I have had 9 Turbo tunes and 9 GTX and GRT triggers installed on my Gamo's.

Good Luck

Gene
: Re: Which CDT tune to get?
: October 06, 2006, 11:54:48 AM
This gun came wityh a one piece mount, and it has that stop pin that goes into the recever. IVe tighted down the mount and used lock tite but i will try the stock screws. Now just to where I put away my torque bits...

But thanks for the input. I spose that saves me quite a bit of cash, expect for that beutiful trigger :)
: Re: Which CDT tune to get?
: Gene_SC October 06, 2006, 12:02:47 PM
Your welcome 88

Also make sure you scope is not moving in the mount itself. Also if your extreme deviation is way out there then that may be the problem and in that case a tune will help.

Do you have a chrony?  Remember that the tighter the deviation between shots the tighter your groups will be and more consistant.

Hope that helps...:)

Gene
: Re: Which CDT tune to get?
: October 06, 2006, 12:05:53 PM
Ok well I just checked the stock. I tightened the front 2 just a tad, but they didnt seem like they were "loose" and dont really seem like they could have an affect on the gun. But what do I know about this im still a n00b at this airgun stuff  :)
Id also like to get a chrony which model dose everyone recommend? like to keep it under $100 if I can.

: Re: Which CDT tune to get?
: Gene_SC October 06, 2006, 12:14:08 PM
The F1 is under $100.00. I did not mean for you to buy one. Maybe you know someone near you that has one so you can check your FPS out. Do a 10 shot test. Remove the high number and the low number and average it out. You can lay it out on a graph to see you deviations.. My S1K .20 has an average of 5fps deviation and that is very good. A 10 to 20 is good to fair. The tighter the better..

If you end up with a large spread then tha could explain some of the problems with sighting. Also don't forget the human error part..:) :)


Gene
: RE: Which CDT tune to get?
: daved October 06, 2006, 12:16:40 PM
Couple of other things to check out first, 88.  First, do you have or can you borrow a chronograph?  A broken spring or bad seal somewhere can cause lots of variation in shot velocity, and that will screw up any chance of getting good groups.  

Second, is this your first air rifle?  In other words, how much air gun shooting experience do you have?  I find that an inconsistent hold on my part is my most common cause of bad groups, or stuff moving around.  And it doesn't take much!  Are you shooting from a bench or off hand?  The Shadow I've used did best just rested on my left palm, and just touching my face and shoulder.  Right hand, thumb and trigger finger only, NOT gripping the pistol grip.  And if you're still using the stock trigger, either order a GRT from Bob AKA CharlieDaTuna, or try one of those new MiniGTX or whatever they call it.  I haven't tried the Mini, but lots of guys on this forum have use the CDT triggers.  I'm sure you've seen their posts.  BTW, the Shadow mentioned above is box stock except for a CDT trigger.  I've shot 1/4 inch groups with in on good days.

Most springers don't do well off sand bags, the CFX is the only exception I know of.  The other question would have to be, how many shots so far?  Some Gamos are notorious for fairly long break in periods.  Defineing long as in excess of 1000 pellets.

Last thing I can think of is, are you still using the factory scope mount?  I know you said you tried different scopes, but the stock Gamo mounts are not known for being especially robust.  I've had good luck with Accushot by Leapers, both 1 and 2 pc.  Around $15.  Lots of other guys here like the 3 B's- B-Square, Beeman, and BKL.  More expensive, but...

Finally, when you do get it tuned, I'd go with the Turbo.  I think the minor extra cost is well worth having parts custom fitted to YOUR gun.  Just my opinion, but hey, I'm at least a little smarter than the average bear...:-).  Sorry I got so long winded, hope this helps.

Dave
: RE: Which CDT tune to get?
: daved October 06, 2006, 12:21:32 PM
Oops, Gene, you're just too damn fast for me! Okay, so we both said about the same thing, he may be faster, but I said it better :-)!  Later.

Dave
: Re: Which CDT tune to get?
: Gene_SC October 06, 2006, 12:24:35 PM
Yes you did Dave...:)  You have a way with words.. he he he

Gene
: Re: Which CDT tune to get?
: October 06, 2006, 12:30:57 PM
This is my first decent air rifle. im very used ot shooting long range with larger calibers .308. Im useing a rest with a leather rest (not a sand bag but i cant define it) also  ive read an article on shooting airguns and they said exactly that, dont control the gun just let it do its thing. ill order me a trigger this week and see if that helps, Hopefully. I know on my ruger .22 I was at its limit for the stock trigger. There was no way to post a better group without a new "lighter" fireing pin and a lighter trigger.

Im going to a gun show this weekend so ill look around for a mount. So far this one looks pretty decent, its solid aluminum but who knows maybe its still acting up. Ive shot around 800 rounds so far out of the gun. might try some different ammo, but as of now it seems that the closer the range the better I do (lol duh) about 20 feet I can get the superdomes yto group right. the 10 meter they totally blow. I have no idea whats goin on but hopefully will figure it out soon.


Thanks guys :)
: Re: Which CDT tune to get?
: Gene_SC October 06, 2006, 12:38:20 PM
Dave could not of laid it out much clearer 88.  Hang in there. The Shadow is a good rifle and the trigger will help you. Make sure you set it up the way you like it.

Also try different pellets. Not all Shadows like Superdomes. I think Dave has had good luck with JSB's. Just look at his other posts. He has tried a few different ones. One thing I have noticed is that a snug fitting pellet usually works well and you do not get allot of strays. Loose one are not to good..:)

Geme
: About Shadow Pellets
: Black Mamba October 06, 2006, 01:02:26 PM
Hey 88, don't give up just yet.

I'd also recommend some pellets for you to try.

Crosman Premier Pointed (Hunting) pellets work very well in mine as do Sheridan Diabolo's and Logun Predators.  At 30 yards or less I find Crosman Hollow Points and RWS Super Points work well.

Keep trying and good luck.

And remember, "Hold Lite".
: Re: Which CDT tune to get?
: daved October 06, 2006, 01:03:34 PM
Pegged it, Gene.  I have had good luck with JSB Exacts, in both my CFX and the Shadow.  Interestingly enough, head size makes a big difference, both guns really preferred the 4.52 mm.  I know of two places to order them by head size, Airguns of Arizona and Airguns Only in Canada.  I ordered a mixed sleeve (10 tins) from Airguns Only in 4 different head diameters just so I could test for what worked best for me.  These are the ones I shot 1/4" groups with in the Shadow.  Some Beeman pellets list head diameter, and 4.52 seems to be the magic number.  Still, Superdomes and Crow Mags do well for me, if either one groups over 1/2 inch at 25 yards, I've either had too much caffeine or not enough beer :-).  Since you mentioned both in you original post, I didn't get into pellets.  That being said, I've NEVER had good luck with ANY pointed pellet.  Someone recently mentioned that the Copperhead pointeds were good in their CFX (sorry I don't remember who) so I got some to try.  Looked more like a shotgun pattern than a rifle group, at 25 yards, 5 shots were close to 2 inches.  Same session, JSB's were shooting into less than 1/2".

I'd definitely ditch the mount and try something else.  Just remember, air gun means 11mm, most rimfire mounts won't work, they use a 3/8" dovetail.  Again, good luck, and keep us posted.

Dave
: Re: Which CDT tune to get?
: October 07, 2006, 07:11:36 AM
Well thanks guys for the replys. I have notied when I put a pellet into the bore it kinda slips in, if i were to tip it back it could prolly fall out. They dont seem to fit tight. I will give the different sizes a shot and get some jsb's aswell. Im a bartender and work was really good to me lastnite :) so0o I can snap up a few tins and a mount.

Im going to a gun show in illinois sunday, is there any brand i should look for while im there besides the jsb's? whta about a tight fitting beeman pellet, which one should I look for if any?
: Re: Which CDT tune to get?
: October 07, 2006, 07:36:45 AM
Well I just found out why my gun dont shoot. I think... its missing rifleing at the muzzle  about 1/4 inch isnt there at the end   unless its supposed to be that way, but id assume it would go the full length.
: Re: Which CDT tune to get?
: daved October 07, 2006, 11:36:41 AM
You sure you're looking at the muzzle and not the muzzle brake?  On my CFX, the muzzle brake extends over 2 inches past the end of the barrel.  And of course, that isn't rifled.  That said, it does look like my barrel isn't rifled for the last 1/4 inch or so either.  Hard to say for sure without pulling the brake off.  But if so, it doens't seem to affect how my rifle shoots.  Two guy that would know for sure, Bob Werner or Rich from Mich, aka Peterdragin.  I know Rich is recovering from shoulder surgery, but he might still be able to answer your question.  HTH and good luck.

Dave
: Re: Which CDT tune to get?
: October 07, 2006, 11:49:54 AM
Don't worry all the gamo's rifling don't go to the end of the barrel, I think they do it so the crown won't get messed up.
Heck the CFX rifling is an inch or so in from the end of the muzzle.
: Re: Which CDT tune to get?
: October 07, 2006, 12:29:01 PM
^^^ whew thanks guys, i was starting ot get a little worried.
: Re: Which CDT tune to get?
: October 08, 2006, 01:42:24 PM
So here is something I learned. I took my digital caliper and measured a few of my pellets. all are around 4.42 - 4.48 (im shure i have some deviation in there due to me but that was the average. Then i measured the bore where you incert the pellet 4.51. So I think its safe to assume its a loose fitting pellet that can be the culprit. jsut like a few of you have said. And for some additional info 4.52 is .178. what ive read if it is indeed correct, the beeman crow mags, and kodiaks are .178 aswell as the jsb exacts.

Just a little fact finding guys. Any additional info you can post more advice is welcome :)
: RE: Which CDT tune to get?
: October 10, 2006, 04:28:34 AM
I pickedu p some beeman crow mags and some jsb predators. Crows are marginally better but the jsbs were significanty better shooters :o BUT its still eratic, this is a 35 yard target this morning. No wind at all and a nice steady rest. After the gun fired the crosshairs would lay exactly back where i had origanally put them. So im taking a wild guess that this is a tune issue maybe velocity? The crow mags at times can be off 6 inches (low) then jump back up, groups for a few more shots the move all over again.

Here are some targets :

JSB Predators @ 45 yards
(http://i47.photobucket.com/albums/f155/eighty8fierogt/jsb45yards.jpg) (http://photobucket.com/)

Beeman Crow mags @ 45 yards
(http://i47.photobucket.com/albums/f155/eighty8fierogt/crowmag45yards.jpg) (http://photobucket.com/)

And some jsb's at about 30 yards
(http://i47.photobucket.com/albums/f155/eighty8fierogt/JsbTarget.jpg) (http://photobucket.com/)
: RE: Which CDT tune to get?
: October 10, 2006, 08:36:40 AM
Sorry kinda new here but I am surpirised that no one has asked if you have cleaned the barrel lately. I bought a used AG from a guy and when I tried to mount a scope on it and sight it in I was having exactly the same results as you.
 I cleaned the barrel ran a few cleaning pellets through it and tried again. Big difference!! I could not keep 2 shots within 1 1/2 inches before and after I could hit the flat thumb tacks that were holding the sheet on.
Give it a try.
: Re: Which CDT tune to get?
: Gene_SC October 10, 2006, 08:57:09 AM
Amazing how simple things can make such a difference..:)

Thanks for your input CavemanDave

Gene
: Re: Which CDT tune to get?
: October 10, 2006, 09:04:05 AM
Barrel has been cleaned, but ill give it a shot. Im sending it to charlie thursday to let him do his work.

Thanks guys, any more idea's ?
: Re: Which CDT tune to get?
: October 10, 2006, 10:14:16 AM
Well after some more incluseive testing. i decided to ditch the rest and go offhand. Well yeha it made a HUGE differance. i dont know why it iddnt like to have its forearm resting on my nice leather pad but it didnt..
This next target will show what I mean. I think ill just hold off on the tune and get my trigger instead. Oh an also i cleaned it too so maybe that helped some.

(http://i47.photobucket.com/albums/f155/eighty8fierogt/jsb_35_yards_offhand.jpg) (http://photobucket.com/)


Thanks guys so far helping me figure this out. Still have no idea why it would rather be shot off hand v.s. a rest.