GTA
All Springer/NP/PCP Air Gun Discussion General => "Bob and Lloyds Workshop" => Topic started by: SwampHunter on January 18, 2019, 01:07:29 PM
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Hello guys, hope I am posting this in the right place, 90% of the time I search anything disco related Bob, Loyd or both turn up! So I am hoping you could offer some advice on my build.
So far I have a double tube kit, marauder trigger, magnum air valve, P-rod gauge port, 4000psi guage, 3000psi screws and am planning on ordering magnum air hammer, bolt, .045 spring and adjuster. As advertised this should put me in the 50 to 60 fpe ballpark. I know you guys custom make pretty much everything but I don't have the ability to do that so have to use "off the shelf" parts.
I am trying to figure out what would be the best barrel to use with this combo, according to magnum air 25gr pellets are the lightest recommended as they should be around 1000fps with 33.9gr around 900fps.
What barrel do you guys think would be the most accurate for this set up? I have heard that Lw barrels can be pellet/speed sensitive and that tj barrels have to have the pellets lubed to work properly?
Thanks in advance for your help!
Probably should have stated to start with , sorry, this is a .22 Cal currently. I wouldn't be opposed to changing to a .25 if there is an advantage to doing so. This will primarily be a small game hunting rifle , hoping to be able to shoot past 50yrds.
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I was gifted a .22 Maximus barrel and the quality, maybe just lucky, was way better than the stock Disco. For 50 yards the stock barrel will usually shot better than the shooter. It’s not all about power but rather shot placement that count. I’m sure others will chime in
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I’d get in touch with Jim Gaska at wicked air rifles . I wouldn’t worry about a TJ’s barrel getting fouled without lubing . A couple drops of 10w shock oil in every tin of pellets should do the trick .
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I’d get in touch with Jim Gaska at wicked air rifles . I wouldn’t worry about a TJ’s barrel getting fouled without lubing . A couple drops of 10w shock oil in every tin of pellets should do the trick .
Ok, how accurate are the tj barrels across the board, are they picky about anything in particular?
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I was gifted a .22 Maximus barrel and the quality, maybe just lucky, was way better than the stock Disco. For 50 yards the stock barrel will usually shot better than the shooter. It’s not all about power but rather shot placement that count. I’m sure others will chime in
I have a Maximus barrel, it wasn't impressive. I may have just gotten a bad one but it shot worse that my Disco barrel
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For a given FPE level, you will find it a lot easier to get with a .25 cal instead of a .22 cal.... I have not had a lot of success with the 34 gr. Beasts in .22 cal, but the Redesigned 25 gr. Monsters in .22 cal are very good.... In .25 cal, both the .25 gr. Kings and 34 gr. King Heavies are very accurate.... Bottom line is that from the same powerplant, you will get a similar velocity ( but more FPE) with a 34 gr. in .25 cal as you will with a .25 gr. in .22 cal.... The choice will come down to how much power do you need?....
You can't go wrong with the LW barrels in either caliber.... If you are going to use a Disco receiver, you will need the 12mm OD version, and then turn down the breech end to fit into the receiver.... Roy at Mountain Air can probably supply that in .22 or .25 cal.... Heck, in .22 cal I would just use the Crosman barrel, some of them are very accurate, it's worth playing the lottery unless you know yours is a dud....
The TJ's barrels are available in 7/16" OD in both calibers, which will slide right into the Disco receiver.... Jim at Marmot Militia can supply them, ready to install.... Either way, you should have good accuracy....
Bob
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For a given FPE level, you will find it a lot easier to get with a .25 cal instead of a .22 cal.... I have not had a lot of success with the 34 gr. Beasts in .22 cal, but the Redesigned 25 gr. Monsters in .22 cal are very good.... In .25 cal, both the .25 gr. Kings and 34 gr. King Heavies are very accurate.... Bottom line is that from the same powerplant, you will get a similar velocity ( but more FPE) with a 34 gr. in .25 cal as you will with a .25 gr. in .22 cal.... The choice will come down to how much power do you need?....
You can't go wrong with the LW barrels in either caliber.... If you are going to use a Disco receiver, you will need the 12mm OD version, and then turn down the breech end to fit into the receiver.... Roy at Mountain Air can probably supply that in .22 or .25 cal.... Heck, in .22 cal I would just use the Crosman barrel, some of them are very accurate, it's worth playing the lottery unless you know yours is a dud....
The TJ's barrels are available in 7/16" OD in both calibers, which will slide right into the Disco receiver.... Jim at Marmot Militia can supply them, ready to install.... Either way, you should have good accuracy....
Bob
Thank you, I didn't realize that the .25 would shoot as fast with the heavier weight, is that to do with the barrel volume being bigger? I think I will put it together with the crosman barrel, I just bought a new one, and see if the accuracy is acceptable. If not and I have to buy aftermarket then it seems like I should upgrade to the .25 if it will get more power for the same air. It's not really that I need the maximum amount of power , it will probably be turned down most of the time. I just figured that it would be easier to already have the power mods done and detune to a level I was satisfied with, then I could always turn it up if need be as I do shoot coyotes occasionally. Seems like if I have to change the barrel the .25 would be the best bet.
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The .25 will shoot a heavier bullet at the same velocity as a .22.... HOWEVER, it will use more air doing it.... you don't get something for nothing.... The base area of the .25 cal pellet is 29% larger than a .22 cal, so there is 29% greater force available to accelerate it from the same air pressure.... Assuming you scale the port sizes appropriately to move the larger quantity of air required for the larger bore, you should be able to drive a 34 gr. pellet in .25 cal almost as fast as a 25.4 gr. pellet in .22 cal....
The downside is that you will use about 29% more HPA per shot to fill the larger barrel volume....
Bob
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TJ's barrels aren't bad at all but it takes some effort to have them working good, they are quite rough at first. Firelapping is mandatory. After that well done there is no fouling problem(really close to none) and accuracy is good. As new they are fouling a lot in my experience of several ones.
As of now, I am not cleaning my Corsair .308 barrel at all. I better not. If I do, it takes about 250 shots to get it shoot again. Thousands of shots for sure.
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The .25 will shoot a heavier bullet at the same velocity as a .22.... HOWEVER, it will use more air doing it.... you don't get something for nothing.... The base area of the .25 cal pellet is 29% larger than a .22 cal, so there is 29% greater force available to accelerate it from the same air pressure.... Assuming you scale the port sizes appropriately to move the larger quantity of air required for the larger bore, you should be able to drive a 34 gr. pellet in .25 cal almost as fast as a 25.4 gr. pellet in .22 cal....
The downside is that you will use about 29% more HPA per shot to fill the larger barrel volume....
Bob
I am working with drop in parts and do not have the ability to do machine work, so it may be best for me to stay with the .22 Cal?TJ's barrels aren't bad at all but it takes some effort to have them working good, they are quite rough at first. Firelapping is mandatory. After that well done there is no fouling problem(really close to none) and accuracy is good. As new they are fouling a lot in my experience of several ones.
As of now, I am not cleaning my Corsair .308 barrel at all. I better not. If I do, it takes about 250 shots to get it shoot again. Thousands of shots for sure.
Sounds like once it's firelapped best not to clean it!
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Travis, are you looking for a powerhouse or a stock shooter in another caliber?
Powerhouse drop in parts are available for the disco, Cothran Valve, JSAR barrel (LW non-choked for slugs) MM barrel rocks JSB 18gr pellets like crazy.
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Travis, are you looking for a powerhouse or a stock shooter in another caliber?
Powerhouse drop in parts are available for the disco, Cothran Valve, JSAR barrel (LW non-choked for slugs) MM barrel rocks JSB 18gr pellets like crazy.
I have bills magnum air valve and related parts already, is supposed to be good for 50 to 60 fpe. Trying to figure out what would be the most accurate barrel/caliber for that setup.
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I would open up the barrel port, transfer to match valve port size and shoot the gun. Short range is good to see if the groups look ok then stretch out its legs and see groups open up. Also, using a couple different pellets at shooting at various fps too.