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Field Target Tech Episode 13 Range Testing, 305 Shots, 1 Fill!!!

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Dragon, 

The stock Marauder barrel is 20". The longer barrel is 26". I still have to determine if my original "old" style barrel, the new tooling standard barrel, and my custom longer barrel have the same twist rate. Unless you install all the Tim Hill parts i described in the rebuild, you'll safely get 120-140 shots at that power level, with all standard Crosman parts.

Tom Holland 
 
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Dragon,

Keep in mind, that once you go for a lighter hammer, you will almost certainly need a lighter spring in the valve as well. I think the key to my high shot count is this:....
High flow valve, with light spring, paired with,
25 Gram hammer,
Large transfer port, between valve and 
barrel,
Lighter, shorter hammer spring that has 
NO preload on the valve, 
Highly polished part's, including inside the tube where the hammer and bolt ride.
Being you do not have all the exact parts i do, I'd do these several things:...

Open up transfer port as far as it can go.
Replace Valve spring to a lighter one.
Install larger transfer port between the valve and barrel.
Replace hammer spring to a shorter, lighter one.
When tuning the gun after the regulator is installed, turn the hammer throw all the way rearward. Then, set the hammer spring in the middle of it's travel. This is your starting point. Take to the range, and shoot it for velocity. Adjust ONLY the regulator to get your velocity, then fine tune with the hammer spring. Do not adjust hammer throw. When all this is done, you will not need the orings in the B Staley tune, or the need of a debounce device. This process is tedious, but worth it. I describe how to do all of the above in my Marauder rebuild.

Any questions, give me a shout 

Tom Holland 
 
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Tom - I am not sure what the stock hammer spring is designed at (lbs), so what lighter spring should I get? I guess the same could be said for the valve spring. I just received my and Huma reg and new hammer. The hammer is of MDS design with aluminum insert. I'm sure of the weight of the hammer, but will check it this evening. I was hoping to rebuild this weekend, and then start the tuning process.
 
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Dragon, I just went to my local hardware store and bought a bunch of springs that were much lighter and maybe about 1/2" shorter. ......whatever spring you use, cannot have any preload on the valve. With the valve spring, you want to go very light. You can get a few at the hardware store. I don't think it matters too much of the valve spring tension, the pressure of the air on the valve will be way higher than the spring pressure anyway. If you look at my Marauder videos, I can depress the valve with my finger. It's 10x less than the original. You might want to make a regulator adjusting tool, as I did, speeds up tuning a great deal. The one I made is on the rebuild video.
 
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Good point, thank you Tom. Yesterday I placed an order to Crosman for a couple new poppets, and a couple transfer ports to create new sizes to tune with. The poppet I have current is right at 8-years old, so always good to have spares. I believe the challenge for me at this point is to balance the stock system I have to achieve an efficient sub 12 ft lb rifle.
 
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Dragon,

Let me know how it goes, if you need any guidance, give me a shout. I'm reasonably sure that with lowering those spring pressures, and having the gun regulated, should at least give you the shot count you had, which is pretty good, anyway, but also make the spread at least half, if not more. Don't try to duplicate exactly what I did, I think the planet's might have been aligned or something....

Keep me posted,

Tom Holland 
 
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Due to the inclement weather here in the Northeast, I will not be posting a range testing video for my next upcoming episode of Field Target Tech.
In liew of a Field testing video, I have decided to go over the finer points of shooting the offhand position for Field Target use. I will cover gun fit, knee riser/palm rest fit, grip, and the advantage of using a shooting jacket and glove. I will also cover techniques and styles of holding steady, and how to modify equipment to fit the individual shooter.
This episode will be posted Saturday or Sunday.

Tom Holland 
 
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