TX200 and high alti...
 

TX200 and high altitude shooting..  

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8800Airgunner
(@8800airgunner)
Joined: 2 weeks ago
Posts: 8
2019-10-28 15:31:14  

I recently got my PW Tuned TX200 back from La after moving to Colorado. I now live at 8800' and not 12' altitude. I've been reading about air density issues in springers at altitude and was wondering if anyone had any thoughts? I usually shoot JSB 8.4s out of it around 15 ft lbs. Should I de-tune it to sub 12 ft lbs or use 10.4 pellets to build pressure before pellet leaves? Or will I simply destroy the seals and piston by not having dense enough air up here to shoot it? I've searched and found a few things but nothing definitive and nothing as high as I am. Mostly just comments about lots of POI drop from reduced velocity etc. I don't care if it shoots hard I just want to shoot it and not have it be a safe queen. Any info appreciated! 


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ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 477
2019-10-28 15:42:55  

I had questions about the same thing several months ago, it could have been a year. If you search on the word "altitude", you should find that thread of posts, and much more that will be useful to you. That includes a neat little formula for how much velocity you can plan on losing per 1000 feet of altitude. That was my question. I've seen it before but I didn't remember it. Others did.

The short version is that it does matter. You tend to lose some velocity, and the shot cycle tends to be more harsh.

Anything you can think of to do to address the latter problem will make your shooting experience more pleasant. It will be easier on your scope, too.

I know you were looking for direct answers, but I don't remember all that information right at the moment. However, I hope I gave you something that proves a little useful.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


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Citizen K
(@citizen-k)
Administrator
Joined: 2 years ago
Posts: 406
2019-10-28 15:49:04  

Or just click the "High Altitude" topic tag, it will list the previous topic/s on the subject.

Forum Janitorial Services Specialist


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8800Airgunner
(@8800airgunner)
Joined: 2 weeks ago
Posts: 8
2019-10-28 16:25:29  

Thanks guys. I just want to make sure I don't damage any internals with the current spring/seal setup I have installed. Reading the links now. 


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Mark.in.AZ
(@mark-in-az)
Joined: 2 years ago
Posts: 98
2019-10-28 18:31:10  

@8800airgunner

I have the same concerns shooting a piston gun here in Phoenix (1200 fasl), then shooting the summer matches at Mormon Lake (7200 fasl).  With my Diana 54 tuned to 12 fpe it is shooting at about 820 fps at sea level.  It shoots 810 fps in Phoenix and drops to 775 - 780 fps in Mormon Lake.  My TX200 is shooting about the same at each elevation.  I would keep a supply of piston seals handy.  The thin air at altitude can be a killer in a short amount of time.

I had the post from the forum on altitude testing saved to my favorites, but when I tried to open it, I got some advertisement for tapatalk, so I guess I lost it.  Do a google search or forum search and you should find info as suggested in an earlier post.

HTH,

Mark


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8800Airgunner
(@8800airgunner)
Joined: 2 weeks ago
Posts: 8
2019-10-29 12:13:40  

Thanks again all that was an interesting read by Dmitry. I should have a box full of pellets in my mail today but its snowing so not sure I'll make it to the mailbox today. I know what my numbers were from sea level so i'll check the drop and chrony it as well once I can find that thing! 


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rj222
(@rj222)
Joined: 1 year ago
Posts: 58
2019-11-06 15:29:15  

My experience is My TX200 shot great years ago at Moron Lake. should have been about 850fs with CPL .I think it is 7600'ev

About 5 years ago I tried again with My TX, I couldn't paper at 15 yds and slams hard. back in California smooth and same hole?? Another shooter had same luck with his 12 fp piston.

I have heard Mark shoots his pistons there.  And there generally isn't many piston shooters at AZ State shoots.

So I shoot PCP's @ Mormon Lake  Heights.

I woulda shot better, If I hadn't missed so many.


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Mark.in.AZ
(@mark-in-az)
Joined: 2 years ago
Posts: 98
2019-11-06 18:35:27  
Posted by: @rj222

My experience is My TX200 shot great years ago at Moron Lake. should have been about 850fs with CPL .I think it is 7600'ev

About 5 years ago I tried again with My TX, I couldn't paper at 15 yds and slams hard. back in California smooth and same hole?? Another shooter had same luck with his 12 fp piston.

I have heard Mark shoots his pistons there.  And there generally isn't many piston shooters at AZ State shoots.

So I shoot PCP's @ Mormon Lake  Heights.

Proofreading; the lost art.....  That would be MORMON Lake, Ron.  Yes, you will need to account for an elevation difference when shooting at almost sea level (at your place in CA) and Mormon Lake in AZ, at 7200 feet above sea level (not 7600 feet).

I chronograph my piston guns at each elevation where I shoot; Phoenix, Camp Verde, and Mormon Lake.  I also make up range cards for each of these locations based on velocity.  I have range cards made up for every 10 fps velocity difference.  When I get somewhere new, I chrono my gun, then pull the range card for that velocity, re-zero my scope and I am usually good to go.

I also have my piston guns set up at 12 fpe or thereabouts.  That way the piston doesn't slam due to thin air at the higher elevations.

Cole, Rex, and I have shot our piston guns at Mormon Lake.  I know that Scott has also, in the past.  We may be the only ones in the club brave enough to do that.  I have been shooting my PCP guns lately at Mormon Lake only because I am tired of shooting by myself when shooting piston.  It is a LOT easier shooting PCP, which is what most everyone who shoots there does.

Hopefully there will be more open piston shooters at next year's nationals at Morro Bay.  That will be just about sea level.

Hope this clarification helps somewhat.

Mark


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EMrider
(@emrider)
Joined: 2 years ago
Posts: 12
2019-11-07 18:31:10  

For many years I frequently took my springers (hw97k and pro sport) from my home at about 200 feet above sea level to altitudes of 7500-8500 feet in the Mammoth Lakes, CA area.  My guns are .177 and tuned to shoot at about 12-12.5fpe at home.  I crony tested one summer and recall that velocity loss was about 12% (from 820fps to around 725fps).  When shooting at altitude the accuracy was normal and the shot cycle was not unusually harsh.  I did a lot of shooting at altitude and never noticed any problems with piston seals.  

R   


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rj222
(@rj222)
Joined: 1 year ago
Posts: 58
2019-11-09 12:01:01  

Well I guess Iam wrong

Or was dreaming

I woulda shot better, If I hadn't missed so many.


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Franklink1
(@franklink1)
Joined: 1 year ago
Posts: 11
2019-11-12 23:26:20  

From my house at 5600 feet to the 7200 feet at the Mormon Lake matches, I lose about 15-25fps. That was with an HW77k and a HW50s. 

I just shot my HW50s at the Rio Salado match last weekend. I didn't chronograph it so can't provide any data there. But I did knock down about the same percentage of targets that I typically do when I shoot a springer (=nothing to be proud of). So, that suggests that my trajectory (fps) wasn't too drastically different. I think Rio is at about 3300 feet above sea level. 

Sure was fun to shoot a springer for a change. The goal for awhile (with the PCP)has been to clean a course so when I shoot my primary PCP rig I really focus. The focus and maintaining that high level of awareness for an entire match really requires serious effort. Don't get me wrong, a nice score is worth the effort, it was just nice to shoot for the fun of it and not worry about misses here and there ruining my score. I guess I'm trying to say with a springer I find myself shooting for the enjoyment of it, and shooting a PCP, find myself shooting with the goal of getting a high score. Both are fun and rewarding, in their own way. 

Mark, when you gonna shoot miss Diana again? 


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Mark.in.AZ
(@mark-in-az)
Joined: 2 years ago
Posts: 98
2019-11-13 17:21:10  

@franklink1

I am planning on shooting Miss Diana this Saturday at our match at BASF.  I haven't had much of a chance since the rebuild, and practice sessions since getting it back have been non-cooperative regarding wind, but, like you, I enjoy shooting a piston gun for the sheer simplicity of it.  Someday I expect to clean a course with a piston gun, just because....


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ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 477
2019-11-13 17:52:25  

@mark-in-az

The man and old friend who bought my own, tuned, RWS 52 won an FT match several years ago.  I think it was in "Hunter Class" (??) (I don't know much about FT jargon).  It was a .22 caliber rifle, no less.  It did have a slightly-softer spring in it, although the velocity was still pretty well up there for that model.

The may still lurk on some of the forums, but I don't know if he posts much.  And, I don't know if he reads this particular forum.  We haven't been in contact for some years, but he once gifted me a JM R1 walnut stock that he finished and hand-checkered himself, the border-less kind of checkering, that is.  It was a beautiful work of art... 

Funding for an absolutely-necessary move to a different residence forced me to sell the R1, and believe me, I still lament THAT sale!   I tuned the rifle myself, and it was a gorgeous, powerful .22 caliber tack driver of a springer.  Last I knew it resided in South or Central America.  (Are you still out there, Ben?).  (That's the buyer's name, BTW, not that of the rifle 😉 ).

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


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Mark.in.AZ
(@mark-in-az)
Joined: 2 years ago
Posts: 98
2019-11-13 18:19:32  

@ekmeister

Hey Ed,

I do not know of the gentleman your reference.

My "Miss Diana" is a D54 that has been detuned to shoot at just about 12 fpe (810 fps) using JSB 8.4 pellets, but am playing with other pellets to see if it can be more consistant / accurate.  The wind at the range (when I can GET there) has not been very accommodating, but then that is the fun of shooting.

My particular Miss Diana sports a Claro Walnut stock by Mike McKeown from Napa, CA.  It allows me to shoot well IF I do my part when shooting AAFTA open piston class.  With the elevations in Arizona varying so much in the areas where I shoot, it keeps me on my toes.


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ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 477
2019-11-13 19:45:02  

@mark-in-az

I'll let him remain incognito, as I think that's his preference.

It sounds like your rifle is pretty nice. In fact, with its recoilless operation, and IF set up properly, it can almost shoot toe-to-toe with some of the pre-charged rifles, as you probably already know. And that's even at higher power than what you're shooting at. (Pardon my grammar). It does require a tougher scope than the PCP's though, if tuned for higher power.

So, if you post some good scores, please copy them here. That would be fun. You know that the RWS/Diana guns don't have all that good a reputation in some corners.

In fact, back when I tuned one 20 years ago for a dentist in Hawaii, he couldn't get anybody else to tune it for him, for that reason. I was new in the business, but he took a chance on me since I was willing, and seemed to know what I was talking about in his mind. He invested more in shipping than he did in the tune.

The thing is, I had already tuned my own 52, including the trigger, so I knew I could do the job. Some of the other well-known tuners said they couldn't be improved, and they wouldn't touch them. After the dentist posted his good report, they started doing them too.

If it sounds like I'm tooting my horn a little, well, maybe just a little. The thing is, I got made fun of for being the new guy on the block, AND for agreeing to tune one of them, so I feel like at least mentioning it in passing is fair. It's not like I harbor any ill will or anything like that. I still tune them, including the model you have, and so do the other tuners.

Just for the record, my hat goes off to Tim Challenger, who worked for RWS in New Jersey back then. I got to ask him the right way to set up the anti recoil screw, and he got his information directly from the manufacturer in Germany. It's the method that's always worked right, and still works. And, James knew what rifle I was using the parts in, and he also gave me some very useful tips that I use to this day.

It's always with JM parts, of course, except in the case of one single solitary spring I had lying around in the parts bin quite some years ago. It was a well made spring of better-than-factory, high quality steel, so I used it.  But, for the record, I could have used a JM spring and gotten the same results.

Anyway, Dr. S. loved the results. But, I don't know if he even has the rifle anymore. Not long after that, he bought one of the first FX Tarantulas that was sold to anyone, if my memory serves me correctly. One of his favorite pastimes was shooting rats at the dump. I wonder if he's still doing that, too, LOL.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


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