Benjamin Benjamin akela not performing in the "cold"

hello everyone! I have a question for all you seasoned pcp vets out there. im new to this, ive been a springer guy for years but just recently got my first pcp air rifle. I have my akela tuned with the hammer spring already being cut down, right now im running the 10.34 hades pellets at 905 fps (great stability, accuracy and power) I noticed the other day when the temp dropped that the fps also drops, makes sense so far...but today, the temp is 49F, and I saw that if I shoot my gun rapidly the gun hardly pushes any air at all. like pellets stuck in the barrel type of thing. if I shoot slowly, it seems to be fine. has anyone else had this problem? I did some quick research and it seems that manufacturers say the cold won't have much impact but im curious to hear some real world experiences. I live in Michigan so it's winter for like 6 months a year these days, so not being able to shoot my pcp would not be ideal. any thoughts?
 
How rapid is rapid? Because yes the plenum needs some time to refill, but unless you're The Flash, I can't fathom being able to chamber the next pellet and fire before the plenum has barely achieved sufficient pressure to expel the pellet from the barrel.

But suffice it to say a cool day at 49F is not the reason. A couple of potential causes to consider:

1. The regulator is set very close to its absolute maximum pressure. Meaning the spool is very nearly deprived of all travel, and the seat does not open adequately for the plenum to refill quickly.
2. The plenum is being very nearly emptied on each shot, making it take a long time to recover.

Or of course some combination of #1 and #2.

You described having shortened the hammer spring which tells me you know a thing or two about tuning, and suggests #2 is less likely.
 
How rapid is rapid? Because yes the plenum needs some time to refill, but unless you're The Flash, I can't fathom being able to chamber the next pellet and fire before the plenum has barely achieved sufficient pressure to expel the pellet from the barrel.

But suffice it to say a cool day at 49F is not the reason. A couple of potential causes to consider:

1. The regulator is set very close to its absolute maximum pressure. Meaning the spool is very nearly deprived of all travel, and the seat does not open adequately for the plenum to refill quickly.
2. The plenum is being very nearly emptied on each shot, making it take a long time to recover.

Or of course some combination of #1 and #2.

You described having shortened the hammer spring which tells me you know a thing or two about tuning, and suggests #2 is less likely.

Your #2 contradicts your initial assessment.
 
I am unsure of the Akela and if there is a gauge that shows regulated pressure, if there perhaps is one, (edit: just checked and it certainly should show regulated pressure based on proximity) definitely try to replicate the issue and pay close attention to the gauge, may pinpoint the culprit. GL

There is a small chance your regulator breathe hole is clogged or otherwise restricted, may need to tear down and clean it up/open it up slightly.

-Matt
 
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The Akela is not regulated from the factory so that ends that talk.
The problem is the mix of shortening the factory spring which I don’t recommend because of this and the cold affecting how efficient the hammer is operating. The Akela’s sear puts friction on the hammer as well. The aluminum breech block will shrink a little and if there’s any lube in the hammer area it will thicken as well.
The fix? Pull the hammer, wipe down bore and hammer and put a new spring back in. You can also decrease some of the tension on the sear to help. This is done by replacing the small spring under the sear adjustment.
 
Ah okay thanks for removing that variable from the equation. But if no regulator is present, I am completely baffled as to how reloading and firing quickly would produce a weak shot.
yep, that's exactly what im thinking. I don't see how I could possibly be reaching all the way back to my cheek to load a new pellet and then fire quickly enough to outrun the system. to add some extra information that I should have included prior, when I say rapidly, were talking maybe 10-15 seconds between shots. so not quick by any means, just quicker than I normally do. about an hour or 2 after this occurred, I took the gun out to zero in a new scope and had no issues (not saying it was the scope causing issues :) ) when this event occurred I did also notice condensation on the block. so maybe the issue was rapid temp change? another thing to mention, my gun is not tuned to be efficient right now, I did some work to it and just tuned it enough to be decent, so maybe the tune is part of the issue as well. someone mentioned the hammer spring being the issue, ive been running this hammer spring at this length for about a month now with no issues so im not too sure that would be the culprit now. im liking the ideas tho and I appreciate everyones input on this. thanks guys
 
If the hammer is anything like the Marauder design, it is a cylinder sliding inside a relatively close fitting tube and as already mentioned, any 'wet' (oil or grease) lubricant here will cause erratic / inconsistent friction. Especially if grease is put here, it will thicken and slow things down in cold weather. One solution is to thoroughly degrease and clean the mating/sliding surfaces and burnish them with dry graphite or powdered molybdenum disulfide lube.

Good luck

Feinwerk
 
yep, that's exactly what im thinking. I don't see how I could possibly be reaching all the way back to my cheek to load a new pellet and then fire quickly enough to outrun the system. to add some extra information that I should have included prior, when I say rapidly, were talking maybe 10-15 seconds between shots. so not quick by any means, just quicker than I normally do. about an hour or 2 after this occurred, I took the gun out to zero in a new scope and had no issues (not saying it was the scope causing issues :) ) when this event occurred I did also notice condensation on the block. so maybe the issue was rapid temp change? another thing to mention, my gun is not tuned to be efficient right now, I did some work to it and just tuned it enough to be decent, so maybe the tune is part of the issue as well. someone mentioned the hammer spring being the issue, ive been running this hammer spring at this length for about a month now with no issues so im not too sure that would be the culprit now. im liking the ideas tho and I appreciate everyones input on this. thanks guys

Scope could be culprit along with what @Feinwerk just mentioned. I'd look into eliminating those two variables. Shocked the Akela doesn't come regulated @ 500$ and being a newer release!

Scopes can certainly be finicky with rather wild temperature swings, but you're saying that it barely pushes any air at all, I am thinking Feinwerk is onto something.

If the issue occurs where shooting rapidly results in slow shots, confirming pressure on the gauge even though its not regulated may provide a clue, as the gun could still have a major restriction somewhere upstream.

Verifying exactly the FPS variance over a chronograph would help, as "barely pushing any air at all" is a shot in the wind, pun intended.

Is there an o-ring present on the valve stem anywhere for Akelas? That would effect performance in the cold. As I said though a tune in the cold should absolutely be a tad different than in the heat.

-Matt
 
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Hi, also had a problem with sudden unexplained power loss recently with my Akela, turned out when using a single shot tray a pellet had dropped backwards down past the probe and had got in front of the hammer causing varying levels of power with each shot and ending with a pellet stuck in the barrel, might be worth checking if that’s the cause.
 
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