FX Crown mk2 hammer weight

Gambler

Member
Feb 20, 2023
280
119
Åmot
Just a question before I take the crown apart.
Ive installed huma spring and a 8g extra hammer weight and been shooting at 155bar.
But now I tried to turn it down to 135-140bar to see if my groupings Will be better at slower speeds. But now I cant adjust on my pw. I set it at 1 and when I turn up my speeds are slowing down. Is that because the hammer is too heavy now? So I have to take the weight and spring out again (i think its so but want to hear here before I start taking it out).
 
Stock hammer weight is good for reg up to 150, if you have heavier hammer then don't go below 150 or the valve would bounce.
Hi Guys,
Your comment on the "Stock" hammer weight and 150bar got me thinking. First, I don't know what the "stock" hammer weight is. I have two Crown MkII and I bought 1 new and 1 used. The new one came with no extra hammer weight. In fact the spring carrier had a long shaft on it to keep the spring from binding. That effectively prevented adding any hammer weight. The second one came used, with a .30 380mm barrel and the Power Upgrade kit (pin probe, tungsten weight, and a different spring carrier). So what is "stock"? Is it no extra weight?
I have since added the upgrade spring carrier to my unmodified Crown and also added the 13 g Huma brass hammer weight. I shoot this rifle in American HFT at 90bar to get my .177 13.4 gr pellets to fly at about 820fps. I am getting single digit ES and StDev and have managed a 200/200 with 17x's on the 30 yd Challange target (here on AGN Target Forum). So I would say it is possible to shoot the Crown below 150 bar with a hammer weight.
I think what most folks forget about adding hammer weights is that the shape of the head of the weight plays a big role. The Huma weight I use has a 4mm long head with a larger diameter on it. That will cause the hammer spring to compress 4 mm more than it would with no weight. That is about the equivalent of turning the Power Wheen from 1 to 21. This means that the best thing to do is to adjust the Internal Hammer Spring screw back out 8 turns (0.5mm per turn). Now the difference in projectile speed is purely due to additional hammer weight. In my case I did a bunch more adjusting to find the rifles happy place. I can absolutely say I found that my ES and StDev 's were significantly smaller with the extra hammer weight than without.

Cheers,
Greg
 
Hi Guys,
Your comment on the "Stock" hammer weight and 150bar got me thinking. First, I don't know what the "stock" hammer weight is. I have two Crown MkII and I bought 1 new and 1 used. The new one came with no extra hammer weight. In fact the spring carrier had a long shaft on it to keep the spring from binding. That effectively prevented adding any hammer weight. The second one came used, with a .30 380mm barrel and the Power Upgrade kit (pin probe, tungsten weight, and a different spring carrier). So what is "stock"? Is it no extra weight?
I have since added the upgrade spring carrier to my unmodified Crown and also added the 13 g Huma brass hammer weight. I shoot this rifle in American HFT at 90bar to get my .177 13.4 gr pellets to fly at about 820fps. I am getting single digit ES and StDev and have managed a 200/200 with 17x's on the 30 yd Challange target (here on AGN Target Forum). So I would say it is possible to shoot the Crown below 150 bar with a hammer weight.
I think what most folks forget about adding hammer weights is that the shape of the head of the weight plays a big role. The Huma weight I use has a 4mm long head with a larger diameter on it. That will cause the hammer spring to compress 4 mm more than it would with no weight. That is about the equivalent of turning the Power Wheen from 1 to 21. This means that the best thing to do is to adjust the Internal Hammer Spring screw back out 8 turns (0.5mm per turn). Now the difference in projectile speed is purely due to additional hammer weight. In my case I did a bunch more adjusting to find the rifles happy place. I can absolutely say I found that my ES and StDev 's were significantly smaller with the extra hammer weight than without.

Cheers,
Greg
I use the same 4mm head tungsten weight you use, but I cut off 15mm of the end going into the spring so it did not colide with the stock spring guide. But maybe ill Just try to trun the internal screw in again first as say.