Originally Posted by russc
I think you should try a valve diffuser and turn initial velocity higher. You're getting an okay shotcount but shooting at 250 fps ain't right!
I think I'll try that. I've been researching diffusers and I have plenty of .45 brass.
Originally Posted by PB Weasel
How long are you waiting between shots? I find the redux likes about a minimum of 8 to 10 seconds for the best valve pressure recharge/ 12ie warm up between shots. Just curious . . .
I would say 8 - 10 seconds. I would take the shot with the chrony up at the barrel (about an inch away) and shoot. Then call the number out to my wife who was writing everything down for me. I would then pump another round in being careful to make sure I only got one round in the chamber. Then pick up the chronograph and take another shot.
I also only loaded 10 shots at a time as this is how I would have it on the field. I kept groups of ten standing by to be ready.
Originally Posted by splattttttt
Underneath is what's now left on NOG(Nelson Owners Group) since Brent decided to leave the sport.
At one time there was much more data through out the forum, but he went and deleted everything but what I was able to copy/paste here.
The information below is very limited, but it is a good starting point for a basic set up.
These days, I'm thankful enough to get 30 shots off of a 12g. That's a bout as many shots I ever need for most games that last 20min. or less.
Written by B; "Nelson style valve tuning for efficiency with 12 grams.
First off forget any notion of getting maximum efficiency from a vertical or bottom line layout. The key is to have the CO2 gas take the shortest path to the valve and remain in a compressed state. These techniques will also work on other set up but will not be as efficient as a direct and shot path to the valve.
Things you may need to arrive at the most efficient set up.
Nelson Spring Kit
Valve body back bottle, bobbed, or drop out any one of these will do.
Power tubes of at least two different sizes these are not necessarily necessary but will make for an efficient set in the long run, I suggest a Lapco #4 & #6. (P is for Phantoms)
A couple of valve seats with o-rings and a couple of cup seals put them together to have ready to go jet sets. These will make for easy tuning down the road but are not necessary.
Nylon spacer 5/8” long x 1/2 “ OD x .375 ID can be found at your local mega home center in the hardware aisle. These usually come three to a bag we will make three different lengths.
A light weight hammer Taso or Lapco will also be a nice addition but not necessary, both are out of production but with some hard work can be found on the internet.
Tools and such needed,
File, (small half round and one flat), hack saw (to cut the spacer down) Crocus cloth (rouge paper) for polishing the power tube some sort of drill to spin the power tube to ease polishing the power tube, oil, 12 grams plenty or a dummy set up for constant air, paint, chronograph and a note book.
First thing clean every thing bolt & hammer, body of the gun, valve. Next polish the power tubes to make them smooth, don’t go over board just want smooth and shiny.
Now assemble you jet sets if you have them (power tube, valve seat, o-ring, cup seal)
The next step is to cut down the nylon spacers the first I cut a 1/2” next at 3/8” and the last a 1/4". The first length may need a bit of trimming to allow the full travel of the power tube you will need to confirm this on the valve body. I cut the spacers down with a band saw but you may also use a hack saw. Try to keep the spacer as square and true as possible, use the files to clean up the ruff edges.
Next come the arduous part tuning, I start with the largest power tube, heaviest spring for the valve, and the lightest main spring with a light hammer. In general a heavy valve spring will be the most efficient one. Put a drop of oil on the valve seat o-ring and the power tube where it intersects. Make sure to set the velocity adjuster to its midway position of adjustment, and the bolt & hammer have some lubricating oil on them. Now starts the long process of tuning for efficiency, remember to let the 12 gram not chill to much take your time between shots don’t rush. You may need to go through all the combinations of tubes, springs and valve spacers you made to get the best combinations for you set up. This is what the note book is for so you can know if you are making progress. Remember to remove your gas source before opening up the valve to do adjustments. In my tuning I go for a velocity of about 265fps to 275 spikes will and can happen due to paint and ambient temperature. Generally the largest spacer will give the most efficiency but rapid shots will suffer low velocity. There is always a bit of a balancing act that needs to be done to fit your style of shooting/ playing. The most efficient set up may not work for your style of play just make sure to have fun and continually adjust to the game."
I've read this before and I'm re-reading this thread: Nelson valve tuning for efficiency.
Lots of good info both in what you posted from B and in the other thread. If/ When I get some extra spending money, I've thought about sending the Duck to B to have him do a full tune up on it.