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Benjamin trial NP to pal rated https://www.airgunforum.ca/forums/topic72145.html |
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Author: | Ace [ Sat Apr 16, 2016 4:51 pm ] |
Post subject: | Benjamin trial NP to pal rated |
Had someone email me if I could install a pal rated NP and also a GTX II trigger for him on his Benjamin trail NP he gave me all the parts to install and mod this for him... so here are the results to which I'm a little confused because the pal rated NP trail says its max fps is generally speaking around anywhere between 1,060 fps and 1,115 fps, and I have read the max Velocity is 1200 fps... I personaly don't like anything above 860fps so I hope this person wont be to disappointed.... so after this upgraded NP piston install, it started off shooting 896fps but was dieseling a bit then after a couple shots it settle down to a pretty consistent 780fps.... I know that you cant go by everything that's written on the box but why is it so low compared to the Max FPS rating... I chrony'd it before the mod and it was 430fps...so 780fps is a very good increase but I'm a little shocked still.. All back together... zeroed in the scope then had a little fun... excuse the grouping haven't shot in a very,very long time 7shots @ 50ft semi rested... |
Author: | ricksplace [ Sat Apr 16, 2016 8:25 pm ] |
Post subject: | Re: Benjamin trial NP to pal rated |
I have a .177 Fury np (same powerplant). After a lube-tune, it chronos 1030 fps with destroyers, 970 with H&N 8.18gr. It's accurate, but a little hold sensitive, even for a gasser. It's a refurb from USA and has the full power gas spring. It has several thousand shot cycles through it with no sign of slowing down. Your velocities seem low for a full power np. Makes me wonder which strut your client ordered. I'm guessing that a change to the shorter piston (making for a larger swept area) would probably make velocities close to yours even when used with the original gas spring. |
Author: | Ace [ Sat Apr 16, 2016 9:09 pm ] |
Post subject: | Re: Benjamin trial NP to pal rated |
ricksplace wrote: I have a .177 Fury np (same powerplant). After a lube-tune, it chronos 1030 fps with destroyers, 970 with H&N 8.18gr. It's accurate, but a little hold sensitive, Yes i found this one hold sensitive as well definitely has a little more kick to it even for a gasser. It's a refurb from USA and has the full power gas spring. It has several thousand shot cycles through it with no sign of slowing down.
Your velocities seem low for a full power np. Makes me wonder which strut your client ordered. I thought it seemed low as well that's why I commented on it, by the way I forgot to mention I was shooting crosman premier 14.3 gr..and I don't know what kit he ordered, maybe this is the proper velocity for this kit, no idea.. I'm guessing that a change to the shorter piston (making for a larger swept area) would probably make velocities close to yours even when used with the original gas spring. that's possible and makes sense but not sure if it would get the fps as high because the new strut is very stiff, this is what he ordered I just installed it... wasn't going to not install the new strut and just install the short piston...the short piston with the stock strut would be better though because the cocking effort would be much less...oh well... thanks for chiming in Rick |
Author: | ricksplace [ Sat Apr 16, 2016 10:12 pm ] |
Post subject: | Re: Benjamin trial NP to pal rated |
Oh. It's a .22! 780 is about right! I have a full power spring and short piston in a Canadian .22 Phantom that is running 730 after a full tune, so 780 sounds about right for a full power gas spring. 780 (19fpe) with CPHP is actually pretty fast for the B18 platform. I was thinking about swapping the piston and strut from my Fury NP with the piston and spring from my Canadian .22 Phantom. (Just switch the guts between the two rifles since the powerplants are the same), but after reading your post, everything is staying put. Both tuned guns are shooting just great, so it's not worth the trouble for 50fps! Thanks Ace! |
Author: | Spaceman88 [ Sun Apr 17, 2016 8:27 pm ] |
Post subject: | Re: Benjamin trial NP to pal rated |
I upgraded the same gun, but I only get around 720 FPS. |
Author: | Ace [ Sun Apr 17, 2016 10:42 pm ] |
Post subject: | Re: Benjamin trial NP to pal rated |
thanks... guess Its good then |
Author: | Chevota [ Wed Apr 20, 2016 6:24 pm ] |
Post subject: | Re: Benjamin trial NP to pal rated |
I too assumed 177 since you mentioned 1200fps. 780 with 14.3 is exceptional considering you didn't modify it. It just might even be a record. Unless it's dieseling... Most people get ~700+- 50, but the +50 is rather rare. I'd hang on to that old nitro spring and trigger blade, there will be someone who wants them. For example I do but shipping would be too much. My guess is the springs strength is ~120lbs which is part # BT5M22-00-1? Does it say on it? It sure looks like it anyway, but if about that strength it makes an excellent spring for people who think the full power one is too harsh, especially for 177. I bet someone might even want the piston since it can be cut down into a full power version but many are reluctant to try it on their only piston. The trigger would be great for someone who has the old stamped steel trigger, and/or if they want to try modding it and again don't want to try on their only one. |
Author: | Ace [ Thu Apr 21, 2016 2:00 pm ] |
Post subject: | Re: Benjamin trial NP to pal rated |
Chevota I too didn't realize that the high fps was for .177... like I said I'm not familiar with these NP rifles this is my firs at working on one, just went by what I read on a site but didn't pay attention if it was in .177 or .22 now I know. As for dieseling it was when I reassembled it if you read above it was shooting @ 860fps for the first 5 to 10 shots then settled down to 780fps, and I actually just finished working on a Crosman venom dusk in .177 chrony showed 1145fps...at first then after some dieseling it settled to 1040fps...as for the old piston & strut & trigger I gave it back to the customer just in case he wants to put it back to non pal... |
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