JM Tune Kit  

  RSS

Uglyjohn
(@uglyjohn)
Joined: 2 years ago
Posts: 29
2019-06-30 08:56:04  

looking to do a self-tune on my HW97. I have another pro tuned 97 that i use for HFT (US). It is incredibly smooth and accurate at 13.5 FPE and I’d like to try to duplicate this. Would a JM Hornet FAC kit work here or would his adjustable sub FAC kit be a better option?  Other options?


Quote
Motorhead
(@motorhead)
Member of Trade
Joined: 3 months ago
Posts: 50
2019-06-30 17:40:50  

IMO ...  most professional tuners DON'T USE kits but spend the time to fit seals correctly be them OEM or aftermarket, know where and what lubes to use threw out the action & address spring twang by manufacturing springs guide & top hat SPECIFICALLY for the spring in use / to be used.   Mass manufactured "Self Tuner" kits simply can't or seldom deliver the fit & finish tolerances of hand fitted parts and assembled with an understanding of what happens during the firing cycle and how to mitigate those negative effects when present.

 

Also relativity ... self tuner kits operate better than OEM parts ... custom manufactured & fitted parts better than self tuner drop in parts and so it goes.  gotta look at it apples to apples.

 

Scott S

Home of ... MOTORHEADS AG TUNING SERVICES
................... @ Northern California USA ....................
Sacramento Valley Field Target Club SVFTC Scott S


ReplyQuote
ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2019-07-01 00:50:47  
Posted by: Uglyjohn

looking to do a self-tune on my HW97. I have another pro tuned 97 that i use for HFT (US). It is incredibly smooth and accurate at 13.5 FPE and I’d like to try to duplicate this. Would a JM Hornet FAC kit work here or would his adjustable sub FAC kit be a better option?  Other options?

You don't mention the age of your rifle, so, first, I want to make a comment about different sized tubes and piston seals that were used in some of the Weihrauch  side-lever cocking rifles, like your 97.  There was a time, I think maybe about 10 years ago, when the size of both tube and seal was increased from 25 mm to 26 mm. 

Wait, I found the info you'll need to know about tube and seal size right there on the JM site, on the Hornet piston seal page:

"Hw77-97 ( over 1" bore-newer guns) For serial no.1446049 and over 77-97 guns. Below this they take a smaller seal. SN info supplied by HW".

I'm mentioning it because it affects which piston seal you can use, and also the power capability by at least a little (larger tube and seal = slightly more power).  

Let me move on to the kits.

The sub-FAC ("OS") kit is really the one that was designed to do what you're trying to do.  It's not a guess.  I've installed both that one and the FAC kit in the new 77's and the 97's.  I do think you may find yourself using all of the spacers with the OS kit to get that far over 12 FPE ( that is, to exactly 13.5).  But, even if you and your rifle prove me wrong, it's just not a big deal to remove a spacer or two.  And, even if you come out at 13 FPE I think I'd call it a win and stop tinkering with it right there.  The guys who do well in FT say that a half a foot pound doesn't make much difference.

For the record, it's OK to consider the spring guides in both kits to be a custom fit, because he makes sure the fit is right in the springs, which he also makes.  (So, with him being the manufacturer of both springs and guides, if the spring size changes a little from one run to the next as can happen, it's easy for him to know the change he needs to make in the guides, and for him to make it).

As far as power, if you have a 97 with a 26 mm tube, he even has a piston seal option available that lets you increase or decrease velocity/FPE by sizing the seal a little differently even if you leave the spacing the same, using either kit or any number of spacers.  It's his Hornet piston seal: 

https://www.airrifleheadquarters.com/catalog/item/251485/1151533.htm

I can tell you that based on the size he makes them, the fit will be pretty-tight and slow as received in almost every rifle being sold (i.e. they vary a little from one to the next), even with all the spacers in there.  He knows some of the rifles vary a little, so he makes the seal slightly over-sized to fit almost every variation you'll run across, AND to allow some room to control the piston speed and thus the power output.  So, not only do you have the option to vary spacing, but you also have the option to vary the sizing of the seal up or down a little to increase or decrease power.  Even with the seal sized down a little, there's still plenty of material left to give you a good seal in the chamber.

Maybe I muddied the water.  I think the sub-FAC kit with spacers is the one that will most-easily get you to where you say you want to go, no matter which seal you use.  Either kit can be used with a factory piston seal, the SGS seal (his improved version of a factory seal), or the Hornet seal.  For the sake of simplicity, or if you don't know that much about seal sizing, the factory seal or SGS seal will probably be the simplest installation.

SGS seal: 

https://www.airrifleheadquarters.com/catalog/item/251485/9946364.htm

Please note that the SGS seal comes in two sizes that vary by just a little, to give you the best fit in YOUR rifle.  You'll notice on the upper right hand side of the page that you have to specify which one you want when you order.  Again, the larger seal can be sized down a little, but I wouldn't bother with that.  The seals are so cheap, it it was me, I'd order one of each size and use the one that gave me the best results I'm after/best fit.

And, yes, his parts and kits are in-fact superior to the OEM parts in almost all cases.  He's the guy (James M. that is) who can be credited with taking 'the twang and rattle and buzz' out of spring-piston air guns many years ago.  I've been getting those results out of his parts for about 20 years now.  He did it by making and selling springs and guides that fit like a hand in a glove, just like they ought to.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


airmojo thanked
ReplyQuote
boscoebrea
(@boscoebrea)
Joined: 2 years ago
Posts: 174
2019-07-01 14:40:43  

 JM is great and so are his kits and parts...I think you will be happy;it is a cost effective upgrade.


airmojo thanked
ReplyQuote
ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2019-07-01 15:41:21  
Posted by: boscoebrea

 JM is great and so are his kits and parts...I think you will be happy;it is a cost effective upgrade.

I think it needs said that there's a reason why JM's parts work well in so-many guns. 

Over the years, he's bought one of almost every air gun of reasonable-quality out there that's popular, to check the fit, and to check for any changes in the specifications-dimensions that need to be accounted for as they arise.  In other cases it was several of the same model to compare them.  Not only does he try to make his parts so they'll fit the 'worst case' scenario, but he often includes things like spacers--and a fairly-detailed explanation on the page for that part--so you'll know what to do to make it work, depending on which variation YOU have. 

In case you didn't know it or didn't catch it as a note somewhere on his site, there have been times where he's also included the field reports from others who have real hands-on experience as to even more information and changes, and accounted for those in the way he makes his parts, too.

All in all, he's made a large investment of his own dollars, time, and energy, to sell a product that will work right, most variations included.  When you factor all that in, the parts he makes might be considered to be a craftsman's 'modest work of art', and at very-reasonable prices.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


airmojo thanked
ReplyQuote
boscoebrea
(@boscoebrea)
Joined: 2 years ago
Posts: 174
2019-07-01 19:34:10  

  I talk to him years ago,I wanted about a 14-16lb kit for my English.22 Tomahawk,he made it and I couldn't have been more pleased...He was saying that some people gave him a hard time about some of his springs,I could tell it bothered him.

 Indeed the man was and is a great service for our air gun community,I call him uncle.


ekmeister thanked
ReplyQuote
ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2019-07-01 21:29:51  

I just realized something that I missed reading a little further up the page, and while I don't see the need to elaborate on what it was, it probably merits a comment or two.

Some people with the right experience and knowledge are able to take the JM kits and do even a little more with them than the average DIY tuner can do in his basement or garage.  The parts can sometimes be custom modified by the right person to fit the small majority of applications where they might not work 100% as well as a drop-in part.  

But, based on my 20+ years of experience in tuning spring-piston air guns, I've found that the majority of JM/ARH parts are suitable for use by both the DIY guy and professional tuners.  The professionals may simply choose to do a little extra final fitting, for the ultimate in the way of a custom application.  Also in my experience, when JM says his parts are applicable to a given make and model for the DIY tuner, he's right on the money.  Said another way, 'A couple thousand well-functioning air guns can't be wrong'.  Their owners might not have been 'professionals', but they often got something reasonably-close to professional results if they followed some basic rules, and any instructions listed on his parts pages.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


ReplyQuote
ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2019-07-01 21:50:14  
Posted by: boscoebrea

  I talk to him years ago,I wanted about a 14-16lb kit for my English.22 Tomahawk,he made it and I couldn't have been more pleased...He was saying that some people gave him a hard time about some of his springs,I could tell it bothered him.

 Indeed the man was and is a great service for our air gun community,I call him uncle.

If you treat him with some common respect, it's been my experience that he'll often bend over backwards to help you out in a pinch if he has the time and energy.  I've communicated with him occasionally over the years, and I know for a fact that many times he's buried in correspondence and questions about things too-far out there to even answer.

I can relate.  I've fielded a couple of thousand emails over the years, literally.  Some are simple requests, some are about getting work done, but some are never going to go anywhere worthwhile, and I really try to avoid the latter. 

One example that stands out:  Fact, a loose muzzle brake on a springer is detrimental to good accuracy.  Those who know about such things say it's because the loose brake alters barrel harmonics.  OK, whatever, that works for me.  All I know is that when I install a brake, I make sure it's tight and it's going to stay that way if at  all possible.  But, one man emailed me and asked, 'Since barrel harmonics affect accuracy, do you use an oscilloscope when tuning an air gun?'   

I kinda sorta understand where he was coming from, but I simply replied, "No" and left it at that.  I never heard from him again, and he never had me do any tuning work for him.  It was apparently just 'something that crossed his mind one dark night when the crickets were chirping, and the dogs had gone to sleep'---lol.

BTW, someone out there may use an O-scope when working on an air gun or firearm, as in while doing some research or in obtaining the pinnacle of accuracy, but I've never found it necessary to do so to get good results in the way of an air gun tune.   Maybe if someone with an O-scope showed up and tested one that came out well, they'd say, "Yep, it checks out here boss".

My point: If you multiply that experience I had by a couple thousand, I think someone might understand why JM usually answers his emails with brevity.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


ReplyQuote
airmojo
(@airmojo)
Joined: 1 year ago
Posts: 151
2019-07-02 18:32:27  
Posted by: ekmeister

One example that stands out:  Fact, a loose muzzle brake on a springer is detrimental to good accuracy.  Those who know about such things say it's because the loose brake alters barrel harmonics.  OK, whatever, that works for me.  All I know is that when I install a brake, I make sure it's tight and it's going to stay that way if at  all possible.  But, one man emailed me and asked, 'Since barrel harmonics affect accuracy, do you use an oscilloscope when tuning an air gun?'   

I kinda sorta understand where he was coming from, but I simply replied, "No" and left it at that.  I never heard from him again, and he never had me do any tuning work for him.  It was apparently just 'something that crossed his mind one dark night when the crickets were chirping, and the dogs had gone to sleep'---lol.

BTW, someone out there may use an O-scope when working on an air gun or firearm, as in while doing some research or in obtaining the pinnacle of accuracy, but I've never found it necessary to do so to get good results in the way of an air gun tune.   Maybe if someone with an O-scope showed up and tested one that came out well, they'd say, "Yep, it checks out here boss".

I would think that using a high-end musical tuner like a Peterson Strobe Tuner would be a lot better than an oscilloscope... I'm convinced that the universe is in tune to the key of Bb, and Bb is my favorite key harmonica to play... 😀 

 

Not sure how you would setup an oscilloscope or musical tuner to check a barrel's harmonics !

Of course there is the adjustable muzzle thingy, like the Whiscombe HOTS and the "Air Tamer" that was offered for the Webley Eclipse that screws onto the barrel's muzzle... and these thingies do work, or at least you have to play around with them to find what position gives you them best accuracy.

I do love my springers... and JM !

Ken H in OH -- Life is One Hole After Another...


ReplyQuote
boscoebrea
(@boscoebrea)
Joined: 2 years ago
Posts: 174
2019-07-02 19:14:33  

Man,you hit a note with me,Bb,my favorite to,like Tenor;Time to fire up some Hawkins and Young,maybe some JJ Johnson....


airmojo thanked
ReplyQuote
ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2019-07-03 12:41:45  
Posted by: boscoebrea

Man,you hit a note with me,Bb,my favorite to,like Tenor;Time to fire up some Hawkins and Young,maybe some JJ Johnson....

This has veered a little off the path, but I still find it to be confusing to go from 'standard' note names and tones to the ones on Bb instruments, like the trumpet as an example (IIRC).  The C note is a Bb, or a Bb note is a C, or what??  I play guitar, bass, and piano a little, but never with orchestra/band lessons to learn the difference. "It's simple.  It's a Bb to you, but on my lead sheets it's shown as a C, so I call it a C".  Or, maybe the other way around?  What?

Don't take this the wrong way, but when discussing it, all of a sudden I feel like I'm trying to understand the differences of the female mind.  Sometimes my brain gets twisted in this tight little knot, and I can't seem to get there from here.

JM tune kits: Read the parts pages on his site, including any notes.  If you don't understand what's being said after that, ask a question.  A post on a forum is fine.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


ReplyQuote
Lewis
(@lewis)
Joined: 2 months ago
Posts: 1
2019-07-04 06:05:07  

I’ve dealt exclusively with Jim for more than 20 years 

His products are absolutely top notch and have never let me down 

There’s no finer fellow than Jim and it’s always a pleasure dealing with him 

 

 


ReplyQuote
ekmeister
(@ekmeister)
Member of Trade
Joined: 2 years ago
Posts: 448
2019-07-05 02:46:11  
Posted by: Lewis (at UTC + 10)

I’ve dealt exclusively with Jim for more than 20 years 

His products are absolutely top notch and have never let me down 

There’s no finer fellow than Jim and it’s always a pleasure dealing with him

I once knew a guy in the same time zone who's 2nd specialty was seeing to it that people's grass got cut.  In my part of hotter than blazes Texas, I never minded cutting the grass all that much, as long as I knew I had a beer being iced down and at the ready when I was done.  One was enough, but there sure needed to be one.

I'm sorry if I disturbed anyone with the above.  I was thinking out loud so loudly, that I see it made it onto the screen.

Safe and Happy Shooting!

Ed, the Airgun TuneMeister

https://www.airguntunemeister.com/


ReplyQuote

Please Login or Register