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AEA HP Carbine TD/Assassin .25 cal without the moderator not cycling in semi-auto

The hammer springs get week. I have mine spaced about 3/8". Velocity on mine dropped about 100 fps a while back. With this spacer its back to where it was 27 g slug at 900 fps. I think you have enough pressure with your setup.

I detuned mine some so it would not cycle so hard. I had it so light that it would not cycle without a pellet in it. Couple months later it became unreliable and didn't sound as strong. When I checked velocity it was down. That is when I realized it needed more hammer spring, I ground down A 5/16 nut and stuck it inside the stock end. Later I made some bushings on the lathe of different widths.

I would try spacers first. I polished the spring guide rod and hammer. Use a good lube and lube the cylinder inside the shroud too. Sorry to lead you astray. Pictures helped me I thought your setup was different. The hole in picture one is a bit over 3/8" looks like that is what yours is from what I can tell.

Here is the sweet spot for me on the cylinder adjustment. You can see about two threads of the rod going past the cylinder. Also this cylinder can get sticky and slow down the cycling. I like running my dry as possible.

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🤔
Looks good to me.
Ok... Interestingly enough, I pulled out the rear spring and just stretched it out. I tried putting in one of those quarter inch shims and it wouldn't allow me to screw the stock and on all the way so I just left it out this time. I did however, make the small adjustment where there is only two threads showing on the blowback piston and sure as 💩.... Bumped her up 20fps 👍

No I don't know if it was one or the other or a combination of both however, if it was the spring, it should revert back to where it was in the near future

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Alright ID of the bushing is .220, OD is .340, height is .250. My guide rod diameter measures .215, the hole in the stock ID is .352. So the bushing OD needs to be small enough to fit into the stock hole and bushing ID large enough to allow guide rod to pass through. The guide rod fits into the guide pilot hole on stock end. (Pic 3) Bushing will ride over the guide rod resting on the outside of the guide pilot hole on stock end, spring will ride on top of this bushing. Numbers I'm giving you are not critical but have to be close.

To install the stock you have to have gun UNCOCKED. Guide rod must be in the guide pilot hole and through the bushing or you cannot get the stock back on. Picture four is how the guide rod and spring should look if the hammer is all the way forward. This is what you want.

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UPDATE:
Searched Lowes, Home Depot, & three ACE Hardwares...no spacers lol...so I used and expansion spring. I figured an already compressed metal spring should work also...which it has ;) . I just cut her down to just about 1/4".....these were the immediate findings with a full top off at 3400psi using 28.24gr H&N Baracuda Hunter Extremes. I was able to get the extra 10-15 I was searching for however, looks like on this one test, the stand deviation/consistency took a hit. I will reload/air up and attempt with a couple mags to see if she flattens out a little otherwise, I'm very content with those #s. Thank you for the assistance and the tips ;)

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12" shroud + 4"moderator with 8 baffles in it

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Do you happen to know what the shroud thread size on you HP TD is? I recently got one of these but the moderator adapter that was sent to me does not fit (I ordered the recommended size). I'm assuming the thread size must be different for the carbon fiber shroud vs the aluminum. Thanks in advance.
 
Alright ID of the bushing is .220, OD is .340, height is .250. My guide rod diameter measures .215, the hole in the stock ID is .352. So the bushing OD needs to be small enough to fit into the stock hole and bushing ID large enough to allow guide rod to pass through. The guide rod fits into the guide pilot hole on stock end. (Pic 3) Bushing will ride over the guide rod resting on the outside of the guide pilot hole on stock end, spring will ride on top of this bushing. Numbers I'm giving you are not critical but have to be close.

To install the stock you have to have gun UNCOCKED. Guide rod must be in the guide pilot hole and through the bushing or you cannot get the stock back on. Picture four is how the guide rod and spring should look if the hammer is all the way forward. This is what you want.

View attachment 326994

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You making these bushings too?
 
Daygo 619
Sent you a PM


Looking at the shot string info above is interesting. On my old spring velocity jumped up and shot count went down. I ordered a new spring and installed and velocity stayed the same with and without spacers. Comparing the length of the spring to the old spring was same length. Wire size though was .8mm thicker on the new spring compared to the old. So I am not sure if they have two strengths of springs for this gun or what.
 
The hammer springs get week. I have mine spaced about 3/8". Velocity on mine dropped about 100 fps a while back. With this spacer its back to where it was 27 g slug at 900 fps. I think you have enough pressure with your setup.

I detuned mine some so it would not cycle so hard. I had it so light that it would not cycle without a pellet in it. Couple months later it became unreliable and didn't sound as strong. When I checked velocity it was down. That is when I realized it needed more hammer spring, I ground down A 5/16 nut and stuck it inside the stock end. Later I made some bushings on the lathe of different widths.

I would try spacers first. I polished the spring guide rod and hammer. Use a good lube and lube the cylinder inside the shroud too. Sorry to lead you astray. Pictures helped me I thought your setup was different. The hole in picture one is a bit over 3/8" looks like that is what yours is from what I can tell.

Here is the sweet spot for me on the cylinder adjustment. You can see about two threads of the rod going past the cylinder. Also this cylinder can get sticky and slow down the cycling. I like running my dry as possible.

View attachment 326729
Great info man! Thanks for that.

Can you or someone remind me of the air gauge thread sizes on the HP Carbine?
I'm thinking about a digital gauge upgrade. Thanks