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All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => German AirGun Gate => Topic started by: Calmark on January 24, 2012, 02:44:05 AM

Title: FWB 124 tune up (with pics!)
Post by: Calmark on January 24, 2012, 02:44:05 AM
Hi everyone,

Here's what I was up to a few days ago.  I finally got around to installing the Maccari Pro Mac tune kit in my San Anselmo "Cobra" FWB 124.  I decided this gun, and not my "new-to-me" San Rafael would get the kit since it had the most to gain, being the roughest cocking and least accurate of the two.  This is a custom made kit from http://www.airrifleheadquarters.com/page/page/251327.htm (http://www.airrifleheadquarters.com/page/page/251327.htm) that comes with front and rear guides that are extremely tight-fitting.  Its tight tolerances are designed to cut down on the vibration of the spring which produces the classic "twang" in most springers.  Also, as you'll see in the pictures, the new spring is much shorter than the original and is a bit stouter.  Some of the lost length is made up for with the spacers, but overall, the length of the spring kit is shorter than the factory spring.  As an added bonus, this kit not only smooths vibration, but generally increases velocity as well with the stiffer spring.  Since a picture is a thousand words, here are a few:

Kit, pre-installation:

(http://img109.imageshack.us/img109/8164/img0126ct.jpg)



Disassembled gun with picture of new spring kit and factory spring:

(http://i34.photobucket.com/albums/d103/markweidert/photo8_zpse68ca775.jpg)

As you can see, the new kit with its different configuration, can really change the whole dynamics of the interaction of the spring and piston with the differing stiffness, length and spacing. 

I also bought a brand-new pivot bolt and screw along with the tune kit.  This gun came to me disassembled and was basically a box of parts when I got it from the previous owner.  He and his friend gave up fixing it after sending the factory spring into the garage wall while attempting to fix the original seal.   :o  Unfortunately, the tiny screw fitting into the end of the original barrel bolt to enlarge the hollow end, thus tightening it, was lost in the process.  If I had known how much this little screw would be problematic, I would have offered less for the gun.   :'(  Especially since the new one from Air Rifle Headquarters cost $35!  :o  With a loose barrel causing a weird lock up and some vertical stringing while shooting, I decided to bite the bullet and do it right.  In the next picture, you'll see the new barrel pivot bolt and screw along with the old one and the silver-colored screw I used for the time-being.  It wasn't the right size, so the barrel was still loose.  Here they are.  Notice the Maccari moly in the left of the picture.  Its nice to add this to a pivot bolt when re-installing to make it nice and smooth!   ;D

(http://i34.photobucket.com/albums/d103/markweidert/IMG_0131_zpsmilucsxe.jpg)

Here's a picture of the whole spring assembled just before reinstalling it into the gun.  The trigger is somewhat unique in that it also has the rear guide on it.  First to go on is the thick metal spacer, then the new spring.  Next up is the front white spacer.  One thing I noticed is that these things are now SUPER tight compared to the factory pieces.  The spring just barely went onto the rear and front guides and I really had to use some muscle to wiggle them on.  Now THIS is how springs should fit, not all loose like from the factory so they rattle around and cause all of that twang!

(http://img3.imageshack.us/img3/8236/img0131co.jpg)

I hope you all enjoy the pictures of the insides of the FWB 124.  Its pretty easy to work on, other than the rear safety sort of getting in the way of compressing the spring in the compressor.  I had already lube-tuned the gun when I first put it together, so the rest was pretty much drop in, while adding a dab or two of moly to lube things up.

Title: Re: FWB 124 tune up (with pics!)
Post by: glassman98 on January 24, 2012, 03:30:28 AM
Nice write up and great pic. Thanks.  Craig
Title: Re: FWB 124 tune up (with pics!)
Post by: s10gto on January 24, 2012, 08:17:20 AM
Very nice! I'm a big Maccari fan myself. Have bought many of his kits , springs, and seals.  I have always been very pleased with the performance.  ;D
Title: Re: FWB 124 tune up (with pics!)
Post by: Mark 611 on January 24, 2012, 10:05:00 AM
yep nice pix good job CM! :P
Title: Re: FWB 124 tune up (with pics!)
Post by: tjk on January 24, 2012, 11:08:04 AM
Nice job with the tune and write up of the JM kit. Just a few questions.  How did the piston seal look, and is it an OEM seal or did you replace it with a JM seal too. And have you performed any pre tune and post tune chrony readings. Have you found the best pellet and pellet weight for your Sporter? The original owners manual from the old ARH, suggest 7.9 grained pellets, but I found my standard Sporter prefered the slightly heavier 8.3 JSB Exacts. Again, very nice write up. Looking forward to some post tune test results posts! ;)
Title: Re: FWB 124 tune up (with pics!)
Post by: bart the fart on January 24, 2012, 11:57:21 AM
WOW good write up Mr. Mark! Cant wait to get my hands on those 124's....Cheers Bart
Title: Re: FWB 124 tune up (with pics!)
Post by: lizzie on January 24, 2012, 07:39:15 PM
Wow- that's wonderful. Thanks for sharing it with us! :)
Title: Re: FWB 124 tune up (with pics!)
Post by: Calmark on January 25, 2012, 04:38:36 AM
Thanks for the comments! ;) I haven't done much testing with the new kit installed yet. Once I do I'll add some more info about power-level before and after along with impressions about the gun's behavior with the kit. I will say though with just a few shots the gun feels like a completely new animal. More to come soon!  :)
Title: Re: FWB 124 tune up (with pics!)
Post by: Calmark on January 27, 2012, 01:14:59 AM
Ok, its time to give some results from the FWB 124's tune with the Maccari Pro Mac Kit.  ;D

Like I mentioned, this kit has transformed the gun's firing characteristics and it feels like a new animal.  First, it removed all of the twang and most of the vibration, due to, I believe, the tight-fitting spring to the guides.  The spring is also much shorter, so it seems like it has less length to move around inside the gun.  The shot also seems to cycle much more quickly than the stock configuration.  The so-called "lock time" really feels shorter and the recoil is now straight-back, more similar to how a gas ram, like a Nitro piston feels than before.  I definitely like the feel of the new shot cycle.  Short and sweet and pretty much vibration-free.

Now, I don't own a chrony, but I wanted to get some idea of the before and after velocities.  I used the next best thing: a paperback book (with thick pages) penetration test.  ;D

Here are some results, using Crosman pointed pellets .177 cal. :



Stock "Cobra" San Anselmo:  121 pages penetration.

Stock San Rafael FWB 124:     129 pages.

Maccari Kit "Cobra" San Anselmo: 211 pages penetration.

As you can see, not only did the gun improve in firing characteristics, it gained a very healthy dose of velocity.  Pages penetrated doesn't exactly equate to fps gain, but it gives an idea of the approximate power gain.  Since I can't give an exact fps gain, all I can really do is take an educated guess, based on the penetration test and the fact that the pellets now smack my steel spinners at 30 yards with a very noticeable increase in force. 

Pre tune, the gun was probably shooting around 750 fps, with its original 35 year old spring and new seal.  With the new kit, I'm thinking its shooting more like 850 fps and has power much closer to my untuned R9 .20 cal.  That's in the neighborhood of a nice 100 fps increase in speed, and about 25% more energy with the 7.9gr pellets used.  Can't beat that increase in speed and power for an easy-to-install kit, not to mention the smoother and quieter shooting characteristics.  ;D

But, I have to mention the ONE downside of the kit.    :o  The lovely, easy-as-pie cocking effort has been lost!   :'(  It was probably at around 18-20lbs cocking effort pre-tune, and was SUPER easy to just cock and shoot without thinking about it.  Post-tune, however, its now noticeably harder to cock, though still not that bad of an effort.  I'd say it gained probably 25% more cocking force needed, putting it around 25lbs or so.  That's to be expected of course, since the power and velocity went up roughly the same 25%.  As a comparison, it used to be closer to my R7's cocking effort.  Now its probably between the R7 and R9, though with nearly the power of the R9.

All in all, it was a great experience installing my first professional after-market tune kit, and I think it was a great success.  The rifle was transformed into a harder-hitting, smooth-firing animal, spittin' out pellets like a true "Cobra" would!   ;)  I'm looking forward to accuracy testing it now that its healthier and has its new pivot bolt and breech seal.  BUT, I think I'll keep my other San Rafael FWB 124 in stock form with its soft spring and "twaaaanngg!" for lazy days of plinking and fun shooting with its marvelously butter soft cocking effort!   ;D  Now this is the reason just ONE FWB 124 or airgun just isn't enough!  8)
Title: Re: FWB 124 tune up (with pics!)
Post by: Motorhead on January 27, 2012, 01:22:51 AM
Such fine shooting rifles,  need to get my repaired previously broken original metal trigger reinstalled because the plastic one in it now not worthy !

Rock on and LONG LIVE the FWB 124/127 rifles !!!
Title: Re: FWB 124 tune up (with pics!)
Post by: Calmark on January 27, 2012, 01:37:40 AM
Yep, with a little bit of know-how on how to replace a few parts, these guns can shoot great for many years!  Definitely long-lived with how well they are built, unless of course the apes at the shipping companies stomp on them!   :'(

Glad to hear you've gotten your old metal trigger back in working order with that repair.  Very good idea you had to use that piece of aluminum in the hollow back for support and to help hold the two pieces and strengthen it while the JB weld set.  ;D

Even though I'm not a trigger expert, let me know if you need a hand with swapping out your plastic trigger with the metal one. 

Good talking with you on the phone today.  Its sure nice to talk to somebody who knows the lingo and doesn't look at you funny when you mention air rifles!

By the way, despite the new "bad" plastic trigger, how do you like the recent changes in your FWB 124 with the new Maccari kit in it?  Have similar or different experiences with it than I did?
Title: Re: FWB 124 tune up (with pics!)
Post by: Motorhead on January 27, 2012, 01:54:04 AM
Only spit 50 or so out sense getting it back from the Maccari piston seal/spring retrofit.
Bit frustrated shooting it because trigger now ( Replaced with an OEM plastic ) does not have any where close to the same feel and set the original OEM aluminum one had.  So .... not really hunkering down driving knats azz shots with it.

Now with that said rifle is still VERY smooth and has it's trade mark springer THUNK as it fires but does seem to be just as smooth or more so once cycling. 
Cocking a tad more stiff but nothing like my sons Benji NP that takes more omph !

Screwed around last weekend fiddling with trigger adjustments ( In vain ) but if on my game rifle still sent JSB 8.4's on the mark at 50 yards !! shooting oak acorns set up on end flipping across the ground.

Guns got more balz without a doubt giving up no accuracy  ;D
Title: Re: FWB 124 tune up (with pics!)
Post by: tjk on January 27, 2012, 10:34:41 AM
CalMark. You said you plan to leave your San Rafael Sporter on its stock form. Check me if I'm wrong, but have you replaced the piston seal in it?  Once the old seal starts to crumble like a crunched macadamia nut, the compression tube can and will probably get a scratched  by the pistons front edge. It's cool that you want to leave it 'soft tuned' for casual shooting, and that spring buzz can still be remedied, but I would strongly suggest changing out the piston seal if you havent already.
Title: Re: FWB 124 tune up (with pics!)
Post by: Calmark on January 29, 2012, 01:50:34 PM
Tjk,

Thanks for the reminder about the stock seal.  Its been at the back of my mind I'm only tempting fate shooting the San Rafael with its original seal (I think).  I do have an extra for it, so I'll probably go in and replace the old one soon.  I don't want to have to deal with all of the crumbly bits and having to clean out the cylinder when it goes. 

What do you suggest for minimizing the spring buzz if I still use the original spring?  I don't know how I'd tighten up the fit, especially since the rear guide is integrated into the trigger group.  Do you suggest a front guide or something?  It would be great to lessen the buzz and still use the stock spring!  ;D

Motorhead it sounds like your gun came back shooting really well.  Get that old trigger back in there and you should be golden.  I wish I could shoot as accurately as you do at 50 yards like that.  I'm still shooting between 20 and 30 yards and while I've gotten better, I still have a ways to go to match you.  Main thing I think is finding the guns' preferred pellets.  I'm well stocked on .22 cal. pellets, but don't have many varieties in .177... yet!
Title: Re: FWB 124 tune up (with pics!)
Post by: Motorhead on January 29, 2012, 07:03:00 PM
Being able to shoot the old girl like that did not come overnight.  Having the 124 as my primary field rifle for over 25 years certainty has contributed no doubt.
You will get there !!  rifle certainly is capable of stellar accuracy !! 


Tjk,

Thanks for the reminder about the stock seal.  Its been at the back of my mind I'm only tempting fate shooting the San Rafael with its original seal (I think).  I do have an extra for it, so I'll probably go in and replace the old one soon.  I don't want to have to deal with all of the crumbly bits and having to clean out the cylinder when it goes. 

What do you suggest for minimizing the spring buzz if I still use the original spring?  I don't know how I'd tighten up the fit, especially since the rear guide is integrated into the trigger group.  Do you suggest a front guide or something?  It would be great to lessen the buzz and still use the stock spring!  ;D

Motorhead it sounds like your gun came back shooting really well.  Get that old trigger back in there and you should be golden.  I wish I could shoot as accurately as you do at 50 yards like that.  I'm still shooting between 20 and 30 yards and while I've gotten better, I still have a ways to go to match you.  Main thing I think is finding the guns' preferred pellets.  I'm well stocked on .22 cal. pellets, but don't have many varieties in .177... yet!
Title: Re: FWB 124 tune up (with pics!)
Post by: tjk on January 30, 2012, 11:53:58 AM
Being that you prefer to keep it soft 'tuned' with the original spring, you could alway band-aid the rear guide with electricians shrink wrap. The thin sleeve type. The thick HD type probably wont work. With little apparent need for speed, a moderate tarring of the wire should suffice. I replaced the spring with a JM 'drop in' spring in my standard Sporter and tarred the wire a bit more than most folks prefer to and still shoots in the mid 800's so I don't think you will lose too much velocity either. 'Spider webbing' your spring with tar and add more as needed. Not the best method for speed guns but your going for a Lincoln town car and not a Ferrari.