Don't beat yourself up.... I wasn't trying to.... *grin*.... Bob
I'd be lost without that milling attachment, and one thing is does easier/better than a mill is working on an angle to the mill/chuck.... super easy to set up for that....Bob
I was away part of the day today, so I only got the new hammer spring preload adjuster done......... the new hammer spring, which is 3" long made from 0.051" wire.... you can see it in the photo.... Tomorrow I plan on making the new hammer....Bob
I used a spring from McMaster Carr, # 9657K427.... However, there is an identical spring available from Century, # 71237.... Both springs are 0.36" OD x 0.051" wire x 3.0" long, and 15 lb./in spring rate.... Century have them available in smaller and larger wire sizes as well.... The gun is not difficult to cock, even set up for 3000 psi.... So here is all the data on how the Grizzly responded to preload changes at both pressures, and with all three pellets tested....At 2900 psi, even with the 70 gr. Bob's Boattail cast bullet, the last two turns of preload did nothing, the gun could still be maxed out, so that is proof that a stronger hammer spring, or more hammer weight or travel, is not necessary.... In fact, the "knee" of the curve is where it says "Flush" on the graph, which is the point at which the end of the adjusting screw is flush with the inside of the rear plug on the inside.... At 1800 psi, the knee of the curve with the 70 gr. BBTs is right about where there is no preload on the hammer spring.... where it says "Zero" on the graph (which is -5T from Flush).... and for the pellets about 1 turn out from there.... In other words, the spring is rattling around lose when uncocked, although only by about 0.050".... This tends to be a fairly efficient setup, as hammer bounce is rarely an issue, so I have hopes that when I put on the tank, which is regulated at 1950 psi, it will be similar.... It appears from the graph that each 200 psi of pressure takes about a turn more on the preload to get back to the knee of the curve, which is a handy thing to know.... and the bullets need about a turn more preload than the pellets, which is typical.... All in all, I'm VERY pleased with these preliminary numbers.... It gives me great confidence that the completed gun will be both powerful and efficient.... and one in which you can tailor the performance to your requirements by simply selecting the regulator pressure between, say, 1600 - 2200 psi.... If a more powerful bullet shooter is required, then using a full length tube (or twin tubes) and running a 3000 psi fill will do the job with the 70 gr. BBTs.... This makes the Grizzly a very flexible platform....Bob
The Carnivore weighs 9.3#... what do you think the Grizzly will top out at?
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