So I purchased a Benji Maximus Euro based upon Steve's review on AEAC. I was excited about the high shot count and adequate power for small game hunting within 40 yds or less. I started with accuracy testing based upon Steve's review and it was spot on. Then I ran it over the chrony and mine is 100 to 150 fps lower than Steve got. Actually mine barely breaks 8fpe. JSB 8.44gr at 647fps average. I know this is a sub 12fpe gun but I wasn't thinking that sub. Has anyone had this problem? Does anyone know what Crosman modified to make it a 12lb gun. I'm thinking porting. I might just send it back.
Benji Maximus Euro Power Problem
- Thread starter torgo
- Start date
I'd send it back for a replacement. Biggest part what I've heard is the Transfer port size is small.
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Ok, I thought I would post an update in case anyone else was having this problem. I got the rifle back from Crosman via UPS ( is there a contest among UPS employees to see how badly they can damage the boxes? but I digress). As I might have mentioned the box was pretty badly damaged and I was worried about the rife. But all seemed OK so I charged it to 2000psi and fired 32 shots over my Chrony. Guess what? 650 FPS. Same as the one I sent in. I wish I would have noted the serial number on the one I sent in to see if this was the same one. So I have an 8fpe gun. Well we wanted a 12FPE gun and we are going to get it!!
Apart comes the Maximus, All looks good, lots of oil on every thing, Cleaned it up and examined the transfer port. I measured it out at .050". Man that is pretty small seeing the FAC version is .120" if I recall. I wasn't sure how much to open this up so I decided to go slow. First I drilled it to .060". Ten shots on a full charge over my Chrony yielded an Average of 701 FPS. Not quite enough. Apart she comes again. This time we go to .065", ten shots on a full charge over the chrony and we are at 743 FPS for an average. One more time, I can change the transfer port now in about 6 min. Anyway, final drill was .072" this brought my average ( all with 7.9gr CPHP) to 836 FPS. EXACTLY where I want it. JSB Exact Heavy 10.34gr are popping out at 772 FPS so that is perfect. Started to rain so not sure of the shot count yet. Hopefully it stays pretty high. I'm getting a lighter spring and a power adjuster to fine tune it.
Anyway that's my story and I'm sticking to it
Apart comes the Maximus, All looks good, lots of oil on every thing, Cleaned it up and examined the transfer port. I measured it out at .050". Man that is pretty small seeing the FAC version is .120" if I recall. I wasn't sure how much to open this up so I decided to go slow. First I drilled it to .060". Ten shots on a full charge over my Chrony yielded an Average of 701 FPS. Not quite enough. Apart she comes again. This time we go to .065", ten shots on a full charge over the chrony and we are at 743 FPS for an average. One more time, I can change the transfer port now in about 6 min. Anyway, final drill was .072" this brought my average ( all with 7.9gr CPHP) to 836 FPS. EXACTLY where I want it. JSB Exact Heavy 10.34gr are popping out at 772 FPS so that is perfect. Started to rain so not sure of the shot count yet. Hopefully it stays pretty high. I'm getting a lighter spring and a power adjuster to fine tune it.
Anyway that's my story and I'm sticking to it
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Good job! I am looking into buying a 177 maximus euro as well. I would be really interested in hearing about the shot string and optimum starting fill pressure and of course its accuracy with 7.9gr Premiers.
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Glad to have found your posting. Exactly had the same problem. Chronied the Euro 177 Max and it was in the 650 fps using 8.44 gr JSB with sometimes erratic 590 fps. Called Crosman Tech and they said the gun is baselined at 800 fps using 7.4 grain crosman pellets. But that's only 10.5 fpe I told the tech guy. He said they design the gun to be UNDER 12 fpe - NOT 12 fpe ! How close to 12, he cannot say.
I too bought the Euro Max based on the AEAC review. That video shows the gun chronied at close to 800 using the same JSB 8.44's. I suspect the gun they send reviewers are tuned to reflect a true 12 fpe gun unlike the ones we buy as consumers.
I've disassembled the rifle and noticed a pinch in the transfer port o ring. ALso as you observed, the transfer port hole was small. Might enlarge it the same way you did.
I hope crosman fixes their quality control on these entry level gun. It leaves a bad taste and makes me leery of buying another entry level crosman.
I too bought the Euro Max based on the AEAC review. That video shows the gun chronied at close to 800 using the same JSB 8.44's. I suspect the gun they send reviewers are tuned to reflect a true 12 fpe gun unlike the ones we buy as consumers.
I've disassembled the rifle and noticed a pinch in the transfer port o ring. ALso as you observed, the transfer port hole was small. Might enlarge it the same way you did.
I hope crosman fixes their quality control on these entry level gun. It leaves a bad taste and makes me leery of buying another entry level crosman.
Upvote 0