Mod.s' and Longevaty

We all talk about making our guns shoot harder or faster.

But what is it costing us. We all know with PCP or CO2 it is costing us shots on a fill up. We get less.

Well what else is it costing us?

What parts are failing because we tuned for speed?

How about the Springers? we know that Power tunes on them also can cause problems. But what.

If we don't tune these guns they seem to shoot for ever. Just what are we paying for performance?

Is it worth it? Sometimes.

[daved]

Hey, Lou,

In my case, I had my CFX tuned for smoothness and consistency.  Gamo claims 1000 fps, we all know that's inflated by at least 10%.  My gun is currently shooting Superdomes at around 900 fps.  That's plenty of power, and still gives way more accuracy than I'm capable of.  Since having it tuned, it's much smoother on the cocking stroke, and the firing cycle is vibration, torque, and twang free.  Pull the trigger and it just goes THUNK!  The cherry on top is the GRT trigger.  THAT'S what we tune for, or at least, that should be what we tune for.  And I do expect it to shoot forever.  Hey, if you want power, either get a 30 fpe PCP, or get something that uses gunpowder.  Course, if you cut loose with a 30-06 out your back door, the neighbors are apt to get a mite irate :-)!  And how much are '06 shells these days?  I know I'm really preaching to the choir here, we all know that a big part of the fun of air guns is constantly tinkering with them.  So there you go, one opinion, FWIW.

Dave

[Gene_SC]

In my case Weiner, all my springers have been tuned by CDT. He does basically a performance tune. He takes a Gamo and turns it into a great shooter. With the combination of the GRT-III or the GTX, Tarantula  spring, deburing, seals, and lube he transforms a basic generic pellet rifle into a fantastic smooth shooting pellet rifle. He never tunes for velocity and that is fine with me. Whether the velocity stays the same, goes up or goes down after a tune, I have always been happy with the results. Like Dave said, most all the vibration and twang are eliminated. I learned that high velocity does not always makes for an accurate shooter. The smoother the better and with low deviation between shots you have a winner.

I think you are correct that guns that are tuned for high velocities do have and impact on the life of the gun.

Gene

[vinceb]

...that is:

1) Start with a half-decent rifle to begin with. No B1's or B2's. Gamo's are good... Quest's, B20's, and other "better" Chinese rifles are OK.

2) Be reasonable - 5-10% velocity increase over ACTUAL (not claimed) factory performance. Sometimes that'll only bring the gun up to the advertised performance. Sometimes not even.

3) Use the right lubes in the gun

...and I don't think there's going to be any real tradeoff in longevity.

A tune on a Gamo 440 .177 that actually produces 1000fps with their "match" pellets is a very successful tune indeed, and one that represents about an 8% increase in velocity (and a 16% increase in power) over typical factory performance. And at that point, it's only doing what Gamo claims it'll do from the factory.

[Gene_SC]

Very true Vince. A good tune is probably beneficial to the longevity of air gun. Most all the Gamo's I have seen actually need a good lube and deburing tune for sure. Probably 90% of the time a new chamber seal, because the factory put them together with the burs in place because of the stamped out manufacturing process of the internal parts.

Good point made

Gene

I'm pretty much in agreement with the rest on this one.If you don't get too extreme,you should see longer parts life from a tuned gun.Even in the real cheapies.You've taken down the rough spots and used correct,high quality lubes.In gas guns,yeah,power costs in gas consumption,(no necesarily in money,bulk co2 is CHEAP) but if you don't use rediculous striker springs,all the parts should last as long as stock.If you cram 50% more spring in a springer or gas gun,all bets are off.Pedal to the metal guns tend not to shoot as accurately as more moderate tunes,but even that's not set in stone.

[vinceb]

Yes, you're right about the cheapies - often they are the ones that benefit the most from a debur and relube. However, it is easy to get seriously frustrated with one... some of 'em won't shoot worth a darn no matter WHAT you do to 'em. And then you don't know if it's the gun's fault or your own!

I really wouldn't suggest trying to get significantly more power out of 'em with heavier springs. Their mechanisms can be marginal with stock parts... and yes, they can get genuinely dangerous when modified. I've seen low-mileage B2's with bent retaining pins and worn sears even with stock parts.

The better cheapies - B4-2, Fast Deer (in .177), and maybe the B3 (I've got no experience with that model) can usually be tuned to be nice, reliable, moderately powered guns... but with their smallish powerplants and low cost I still don't think I'd suggest heavier springs...

I guess I wasn't clear,I agree that  heavy springs are a bad idea in general.I've found VERY few springers that gained much power with a stiffer spring,and any power gain was usualy offset by nasty firing behaviour.Sometimes the right combo of an upgrade in quality,slightly stiffer or more preload,and a slightly lighter or heavier piston will give a better combination of power and recoil,but it can take a lot of fiddling.The notable exception was a b-21 that gained almost 100 fps when a macarri GSI spring replaced a good stock spring.The gun had been pretty much optimised for the stock spring,and shot very sweetly that way.The GSI was only a little sharper in recoil,with a noticeably higher cocking force,butI still can't shoot it as accuratly as before the change.It may be a candidate for the rail recoiless system I've wanted to build... I suspect that the better seal that goes with a carefull hone is as important as anything else in the cheapies.I've never seen a  good cylinder bore in any chinese springer as sold (I've worked over a couple dozen from $25-$150)