GTA
Airguns by Make and Model => Benjamin Airguns => Topic started by: Hsuny12 on June 12, 2014, 06:13:59 PM
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I have been using the Canadian regulated version (495fps) of this gun for a few months now and love it. Then I decided it was time to purchase the repair kit and GTR trigger from scopesandammo and get the gun shooting to its full potential. The trigger mod is a must if you own this gun, it makes shooting remarkably easier. As for the piston and gas strut upgrade, I went from 440 fps with 6 footpounds to almost 700 fps and 16 footpounds immediately. I have only put about 20 shots through it so I'm sure it will only get better with time. The noticeable changes are that the barrel now cocks to about 140degrees (originally 90 degrees), this is due to the shorter piston. The gun has more recoil and the sound has increased slightly. If anyone has any questions about the details of this upgrade let me know and I will do my best to help.
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Nice to hear your NPAW has been upgraded. May I ask what gas ram you have replaced it with? Where did you get it from?
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Nice to hear your NPAW has been upgraded. May I ask what gas ram you have replaced it with? Where did you get it from?
Not to pride in on the convo...but he may have gotten it from crosman...or anther gun. Im glad to here about the upgrade. Ive seen some people get 18fpe with the NP .
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I was wondering about detuning a U.S. gas ram gun by using a canuck version ram.
What pellet weight were using?
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The parts came from scopesandammo.com there is a package called Benjamin Trail Repair kit. It comes with the piston, piston seal, breech seal, and the Nitropiston Gas-Ram (for the high powered version).
The parts I took out of my original gun could be used to de-tune a higher power one. I have attached some photos to show the comparisons between the new and the old parts. The Piston is obvious, the gas-ram is much the same but has a much thicker piston shaft.
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Forgot to include, I was using 15.89g JSB Jumbo Exact Jumbo Diablo with a Combro cb-625 MK4 Chronograph to Measure FPS/Energy. It's my first time using this chrony so I don't know how accurate it is.
My gun also loves the standard Crosman Premier Dome, Crosman Premier Hollow Points, and Discovery PCP Hollow Points (all 14.3g)
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Nice write up.
Interesting that the piston and ram is so different from the high powered kit compared to the detuned one,which as I'm finding out isnt their method of detuning for all their models:I recently purchased a legacy Jim Shockey signature Series which as it turns out only comes in the detuned version up here, So I also purchased that exact same kit from Eric@scopesandammo which is used for a few models which does not have that extreme of a difference in ram/piston when compared to the stock detuned parts.. The original ram that came with the rifle was no different then the one supplied in the high power repair kit sold by Eric (I still used the new one however) and the only difference in the pistons was that the one in the gun as from the factory had the bleeder hole as the method of how they detuned the gun.
Anyway I digress. Congrats on the upgrade!
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I have read that some Benjamin Trails also come with the hole in the piston as a detuning method. I was hoping that mine was that way but wasn't so lucky. I must say that before the upgrade the gun was a pleasure to shoot, but now it's even better. Still waiting for it to quiet down a bit, instead of a "thup" sound like before, it has a much louder "smack" sound.
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If its stopped dieseling(20shots?proablly not) It'll probably never quiet down to the level You think it should. I have a tuned Optimus with over 8000+ rounds down the barrel and it hasnt queited down much and this legacy has around 500 through it and it still goes "TWACK!"Just the same as the day I did the upgrade.Sigh.. what I'd give to change the sound moderator laws up here
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No dieseling because I didn't lube the cylinder with anything once it was de-greased. I only used a small amount of white lithium grease on the head and tail of the piston, and a bit on the ram as well. Nothing in the front of the piston seal either, just the sides.
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I replaced the Xman OEM gas ram with a 55 kg brazilian one. My NPAW shoots at 616+ fps (15+ ft lbs) with 18.2 gr pellets. It is difficult to increase the fps with only a 25 mm combustion chamber. Anyway, my NPAW is dead accurate up to 40 yards. It is a joy to shoot it with so much less recoil than my NPXL.
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always wanted to find one of those low power NP rifles... they sold out quick and most people hold on to them... hsuny... what is the model number on your breach?
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The model number is BT5M22SNP.
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thanks...
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6 years later i found a canadian market crosman... jim shockey steel eagle. 495 fps (i wish!!!). model 7 BSSNP22TX. so smooth... so slow... somewhat accurate. shooting crosman prems at 415 fps... i truly was expecting smoother. next step: finding what detunes it and trying to bring it up to an acceptable 550 fps... 10 fpe should do. any ideas?
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6 years later i found a canadian market crosman... jim shockey steel eagle. 495 fps (i wish!!!). model 7 BSSNP22TX. so smooth... so slow... somewhat accurate. shooting crosman prems at 415 fps... i truly was expecting smoother. next step: finding what detunes it and trying to bring it up to an acceptable 550 fps... 10 fpe should do. any ideas?
In my experience these are detuned using a longer piston and weaker gas ram, BUT Crosman also used a piston with a small hole drilled in the face of the piston (and the full power gas ram) on some others. Check at what angle the barrel is at full cock, with a ''long'' piston, it should be about 90°.
To up the power at the level you want may not be easy with a gas ram. I believe there are at least 3 gas rams for the first gen NP rifles, one with the part number starting with BT5M (weakest), one is BT7M, and a full power BT9M. As for myself I'd try ''playing'' with the sear notch position in the piston, gradually trying more forward position to get to the power you want. Or try a ''short'', standard piston with the weak ram you probably have. To be sure of the detuning method I guess you'll have to take the rifle apart, please post pics if you do!
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ok. many revelations...
i have now 300 shots through the steel eagle. it has finally stopped smoking and dieseling (it had smoke actually blow out of the trigger unit!!!) and it has settled at 408 fps with crosman prems, and have also shot strings with RWS hobbies 11.9 gr (avg 476.4 fps) and Jsb exact RS 13.43 (avg 448.9 fps). Took shroud off , cleaned bore and started shooting. best groups so far have been the crosman premiers, with pellets doing .8 in groups (5 shots) at 15 yards. also stretched to 35 yards and groups grew to 1 1/4 in. Now mind you, all these shots were from the knee or resting on elbows.
the first thing i did was actually steel wooled the trigger blade. its rough to the touch and that made it a lot more pleasant. the trigger is untouched as it breaks evenly every time. best benjamin/ crosman stock trigger yet... rifle shoots with a mild nudge to the shoulder and it is as quiet as a R7, if not more. very back yard friendly. in fact i would go as far as saying that this is all the rifle you need for back yard plinking or critter control, if you are in less than 1/2 acre. it is quiet, extremely easy to shoot accurately and being a .22 you still have enough oomph to drop pest birds or squirrels and chipmunks up to 30 yards.
Mine is scoped with a bushnell 3-9 30/30 and zeroed at 15 yard i have 3.5 fpe left at 35 yards. using the magnification wheel i can adjust the point of aim (the thick below the intersect) from 24,25, 26,27,29,32 and 36 yards going from 9x to 3x. the rifle is full sized but not unmanageable. the cocking effort is ridiculously low, maybe 12 to 14 lbs? the stock is very comfortable to the touch and sits nicely on your palm. at this power level it is not a very hold sensitive rifle. The rifle will be capable of headshoting a squirrel or rabbit out to about 35 to 40 yards if you do your part. pass through will be nil. it is not a powerhouse but it will dump all of its energy into the quarry upon impact. At 5.3 fpe at the muzzle practice is definitely recommended before you try to dispatch varmint from your yard, but as pleasant as it is to shoot, you'll go through many tins of pellets and not even break a sweat. i literally run out of sunlight... think R7 fun on a full size rifle... I can't believe this things are not more popular here. Crosman, if you read this, this type of gun would be fantastic! As per more power... maybe make it so it does a solid 500 fps with a med weight pellet (your 14.3). mine i think i'll keep at 408... its just that much fun.
conclusion: while following canadian law crosman has created a great backyard plinker, one that not only would satisfy the more "target specialized" in us, but also could double as a garden protector, minor teaching tool (or non shooting wife... mine dislikes all shooting things but she was all smiles when the can started dancing at 15 yards on her 2nd shot...) and proved that big fps numbers may not give may sell one gun to a newbie... but a civilized, controllable power level will promote the sport, provide a better shooting experience and may entice more sells...
5.3 fpe... who knew?
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ok. many revelations...
i have now 300 shots through the steel eagle. it has finally stopped smoking and dieseling (it had smoke actually blow out of the trigger unit!!!) and it has settled at 408 fps with crosman prems, and have also shot strings with RWS hobbies 11.9 gr (avg 476.4 fps) and Jsb exact RS 13.43 (avg 448.9 fps). Took shroud off , cleaned bore and started shooting. best groups so far have been the crosman premiers, with pellets doing .8 in groups (5 shots) at 15 yards. also stretched to 35 yards and groups grew to 1 1/4 in. Now mind you, all these shots were from the knee or resting on elbows.
the first thing i did was actually steel wooled the trigger blade. its rough to the touch and that made it a lot more pleasant. the trigger is untouched as it breaks evenly every time. best benjamin/ crosman stock trigger yet... rifle shoots with a mild nudge to the shoulder and it is as quiet as a R7, if not more. very back yard friendly. in fact i would go as far as saying that this is all the rifle you need for back yard plinking or critter control, if you are in less than 1/2 acre. it is quiet, extremely easy to shoot accurately and being a .22 you still have enough oomph to drop pest birds or squirrels and chipmunks up to 30 yards.
Mine is scoped with a bushnell 3-9 30/30 and zeroed at 15 yard i have 3.5 fpe left at 35 yards. using the magnification wheel i can adjust the point of aim (the thick below the intersect) from 24,25, 26,27,29,32 and 36 yards going from 9x to 3x. the rifle is full sized but not unmanageable. the cocking effort is ridiculously low, maybe 12 to 14 lbs? the stock is very comfortable to the touch and sits nicely on your palm. at this power level it is not a very hold sensitive rifle. The rifle will be capable of headshoting a squirrel or rabbit out to about 35 to 40 yards if you do your part. pass through will be nil. it is not a powerhouse but it will dump all of its energy into the quarry upon impact. At 5.3 fpe at the muzzle practice is definitely recommended before you try to dispatch varmint from your yard, but as pleasant as it is to shoot, you'll go through many tins of pellets and not even break a sweat. i literally run out of sunlight... think R7 fun on a full size rifle... I can't believe this things are not more popular here. Crosman, if you read this, this type of gun would be fantastic! As per more power... maybe make it so it does a solid 500 fps with a med weight pellet (your 14.3). mine i think i'll keep at 408... its just that much fun.
conclusion: while following canadian law crosman has created a great backyard plinker, one that not only would satisfy the more "target specialized" in us, but also could double as a garden protector, minor teaching tool (or non shooting wife... mine dislikes all shooting things but she was all smiles when the can started dancing at 15 yards on her 2nd shot...) and proved that big fps numbers may not give may sell one gun to a newbie... but a civilized, controllable power level will promote the sport, provide a better shooting experience and may entice more sells...
5.3 fpe... who knew?
Us, Canucks ;) ;D. Very glad you discovered the joys of low-FPE shooting sir :D. Also expect less wear on the rifle, and happier scopes!
I have a 495 fps Benjamin Trail NP AW in .22, and it's a very solid target gun. Rested, I get 3/8'' groups @ 100 feet. Standing it's in the 1/2''-3/4'' range. Rested @ 50 feet, it's a ridiculous and boring pellet-on-pellet affair ;D.
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i know! i generally have been reducing most of my guns to the uk 12 fpe limit, and that makes it more enjoyable. even the 5.5J italian limit was fun, yet .22 is not something they play with. this 495 fps limit truly puts airgunning as a back yard activity, on par with frisbee or badmington... what kind of numbers are you getting from yours? have you modded it at all?
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i know! i generally have been reducing most of my guns to the uk 12 fpe limit, and that makes it more enjoyable. even the 5.5J italian limit was fun, yet .22 is not something they play with. this 495 fps limit truly puts airgunning as a back yard activity, on par with frisbee or badmington... what kind of numbers are you getting from yours? have you modded it at all?
It's shooting a CPUM domed 14.3 grains pellet @ 422 fps. As far as mods, not really, just a good home tune (clean, deburr, polish trigger parts and re-lube), it simply didn't need more. I'd like to eventually add bronze barrel pivot washers, an adjustable two-stage trigger, and maybe a gas ram bushing if needed. Other than these easy mods, I just can't figure what else could be ''improved'', there's no need to :D.
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... what have i done... i went in for a little lube and a fiddle, and i found a hole in my piston... then i found the jbweld... so its all back together, its 11 pm and out i go to test, just one shot. wow... that pellet flew into my backrest tree so hard! its a bit louder, still seems smooth (trigger got love and its very much a better unit now)... i'll chrony it tomorrow but im thinking its a bit "faster" than the leisurely canadian pace from before. it had a short piston, a #6 ram and a hole in the piston... i'll report after work.
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ok. so 75 shots down the pipe. avg with crosman prems HP is 621.5 fps. louder, much louder than before... almost like a normal np from the US... I bet it will quiet down a bit with use, but never as much as before. shot cycle is stronger. i find myself anticipating the shot... trigger came out good. did a group at 10 yards. stacked pellets in top of each other. at 35 yards i hits a 1 inch disc most of the time (like 8 out of 10 times) but truly i think it was me. (anticipating the shot). it is now a rifle capable of critters out to 50 yards without a doubt. Amazingly enough it is the level of tune on a UK gun. I hope it breaks in a bit... i hope it to be a bit mellower on the shot cycle... maybe i'll reopen it but now im not sure what to do to make it smoother. i lube tuned it and it literally has not smoked at all from shot 1. i used very light moly and sanded the burrs and edges til they were soft to the touch. any ideas?
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week later update. got close to 500 pellets thru... she went down from 620s to an average of 589 fps with crosman prems 14.3. the loudness... it was a bit too snappy and i went in the shroud to see if anything could help (the snappiness felt more like excess air turbulence than internal noise). taken apart i too the front part of the "baffle" which essentially centers the shroud on the barrel (by the way, the barrel is short... like 16 inches). then i noticed that the air was just travelling inside that "baffle" but all of it could only come out behnd the pellet. so thinking to use the space inside the shroud as a still air chamber, i drilled nine holes concentrically along the baffle lenght, allowing some of the air to escape into the shroud. i drilled 2 small holes next to the exit hole of the baffle (there are 6 divets around it... so took 2 across from each other and drilled them open. Night and day. it is now as quiet as an R7 again, and knowing that the speed dropped a little it has finally come out right... i have a UK benji!!! i like the shot cycle and the power level is good for pesting good size critters on any size yard. i wish crosman sold a version of this here for everyone to enjoy.