In the early/mid 2000s, some of my very best memories of paintball was at a Waynes World 24hr Scenario in Florida. My best friend and my brother rocked that place and at night time, with PGP2Ks and homemade rain covers. The things were absolute hammers, though I polished the barrels. At the time, paintballs fit the bore and with the high-viz sites, they hit where we aimed. It has been while, but I recall managing 20 balls or so out of a 12 gram. Like many others, I love the feel of old brass, but with paint sizes AND the poor efficiency...I do not see them getting much game time. Only recently did I get my old guns back operating and have been enjoying tinkering. So...I would like to organize some information and data here regarding 12g Efficiency and Sheridans. Everything I have managed to find has been very abstract and not concrete.
As it turns out, I own an App called Ballistic-X which measures shot groups in the firearm world. While I am not a math guy myself, I do nerd out on some data!
The following will be edited and added to as credible sources are cited and verified (will likely be a mess to start):
1. Sheridan Paintball guns were adapted from Sheridan pellet guns which seems to not be optimized for efficiency.
2. Sniper/Autocockers were very similar in design in format with short hammer travel.
3. Nelson Valves are inherently more efficient at least in part because of hammer travel distance.
4. Palmers seemed to do the most in pioneering efficiency which became less relevant as paintball evolved with CA.
5. Palmers maxed out on the efficiency of tuning Sheridans which prompted them to make their own platforms with different dimensions.
“As compared to the Sheridan setup, the valve chamber volume is much larger, a lighter hammer travels almost three times as far before striking the valve, there is no pre-load force on the valve when the hammer is forward and each burst of gas is allowed to reach its full potential.”
6. Modded Sheridans managed almost doubling their efficiency when tuned properly. This included opening transfer port, minimizing 12g pierce depth, and reducing volume in valve.
7. Hammer Travel is limited by Bolt. Spring compresses very little and has zero preload.
8. Overbore barrel is likely reducing efficiency by 20% or so.
Questions:
1. Why do Sniper/AC manage better efficiency even though they have similar design, hammer travel, etc?
- Details on approach -
Valve Work:
Cartridge Valve (P68, Late PGP, PGP2k)- Limited improvements here compared to Component. Common mods are sharpening pierce pin to minimize hole in 12 gram, opening transfer port, milling groove for second O-ring on valve body exterior.
Springing: Increasing force of hammer
As it turns out, I own an App called Ballistic-X which measures shot groups in the firearm world. While I am not a math guy myself, I do nerd out on some data!
The following will be edited and added to as credible sources are cited and verified (will likely be a mess to start):
1. Sheridan Paintball guns were adapted from Sheridan pellet guns which seems to not be optimized for efficiency.
2. Sniper/Autocockers were very similar in design in format with short hammer travel.
3. Nelson Valves are inherently more efficient at least in part because of hammer travel distance.
4. Palmers seemed to do the most in pioneering efficiency which became less relevant as paintball evolved with CA.
5. Palmers maxed out on the efficiency of tuning Sheridans which prompted them to make their own platforms with different dimensions.
“As compared to the Sheridan setup, the valve chamber volume is much larger, a lighter hammer travels almost three times as far before striking the valve, there is no pre-load force on the valve when the hammer is forward and each burst of gas is allowed to reach its full potential.”
6. Modded Sheridans managed almost doubling their efficiency when tuned properly. This included opening transfer port, minimizing 12g pierce depth, and reducing volume in valve.
7. Hammer Travel is limited by Bolt. Spring compresses very little and has zero preload.
8. Overbore barrel is likely reducing efficiency by 20% or so.
Questions:
1. Why do Sniper/AC manage better efficiency even though they have similar design, hammer travel, etc?
- Details on approach -
Valve Work:
Cartridge Valve (P68, Late PGP, PGP2k)- Limited improvements here compared to Component. Common mods are sharpening pierce pin to minimize hole in 12 gram, opening transfer port, milling groove for second O-ring on valve body exterior.
Springing: Increasing force of hammer
That's because most of the energy in that cartridge went to uselessly expanding into the chamber and hose. You pulled the bowstring all the way back, but then let it ease forward almost all the way before releasing the arrow.
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