New TX200 .177...how fast is too fast?

[cmburkhalter]

Hey all!



I think I’m getting to the end of my break in, as I’m getting ragged hole groups at 20 and 50 yards now . I did have to remove the stock and oil the action in the pivot points on the cocking arm. At first I got OK groups with H&N Baracuda Match, the with H&N Baracuda FT. I decided I’d get to around 1000 shots before trying to really dial it in. I’ve noticed with pellets heavier than 10gr I get a very slight spring twang, however keeping the pellet weight down seems to keep the rifle quiet .

I had some H&N Terminators laying around and wow - I can’t believe the groups I’m getting with these pellets. IDK if it’s because they’re more lightweight that they’re easier to shoot or what, but these things are making ragged holes for me at 20 and 50 yards, even in slight winds. 


On to the question. Every so often, one of these shots will break the sound barrier, usually the first of the group if I’ve put the rifle down for a little while. 


Is this OK? By my numbers with chair gun, at 1125FPS I’m generating just over 20 FPE! The energy retained at 50 yards also seems plenty for small game should I decide to get there, so...will I damage my mew TX200 shooting at these near-sound-barrier speeds?

Thanks everyone!

Best,

Chris

 

[Odoyle]

Looks like your oiling did some migrating to add diesel fuel combustion for occasional supersonic shooting. 

That's the only logical explanation for it.

Wipe everything dry and stick with the heaviest pellets for another 500 rounds before shooting lighter pellets and now you know what not to do in the future.

 

[Odoyle]

It is unhealthy for the spring gun to diesel. Surely introduce unnecessary wear and stress to destroy the internals.

Some do it on purpose just for high power kicks by deliberately oiling the transfer port with petroleum based lubricant which you probably used not realizing they are burning their gun from the inside out.

 

[cmburkhalter]

@odoyle I took your advice a step further since I was seeing grease streaks on the breach cover.

I decided to strip it down and what I found was grease had crept in to the compression chamber. I wiped it all clean and reinstalled the piston with just a little graphite power, not touching the grease on the spring and rear of the piston sleeve. No more dieseling now .

Thanks!

 

[Odoyle]

Let's see some pics of that bad boy!

 

[270windude]

And video. I’ve always wanted to watch an unedited and non airgun commercial video of someone shooting .2 sized groups at 20 yards, let alone 50. 

 

[cmburkhalter]

@Odoyle, here you are . 20 and 50 yards, the 3” target is 20 and the 8” targets are 50 yards. I took these this morning on fresh paper, shooting the H&N Baracuda Hunter Extremes. @270windude sorry, I don’t have the ability to take video...yet . Not .2”, but darn nice for a springer I think, and I’m pretty sure the rifle is capable of better than I am at this point!

 

[SixGlocks]

burkhalter, what did your pellets actually chrono at?

 

[cmburkhalter]

@SixGlocks, not sure, used 1125FPS since that was the sound barrier at the given temperature and humidity when I was hearing the loud shots. Will be borrowing a buddies chrony soon .

 

[SixGlocks]

1,125 fps is pretty damn fast for a spring gun. I think you might find the actual numbers to much lower.

 

[GoldenStateAIRGUNer]

That rifle is rated at 930 fps with light pellets. At 1125 fps I'd definitely say the dieseling is happening.

 

[Hubertus]

which chronograph are you using ?