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Model 74 Semi Auto |
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cobalt327 ![]() Red Ryder Member ![]() ![]() Joined: November-15-2013 Points: 2676 |
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Will do- thanks!
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cobalt327 ![]() Red Ryder Member ![]() ![]() Joined: November-15-2013 Points: 2676 |
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Took it apart for a good cleaning. I removed the barrel and the co2 cradle from the valve and opened it up. No plastic so I used carb cleaner then blew it out w/air. Nothing obvious was found but hopefully it'll be back to its former glory, I'll probably try it out tomorrow. Too bad I know nothing about how to step up the power, this would have been a good time to replace springs, etc. Oh well- if it's still not shooting right I'll have it back apart again. Anyone know what I could do to pick up 30-40 fps?
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the fuse ![]() Red Ryder Member ![]() Joined: January-20-2013 Location: NY Points: 1694 |
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I'm happy with a steady 250 fps for this little plinker. More shots per cart.
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All I'm for is the liberty of the individual.
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cobalt327 ![]() Red Ryder Member ![]() ![]() Joined: November-15-2013 Points: 2676 |
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I'll be happy... well, happy enough... if I see even 250 fps again. But considering it gets 200+ shots per cylinder, I could live w/less shots and a little more power. All my backyard targets except for the 10M are at 20-25 yards which is about right for me and a BB gun shooting at least 300 fps. At that range the 74 can hit but it's more like shooting a mortar than a gun.
Anyway If it comes back to life I'll post a 10 shot string w/a fresh cartridge and give it the same 1/2 min. rest between shots to see what the MV and ES is now. Before all this happened, I saw anywhere from 235 to 260 but that might have been due to not waiting for it to warm up some between shots.
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FREEBIRD ![]() Red Ryder Member ![]() Joined: February-01-2013 Points: 365 |
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I'm happy with mine as well, I was denting cans at 65 ft. so it's good for targets. That co2 gets cold and the gas cannot turn back to liquid and it slows down. I put mine in a room with the door closed and we have the heat on, I checked the temp of the gun and it was about 76°F it would penetrate the bottom of cans at 35 ft and the little puff of vapor would come out, so it was operating pretty good. When the gun is warm mine will shoot a flat trajectory at 65ft. I have seen a few you tubes where someone said they added weight to the hammer and got 300FPS out of it, but no vid of the disassembly. Honestly if it does 250 its great for a bb gun with that high of a shot count, I am going to focus on the accuracy of it, I think a lot can be done.
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cobalt327 ![]() Red Ryder Member ![]() ![]() Joined: November-15-2013 Points: 2676 |
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The barrel acts as the trip for the valve unless I'm mistaken. I'll try a small amount of preload on the barrel "recoil" spring and see what that'll get me. FWIW, not looking to shoot the moon but an honest 300 fps should be doable. And even if that cut the shot count in half, I can live w/it.
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cobalt327 ![]() Red Ryder Member ![]() ![]() Joined: November-15-2013 Points: 2676 |
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Nothing doing- still around 200 fps w/the occasional shot a bit higher. Highest I saw today was 213 fps. Temps are relatively equal between days, around 70 F here. I got to thinking, and the only thing that's different is the co2 cartridges I'm using. The MV that I recorded first that were in to 250 fps range was made using the supplied Daisy-brand co2 (2 were supplied w/the gun along w/BBs). And if I'm remembering things correctly, the velocity drop started when I switched to Crosman co2 that I bought at Walmart a month or so ago. I have a Daisy carto left, but if I understand things right the pressure of a co2 cartridge is the same as long as it's co2 and contained in a pressure tight vessel. In other words, I don't think a carto could be "under pressurized", although it might be under filled, weight-wise. Anyone got any thoughts on this? |
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FREEBIRD ![]() Red Ryder Member ![]() Joined: February-01-2013 Points: 365 |
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C02 self regulates, it will never go above 900 psi, unless you get it too hot. I think the fps gain would be in the spring pre-load, let us know if you decide to do it.
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the fuse ![]() Red Ryder Member ![]() Joined: January-20-2013 Location: NY Points: 1694 |
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Sounds like it's starved for gas. Maybe the oil you added fouled a filter in there.
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All I'm for is the liberty of the individual.
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cobalt327 ![]() Red Ryder Member ![]() ![]() Joined: November-15-2013 Points: 2676 |
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Even after I used Pellgun oil on the tips of 2 cartos there was only a very scant amount of oil inside the valve. I cleaned it entirely before I retested it the last time. I didn't leave it dry, but close to it and it didn't help, velocity was still around 200 fps. Everything moves freely and nothing is bent or broken, etc.
I added 1/2" preload to the recoil spring (see photo below), tomorrow I'll see what this does to the velocity. If the preload doesn't help, the next thing I'll try is a weaker return spring in the valve. I might end up wanting to balance them both, because just adding preload to the recoil spring increases the trigger pull. But even w/the 1/2" preload, the pull weight's not much more than it was originally. The balance on this gun is pretty good- it balances right on the loading door. But it's so light that it hinders accuracy when I'm shooting offhand. So I added lead wheel weights to the empty spaces in the forearm, it holds 9 ounces w/room to spare. I like a little more forward weight so I added an additional 6.5 ounces to the stock. Feels nicer to me now. ETA- Added another 2 oz. to the stock. The accuracy is excellent on this gun, and I wasn't really expecting it to be. But it shoots to point of aim, only the elevation varies depending on the velocity. Once it's sorted out this will be a fine gun for backyard use. ![]() |
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