GTA
Airguns by Make and Model => Benjamin Airguns => Topic started by: cheerIO on January 16, 2012, 11:23:50 PM
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Hi Guys,
I just recently got interested in airguns and found this forum. After reading and reading I decided to go for a Trail NP as I wanted something with good customer support and didn’t mind working on stuff, like doing my own tune and changing the trigger.
Well I have had the gun for two weeks and a little over a thousand rounds. Even after a tune, I have never seen the accuracy that you guys talk about when referring to a good shooting gun. My groups with my best acting pellets (HN FTT’s) at fifteen yards are still about an inch and half. The pellets don’t group any better if I pull the gun into my shoulder or have a gentle artillery hold.
I also noticed that through out the day, as the temperature dropped from 70 to the 50’s, the POI changed and the groups would get worse. This got me thinking of the effects of floating a barrel on my firearms which lead me to think of the tension that the shroud was putting on the barrel as it pulled it when it is tightened. So I tried this:
All shots at fifteen yards,
Shroud tight: 1.5” group
Loosened 1/2 turn: 2” group
Loosened 1 turn: 3/4” group
Loosened 1 1/2 turn: 1 1/2” group
No shroud: 3/4” group
I saw this pattern and was then sure that the tension of the shroud was affecting the barrel. I decided to find out why and check the straightness. The barrel is 0.514 thick at the breech end and 0.515 at the muzzle end. This is near enough I would just call it the same thickness its entire length.
The first pic is a straight edge on the top of the barrel. Pretty straight.
Next is holding it to the bottom of the barrel. Still good.
Next two pictures, the left side of the gun laying down. Uh Oh. Quite a bit of daylight coming through there. I can fit about 23 thousanths of shims under the end of the ruler.
Last two with the right side of the barrel laying down, the two ends of the rule touch and there is light coming under the middle. Looks like the barrel is bent in the middle into a “U” shape.
So I just wanted to ask. What do you guys think? I have put a lot of effort into this gun but I am pretty sure that this bend is causing me problems. I wouldn’t think that this kind of thing is acceptable, but is it a common occurrence?
I got the gun from Amazon so it is no problem exchanging it. At this point, I think that is what I am going to do.
And I just wanted to thank you all again for this great resource.
P.S. I don't know why but all my pics got flipped upside down when uploaded. I think you can see the rule and the barrel good enough in most of them to get the idea though.
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Welcome to the GTA. I agree. Send it back.
Richard
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Don't mess with it. Take it back. Not worth the headache. There are good ones out there.
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Crosman will replace it. I agree it is not worth the time to deal with it. BEEN THERE AND DEALT WITH IT.
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...Looks like the barrel is bent in the middle into a “U” shape...is it a common occurrence?...
I have only one gun but i have one spare barrel for TraiL NP & one for Trail NP XL. All three barrels have warp just like yours. So yes it is a common occurence...just not commonly known. Now several questions occur. First, how important is that amount of warp? Is that amount of warp causing poor grouping? I doubt it. Many claim that only the last few inches of bore need be straight. Second, even tho there is barrel warp, is there also Bore warp? In other words, maybe the bore is actually straight or straighter than the barrel. Third, how likely is it that any replacement is going to be straighter than ours? My guess...slim & none. Not trashing Crosman just stating my personal experience. I can find no source of drop-in aftermarket barrel or i would have bought one already.
Welcome to GTA and thanks for posting that.
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Welcome CheerIO,
Nice to know this stuff and thanks for the hard work on the analyzing.
Delino
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Welcome to the GTA....and yep, send it back.
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Thanks guys for all the comments and advice.
Oh and one thing that I forgot to put in the initial post: As soon as I loosened the shroud the first bit, The center of the groups shifted right and down about 3 1/2 inches.
Any ways, I requested a return from Amazon. They are overnighting me a replacement and I have 30 days to return this one. So I will have them both on hand to compare and let you know if this is par for the course
John, I hear what you are saying and it was something that I slightly expected. We'll see when I get this new one I guess.
Thanks again for all the help.
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Welcome to GTA and the sport. Though aggravating, it seems as others have stated the problem isn't uncommon at all. I'm just an average air gunner but this does present some questions for me. Maybe some of you guys can chime in here. It would seem to me despite some runout on the barrel it should still be consistent enough to hold a tighter group. At least a short ranges. It just seems the pellet would be consistent in it's
projection. I would also question group difference with a few other brands of pellets. The OP indicates to me the same pellets are being used possibly. We all know pellets can make a big difference in group size. I would also suggest insuring all the screws are good and tight if you haven't done so. Sending it back could prove to be an unnecessary expense and inconvenience considering the input I'm reading here on the model in question. Still nobody could fault sending it back. Just a few thoughts and I'm looking forward to reading responses.
I'm kinda curious about the cal. also?
jim
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It's a shame that Crosman hasn't put there foot down on the Quality Control. Whether it be here in the States or Abroad. Yes Crosman stands behind their products. But poor QC costs everyone.
I have a Trail NP and a Titan. Thankfully no Issues as I have read about . I still love Crosman products,But people will only put up with so much for so long.
*** Call Crosman , Explain the problem. Then ask them to send you a call tag. That way they pay the shipping. *** Crosman stands behind their products.= It's the safest place to be. ;)
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Dude gret a box, pack it up and send it back, stop before you give yourself a heart attack, its not worth it, you just got a bad one, my titan outta the box shoots 5 in a cloverleaf at 25 yrds. nontuned. with a gtr-3 trigger and weaver 3x9 scope and a clip on bipod. AFTER YOU MAIL IT JUST WAIT AND THEY WILL SEND YOU A NICE NEW ONE , THEN SIGHT HER IN AND HAVE A COLD BEER AND WATCH A NICE ACTION MOVIE WITH AT LEAST 5 GRENADES IN IT. :)
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Jim:
It is a Benjamin Trail NP All Weather
.22 caliber
I have tried three pellets so far. I should have three different tins by the end of the week.
1. Crosman Premier Hollow Points: used these for break in. They grouped OK in the beginning but started to spread. Sometimes they group great and other times at an inch or so. But fairly regularly I get a flyer 2 or 3 inches off. Since I got this gun for pest control I can't risk the flyers.
2. Predator PolyMags: I so wanted these to work. But they fit too loose in the barrel and don't group at all.
3. H and N Field Target Trophies: I have had the most consistent groups with these although many times when I pick the gun up the first shot is a flyer low and too the right. I don't get that.
I am fairly experienced with firearms and am confident that I can shoot a good group. One hole's not a problem at 25 yards with any of my .22 rifles. Currently I sit in a chair with a sawhorse infront of me, rest the foregrip on the back of my hand and support the back of the rifle lightly enough that it can move backwards under recoil.
I got the rifle and broke it in with a tin of CPHP. After not seeing much improvement after 500 rounds I broke it down and gave it a light tune. Cleaned the bore with JB non-embedding compound, replaced the "Factory Damaged" seal with a Titan, cleaned and moly'ed in the right places, and polished the sear to smooth the trigger a bit. Switched to a 4x16x40 Centerpoint scope, moved the rings all the way forward and all the way back, and loctited it all over night. 50 rounds or so after the tune it was shooting really well. Before the tune my groups were over 2" at fifteen yards. After, I was hitting 3/4". For some reason that has been opening up again. Best I can do is a 1" group now at 15 yards.
The weird thing is I can hit a:
1" group at 15 yards,
2" group at 30 yards, and then
1 3/4" group at 50 yards.
The gun is just very temperamental and inconsistent to me. I just got up from writing this to shoot five pellets. First round dropped 1 1/2" low, then three pellets touching, then another 3/4" low off the group. The thing is, they all felt like good solid shots to me. I didn't pull anything and I could see everything through my scope so my follow through was good. I believe that the gun just shoots all over.
My replacement will be here tomorrow so maybe that one will just tell me I stink at airguns. ;-) I hope not. And guys, there is no cost in a return. Amazon overnights a replacement product out to you and gives you a return shipping label and 30 days to return the first unit. Very easy. I buy everything I can through Amazon. Always painless no questions asked.
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Thanks for the additional info. It really helps me to understand your ordeal. It sounds as if you have everything going in the proper direction and the rifle just isn't doing it's job. I'm confident you'll see a big difference when the replacement arrives. Even if the groups tightened up for you with the original at this point you may not regain confidence in it. It's a shame we pay our money for an expected quality and the factory doesn't deliver. I happens with the best though. Glad Amazon is holding up their end. Let us know how it turns out.
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welcome and hope you enjoy this place. but i would send it back
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To the OP, what you are describing sounds like power fluctuations... perhaps a bad piston seal or failing breach seal, or too much lube in the cylinder. Anyhow, since a new one is on its way, best wishes for happy shooting. I had to send at least one back in my time as an airgunner.... 8)
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dukemeister:
Thanks for the input. I will take this one apart tomorrow and inspect the piston seal. Maybe I buggered it up on install. I was really careful though and the Titan seemed much more substantial than the factory seal. I didn't lube the cylinder. I wiped a drop of silicone oil around the edge of the seal and moly'ed and inch behind it on the piston and an inch on the opposite end. Today while shooting I laid a half of a tissue over the breech seam but I did not see any evidence of puffing while shooting.
Anyway. I'm hoping for the best tomorrow. Thanks again guys.
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Well, I got my replacement in today. I only have 150 rounds through it but it is shooting much tighter than my first gun. I'm not going to tear anything down at the moment cause I have a chrony on order and it should be here by the weekend. After I do some comparative measurements I will take them both apart and inspect them.
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Let us know how it goes. When you get that gun firing on all cylinders, it will one hole consistently at 25 yards. Ive had an ordeal with mine. It keeps eating piston seals. They are rough and scoured where they seal up against the cylinder wall after a few hundred shots. I can actually see the cuts in them that run parralel to the tube. Must be some real rough areas in the tube somewhere. Anyway, they start out one holing and then spread to an inch or worse after 2-300 rounds. Its done this consistently for 3 seals now! Arrr!
I have a new compression tube on the way. Hope this fixes it??
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Welcome.
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Well, I got my replacement in today. I only have 150 rounds through it but it is shooting much tighter than my first gun. I'm not going to tear anything down at the moment cause I have a chrony on order and it should be here by the weekend. After I do some comparative measurements I will take them both apart and inspect them.
Good turn around time and glad this one is doing better for you. Keep us abreast of the results when you tear the other one down.
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Jim:
It is a Benjamin Trail NP All Weather
.22 caliber
I have tried three pellets so far. I should have three different tins by the end of the week.
1. Crosman Premier Hollow Points: used these for break in. They grouped OK in the beginning but started to spread. Sometimes they group great and other times at an inch or so. But fairly regularly I get a flyer 2 or 3 inches off. Since I got this gun for pest control I can't risk the flyers.
2. Predator PolyMags: I so wanted these to work. But they fit too loose in the barrel and don't group at all.
3. H and N Field Target Trophies: I have had the most consistent groups with these although many times when I pick the gun up the first shot is a flyer low and too the right. I don't get that.
I am fairly experienced with firearms and am confident that I can shoot a good group. One hole's not a problem at 25 yards with any of my .22 rifles. Currently I sit in a chair with a sawhorse infront of me, rest the foregrip on the back of my hand and support the back of the rifle lightly enough that it can move backwards under recoil.
I got the rifle and broke it in with a tin of CPHP. After not seeing much improvement after 500 rounds I broke it down and gave it a light tune. Cleaned the bore with JB non-embedding compound, replaced the "Factory Damaged" seal with a Titan, cleaned and moly'ed in the right places, and polished the sear to smooth the trigger a bit. Switched to a 4x16x40 Centerpoint scope, moved the rings all the way forward and all the way back, and loctited it all over night. 50 rounds or so after the tune it was shooting really well. Before the tune my groups were over 2" at fifteen yards. After, I was hitting 3/4". For some reason that has been opening up again. Best I can do is a 1" group now at 15 yards.
The weird thing is I can hit a:
1" group at 15 yards,
2" group at 30 yards, and then
1 3/4" group at 50 yards.
The gun is just very temperamental and inconsistent to me. I just got up from writing this to shoot five pellets. First round dropped 1 1/2" low, then three pellets touching, then another 3/4" low off the group. The thing is, they all felt like good solid shots to me. I didn't pull anything and I could see everything through my scope so my follow through was good. I believe that the gun just shoots all over.
My replacement will be here tomorrow so maybe that one will just tell me I stink at airguns. ;-) I hope not. And guys, there is no cost in a return. Amazon overnights a replacement product out to you and gives you a return shipping label and 30 days to return the first unit. Very easy. I buy everything I can through Amazon. Always painless no questions asked.
My Trail NP all weather shoots the RWS Superdomes great the CPHP are all over the place.I can hit a can at 50 yards easily but the gun is hold sensitive.The Superdomes can be ordered from WW site to store.