SlartyBartFast
06-12-2002, 10:40 AM
Thinking about the bolt cycle (open-bolt) required to fire a paintball I figure a bolt has four states:
1- Waiting for a ball to fall into the breech.
2- Travelling forward to chamber the ball.
3- Waiting for ball to leave barrel.
4- Travelling back to open breech.
Considering an open-bolt system, what is the optimum waiting time or acceleration for each stage?
1- As long as the ROF (rate of fire) will allow. 1/ROF minus time for other three stages.
2- As fast as the ball can handle. What is the maximum acceleration a PB can handle?)
3- Fixed time for ball to accelerate to end of barrel. From the Data Graph supplied by Tom Kaye, this would seem to be in the range of 4.5 to 5 ms (or am I reading the graph wrong?).
4- As insanely fast as possible.
Anybody have more concrete data/ideas?
Analysing the travel in this manner also had me thinking about the Open Bolt/Closed Bolt debate. The states are the same regardless of whether the marker is open-bolt or closed-bolt. In a closed-bolt system the sequence just runs 3-4-1-2.
I figure WARPIG has conclusively demonstrated that one is not better than the other as far as accuracy is concerned when all other variables are the same. But if you think of the bolt timing, open-bolt does show two large advantages. The bolt can stay open for as long as possible giving far more time for a ball to correctly feed. This gives highly reliable feed at low speed and (second advantage) high ROF performance is only limited by the feed system. In a closed bolt system, the bolt opening has to be timed which means either sacrificing maximum ROF for reliable ball feed or sacrificing ball feed reliability at high *AND* low ROF by timing bolt opening for high ROF performance (AND your performance is still affected by feed system performance).
So an open-bolt shows two advantages:
1- Reliable low ROF ball feed.
2- Maximum high performance ROF.
The bug in the ointment is of course Blowback. But if you could control the bolt travel precisely and hold the bolt forward for an adequate length of time, blowback would be eliminated.
The other bug (as far as some are concerned) would be the possibility of short-stroking the trigger on the Automag. Could the sear pin that connects the trigger to the sear be designed in such a way that the trigger and sear are 'disconnected' as soon as the sear is moved? The trigger would then have to be fully released to 'reconnect'. This isn't such a far fetched design problem as this is how all(?) open-bolt full-auto firearms perform when in semi-auto mode.
One thread and three issues. If discussion is lively I'll rephrase the different points and start individual threads.
Any Thoughts?
1- Waiting for a ball to fall into the breech.
2- Travelling forward to chamber the ball.
3- Waiting for ball to leave barrel.
4- Travelling back to open breech.
Considering an open-bolt system, what is the optimum waiting time or acceleration for each stage?
1- As long as the ROF (rate of fire) will allow. 1/ROF minus time for other three stages.
2- As fast as the ball can handle. What is the maximum acceleration a PB can handle?)
3- Fixed time for ball to accelerate to end of barrel. From the Data Graph supplied by Tom Kaye, this would seem to be in the range of 4.5 to 5 ms (or am I reading the graph wrong?).
4- As insanely fast as possible.
Anybody have more concrete data/ideas?
Analysing the travel in this manner also had me thinking about the Open Bolt/Closed Bolt debate. The states are the same regardless of whether the marker is open-bolt or closed-bolt. In a closed-bolt system the sequence just runs 3-4-1-2.
I figure WARPIG has conclusively demonstrated that one is not better than the other as far as accuracy is concerned when all other variables are the same. But if you think of the bolt timing, open-bolt does show two large advantages. The bolt can stay open for as long as possible giving far more time for a ball to correctly feed. This gives highly reliable feed at low speed and (second advantage) high ROF performance is only limited by the feed system. In a closed bolt system, the bolt opening has to be timed which means either sacrificing maximum ROF for reliable ball feed or sacrificing ball feed reliability at high *AND* low ROF by timing bolt opening for high ROF performance (AND your performance is still affected by feed system performance).
So an open-bolt shows two advantages:
1- Reliable low ROF ball feed.
2- Maximum high performance ROF.
The bug in the ointment is of course Blowback. But if you could control the bolt travel precisely and hold the bolt forward for an adequate length of time, blowback would be eliminated.
The other bug (as far as some are concerned) would be the possibility of short-stroking the trigger on the Automag. Could the sear pin that connects the trigger to the sear be designed in such a way that the trigger and sear are 'disconnected' as soon as the sear is moved? The trigger would then have to be fully released to 'reconnect'. This isn't such a far fetched design problem as this is how all(?) open-bolt full-auto firearms perform when in semi-auto mode.
One thread and three issues. If discussion is lively I'll rephrase the different points and start individual threads.
Any Thoughts?