Improved Viper with GRT III Trigger

[JohnkIrch]

I  have a GAMO Viper .177 rifle with a terrible trigger feel. I almost feel like I’m going to get a hernia from the travel and let-off pressure. While I don’t expect it to be like a Smith and Wesson trigger, I’d like not to turn blue before it lets off.

The trigger for my GAMO Viper .177 came today – 3 days after I ordered it! I installed it in about 15 minutes and took it out to the back yard to test the trigger pull. Frankly, even after all the comments from other users and Charlie's promise that it might even surpass my S&W, I was surprised. First shot went off before I was ready; after straining on the factory trigger the light touch was really a surprise. Ten or so shots later I am getting the feel of it. I’m going to need sandbags and a rest to zero it in. Age has taken most of my old steadiness away (offhand won’t cut it anymore).

 
John in Dleware

[longislandhunter]

Welcome to the forums John.  Yeah, those triggers are surely a dream.  Literally can transform you gun.  Enjoy.    

Looking forward to your future posts, and if if you hunt be sure to post your stories and pics in the "Hunting Gate".  We just love to see pics of air gun terminated critters  

Jeff

[leftcoast1]

Welcome to da family. Hope to see you around these parts as often as you can. Feel free to ask any questions and share you airgunning experiances. Again Welcome.

[Big_Bill]

A BIG GTA WELCOME John,

Your now family here ! Take off your shoes and share your stories with us all !

And if information's your need, we have lots of knowledgeable people here, heck I'm always learning something new ! even when I don't ask a question !

Like you John, I can't handle shootin offhand for too long, the heart won't supply enough oxygen to keep me steady, or holding the rifle for too long. But I get buy until I have to put her down..:-)

We all look forward to your posts, so come here often.

CAUSE THE GTA IS A GREAT PLACE TO BE !!!!

Can anyone email me Bob's instructions? i lost mine and want to try lightening up the trigger some.

[leftcoast1]

I believe he has a PDF link on his site.

[nyairman]

Hi John and welcome to GTA. Yes the GRT III is a great improvement to my Gamo's as well. Once you are used to it, your accuracy will improve even more . If there are any doubters out there, you need to try one out. It will make a good shooter into a great one.

Greg

[davee1]

Hi John!!! 2 things...a hearty welcome to you and ya gotta love those GRT3 triggers!!!

This forum is a great place to talk, learn, share, its just a great place to be!!! If you are not sure about something...ask away! There's plenty of folks here with great experience and ideas, who want to help. You won't find any "holyier than thous" here...these people here are regular family kinda folks. Have fun!!!

[JohnkIrch]

I want to thank all you guys for the big welcome! I bought the Viper to get rid of garden pests. Before the trigger, I nailed a Flower Eating Bunny in the back of the head at about 50 feet from my bathroom window. Later I tried the PBA pellets on a groundhog, He lumbered off and I don't know if I hit him or scared him, but he hasn't come back in a couple weeks!
My first shot with the gun was at a 10 meter target 1/4" off the bullseye using Crossman pointed pellet. I figured that was good enough, but after the groundhog I thought maybe I'd do a little more shooting to determine the real accuracy. Well, the PBAs scattered all over the place. The trigger was getting on my nerves, then I came across Carliedatuna's web and ordered the GRT III trigger. Since then I've fired about 25 shots with mixed results. Mostlly I'm still getting used to the light trigger pull. But I'm still scattering shots. I'll set up sand bags and a rest to steady the gun and try an assortment of pellets to get the best groups. Suddenly, Im aware of the spring twang that I didn't notice before. Should I be concerned?

[leftcoast1]

Spring twang is normal some are worse than others. I would start by taking the PBA pellets walk over to the garbage can an toss them in. If you cotinue to shoot them you could destroy the seal and other things. The PBA's skirt does not expand allowing some air to pass by and causing the piston to slam ino the end of the chamber. Try a box of Crosman Premier domed in the cardboard box 1250 count. Even better Stright Shooters sells a sampler pack for 25.00 I think it has 12 different pellet types.

[CharlieDaTuna]

I think that Jason is right. You need to find the pellet that will work best in you gun and that for the most part is trial and error. Plus, determining hold sensitivity. There are articles in the "Library" I believe as well as on my website addressing it.

 One other point though and that is sand bags  (or any hard or somewhat solid surface) as a rest do not work well with many springers and often have an adverse effect on accuracy. There are of course the exceptions though.

John,

I have the Viper and I'm pretty happy with it.  The first step you took, installing the GRT III, was a vast improvement over the stock gun.  However, if it's like mine, the spring twang is horrendous.  I didn't mind at first, but now it's starting to bug me.  Just like the stock trigger did.

As for pellets, I was looking for a shortcut.  I tested pellets that others found good in similar guns.

My gun shoots these best in this order:

JSB Predators (I use them for pest control and I'm still shocked that they shoot better than the domes)
JSB Exacts
CPL's
Superdomes
Gamo Hunters

I have tried others and have not been impressed.  I also have a few more that I plan to purchase in the future.  If you're a target guy, I would say that the Exacts, CPL's, and Superdomes would be a very good start.  Keep in mind that my gun is relatively new and has just under 1000 pellets through it.

Rob

Ok, after you have read and followed most of the previous posts keep this in mind.  I bought a viper and after 75 shots I was ready to throw in a ditch, literally.  I have been shooting powder burners forever, and could not believe the inconsistency I got from the viper.  That is when I started READING this forum.  

Now I have a bit more knowledge.  So I kept shooting and getting mixed results.  I figure the scope has to be bad, because no matter how much I bore sight, adjust, and re-adjust I can't get or stay on target.

Then I did some more research and found the Library on this site.  And in the Library I found several good articles in the Shooting Guide.  After reading these I found that I was the problem, not the gun.  Springers shoot a lot different then powder burners.  Here is a summary of what I learned that allow me to consistently shoot the center out of a 1" Stick on Target dot at 25 yards.

First, never hold the gun!!  Support the gun.  There is a very real distinction here.  You want to support the gun and keep your sight lined up with the target until well after the shot.  This allows the gun to 'travel' back and forth on a straight and level plane.  If you hold the gun, it will not be able to travel and will torque, jump or spin and you will not stay aligned with your target.

Until you have the gun shooting like you want it, i.e. tight consistent groups, keep your target close.  This will minimize the distance to the target and will minimize how far off your Point of Impact (POI) is from your Point of Aim (POA).  You will also be able to see your POI of impact without walking back and forth to the target.  Keep in mind that at ten yards your POI will be a couple inches lower then at twenty or thirty.  Your pellet will travel in an arch, so you will have to play around to find a pellet that gives you the desired POI at any given distance.

This is a very long post so I will wrap it up with this last peace of advise.  

Your POI will change from your POA if you use a rest versus supporting the gun by hand.  Decide how you want to shoot the gun - target, hunting, plinking - and sight your gun for that use.  I personally prefer to shoot sitting with my elbows on my knees and my gun laying across my open hand.

Just shoot and have fun.  The consistency will come when you get in the groove!

John,

I replied to a similar thread titled "To Detune or Not?".  You may want to read that reply for more details.

Basically you need to learn to let the gun 'travel' when it is fired.  You must support the gun and keep it aligned with the target with out impedeing it's back and forth motion.

When you shoot the gun do not hold it tight.  The tighter you hold it the more it will torque which causes it to jump.  If you gently hold the gun it will move back when you release the trigger and forward when the spring and top hat reach the end of the spring guide.  If the gun is stabilized so it does fall during this motion, but allowed to travel it will stay aligned with the target and your groups will tighten up. Only use enough grip, and or preasure to keep the gun upright and aligned with the target.

Once you get a feel for this you will enjoy shooting your viper and have fun instead of frustration.

[JohnkIrch]

Hi, Rob
I've ordered the Sampler from Straight Shooters, in the meantime, I've tried several locally available pellets and found that the GAMO Hunters group best. I'm still getting flyers and they all go right and high, so I think it may be a holding problem. I'm shooting from a pair of bean-bag rests and learning to control the recoil as Russel has described in his post on "Detune or Not"
Thanks to all of you for your help, I've learned a lot in the past week, and expect to learn even more as we go along.
John