GTA
Airguns by Make and Model => Vintage Air Gun Gate => Topic started by: Rat Sniper (AKA: PaulT58) on February 20, 2017, 12:21:27 PM
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Hey everyone! I'm new here and though I have owned air guns for most of my life, I have always been more of an avid shooter and never really got into taking them apart, repairing them, or modifying them. My current collection is listed below, but the focus of this post is the Smith & Wesson Model 79G.
This pistol belonged to my Dad and he was in the process of restoring it when he passed away. My Mom gave it to me, and in honor of my Father, I'd love to get it working again.
Steve (scp52) was kind enough to send me a link to a Seal Replacement Kit and a nice .pdf Illustrated Parts Breakdown, of this pistol. But, since I have never done much more than tighten screws, I'm looking for anyone who may have a S&W 79G or has any experience with rebuilding one. Thanks in advance for any help. Here are a couple pictures of it as it currently sits in its original box...
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That's one very nice looking pistol. I know the sentimental value makes it priceless, but I got curious and looked it up at the Bluebook of Airgun Values and got this. I know it doesn't help answer your question but thought I'd throw it in:
MODEL 79G
- .177 cal., CO2, SS, styled after S&W Model 41 semi-automatic pistol, gun blue finish, brown plastic grips, 8.5 in. barrel, 475 FPS, fully adj. sight, 42 oz. Mfg. 1971-80.
View Historic Prices
Grading 100% 95% 90% 80% 60% 40% 20%
$175 $150 $125 $100 $75 $50 $35
Last MSR was $53.45.
Add 50% for orig. box with can of S&W pellets and box of CO2 cylinders.
Add 30% for orig. box with plastic envelope of pellets and CO2 cylinders.
Add 25% for early pistols with adj. trigger.
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There's a disassembly guide here:
http://anotherairgunblog.blogspot.com/2009/02/smith-and-wesson-model-79g-disassembly.html (http://anotherairgunblog.blogspot.com/2009/02/smith-and-wesson-model-79g-disassembly.html)
You can find other blogs with modification tips by Goggling "s&w 78g 79g blog".
Also, there was a previous thread on this forum that may help:
http://www.gatewaytoairguns.org/GTA/index.php?topic=54347.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=54347.0)
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I rebuilt my 78G on the couch, as long as nothing is corroded it should come apart fairly easy, I was intimidated at first reading the posts about it but it wasn't all that bad.
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That's one very nice looking pistol. I know the sentimental value makes it priceless, but I got curious and looked it up at the Bluebook of Airgun Values and got this. I know it doesn't help answer your question but thought I'd throw it in:
MODEL 79G
- .177 cal., CO2, SS, styled after S&W Model 41 semi-automatic pistol, gun blue finish, brown plastic grips, 8.5 in. barrel, 475 FPS, fully adj. sight, 42 oz. Mfg. 1971-80.
View Historic Prices
Grading 100% 95% 90% 80% 60% 40% 20%
$175 $150 $125 $100 $75 $50 $35
Last MSR was $53.45.
Add 50% for orig. box with can of S&W pellets and box of CO2 cylinders.
Add 30% for orig. box with plastic envelope of pellets and CO2 cylinders.
Add 25% for early pistols with adj. trigger.
That's pretty interesting, but like you said, you can't put a price on the sentimental value. Thanks...
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There's a disassembly guide here:
Link removed because I'm not allowed to post external links! Must be a newbie thing!
You can find other blogs with modification tips by Goggling "s&w 78g 79g blog".
Also, there was a previous thread on this forum that may help:
http://www.gatewaytoairguns.org/GTA/index.php?topic=54347.0 (http://www.gatewaytoairguns.org/GTA/index.php?topic=54347.0)
Thank you for this links! Funny, I search specifically for S&W 79G and never got a hit, and you post a thread that specifically deals with the tear down of the 79G! Got to love computers!
I must say though, after reading that tear down thread, I'm not real eager to dive into this project. Although, I probably should tear it down before I start ordering parts just to see what exactly I'll need. My problem is, if more than a few hours go by after I take it apart, I forget how it goes back together! It not worthy getting old!
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I rebuilt my 78G on the couch, as long as nothing is corroded it should come apart fairly easy, I was intimidated at first reading the posts about it but it wasn't all that bad.
Okay, wish we were closer because I'd be visiting your couch! LOL!
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Order the reseal kit, set out a towel on the kitchen table and go to town, I don't remember details as it was about a year ago but it really wasn't hard, the guide in the front was what I was worried about as I'd read the horror stories but mine was easy there... it might be worth looking into where it is leaking as I think my main leak was in the CO2 cap, I think there's 2 O rings in it...
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Well, I have a set of o rings on order so when they arrive I'll attempt a tear down and see how things go. Any recommendations on what to use to degrease the parts as I disassemble the pistol? I'd like to give it a good cleaning and then relive everything before putting it back together. Will Hoppe's No. 9 Gun Bore Cleaner work, or would it be too harsh? Thanks...
Paul
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Paul,
One thing that you can do to help ensure you get it back together correctly is to take pictures at each step of the disassembly, and set the parts aside in the order that they come off. Have the disassembly blog up on the computer too, and try to do it when you have enough time to complete the job without interruption. You'll do fine, I've done a couple of these and it isn't that difficult.
Hoppes should be just fine, but be careful about getting strong solvents on the painted areas or plastic grips. Get some Pellgun oil so that you can put a small drop on the tip of every other CO2 cartridge, and lightly oil the internal steel parts as you would any firearm.
You'll be impressed with the power and accuracy of the S&W 79G, they're a lot of fun to shoot.
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Paul,
One thing that you can do to help ensure you get it back together correctly is to take pictures at each step of the disassembly, and set the parts aside in the order that they come off. Have the disassembly blog up on the computer too, and try to do it when you have enough time to complete the job without interruption. You'll do fine, I've done a couple of these and it isn't that difficult.
Hoppes should be just fine, but be careful about getting strong solvents on the painted areas or plastic grips. Get some Pellgun oil so that you can put a small drop on the tip of every other CO2 cartridge, and lightly oil the internal steel parts as you would any firearm.
You'll be impressed with the power and accuracy of the S&W 79G, they're a lot of fun to shoot.
Thank you for the advice! I've already reviewed the disassembly blog and was going to have that up while I took it apart, but taking pictures of each part before I remove it it a great idea! I'll post my results when I'm done.
I think I'm getting the bug because I just ordered the steel breech kit for my 1377, a new 2240 and a steel breech kit for it from Crosman using their discount code! Got all 3 for $117.83. I can see this new hobby could be dangerous!
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I finally got all the parts I needed to rebuild my Dad's 79G. I replaced all the seals and degreased and cleaned it up and got it back to tether with no issues. Some of the O rings were a real pain to get on, those little buggers can be stubborn! It's now shooting, but I an experiencing some leakage when it's fired. It feels like it blowing our just above the grips, which makes me thing it's the port between the chamber and the barrel. Like the Crosman setup, there were no seals here, just a metal to metal connection. Any tips on how to fix this seal would be helpful. Other than that it's shooting just fine and I'm excited I was able to get it back in service. Today, I'll spend a little time getting it sighted in!
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It's been a while since I had one of these opened up, but I'd imagine that the "freezer tube" mod would work. Just get a short length of the plastic tubing that's used to connect refrigerator ice-makers, and cut off a piece that's the same height as the transfer port button, then replace that metal button with the piece of plastic tubing. The plastic will get a better seal than the metal-on-metal of the transfer port button.
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It's been a while since I had one of these opened up, but I'd imagine that the "freezer tube" mod would work. Just get a short length of the plastic tubing that's used to connect refrigerator ice-makers, and cut off a piece that's the same height as the transfer port button, then replace that metal button with the piece of plastic tubing. The plastic will get a better seal than the metal-on-metal of the transfer port button.
Interest idea, I'll have to look around and see if I have any spare tube laying around. Can't see buying a tune from the hardware store just for a ⅛" piece, especially since these things normally come in 3' to 5' lengths! The current tube is smaller on the top than the bottom, does that matter? Thanks...
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Duplicate! Computer issues this morning!
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Paul,
That looks in incredible shape and to top it off it has sentimental value! A keeper for sure!
Coincidentally, I just resealed one this week. Did you get the reseal kit from MAC1 with the new poppet? Great kit. So here's my advice...
1) Get the kit from MAC1 with the poppet
2) When replacing the tiny orings on the exhaust valve first get the hottest tap water you can and drop those little suckers in there for a few minutes. It makes getting them on much easier.
3) place a tissue over the loading port and shoot. This will tell you if you have a transfer port leak.
4) if you do have a TP leak first check that the barrel has not twisted on you. It can easily and then you won't get a good seal.
5) depending on the shape of your TP you might want to cut a new one from some ice maker poly tubing
6) if it all seals up and you have low power, check the power adjuster. Yeah, I didn't know this and was wondering what was up. The threaded screw in the front of the barrel adjusts the power. Note that there is also a screw inside the adjuster.
That should do it. It is a pretty easy reseal job and only takes a few minutes.
Andy
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Paul,
That looks in incredible shape and to top it off it has sentimental value! A keeper for sure!
Coincidentally, I just resealed one this week. Did you get the reseal kit from MAC1 with the new poppet? Great kit. So here's my advice...
1) Get the kit from MAC1 with the poppet
2) When replacing the tiny orings on the exhaust valve first get the hottest tap water you can and drop those little suckers in there for a few minutes. It makes getting them on much easier.
3) place a tissue over the loading port and shoot. This will tell you if you have a transfer port leak.
4) if you do have a TP leak first check that the barrel has not twisted on you. It can easily and then you won't get a good seal.
5) depending on the shape of your TP you might want to cut a new one from some ice maker poly tubing
6) if it all seals up and you have low power, check the power adjuster. Yeah, I didn't know this and was wondering what was up. The threaded screw in the front of the barrel adjusts the power. Note that there is also a screw inside the adjuster.
That should do it. It is a pretty easy reseal job and only takes a few minutes.
Andy
Thanks Andy! Do you have a link to the kit you used? I just got an o ring kit from eBay, it didn't even list the sizes or part numbers for the different o rings, so I pretty much guessed based on the size of the o ring and where it was suppose to go. All the o rings in the pistol were severely deteriorated, and it took quite a bit of cleaning to get all the gunk out. I wish I had known about the hot water tip, my fingers are still sore from working some of them into place. I'll check the barrel alignment as well, I didn't think about it being twisted a little. When i first put it together I forgot to snug the set screw, so I did make use it was fully seated against the breach, bit did not wriggle it back and forth to see if it was misaligned.
I did the same thing when I first shot it, the power adjuster was on full low power. and it didn't have enough umphf to push a pellet down the barrel, which I feel is another indicator I have leak. After I cranked it to high power it shooting pellets, but doesn't feel like it has the power it should. I don't have a crony, so no way to actually test it, other than shooting it at stuff! I'll play with it a bit more later today and see if things improve. If not then I may try the poly tube trick! Thank you for your advice!
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Paul,
I just looked at the ebay kit. Yeah it is cheap but it is cheap. LOL It looks like standard nitrile or buna O-rings. They may, or may not, work. Trouble is they will absorb CO2. Also, no way will they be as durable as urethane. So if you are keeping it you might want to pay the $40 or so to get a full kit. But then they are easy to reseal and you can buy a lot of orings for $40. I chose to do it once and be done with it for many years.
Here's the link...
http://www.mac1airgunshop.com/smith-wesson-rebuild-kit-for-co2-pistols-p/sw78reki.htm (http://www.mac1airgunshop.com/smith-wesson-rebuild-kit-for-co2-pistols-p/sw78reki.htm)
These are sized right. And because they are urethane you don't have to worry about leaving CO2 in and deteriorating the orings.
I should have also put in another two tips...
7) if using the TimmyMac kit assemble the main and exhaust valve then put in toaster oven at 180-200 degrees for 15 minutes
8) assemble (um 200 degrees is still hot so let it cool!) and then put back in the toaster for another 15 minutes
if you do this the seals will be happy and you will too. absolutely no leaking on this one!
P.S. I'm not sure but I will surmise that the lower mass of the MAC1 replacement poppet may give more shots. I have shot a ton of shots on the rebuild and I don't recall getting this many before. May reduce dwell and make it more efficient. IIRC what it was shooting before, it is actually shooting about 10-15 fps faster now.
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For the record, I got the same kit off of ebay and it's been holding for a long time, even holds CO2 for a couple weeks at least... I haven't shot mine in a while though
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For the record, I got the same kit off of ebay and it's been holding for a long time, even holds CO2 for a couple weeks at least... I haven't shot mine in a while though
Just the urethane seals without the new poppet are $20. Yeah if you could source the urethane rings it might cost you a $10 but someone's gotta make a living too. The nice thing about the urethane is they aren't going to dry up anytime soon like nitrile/buna.
I should have also put in tip 9) use plumbers grease (silicone) on the urethane orings.
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Well, I took Dad's pistol out today, I was going to sight it in and when I went to shoot it, nothing, just a pfft sound and the pellet never left the barrel! I thought maybe the CO2 had leaked out over night, but when I went to loosen the knob that holds the cartridge i got a nice cold blast of CO2 as it escaped the chamber! So, I put in another CO2 Cartridge, charged her up, and nothing. Just a click of the trigger mechanism. So, I'm not sure what's up, but it's currently fully charged with a fresh CO2 Cartridge, and I'm not real excited about releasing it and getting another cold blast, so I may let it sit a week and see what happens.
In the mean time, I went a head and placed an order for the MAC1 Kit. I went cheap the first round because I did not know if the pistol would even work at all after replacing the seals, I know now it does, so I don't mind investing a little more into it and having it last a long time after it's fixed. I just can't imagine what is sticking at the moment that causing it no to release the CO2 charge. Hopefully, the MAC1 kit will fix this also.
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Wow, thats a complete package deal! Where were those manufactured?
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Wow, thats a complete package deal! Where were those manufactured?
From what I can tell, they were made by Smith & Wesson. The side of the barrel has Smith & Wesson, Springfield, MA, which, ironically, is where I was born!
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Nice! It sounds like its definitely worth it to finish this one. I really try and hold on to USA made items these days.
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Hey this just popped up in my recent threads again. Reading it I should clarify that you put in toaster without the grips on. Don't want you to melt your grips! Yeah 120-150 degrees should be plenty.
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Very easy pistol to work on compared to others that is. I buy orings in various materials, hardnesses, and sizes from Orings Inc. They are cheap and happy to sell them in any # you want. The shipping charge is the same whether you buy 3 or 300, so I wait till I need a bunch.
Sounds like you may have a piece of cheap oring that plogged up the works. Some piece of something must have been in there and it either is blocking the valve stem from depressing when the hammer hits or it's blocking one of the gas ports. The hammer is slamming home when you pull the trigger right? In any event you need to take it all apart and see what's what. No harm will come of you carefully unscrewing the piercing cap and letting the Co2 slowly leak out. Want to use padded pliers so no damage is done to your piercing cap. Or you can wait for the Co2 to leak out. Trouble with that is it may take years, if the seal is good in there. My 78G holds for......well till I shoot it again. Many months, sometimes. BTW I was very tentative when I first thought to work on my guns. It gets easier and easier. Good luck
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Just finished re-sealing my 79G with a MAC1 kit and it worked great. Getting an old one apart was puzzling as some stuff was stuck with gunk buildup. My disappointment is that I can't improve my non-adjustable trigger. I polished the trigger's sear surface, but the striker's sear face is internal and not accessible for polishing. There is no good place to add a trigger stop screw to reduce backlash. Trigger pull measures 2-3/4 lbs. Not bad, but it's a long, creepy pull with a lot of backlash. I can control it on a bench rest, but offhand work is difficult. I quit fiddling with the trigger as I don't like re-assembling the gun too many times, tightening steel screws in zinc die-castings.
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I finally got some time and finished repairing my Dad's S&W Model 79G. I installed the MAC1 rebuild kit and did the refrigerator hose port mod instead of the stock port. It's now working flawlessly and is holding CO2 with no leaks.
I sighted it in with some JSB Exact RS 7.33 gr pellets and ran it over the chrony as well. I did some research, and from everything I can find, it appears the stock 79G was rated at 475 FPS (High) and 350 FPS (Low). It does have a power adjustment under the barrel. I have no idea where mine is set right now, but based on my results, I'm guessing high.
Pyramid Air did a test and review on the 79G back in August 2006. The test environment was 84 degrees and 14 ft elevation. They cronies it using RWS R-10 7.0 gr pellets and got a high of 516 FPS and a low of 466 FPS for an average of 506 FPS.
Mine seems to be running a bit higher, but that may be because the refrigerator hose mod seems to have a larger opening than the stock port tube, so it's probably allowing a slightly larger volume of air through. My results today are below. The temp today when I tested was 80 degrees, and I live in Florida, so my elevation probably isn't much different, however, I think we are sitting closer to about 37 ft above sea level!
High: 545.8 FPS, Low: 540.2, Average: 543.44 FPS.
The target below if from sighting it in at 15 yards, shooting freehand as well as shooting through the chrony. And, i didn't shoot my chrony!
I'm very happy with how this turned out!
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I finally got all the parts I needed to rebuild my Dad's 79G. I replaced all the seals and degreased and cleaned it up and got it back to tether with no issues. Some of the O rings were a real pain to get on, those little buggers can be stubborn! It's now shooting, but I an experiencing some leakage when it's fired. It feels like it blowing our just above the grips, which makes me thing it's the port between the chamber and the barrel. Like the Crosman setup, there were no seals here, just a metal to metal connection. Any tips on how to fix this seal would be helpful. Other than that it's shooting just fine and I'm excited I was able to get it back in service. Today, I'll spend a little time getting it sighted in!
most likely the barrel isn't lined up with the transfer port. the single biggest problem I've found on the ones I've worked on. that, and the hole in the valve body is too small to allow the transfer port to properly seat in the valve. once you address those issues, you won't have any leaks coming from the barrel ever again.
also, when you adjust the barrel, and re -tighten the barrel screw, ( the one on top, just forward of the breach ), make sure you don't over tighten it, or it will push the barrel out of alignment, causing the bolt to bind, or, refuse to close at all.
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I finally got all the parts I needed to rebuild my Dad's 79G. I replaced all the seals and degreased and cleaned it up and got it back to tether with no issues. Some of the O rings were a real pain to get on, those little buggers can be stubborn! It's now shooting, but I an experiencing some leakage when it's fired. It feels like it blowing our just above the grips, which makes me thing it's the port between the chamber and the barrel. Like the Crosman setup, there were no seals here, just a metal to metal connection. Any tips on how to fix this seal would be helpful. Other than that it's shooting just fine and I'm excited I was able to get it back in service. Today, I'll spend a little time getting it sighted in!
most likely the barrel isn't lined up with the transfer port. the single biggest problem I've found on the ones I've worked on. that, and the hole in the valve body is too small to allow the transfer port to properly seat in the valve. once you address those issues, you won't have any leaks coming from the barrel ever again.
also, when you adjust the barrel, and re -tighten the barrel screw, ( the one on top, just forward of the breach ), make sure you don't over tighten it, or it will push the barrel out of alignment, causing the bolt to bind, or, refuse to close at all.
Thank you! I did the refrigerator hose mod for the transfer port and it seems to be holding up well. I shot about 100 pellets through it yesterday getting it sighted in and running crony numbers on various pellets.
I did run into the problem with the barrel screw and had to back it off a bit. It still seems the barrel is slightly out of alignment (to the right) so I'll probably play with it a bit more today and see if I can get it better aligned. Other than that, I'm quite happy with how it turned out, and I think my Dad would have been happy as well. He was a tinkerer, so he was always taking stuff apart to fix or improve them. I think he had purchased this for that very reason, but unfortunately, never had the chance to get it working. I'm happy to say it is now, and I'm glad I got the change to get it that way!
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Awesome work Paul!
Glad it worked out for you and your Dad would be happy you are enjoying it.
I believe yours is hotter because of the Mac1 kit. I should have also said that I polished up the poppet shaft. Mine was a bit rough. I too noticed an increase in fps. Yours is very healthy.
On another note, after getting a 78 and a 79, I also got Crosman MK I and a MK II. The MKs do have better triggers but I get 50% more shots per cart with the S&Ws at same power. Don't know if that's universally true but the shear number of shots per cart with my S&Ws amaze me.
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Awesome work Paul!
Glad it worked out for you and your Dad would be happy you are enjoying it.
I believe yours is hotter because of the Mac1 kit. I should have also said that I polished up the poppet shaft. Mine was a bit rough. I too noticed an increase in fps. Yours is very healthy.
On another note, after getting a 78 and a 79, I also got Crosman MK I and a MK II. The MKs do have better triggers but I get 50% more shots per cart with the S&Ws at same power. Don't know if that's universally true but the shear number of shots per cart with my S&Ws amaze me.
I didn't count the actual shots per cartridge, but it sure lasted much longer than a cartridge does in my 2240 or 2300S! Power is better too! I ran all three through the chrony with the Gamo Platinum PBA CHS pellets just to see what the maximum FPS was for each. The 79G is putting out way more! The only pistol I own that will better it is my 1377 with the steel breech kit and 25% larger transfer port.
Pistol Platinum PBA Premium Hollow points
79G 606.78 FPS 517.3 FPS
2300S 541.44 FPS 467.52 FPS
2240 510.02 FPS 477.14 FPS
1377 672.14 FPS 580.90 FPS (10 Pumps)
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I finally got all the parts I needed to rebuild my Dad's 79G. I replaced all the seals and degreased and cleaned it up and got it back to tether with no issues. Some of the O rings were a real pain to get on, those little buggers can be stubborn! It's now shooting, but I an experiencing some leakage when it's fired. It feels like it blowing our just above the grips, which makes me thing it's the port between the chamber and the barrel. Like the Crosman setup, there were no seals here, just a metal to metal connection. Any tips on how to fix this seal would be helpful. Other than that it's shooting just fine and I'm excited I was able to get it back in service. Today, I'll spend a little time getting it sighted in!
most likely the barrel isn't lined up with the transfer port. the single biggest problem I've found on the ones I've worked on. that, and the hole in the valve body is too small to allow the transfer port to properly seat in the valve. once you address those issues, you won't have any leaks coming from the barrel ever again.
also, when you adjust the barrel, and re -tighten the barrel screw, ( the one on top, just forward of the breach ), make sure you don't over tighten it, or it will push the barrel out of alignment, causing the bolt to bind, or, refuse to close at all.
I'll just ad that longhunter just rebuilt one for me that the seals were completely corroded, and as he found, the barrel/frame/ports were not aligned properly.
It's now in tip top shape and works like new. So his suggestion is likely spot on. :)
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Awesome work Paul!
Glad it worked out for you and your Dad would be happy you are enjoying it.
I believe yours is hotter because of the Mac1 kit. I should have also said that I polished up the poppet shaft. Mine was a bit rough. I too noticed an increase in fps. Yours is very healthy.
On another note, after getting a 78 and a 79, I also got Crosman MK I and a MK II. The MKs do have better triggers but I get 50% more shots per cart with the S&Ws at same power. Don't know if that's universally true but the shear number of shots per cart with my S&Ws amaze me.
I didn't count the actual shots per cartridge, but it sure lasted much longer than a cartridge does in my 2240 or 2300S! Power is better too! I ran all three through the chrony with the Gamo Platinum PBA CHS pellets just to see what the maximum FPS was for each. The 79G is putting out way more! The only pistol I own that will better it is my 1377 with the steel breech kit and 25% larger transfer port.
Pistol Platinum PBA Premium Hollow points
79G 606.78 FPS 517.3 FPS
2300S 541.44 FPS 467.52 FPS
2240 510.02 FPS 477.14 FPS
1377 672.14 FPS 580.90 FPS (10 Pumps)
IIRC I was getting just over 80 shots per cart in my 78g. Yes they are efficient!
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Hi guys, any idea if the frame and slide can be anodize? The paint are chipping off on different parts of my 79g.
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I don't know if you can annodize pot metal. You could have it powder coated, though.
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I don't know if you can annodize pot metal. You could have it powder coated, though.
Is it safe to do powder coating since it will require baking or heating after the coating is applied? My concern is, isn't there some sort of seal between the grip frame and the piece of metal where we screw in the piercing cap that may get damage by the heating process?
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nope on the anodising
tried doing some cast ally the other day and that doesn't either
it can be plated though and I'm looking at getting a nickel tank set up
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I don't know if you can annodize pot metal. You could have it powder coated, though.
Is it safe to do powder coating since it will require baking or heating after the coating is applied? My concern is, isn't there some sort of seal between the grip frame and the piece of metal where we screw in the piercing cap that may get damage by the heating process?
The seal is on the cap. Even if it was in the frame, you would just remove it before powder coating.
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Thanks guys for the replies!
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There is a second sneaky oring seal inside the piercing cap as well. It seals the piercing pin itself. You need to knock out the pin that holds it together and take the piercing cap apart to get at it. Probably wants replacing anyway......while you are at it.