The subject in question is a Diana 350 magnum, ts-5 trigger, that I can't get any consistency out of. I'm using the artillery hold, lightly held, open irons, two different scopes, and mounts, everything torqued (though getting a definitive number for scope mounts and rings has proven vague), and 8 pellets from 5 manufacturers. Stock bolts have been checked for tightness before every session. With this supposedly high craftsmanship rifle I would expect less then an inch groups at 25yds easily, which I get... sometimes. And then it goes to 1.75" - 2.5" (or more - some over 3"). Barrel has been cleaned, though not after every session. Anyhow, I will try to attach some photos of the crown. On my powder guns this would be unacceptable. My question: Is this a "normal" crown for a Diana 350 magnum? It appears to have been roughly cut off on a lathe, and then rifled (I assume button rifled, but don't know) because slight metal extrusions are sticking out where the rifling exits the barrel. There is no chamfer or smoothing, only an outside (rough) bevel. So, to you other Diana owners, how do your crowns compare? And any further recommendations on how to get this thing to shoot, please let me know.
Diana 350 magnum crown - is it normal?
- Thread starter sammich
- Start date
Here lies your problem. That is the worst barrel crown attempted repair that l have ever seen. Replace the barrel, that one is toasted. I have never had a barrel recrowned but maybe it is a option, others might help out in that regard......
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If you have a drill, get yourself a single cut carbide burr in a teardrop shape then with minimum force recut that barrel crown. The single cut will leave a very smooth finish and the teardrop shape will center itself. Been doing this for over 30 yrs and it works extremely well. Also check the loading port, as I have saw this same poor cut where the pellet loads. Someone let this slip by in the quality control area !! Unfortunately I have saw this on ocassion from many brands, just a slip in qualitu control !!!
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I see you're new to the forum so welcome.
That's sadly a bad factory crown. It can easily be fixed.
I agree that you shouldn't have to do so though with that "German" airgun.
That's sadly a bad factory crown. It can easily be fixed.
I agree that you shouldn't have to do so though with that "German" airgun.
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OOF that's ugly. Hope you get it fixed soon!
Looks like either the ruffer pass went too deep not leaving material for the finish pass...
Or the finish pass tool was chipped, cut air... then... unfortunately... nobody noticed...
-The fact that nobody noticed is the weird part
Heck, that detail/part/barrel may have even been involved in a machine crash now that I look at it closer.
Looks like either the ruffer pass went too deep not leaving material for the finish pass...
Or the finish pass tool was chipped, cut air... then... unfortunately... nobody noticed...
-The fact that nobody noticed is the weird part
Heck, that detail/part/barrel may have even been involved in a machine crash now that I look at it closer.
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Thank you all for your quick replies, and forum welcomes. The verdict seems to be that this is not the "norm" for the supposedly great German guns then, right? That was part of the point in avoiding the Chinese stuff in the first place. Anyhow, -bandg- I have done the round head brass bolt trick on a .22 that had been dropped on its muzzle more than once, and it at least looked better afterwards. (The barrel was in such bad shape internally as well that I'm not sure it helped any, though!). -airshot- I am not familiar with the bit you are talking about, but will find one. I do have drills, and access to a machinist lathe if that can be of help (I'll look at it in the next couple of days to see if I can get this barrel into it). Is there a particular size bit I need to find for this .22 barrel?
I did not get this as a new gun, but it came from a hard case (a friend's) and went into a hard case (mine) and has no nicks or scratches of any kind (not abused, in other words). I was shocked when I took a closer look at this crown, though.
I did not get this as a new gun, but it came from a hard case (a friend's) and went into a hard case (mine) and has no nicks or scratches of any kind (not abused, in other words). I was shocked when I took a closer look at this crown, though.
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Carbide burrs are qyite common, using onevwith a single cut will cut less material and leave a finer finnish. The teardrop shape has a smaller end then swells to a larger diameter, make sure you get one larger than 9/32 at large end to allow chamfer on your .22 barrel. These typically have a 1/8" shaft to chuck up in your drill. Lathe is not necessary as the burr will center itself, again the reason for using a single cut and not a double cut burr. Ebay, Amazon, and good hardware stores will carry them normally where the dremel type tools are at. Use just enough pressure to allow the burr to cut, the single cut removes small amounts and leaves a nice finnish!! Be sure you clean all those little fine chips from the barrel.
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Update and closing statements: I re-crowned using recommendations in this thread (worked well, so thanks again), plus polishing with dremel wheel and conical attachment. Accuracy still isn't there, but now it is more consistent and slightly more accurate. I wouldn't hunt with it, nor would I be competitive in events, but it will be fine as an overpriced plinker. Chinese quality at German prices. As stated, though, at least it is relatively predictable now.
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Random lame thought but did you try pushing a pellet through the barrel from breech to muzzle to check for tight/loose spots?? Came to mind because too tight or too loose a choke will also cause issues and considering what that crown looked like, well.....
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I did not, and I'm not sure how I would tell if it was too much of either. I can tell it is a choked barrel, but that's about all I know. Do you have any references for checking this?
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Here's one at least and written by nervoustrigger: https://www.gatewaytoairguns.org/GTA/index.php?topic=130555
He's a member here also and will probably happily help with questions you may have. Probably any number of other members who also have plenty of experience with this, because while it's something I know of from reading the forums, it's also not something I've tried myself as yet.
Apologies for not being able to help more with the totally indepth stuff.
He's a member here also and will probably happily help with questions you may have. Probably any number of other members who also have plenty of experience with this, because while it's something I know of from reading the forums, it's also not something I've tried myself as yet.
Apologies for not being able to help more with the totally indepth stuff.
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The last Diana I worked on had a pretty tight choke, too tight IMO, and was extremely pellet picky. I ended up chopping the choke off, and rechoking it to a less aggressive one.
Also, a carbide burr used freehand is an extremely crude tool to use for something as important as a crown. Please use an aircraft countersink with a fitted pilot at least, to ensure that it is square to the bore. You can find them on tool supply sites, even Amazon, or Brownells sells a high quality version of the same thing for more money.
Pushing a pellet through is good advice, and will tell you a lot about the finish of the bore, size of the bore, and how your crown turned out. Even when cut on a lathe with a less than perfectly sharp tool, there can be a tiny almost unnoticeable burr rolled onto the inside that will destroy consistent accuracy. Make sure to check for it, as well as a super tight choke and roughness within the barrel.
Also, a carbide burr used freehand is an extremely crude tool to use for something as important as a crown. Please use an aircraft countersink with a fitted pilot at least, to ensure that it is square to the bore. You can find them on tool supply sites, even Amazon, or Brownells sells a high quality version of the same thing for more money.
Pushing a pellet through is good advice, and will tell you a lot about the finish of the bore, size of the bore, and how your crown turned out. Even when cut on a lathe with a less than perfectly sharp tool, there can be a tiny almost unnoticeable burr rolled onto the inside that will destroy consistent accuracy. Make sure to check for it, as well as a super tight choke and roughness within the barrel.
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Well Thumper, that sounds like pretty advanced gunsmithing. Re-choking a barrel? No idea how that is done. And how would a pushed pellet tell me about the crown? I thought it just indicated bore size. Plus, once it passes through the choke it will be deformed differently than from the rest of the barrel anyway. And what is "too much choke"?
I do understand the need for pilots. Even the bore hole isn't necessarily centered in the barrel itself, so it would seem important to have the crown perpendicular to the hole more-so than the barrel. But maybe that's too picky.
Anyhow, lots of new questions have come up now. But maybe best to just walk away and buy something different (from China this time!). I have two springer rifles, one springer handgun, and a couple of pumpers, and one CO2. Of the bunch this one cost significantly more, and shoots the worst (except maybe the CO2 model. It seldom sees the light of day anymore, either, but it is a repeater, so has that going for it). The old adage "You get what you pay for" doesn't always hold true, it seems.
But I will at least slug the barrel and see what that comes up with. I don't have access to a bore scope anymore, but that might have told me some things, too.
I do understand the need for pilots. Even the bore hole isn't necessarily centered in the barrel itself, so it would seem important to have the crown perpendicular to the hole more-so than the barrel. But maybe that's too picky.
Anyhow, lots of new questions have come up now. But maybe best to just walk away and buy something different (from China this time!). I have two springer rifles, one springer handgun, and a couple of pumpers, and one CO2. Of the bunch this one cost significantly more, and shoots the worst (except maybe the CO2 model. It seldom sees the light of day anymore, either, but it is a repeater, so has that going for it). The old adage "You get what you pay for" doesn't always hold true, it seems.
But I will at least slug the barrel and see what that comes up with. I don't have access to a bore scope anymore, but that might have told me some things, too.
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A shame considering that it's german made and quite pricy too. Maybe it's just a lemon. Could it be that it's a magnum? I mean, it might sound ignorant but from what i've read magnums are a bit harder to use than their more timid counterparts. Could be completely wrong though.
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It sounds like you and I got the same rifle! When I got mine new, it shot horribly too. Also had a bad crown. I took it to a gunsmith and had the barrel shortened by about six inches and of course had it recrowned. That helped. Still was my harshest, least accurate rifle. Got a .22 barrel from Mike Mellik (hope I spelled that right) that was for a Chinese version of this rifle. He shortened it to the same length as my original barrel and gave it a nice crown. Now it is much better. It is still fairly harsh to shoot but it is very accurate now if I really pay attention to my hold. I pull it out from time to time and put some pellets through it. It really forces me to pay attention to my hold and that makes me shoot my other springers much better. It is amazing how different my other springers shot cycles feel compared to this one.
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I guess it comes down to whether it is still worth "throwing good money after bad", as they say. Currently, at 25yds with target pellets it can hit a median of 1" (half under, half over). With field pellets I can count on just over 1.25" for that call. Not really useful, but as you pointed out, good to work on hold and such. (I'm sure many readers of this are just thinking "probably the shooter, not the gun"... maybe. But I have another magnum springer that shoots fine, as do my other "regular" springers, soooo... maybe it IS the gun in this case... who knows! 
I guess all companies have their bad days of production (Friday right before they went on strike, perhaps?!). But in the end it just means I'll never buy a Diana / RWS again. Lots of "good enough" Chinese guns out there for a lot less money (those I expect to have to work on!).
I guess all companies have their bad days of production (Friday right before they went on strike, perhaps?!). But in the end it just means I'll never buy a Diana / RWS again. Lots of "good enough" Chinese guns out there for a lot less money (those I expect to have to work on!).Upvote 0
"I'll never buy a Diana/RWS again". One view. One could also look 4 posts down to see the opposite view.
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