GTA
Airguns by Make and Model => Benjamin Airguns => Topic started by: Finchlake on February 09, 2012, 04:49:30 PM
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I bought a Benjamin Trail NP XL Air Rifle 22, love this gun. I've had it about a month and fired about 100-200 rounds through it. I am having a problem I was hoping someone could help me with. I normally shoot at 35 yards, after I shoot a few rounds the POI will drop radically, sometimes 8"-12". I'm shooting at paper targets from a rest so I can see what it is doing.
Any ideas what's is going on, and how I can fix it ?
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The scope screws and rings need to be checked, or you arent holding in the same spot every time.
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Hey Thanks, I guess I should have covered that. I changed scopes, put on a leaper 3 x 9 x 40AO. I put blue locktite on all the scope screws and all the stock screws, in an attempt to solve the problem my self.
Also been try different holds to see if that makes a difference.
Thanks
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if its stock it is most likely the piston seal internally it is an easy fix if you make a spring compressor which takes about an hour and you are somewhat mechanically inclined even if its not the piston seal it is a huge variable to eliminate
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Another thing that nobody here ever mentions is Lapping the scope rings.
Although the rings are supposedly cut from a single extruded bar, sometimes they get high points inside the scope tube contact surface. This results in us having to screw the rings down almost to the point of crushing the scope tube to prevent the scope from shifting slightly with the recoil of each shot. Believe me , Air Guns have as much or more recoil than many heavy rifles.
Frequently scope rings are painted instead of blued or in the case of aluminum rings being anodized.
If you leave the rings on the rifle and just remove the scope you can wrap some 400 wet and dry paper around a dowel and rotate it in the scope "bed" across both sets of mounts at once, and see if you scrape off any high points in the aluminum surface.
Frequently shooters will just throw on and clamp up the scope rings and then install the scope and continue to zero the scope. Sometimes the rings can be minutely canted due to grit or excessive paint or a damaged surface.
Wax the scope tube with some furniture wax and when you re-install it put a small amount of blue Loctite on the rings surface. The loctite will adhere to the rings and not the scope. At some time in the future when you take the scope out of the rings again you will see where the loctite filled the voids and mis alignment sections of the rings.
"Hold into the Wind"
Jim
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No spring compressor is needed on the xl series air rifles, the end cap screws off. David
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Thanks Jim, that's an area I hadn't considered. Good write up. The scope rings I used were "UTG Airgun .22 High Profile Integral 1-Inch Ring Mount" I think are good rings.
I called Crosman since I made the first post, and described the problem to them. Crosman is sending me O-Rings for the barrel seal. They were good to talk to, and seemed to want to help.
Crazy thing, I went back out and shot it some , and the elevation is back on. Not sure how long it will last. It seems to be on when I first start shooting and then unexpectedly drop. Sometimes when this happens it make a funny sound.
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Not sure if we have the same issue but I have shots or fliers that go off after it seems I get the scope zeroed. Found out I have been shooting the gun with the barrel resting in the "Y" grip of my San Angelo gun vise. From what I was told here and on a video a major no no! I am going to go to the sporting good store to get a shooters bag and do some bench shooting while resting the guns stock on it while doing the artillery hold.
Will let all know how this goes. Just a thought if your doing what I have been doing. Good luck.
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Sounds similar, I have the scope zeroed, Sometimes it stack several shots, and I think, "I love this Gun", and then it just starts throwing fliers, mostly low. I was shooting from my sand filled, leather shooter bag. I practice the artillery hold, I keep my hand off of the front of the rifle.
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Sounds similar, I have the scope zeroed, Sometimes it stack several shots, and I think, "I love this Gun", and then it just starts throwing fliers, mostly low. I was shooting from my sand filled, leather shooter bag. I practice the artillery hold, I keep my hand off of the front of the rifle.
What type/brand of pellets are you shooting?
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Crosman Premier Hollow Point and Benjanin Discovery 14.3gr. these are the only two pellets that I can get locally.
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One thing I forgot to emphasize about lapping the scope rings is that the lapping must be done sideways at right angles to the line of the barrel. You do a sideways rocking motion and NOT fore and aft.
You have to do the tops of the mounts as well. Just screw them down tight and the 3/4 inch dowell with the 400 wet and dry paper will still fit inside the mount.
Another reason for vertical strings when you are shooting off of bags is that the rear sling stud grabs on the rear bag and the recoil throws the shot off. remove the sling swivel stud.
Placing the rifle on the bags in the same position every time is critical too.
What I do is is to continue to look through the scope after I've fired the shot and watch the pellet strike and observe where the crosshairs ended up from recoil with respect to the pellet hole,
The crosshir reticle will always jump off dead center aim point on recoil BUT THE FINAL RESTING PLACE SHOULD ALWAYS BE THE SAME. Then you will know that the rifle was on the bags in the same place and your hold was always the same.
Many Bench rest Shooters put a good dusting of Baby Powder on the bags to facilitate smoother recoil.
Try it, you will like the smell. :-)
`Hold into the Wind`
Jim
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This one doesn't seem to be the scope mounts. You can do a tissue paper test to check the breach seal, but I'd put my$$$ on the piston seal, the stock screws, or alive jam. JMO
pv
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My God this post sounds familiar..my Trail NP does the EXACT same thing. New scope didn't help and went thru every conceivable fix without an overhaul as its still under warranty. Also got a trigger....much better. The only thing I have found that helps is cleaning the barrel and the pellets. If I fail to clean the barrel its all over the place. I have H&N FTT's coming and if it still shoots 4 to 6 inches low every 15 shots for a couple rounds, I will tear it apart. I'm only shooting at 30 ft and don't believe CPHP's can be so bad they cause me to miss the whole trap off a rest. We will see how the new pellets do...
Wish I had a Chrony....
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All kind of good reply's coming in, Is this a great forum or what. Evey bit of of this is helpful at some point.
I'm shooting off the porch rail with only the front bag, I try to position the gun at the exact same point on the bag each time. I have tried different positions on the bag, and I can see the gun change POI with different positions, but this is a minor change, not the drastic drop I get when it decides to go haywire. Baby power on the bag, I think the wife has some, I'm sure I can slip that out to the shooting range. ;)
Tissue paper check of the breach seal, I suppose you just lay a piece of tissue paper across the seal and fire the gun. I am kind of wondering about the piston seal, sometimes I go back out to shot (without any adjustment to the scope) and the darn thing is shooting back at zero. After a few shoots it drops, it also makes a different sound when it's doing this.
I have not been cleaning the barrel, I had read other post that recommend not to clean the barrel. I'm not against cleaning the barrel, I would clean it every shooting if it gave me consistent groups. I always clean the barrels on my powder burners.
Thanks everyone
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Yes lay a single sheet of tissue across the breech area then fire the gun. Pay attention to the sheet when you fire the gun. If you see it rise up from the air escaping than your breach seal may not be extending out far enough to give you a good seal everytime.
A couple of things to try.
1. Try using a firmer hold on your gun. I know everyone talks about the "artillery hold" but I found my first Trail XL preferred a tighter hold.
2. Try cleaning the barrel. Clean it real good. My replacement Trails barrel was filthy. There can be a lot of left over stuff from the rifling process in the barrel. I used a brass brush on a coated Otis pull through several times, followed by patches soaked with Ballistol.
3. Try some different pellets. Sounds like you only have two brands/types locally available. If you have to order some online or doing a trade here.
4. Are you using the stock trigger? Consider buying a aftermarket one.
A POI shift of 8 to 10 inches is not caused by a piston seal. That sounds like a barrel lock up, scope, trigger and or hold issue. How tight is the barrel tension? When you cock the rifle, and let go of the barrel, it should remain in position, not fall from it's own weight.
Nathan
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:D I had the Trail.22 I sent it back. I am not dealing with a pragmatic rifle. I will do a good tune and replace the piston seal as usual but out of the box it better show me something first. my benji trail was just to pragmatic for me to want to keep her, and that was after i chased down her demons.
There are plenty of rifles out there that are worth having , and after a good tune become keepers .
Heck a cheep beeman rs2 out of the box was so accurate i thought i was seeing things.
best wishes and hope you make out alright.
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Like HNT5 said, bet it is lock up issue.
Brass washers from www.airguntoys.com (http://www.airguntoys.com) fixed my lockup issue, also had the pivot bolt problem with it not staying tight, drilled and tapped a set screw for that, replaced trigger 10 minutes after taking the gun out of the package. I have also replaced the piston seal, which got raid of the first 10 shots in a vertical line at 30 yards, added more power, and surprisingly less kick.
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Like HNT5 said, bet it is lock up issue.
Brass washers from www.airguntoys.com (http://www.airguntoys.com) fixed my lockup issue, also had the pivot bolt problem with it not staying tight, drilled and tapped a set screw for that, replaced trigger 10 minutes after taking the gun out of the package. I have also replaced the piston seal, which got raid of the first 10 shots in a vertical line at 30 yards, added more power, and surprisingly less kick.
Hi.
the brass washers you mention solved you lock up issues, what was the problem you had, and how did the brass washers solve that problem? , thanks
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The brass washers stabilize the breach to receiver fit as the plastic ones lose their tension after a while and get sloppy. This will usually correct left-right variations. The alive jam lock-up controls the vertical stringing. Adding a small washer behind the spring will usually tighten this up, in some cases, it can be necessary to file a bit off the forward shoulder(non-pointy end) to allow a bit more travel if it is contacting the pivot bushing.
pv
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barrel lockup, i have an older winchester 800x that does the same thing. the barrel has a bit of up/down play when in battery
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WOW, all these theories has my head spinning, I think I'll put the gun up and get my jig pole out and go crappie fishing. :o
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:D Thanks I'll remember that info.
In another post. A member said he would shoot bulls eyes then after 10 shots his poi would drop so he ran a dry cleaning patch down the barrel cupple times and then it would shoot again perfect bulls eyes. then 10 shots later it would start to drop again
I use cphp because they are inexpensive and work well with my rifles, but now I am going to wash them to remove the powdery substance and dirt and loose lead chips found in a tin.
but un like others I will not be spraying any lubricant on them, just thoroughly blow drying them
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I went and bought some patches and Goo Gone. I made a cleaner out of weeder line, and gave the barrel a good cleaning. It was filthy, patches just kept on coming out black. A cold front is passing through here today, It's to windy to try to shoot a good group. I let you know if this makes a difference.
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:D I would wash the pellets with soapy water. use a jar and a small screen sive to empty the dirty water and pellets into
I air dry them on a towel with a blow dryer but i don't spray any lube on them afterwards i bet that will keep your barrel clean
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Like HNT5 said, bet it is lock up issue.
Brass washers from www.airguntoys.com (http://www.airguntoys.com) fixed my lockup issue, also had the pivot bolt problem with it not staying tight, drilled and tapped a set screw for that, replaced trigger 10 minutes after taking the gun out of the package. I have also replaced the piston seal, which got raid of the first 10 shots in a vertical line at 30 yards, added more power, and surprisingly less kick.
Hi.
the brass washers you mention solved you lock up issues, what was the problem you had, and how did the brass washers solve that problem? , thanks
POI was all over the place before I installed the washers, it also got raid of my barrel droop.