GTA
General Discussion To Gateway To Airguns => China Gate => : man00 August 22, 2009, 05:15:04 AM
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Just got it this week from Mike, so I haven't put many shots through it.
Gun finish was okay nothing broke when it came in and all the screws were still in it.
After a few shots of shooting at nothing I decided to test the FPS
Diabolo Exact 15.8 high was 676fps low was 601fps. This was shooting ten times
I never could get it on target, first shot low and to left, next would be to the right, then high. Not using a scope, but a scope is needed on this rifle or at least for me.
Like I said the gun is not broken in at all (only 50 shots through it at the most, so it should get better..maybe
I bought some sights for the RWS 350 I may try on it at a later date and go from there. But at this point in time I wouldn't take it out hunting, it needs some more shots first.
This isn't meant to be a review of the gun just my thoughts after a very few shots . It shoots harder than the Avenger 1100 but not near as accurate out of the box.
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Ronnie, Check the skirts. By that I mean, once you load the pellet,...hold the barrel up into the sky,..or other bright light and look into the breech for any daylight showing through if you can. This is a sign that you'll get "blow-by" when the compressed air hits the skirt of the pellet. Exmp, with my .177 if I load a 8.4 JSB or an 8.8 Beeman FTS in it and seat it properly,..I can still see just a hint of light between the skirt and the barrel rifleing at the breech. With these I'm shooting in the 995 to 1010 fps range,...but if I load a 8.8 Cro mag,..I see no daylight at all,...and am now shooting in the 1070 fps range. Just checked it a few minutes ago. Same thing with my .22,...but the best speed and accuray pellet ( with no blow-by) seems to be the14.5 RWS SD's. The .22 Cro's work good to, but with the tamer Macarri spring,..the FPS's drop off a good bit. Those springs are built for comfort,...not speed. Remember my friend,...I warned ya about those Chinese springs!!! They got some juice don't they?!?! LLH Just keep shooting it,... and it will get better!!! tjk
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I didn't find cocking any harder than the avenger, yeah I think it will get better with more shots.
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676 with a 15.8 gr pellet- that's just a whisker over 16 ft•lbs. Shouldn't a B28 be doing nearly 50% more than that? I thought the B28 is a Diana 350 copy, I could be mistaken though. Does blow-by affect velocity that badly? :o
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it should be shooting harder than that, didn't I chrony it at 800 fps with Hunters??? When I sighted it in it was getting 3/4 inch or less groups at 20 yards....wonder whats up here...
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Ronnie,...what pellets are you useing/testing with your 28???? tjk
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before you throw a scope on it learn how to shoot it without, these things are tricky and putting a scope on it doesn't help until you get the right hold down...it can take alot of trigger time to get it right,,,,TJK can give you tips on how to do that.....I can't help much any more I just grab them and shoot....
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Diabolo Exact 15.8 and 16gr polymag
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yeah I seen that on the box, I went back later today and shot another 50 shots. FPS stayed about the same. and my target was just a paper plate. Shots were all over the place at 15-20 yards. Not three shots in row even hit the plate...I came back home and got the Ruger 10/22 just to see if my eyes were that bad. Took another plate with me and with the 10/22 no problem hitting the plate dead center each shot, killed a few turtles while there. I'm not bashing the gun, I will give it some more time and like I said it shoots harder than my Avenger 1100 .22 I had.
I not impressed at all with the sights so far, I may or may not add the scope..too early to say right now.
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get some other pellets to test, doen't look like it likes what you have....Try Gamo Hunters and RWS superdomes
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Got some RWS Superdome .22 Cal, 14.5 Gr today and went out to shoot a few. Shot five times through the chrony..results were 681, 673, 668. 670 and 663.
I did notice a lot of dieseling but not after each shot the worse was after the 4th shot through the chrony. Didn't have the time to work on grouping in the sights today.
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This really has me thinking Ronnie. Ok let's start from the beginning,...What specs does your rifle have,...eg,..factory seal, or Macarri seal. Spring,..Factory or Macarri spring. Top-Hat,...Did Mike instal a metal or delrin TH? What all pellets have you shot through this rifle? Name them all. If you do not seat a pellet correctly,..you will not get a consistant chroney reading. Did your rifle come with a champhered breech loading port,..or is it straight cut like a Diana? I'm not trying to insult you at all,...but these technicallities are very important for diagnosing your velocity and accuracy problems. Dieselling is perfectly fine,...if it's detonation,...when your gun goes "Bang" like a .22 rim-fire,..then we need to look into it. Heavy Dieselling can and will occur with light or loose fitting pellets,...and if dieselling is very prevelent,...this may result from light/loose fitting pellets,...resembling dry firing,...too much blow by during the firing cycle. I really am concernned here,...because your numbers are kinda low. Accuracy wise,...they are a trick to figure out how to shoot,...and that will come in time...besides the "irons" ain't all that great either!!!! LOL's Please give us a detailled desciption of you rifles make up,..parts wise,...and what pellets you've shot through it thus far. Then we can make a better judgement and accertation of what the hecks going on with your B-28. Mike's here for ya,..I'm here for ya brother,...the GTA's here for ya,...everybody here wants you to conquer this Dragon!!!! I know we can do this together!! tjk
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Check your breech seal. I am getting 680 with my Panther you should be a lot higher.
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tjk - 8/24/2009 4:57 PM
This really has me thinking Ronnie. Ok let's start from the beginning,...What specs does your rifle have,...eg,..factory seal, or Macarri seal. Spring,..Factory or Macarri spring. Top-Hat,...Did Mike instal a metal or delrin TH? What all pellets have you shot through this rifle? Name them all. If you do not seat a pellet correctly,..you will not get a consistant chroney reading. Did your rifle come with a champhered breech loading port,..or is it straight cut like a Diana? I'm not trying to insult you at all,...but these technicallities are very important for diagnosing your velocity and accuracy problems. Dieselling is perfectly fine,...if it's detonation,...when your gun goes "Bang" like a .22 rim-fire,..then we need to look into it. Heavy Dieselling can and will occur with light or loose fitting pellets,...and if dieselling is very prevelent,...this may result from light/loose fitting pellets,...resembling dry firing,...too much blow by during the firing cycle. I really am concernned here,...because your numbers are kinda low. Accuracy wise,...they are a trick to figure out how to shoot,...and that will come in time...besides the "irons" ain't all that great either!!!! LOL's Please give us a detailled desciption of you rifles make up,..parts wise,...and what pellets you've shot through it thus far. Then we can make a better judgement and accertation of what the hecks going on with your B-28. Mike's here for ya,..I'm here for ya brother,...the GTA's here for ya,...everybody here wants you to conquer this Dragon!!!! I know we can do this together!! tjk
Pellets used so far Diabolo Exact 15.8 , RWS Superdome, and few Polymag 16gr. The rifle came with the I guess basic tune that Mike does. Nothing extra that I know of.
Looked at my breech seal and it doesn't stick out like in this RWS 34 here is the link
http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=12899&mid=104130#M104130
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Well I guess it doesn't really matter if the gun is working 100% or not since I read on the forum here that Flying Dragon Closed.
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you mentioned that the breech seal doesn't seem to be sticking up as much as the one in the pic you showed.. Do you mean it does stick up, just not as much, it's roughly flush with the face of the breech, or is it below the face of the breech?
Some Diana rifles recently have had issues with low breech seals, namely the 34's and the 350's. I noticed in the numbers you posted earlier that the muzzle energies for the shot strings you listed came out at only .2 fpe apart. So the rifle, while having issues, is curiously consistent in that regard. And having a low breech seal would be a "consistent" problem shot to shot.
I don't know if you have, but if you haven't you might want to read through this post and it's replies:
http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=12000&mid=93881#M93881
as well as this PA blog post:
http://www.pyramydair.com/blog/2008/04/shimming-diana-breech-seal.html
Good luck, hopefully the issue is simply the breech seal, because if so it should be an easy fix.
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man00 - 8/25/2009 9:21 PM
Well I guess it doesn't really matter if the gun is working 100% or not since I read on the forum here that Flying Dragon Closed.
Drop Mike an email, he will make it right. Don't take his closing as a dissapearing act, Mike has been around for a long time and has a great following, doubt he will dissapear completely.
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Check the area around the breech seal and where the seal contacts the action port. If there is evidence that air is leaking,..you will see it most of the time. A properly working seal will leave a distinct "O-Ring" mark on the action,....if you're experienceing air leaking through or around the seal,,...this mark will look to be 'blown" out to one side via escaping compressed air. Evidence that there is a problem!! Try the tissue paper trick if you don't see any visible signs. tjk
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Your #'s do sound low for a factory sprung 28. EM Mike, he'll re-work it I'm sure. In the mean time,...I'd try a different pellet with a snugger fitting skirt. tjk
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the B28 tuned by Mike shoots between 840-850 fps with 14.3 gr. pellets at least mine does
I don't think the pellets are the culprit since I shoot Gamo, RWS, Crosman and velocity is not an issue but accuracy does matter with different pellets
your problem is the breech seal, change it and do another string of pellets, if this does not work then we go to plan "B" that spread of 601 low and 676 high in fps is to erratic with a 75 fps difference between them
warren
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Ran across a review on the "BAM" don't know if they the same as Xisico or not. This was in the 177 cal, using 11.6 grain fps was 539. So mine I guess isn't too far off.
http://www.airgunadvice.net/viewtopic.php?t=7239&highlight=b28