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Career Air Rifles

Korean Air Rifles

How to adjust pellet stop and change shuttles

Korean Air Rifles

The Koreans are famous for building very accurate and high powered PCP's (Pre-Charge Pneumatics). The most popular of these has been the Career 707 II rifle. Currently the work Mac1 does to tune or prep the gun for sale involves making the pellet shuttle mod and the power wheel modifications. Many of the mods we did to older Careers have been incorporated into the factory gun so the older ones need more work than new ones to make them Mac1 Style.
In stock form the power wheel only adjusts thru 12 clicks of the adjuster. We alter the adjustment range so the gun can be turned down all the way to power levels you can use in the garden that are very quiet. The adjuster is altered to 18 clicks for a finer adjustment per click. Our guns adjust from 8-80 ft. lbs.
Shuttle mod. When a gun has had the shuttle mod you can use the Korean Eun Jin factory ammo, Kodiaks, and Crow Magnums. If the gun is made available with an extra shuttle that is not modified you can also use the factory pellet stop adjustment and swap out the shuttles so you can adjust to use shorter ammo.
Careers maker Shin Sung has brought out two new rifles recently. The Career models 300 & ? which feature a revolving 6 shot cylinder so pellet stop adjustments are a thing of the past. The 300 is not carried by us as we see no specific advantage this model has that the newer ? doesn't. The ? looks very much like a British PCP (Air Arms 300). This is a step up in cosmetics over past Korean guns but the development has not impressed enough for us to carry it. Shin Sung have replaced the exhaust valve on all the guns they make with a fairly soft mainseal and power is off as well as reliability,
Eun Jin makes a rifle called the Sumatra which John Burroughs was substantially involved in developing. His expertise is instrumental in providing us with a rifle we can be confident in. The Sumatra did not enjoy a power wheel like the Career up until recently when the Shin Sung patent ran out. Since the Sumatra adjusts as easily as a modified Career it is our favorite of the Korean Airguns.

To adjust the pellet stop and change shuttles:

Remove the clip and clear the rifle.
Cock the lever open all the way.
Remove the front and rear receiver screws from the top of the frame.
Slide the stock and upper frame off the lower frame.
Pull the cocking plate up from the front and the shuttle will be free to fall out the right side.
Replace with the factory shuttle and lower cocking plate onto index pin.
Point the gun down and put the pellet you want to adjust for in the shuttles pellet hole.
The pellet skirt needs to align with the back of the shuttle. When adjusting the modified shuttle the longest pellet you are using is the one you adjust for.
Loosen the screw retaining the pellet stop in the left side of receiver in front of magazine slot.
Move the pellet stop until the rear of the skirt lines up with the rear of the shuttle.
Then tighten it and reassemble.

Don't try to use a modified shuttle with short pellets. It will not usually feed properly. If you want to shoot short ammo you will have to have a non-modified shuttle dedicated to adjustability rather than versatility amongst the heavies.
The versatility of these power adjustable rifles is only realized when you get a chrono and discover exactly how consistent you can keep the power with systematic adjustment of the power wheel. The best accuracy will be had at 850-900 fps with heavies. Learn how to keep it in that range from a full charge by making notes that relates power wheel settings to gauge settings. Long guns can get over 70 and Carbines over 35 shots in this fashion.
The charging methods are important. Always squirt a little air out to clear any debris out of the charging adapter/probe prior to charging. Slide the charging probe into the hole of the dust cover and when you open the valve let pressure build slowly. When you reach your preferred fill max or the tanks pressure turn the tank valve off and bleed the line rapidly. If you fully top the gun with the pump you can take it up to 3200 with no problem. Make sure you ONLY USE THE BLEEDER ON THE PUMP. The bleeder on the gauge and yoke should not be used when using the pump. The bleeder on the pump also acts as a water trap. You must use it to throw the water overboard. Do it rapidly for best results. For those pumpers it is advisable to have the shortest hose possible with the smallest ID for best pumping results.
The cleaning of the gun should be done regularly. The removal of the shuttle or pellet cylinder is the best way to do a thorough job. The Crown Saver pull through system is what we recommend. Always pull to the muzzle from the breech. A moist patch can be helpful to break up junk in your barrel but wait till you have pulled a few dry ones first to get the bulk of the junk out. In .22 2- 30 cal patches work well folded over three times. .177 can work well with one .30 cal patch folded in thirds. Experiment until it draws firm but not overtight.
The trigger should be set to a minimum of 2 lbs. If you change the trigger it may not be appropriate for field work. This is no match trigger and should be around 2 lbs. for safety.
You cam use the guns gauge as a guide to maximizing useable shots if you make notes. Getting the most from a Korean gun or any unregulated Airgun is all about understanding what it will do at various pressures. Korean PCP's are some of the finest rifle values I have ever sold.
The Career 9MM is a new offering from Shin Sung that is amazingly powerful. It pioneers a new airgun caliber and is successful in getting 1" groups at 50 yards when properly prepped. Stock guns have issues and should be altered when purchased to avoid problems with accuracy and reliability relating to the bolt o-ring degradation. This repeater has more power on tap than any of the Korean PCP's at around 125 ft. lbs.