Increasing crown hammer weight

[Glem.Chally]

You can always squish a pellet between the hammer and weight. Adds minimal length to the assembly and is fast and basically free. Play with weights.

You don't want to do that for long. Once the pellet flattens, it will eventually start to flake and turn into nasty crap that makes a mess inside of the action.

Have you experienced that? I had one in for quite a while in the Royale at 60+fpe and never had it flaking. I packed it into place and it stayed together.

 

[mtnGhost]

Yeah, the pellets flattened and got REALLY thin, like down to around a few thousandths of an inch and started making a nasty mess. At that point, I just decided to start turning brass weights.

 

[Long_Gun_Dallas]

Good point. I've only made one weight. Havnt seen the need to make another. Though, I may make a couple more yet. One for 30 cal, and a bit lighter one

 

[mtnGhost]

If you know what reg pressure you want to support, you can get the hammer weight precise - 12.6 grams was what it took to open the valve all the way to 180+ bar (ysing modified spring guide), I just wound up using that full time for all higher pressure tunes, and decided to use an unmodified spring guide with no weight for lighter tunes (up to 145bar or so, which is what the factory setup could handle on my rifle). 

 

[Long_Gun_Dallas]

Oh, wow. I've actually got a .25 pistol I'm tuning and it's operating at 170 bar. But I wouldn't have thought to put that much weight in the crown. Currently I just use a 7gm weight @155 bar in 22 cal. And no weight at 131bar 

 

[mtnGhost]

Yeah, 7 grams will buy you around 160bar. My tune for 30 grain slugs requires around 170bar, so I just kept making them heavier and heavier (using the same length on the hammer head / flange), until I could open the valve for max reg pressures.

 

[Long_Gun_Dallas]

Yours is 22 caliber as well? Or 25? I feel I'm at the ceiling for flow capability on the 22. Without doing some type of extreme modification... Mine also seemed to like 30gr the best as far as utilizing volume and expansion is concerned. 

And the gun loses efficiency or power on either side of 155bar regardless of hammer tension. (maybe it's actually 160 and my gauge is a bit off?) But my current tune shoots 25gr slugs @950fps. The gun can shoot them around 1050, but there's too much turbulence or vibration

 

[mtnGhost]

22 cal only with my Crown(s).I know what you mean about flow limits, at a certain point the gains from reg pressure aren't as steep. I have had mine up to 74FPE though, I have probably squeeze another 5FPE out of it, but meh.

 

[Long_Gun_Dallas]

Whew! That's smokin! I havnt really seen any projectiles that like being pushed that hard. But I might try a 9gr weight and test the 36gr boat tails again. Something just wasn't clicking with them. But 2/3 were hole in hole at 100 yards 1/3 were about 3-4" off all the boat tail slugs I have like low speeds, though. 920 and less fps. But I could only get 36gr up to about 880. 

I do have a slew of various weights and designs of projectiles I need to test. I should probably get back out and do that, haha. 



Thanks again for sharing your experience. 

 

[Strobing_NYC]

So I finally got ahold of FX and ordered a hammer weight for the Wildcat cut a bit off not much and cut the spring guide,. I also put the HUMA reg in @ 155 bar shooting 44.75G JSB's I'm only getting 843fps or so I am going to try and bump the reg up some more. 

 

[Long_Gun_Dallas]

You probably need a much larger valve seat. The standard one is sized for 22 caliber. Anything bigger, and it's a bottleneck in the system 

 

[mtnGhost]

I'm not sure what the Wildcats max out at. IIRC, @CHUCK pushed that envelope with his build(s). The plenums are kind of small in them.