What's the difference between these pistons?

[Stickstoff]

I've noticed that the NP rifles seem to use 3 different pistons for what seem like nearly identical guns otherwise. Does anyone know what the differences are?

Crosman Titan .22, Trail NP
BT9M22-03-100A

Nitro Venom, Crosman Titan .177, Benji Regal
BT9M22-03-100B

Benji Titan
BW7M77NP-01-100

The Remington guns have different numbering but I think those equate to a Trail XL if I'm not mistaken.

[Airgun.Sniper]

 Most likely power out put.  Not quite sure though.

[56S]

I'm almost certain the Benji part number with the 7 is for the lower powered version.  The difference between the A and the B is in my guess very minor.  Just got a gas ram with the A and it had a threaded base where the other without the A did not.

[JR]

Only major differences I know of on the rams is, one has a hole drilled in it to lower the power, one is for the spring version and one has a divot for the ram end. I worked on a few NP Trails, Venoms and a couple of Titans all the pistons looked the same to me from what I remember.

[Motorhead]

Not sure of numbers ... But pistons for RAMMED/ NP use will have a centering dimple at piston end for ram stem.
Spring pistons will be flat for spring to seat upon.

Just FYI ...

[Stickstoff]

I'm almost certain the Benji part number with the 7 is for the lower powered version.  The difference between the A and the B is in my guess very minor.  Just got a gas ram with the A and it had a threaded base where the other without the A did not.

Yup. The Benji Titan .177 with the BW7M77NP-01-100 is lower rated at 695fps now that I look. And, as said above, the differences between the A and B are probably minor revisions. Probably around 5/7/2010.

Thanks!

[woodbutcher]

I have a Benjamin Titan BW1K77NP. The piston on mine has a slight inward curve at the open end. The washer & bushing I ordered don't fit my NPSS The brass washers are to thick and the bushing won't fit inside the piston. Is it because the SS uses a different piston?

[BmaS]

I have a Benjamin Titan BW1K77NP. The piston on mine has a slight inward curve at the open end. The washer & bushing I ordered don't fit my NPSS The brass washers are to thick and the bushing won't fit inside the piston. Is it because the SS uses a different piston?

Yes, the SS uses a different piston.  SS stands for Short Stroke.  The travel of this piston is shorter than the one used in the Titan/Trail/Venom

[bambam]

I too would like to see more images of those pistons. I believe that I am very close to a gas ram upgrade for the venom but have one hurtle to overcome.  Putting that issue aside, I need images of those pistons, esp. Up inside the piston head, measurements if possible. Also I have noticed that the piston in the venom model has a spacer inside the piston head. Definatly added to the piston,not part of the piston. If this mod is at all possible that spacer has to come out or an alternate piston with out spacer must be found if not made. I have no idea about this mod even surviving the testing stage once it is completed. Many hours of shooting and examination of parts will take time to know if this will be a sound mod. I have tried all parts but have been stopped by this piston spacer issue. I do believe that this can be done, but it must be done right. The only solution as it stands is to drill a small hole in the piston head that I can use to reach through and drive the spacer downward out of the piston head. This leaves a hole that of course will need filling later. Not the best idea. Also I have no idea as to just what is under that spacer, perhaps another ram seat? Perhaps room to make a new ram seat? But that  approx. 1 inch spacer is the first major problem. Side note... Even the Remington models use the crosman parts, perhaps one of those may provide an answer?
Any thoughts are welcome. If this pipe dream lol, is to ever work I will share the info here first. I do think it could add as much as 150 fps to the current stock levels. Putting it in the mid-hi 800s with lead. The only noticeable draw back so far is that the rifle is twice as hard in cocking force, could be a future barel stress issue. hope it translates down range in hi fps. May need better breach seals too. Oh well, one hurtle at a time. Foremost is the piston spacer issue.
Bambam

After thought.... Does any one have an old used venom piston that they may be willing to send to me for experimentation's
I really need to get under a spacer and see what's up. I would be willing to pay for the postage as well. The sender will be the first informed of the success or failure of this venture. It just seems a waste to ruin a good piston. I do not need anything else like seals etc. Just the piston will do. FYI it will not be usable after examination.  Thanks. Bambam

[Gmman1960]

I've tuned a titan, Venom, Two Remington NPSS and a Benji NPS (identical to NPSS). The NPSS and NPS use the same piston, ram, and seal. The Titan, Venom and Nitro version of the Fury all use the same B-18, 19 frame. Slight variations between them that is sort of like the difference between Chevy Tahoe and a GMC Yukon. No real power differences between them. If you are thinking of trying to boost the power by increasing the preload on the gas ram.....it won't work. Increasing preload produces more energy on coiled springs until you get spring bound where you can't compress it anymore. The gas ram has a linear power output. In other words it makes pretty much the same amount of force at the beginning of the stroke as it does at the end. So shimming it will only shorten the stroke and actually decrease power. And you can't make the stroke any longer because there is only so much room for the piston travel in the compression tube. So if you remove a shim the only thing you accomplish is to decrease the preload on the ram. The concerns about barrel stress therefore are not going to be realized. I read a thread on this a long time ago on here somewhere with the math and physics explained in great detail. The bottom line was that the stresses involved with adding that much power go beyond what the internal parts can handle. If you are looking for more power you can to upgrade to the XL version which has a considerably more robust parts to handle the stresses of the increased power. The downside of that is that they are more hold sensitive and harder on scopes. If you really want to try to mod a piston I am pretty sure you can order one from Crosman for less than 20 bucks.

[bambam]

Tuning? please we are not talking about the tune. First off ... you are correct. second off, I am INSPECTING the space under the piston spacer that is not visible, NOT MODDING THE PISTON. That is why I am NOT doing it in that way, and yes my approach nullifies these issues that you have raised. all of those issues have been over come already. in fact the removal or lack of that spacer is what it will take to ensure that those other issues you have raised are none existent. I am not going into details about "by what" and "how" I have achieved this. My engineering degree and 40+ years of experience begs to differ... lol no offense intended. In fact all other components have already been tested and have passed as expected. I have done my math and inspections on its application to this rifle, studied its abilities for well over the last 2 years. I have seen the existing math, as for this mod the existing math needs to be rewritten. I think you have assumed that just a spacer will make it happen, or shimming the gas ram? or perhaps a piston mod?  not that simple. And I not that ignorant. This is NOT the only way when another has been found. As for the coil spring issue?... the venom does not have one. the piston stroke reduction is the problem NOW, it must be maintained to the original specs. I can tell you that in all of the internet informational posts here and abroad that i have read on this and other models, I have never seen this approach tried? so here we are trying it for the first time perhaps. If I could explain in details, I am sure that you would agree, you are at the analysis point now that I reached about a year ago. and "kudos" to you sir you are correct. I just wish I could give more info. but it is not some thing you just hand over. People could be hurt if done incorrectly. Even if I get my prototype installed I will not release the info. on how to achieve this until I am satisfied that it will be a stable viable mod. That any back yard gun smith or less could install. All of these criteria must be met or I release nothing. I will have no blood on my hands. My philosophical bent, sorry.  I fully admit this may all be in vain, a failure, flop'ola? BUT.... it could just be the answer we have all been looking for. ALSO... This mod very well could be applied to other similar models that share the same internal designs by Crosman/Benjamin.  I have no intent on scalping this for cash or anything else. The end all answers will be shared openly with all... as it should be.
After all... it's all for fun.... NOT $
I ain't rich, that's why I own a venom...
best regards, bambam
 
Side note... "naysayers" and "it can't be doners". Those that wish to smash brain pans...  Please... this is just counter productive. Does any body seriously want this mod? or just me? The piston search for the answer continues. Perhaps I should just purchase a new piston and examine it in private. After I have assembled my prototype I just may be able to sell the mod in a kit for a lot of $$$$$$$ and screw all the world Aaa-hahahaha "rubs hands together with evil sneers".... just kidding guys. lol.... bambam.

[bambam]

Question.......
Gmman1960,
Good Sir, Have you ever come across a factory made piston that does not have that approx. 1 inch spacer inside the head of the piston? in my case it would have to fit the venom's body as the original does.
I realize this is a very long shot in the dark here lol but thought I would ask.
Thank you for your input and experience.... clearly great minds think alike.
Best thoughts ... bambam

[Gmman1960]

No I can't say I have ever seen such a piston. I was partially answering the original post about the differences between pistons. I thought you might be trying something that has already failed so if you have a genie in a bottle then carry on and forget everything I said.....

[bambam]

100% my -bad... sorry I did not realize that, I should have read everything a bit more close, my apology.
and thanks again for the input. i wonder myself if this will make it to the final stage of "safe to use".
that is why I am trying to be a bit, careful ? here. 
lol I sure hope that Mr.genie's magic has just one more wish left in him?  hehe.
I am not sure about the first noticeable dif. being the much harder cocking. I have seen an improvement in actual performance in the first and only 10 rd day, then another tear down. even with the 1 inch piston travel decrease now.
but not enough to justify all of the time and effort to get there.  Prolonged use may display another unknown weakness to it as well? wish, wish, wish... how many was that now anyway? poor'ol genie lol

thanks my friend... bambam

[OleTomCat]

Question.......
Gmman1960,
Good Sir, Have you ever come across a factory made piston that does not have that approx. 1 inch spacer inside the head of the piston? in my case it would have to fit the venom's body as the original does.
I realize this is a very long shot in the dark here lol but thought I would ask.
Thank you for your input and experience.... clearly great minds think alike.
Best thoughts ... bambam

Bam,

I have a couple that I have modified to use gas rams in Gamo guns if you want one send me a Direct Message and we can work something out...