Question for the Tuners

[Roadworthy]

I just self tuned my Nitro Venom.  The groups are quite erratic.  Does the gun need broken in again, like with another 300 to 500 pellets before it settles down?

[Bullit]

Don't know what all you did...but in general, it needs shots to settle.

[Roadworthy]

Needing shots to settle was a good, safe answer.  I suspected that as well.  I replaced the nylon pivot washers with brass.  I pulled the gun apart, cleaned the gunk out of the cylinder where the compression piston goes, and then ran 600 grit silicon carbide paper through it on a dowel spun by my electric drill.  I rinsed it out with alcohol, dried it, and lubed it with moly paste.  I smoothed other sliding surfaces and lubed them with moly paste as well.  I did the Q-tip test on the barrel and nothing snagged.  The only previous mod was the GRT-III trigger.  It now operates smoothly, it just hits erratically.  It sounds like I'll know more after a few hundred pellets.  It is a victim of the misaligned Weaver rail.  I have adjustable mounts ordered to work around that.  At this point I'm not after accuracy, just groups.  Thanks for the input.

[OleTomCat]

Typically when I get done tuning a gun it is going to group in one area or another, maybe not the exact same spot as before but it will still show me some sort of grouping and not a shotgun pattern, the groups will tighten as the gun breaks in the new seals and the lubes get evened out, I usually shoot about 100 pellets through a gun after the tune, first 50 to get things settled and evenly distributed, the second to get chrony and group info for the client....

[Motorhead]

If gun before tuning was accurate ? ... it should settle in once more after a few tins to be accurate once again 

If however gun had been a dud for accuracy all along .... don't be surprised if gains your expecting / wanting don't materialize 

[Roadworthy]

From the time I've spent here I have the distinct impression some of the more knowledgeable folks are chiming in.  The gun was not accurate to start with, hence trying the tune.  I will run a tin or two of pellets to see if things improve.  Knowing the Weaver rail is canted and I've got a droopy barrel I don't really expect accuracy, that's too much to hope for.  Consistency would be good, though.  Having put it back together I've narrowed it down to three things - me, the rifle, or the scope.  Wait - that's where I was when I started the process.  I'll be patient, shoot up a tin or two, and see what happens.  I do appreciate the input.  I started playing with airguns in July and it's a pretty steep learning curve, not to mention the tuition in the school of experience.  Thanks again.

[Flatcar1]

I had the same issue with my Summit, almost gave it to my grandkids to play "army" with. As a last resort, I chopped 2 inches and re-crowned the barrel, now it is my favorite shooter and I have the best scope I own setting on it. I am so glad that I didnt give up to soon. You might give that a try because mine didnt snag the Q-tip either but there must have been something wrong with the "business end" Good luck and dont give up on it.

[Bullit]

Don't know if this is the same air rifle you have posted about before... but from your first posts, to your current posts, it sounds like the love/hate that others before have had.
I'll say that we got great responses when they finally got in balance with their rifle, with a good artillery hold.  Kinda like a lightbulb that went off in them.  Breakbarrels are a technique.
I do hope you didn't persue pushing patches thru it with brass wire or rods though.  You mighta made your problem.