GTA
PCP - HPA - C02 Gate => Crosman Discovery Forum => : noisemedia January 19, 2010, 01:08:02 PM
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Hey guys,
So Ive been enjoying my new discovery over the last few days, but Im troubled by its inaccuracy so far. Ive read on here about POI changing frequently and I think that might be a problem for me. Before I send this back to PA (for another that likely shoots the same way) what can I do to tighten this thing up? I love the style and feel of the rifle its just not shooting well for me.
Ive read about barrel bands. Whos moved theirs? Did it actually help? Ive read yes and no so far...Also, should I add another? Its raining like crazy here so I wasnt able to get out today and test that out, but I plan on trying that as soon as it dries up.
Before we go any further, I dont think this has to do with pellet choice. While it is quite picky Ive found that it shoots the cheapo crosmans, CPHP, Kodiaks, and JSB's very well. The thing is I notice that every time I go back out to shoot it its very inconsistent. One more thing, Ive also tried two scopes, and the results are the same. Its just kind of...all over the place. Of course, I havent mentioned my shooting technique...but its from a rest so I dont think that has much to do with it.
Anyway, I'd appreciate some feedback if anyone has any.
Thanks!
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The Discos' are supposed to be pretty accurate. Maybe it the band (Earlier models had some loose bands) or maybe there's a burr in the crown. Check that with a Q-Tip.... Good luck.
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AHHH the crown. I didnt think of that. I will check it out, thanks.
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Just got my Disco and will be working out its idiosyncrasies.The barrel is not on straight for beginners and the band is a sloppy fit.
Any way. Have you found its sweet spot? Maybe that could be part of the problem.
Terry in LP
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I added another barrel band to my Disco. It didn't change accuracy but it does keep the barrel from moving.
One other thing if you haven't already done it - make sure the screw attaching the stock to the action is tight. I tightened the screw up on mine and it greatly improved accuracy.
Hope you figure out the problem.
Brian
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Funny you should say that because it seems the barrel is not straight either. It seems to angle to the left slightly but Im not sure what to do about that. Interestingly, it also tends to shoot up and left quite a bit. Maybe its in my head though....doesnt seem like it though.
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I think I've read somewhere that barrels on the disco are a 50/50 bet.
Some come with really good barrels and some don't.
Sounds like you may have one of the rough ones.
Like it was mentioned, the crown is a good place to start.
You might also try moving the barrel band a little at a time out toward the end of the barrel.
It comes from the factory nearly touching the stock. Out toward the end may provide more support.
One other thing is to try shooting it with the open sights. You might be having a scope problem and not know it.
Ray
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Thanks Ray! Im heading out in a few minutes to test this barrel band theory. Hopefully it works!
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Don't fret I had to clean up the crown on mine and now she shoots one holers all day,if I do my part,lol.I also added a 2nd barrel band but like mentioned earlier didn't do much.The one thing that threw me off being my first PCP was the POI change as my air preasure changed.Learn to stay in your sweet spots and she'll make you a little less nuts.
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Posted a bit back on another board:
Been working on it for months. Two barrel bands do seem to keep the point of impact from wandering around day-to-day. the custom ones (will have to look up the maker) with 4 screws do seem to help stablize things.
Making sure the breech is well fitted to the air tube helps accuracy a good bit. Too long a transfer port, and you'll see the breech isn't sitting down against the air tube (breech only has a small "foot print) on the tube, and needs all the contact it can get). Too short a transfer port and the damned thing leaks. Don't crank down on that dinky breech screw hidden under the bolt or it will just break.
Clean barrel well, check the barrel crown, and check the beech for burrs around the transfer port. Pushing pellets 1" into the breech, then removing will give you and idea of the transfer port is damaging them when loading.
Tried 30 shots (in the best of the sweet spot for each test) as 6 targets of 5 shots each at 20yards, looking to sort out the best pellet choices.
(click on pictures to enlarge)
This is where I left it sighted in 2 weeks ago:
(http://i157.photobucket.com/albums/t50/ribbonstone/th_DSCF0484.jpg) (http://s157.photobucket.com/albums/t50/ribbonstone/?action=view¤t=DSCF0484.jpg)
So I started with the same pellets today:
(http://i157.photobucket.com/albums/t50/ribbonstone/th_DSCF0504-1.jpg) (http://s157.photobucket.com/albums/t50/ribbonstone/?action=view¤t=DSCF0504-1.jpg)
Different target styles, but the POI stayed pretty stable… quite close to where it was left, which was the whole point of all the barrel band fiddling.
So tried the following pellets as well:
(http://i157.photobucket.com/albums/t50/ribbonstone/th_DSCF0502.jpg) (http://s157.photobucket.com/albums/t50/ribbonstone/?action=view=DSCF0502.jpg)
(http://i157.photobucket.com/albums/t50/ribbonstone/th_DSCF0503.jpg) (http://s157.photobucket.com/albums/t50/ribbonstone/?action=view¤t=DSCF0503.jpg)
Haven’t a good reason, other than barrel vibration/harmonics, for the POI to be generally off to the left with the JSB pellets.
The CP’s were out of the running almost with the first group, but kept on shooting for 30 shots even though it was evident they weren’t going to be in the top 3.
(http://i157.photobucket.com/albums/t50/ribbonstone/th_DSCF0506.jpg) (http://s157.photobucket.com/albums/t50/ribbonstone/?action=view¤t=DSCF0506.jpg)
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Thanks for the info guys. I had a few minutes outside this morning to check the barrel band theory and I couldnt really tell much if any difference. Ive also ordered another scope, just in case it actually is a scope thing. Ive inspected the Muzzlebrake and the crown but to be honest I cant see anything on the crown that appears to be causing a problem. Then again not like I would know what to look for anyway. If anyone knows where to get those barrel bands, give me a holler. Thanks again!
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For the crown take a Q-tip, push one end into the end of the barrel and then pull it out again. If there are any burrs or nicks in the crown then when you pull out the Q-tip you will see cotton fibers getting caught on the burrs. If the Q-tip comes out cleanly and no fibers get "caught" then it should be ok.
Jeff
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Awesome, thanks Jeff.
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My first Disco has the poi shift problem also so the bolt kept flipping up after firing it. It was Mac1 tuned disco, so much for the "tuned" disco. I bought one from Sunshine Air when they had them on sale for $155 (what a deal!). It does not have the problems the first one had. Perhaps I got luck but out of the box it is a shooter. If I would have had problems I would send it to Mike T for one of his tunes. I took one of his in a while back in a trade and it is sweet. Good trigger, second 4 screw barrel band and back yard friendly.
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thanks for the advice guys. Im going to make sure and try this barrel band idea, the crown, and this new scope i ordered as soon as it stops raining long enough. And its southern california too. Oh well.
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Thanks for the advice everyone. After struggling with this gun for over a week now Ive decided to return it to PA. I may end up buying the Marauder instead...but I havent made up my mind yet...then again I really did like this Discovery, it just doesnt shoot properly. Anyway...life goes on.
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If you're gonna return it but really liked the Disco platform then there's always the Katana.... Has the Marauder match grade trigger, a stock better suited for adults and also a choked barrel...... it's more money of course but something to think about....
Jeff