.22 stopped grouping

[VSS]

It's all gone bad

Since getting loads of advice and help off this site when I first bought my brno #2 (and couldn't shoot for toffee), and putting in lots of practice, I've got used to groups which are more-or-less single holes at 50 paces; headshooting bunnies out to 80 yards with ease; and even the occasional 100 yd+ bunny.
Now it's all gone to pot! Literally overnight. One day it was fine, knocking over rabbits as usual, then the next day it was all over the place. Missed every rabbit I shot at. Went home and tried it on a target, which ended up looking like it had been raked with a machine gun not punched with a precision rifle!
At this point I ran out of ammo. At long last managed to restock, and have another go. Gave the barrel a good clean, which improved things a bit - but not enough to trust it on rabbits beyond 50 yards. Tried firing a group without the mod (a parker-hale), which was much tighter, so dismantled the mod and cleaned that too - it was really crusted up. A lot better after that, but still big groups - as much as 1.5" at 50 yards, which is no good.
I did notice, when cleaning the mod, that one of the baffles in the middle of the stack has been clipped slightly. This hadn't happened last time I cleaned the mod, and looked fairly recent.
So, how can one baffle in the middle be clipped and all the others be ok?
What could have caused a bullet to clip it?
Is this slight damage sufficient to wreck my groups?
Or is there some other underlying cause that's resulted in both the poor grouping and the damage to the mod?

Any suggestions welcome...

 

[Muir]

It's all gone bad

Since getting loads of advice and help off this site when I first bought my brno #2 (and couldn't shoot for toffee), and putting in lots of practice, I've got used to groups which are more-or-less single holes at 50 paces; headshooting bunnies out to 80 yards with ease; and even the occasional 100 yd+ bunny.
Now it's all gone to pot! Literally overnight. One day it was fine, knocking over rabbits as usual, then the next day it was all over the place. Missed every rabbit I shot at. Went home and tried it on a target, which ended up looking like it had been raked with a machine gun not punched with a precision rifle!
At this point I ran out of ammo. At long last managed to restock, and have another go. Gave the barrel a good clean, which improved things a bit - but not enough to trust it on rabbits beyond 50 yards. Tried firing a group without the mod (a parker-hale), which was much tighter, so dismantled the mod and cleaned that too - it was really crusted up. A lot better after that, but still big groups - as much as 1.5" at 50 yards, which is no good.
I did notice, when cleaning the mod, that one of the baffles in the middle of the stack has been clipped slightly. This hadn't happened last time I cleaned the mod, and looked fairly recent.
So, how can one baffle in the middle be clipped and all the others be ok?
What could have caused a bullet to clip it?
Is this slight damage sufficient to wreck my groups?
Or is there some other underlying cause that's resulted in both the poor grouping and the damage to the mod?

Any suggestions welcome...

I can tell you what it isn't. It isn't the rifle proper. Rifles just don't stop grouping over night. Might be the moderator, the LOT of ammo... whatever... but it's not the rifle unless you did something to it. Quit cleaning the rifle, btw. It does nothing to aid grouping. A scant drop of oil on a patch down the bore, two dry patches to follow: That's all it needs, if that.~Muir

 

[8x57]

You did use the alignment rod when re-assembling the moderator baffle stack didn't you?

 

[User00030]

I can tell you what it isn't. It isn't the rifle proper. Rifles just don't stop grouping over night. Might be the moderator, the LOT of ammo... whatever... but it's not the rifle unless you did something to it. Quit cleaning the rifle, btw. It does nothing to aid grouping. A scant drop of oil on a patch down the bore, two dry patches to follow: That's all it needs, if that.~Muir

Muirs right but just check your stock screws havnt come loose as well or maybe your just having a bad shooting day

 

[shakey jake]

Had the same thing with my 17 don't waste any more ammo till you borrow a second scope mine just gave up over night tried a mates spare and grouped like always had

 

[palmer_mike]

Is it a free floating barrel?
if so check the barrel channel is still clear of the barrel also check no grit or similar has been trapped between stock and barrel....

 

[Humpers]

Is there a chance that the crown might have been damaged between the rifle firing well and badly? Or corroded if you left the mod on after shooting?

 

[Klenchblaize]

Its a pity you didn’t retain some of the ammo that was producing 50M bughole groups as this would be one less variable to ponder.

K

 

[FrenchieBoy]

VSS - You ask if the slight clipping on just one baffle is enough to effect your grouping - The simple answer is yes! It sounds like the one baffle was reassembles slightly out of lile when you previously stripped and cleaned the moderator. If it were me I would straight away try shooting the rifle without the moderator and see how it groups. If the grouping is back on par then you have your answer. Just out of interest what moderator are you using? - If it's a Parker Hale then you are surposed to use the ascembly rod to line up the baffles when reascembling it!
I am assuming that you have carefully checked the crown for any slight damage - Its surprising how the smallest little dink in the crown can effect the way the rifle groups.
The next thing would be to check all of the scope mounts are tight and that the barrel is fully floating (If the barrel was floating when it was grouping well)
If all is well then it would pay to try to find someone with a spare scope and try that - You can get a scope "let go" any suddenly and without any warning - A knock when putting the rifle into the cabinet is very occasionally all it needs!
It could be one of a hundred things that are causing the problem that you are suffering from but those are the things that I would check first!
It is even possible that you have got a duff batch of ammo!
The only cleaning my 22LR gets is the woodwork wiped down and oiled with a drop of walnut oil, a very lightly oiled cloth through the barrel every couple of hundred rounds and the action cleaned and oiled occasionally.
Hope you get it sorted mate!

Just out of interest - What rifle is it? I once had an Anschutz 525 do exactly the same with me and it turned out to be the barrel locking screw which had come slightly loose - A quick 2 minutes with a screw driver had it back up on song.

 

[bigoak]

Check all your screws. Action, scope mount etc.
If your barrel is leading up it will gradually decrease in accuracy.
My 1710 shoots awesome after a couple of patches of hoppes#9 followed by a few dry patches.
Check the Mod. My bet its either that or a loose screw somewhere.

 

[User00003]

firstly, you may need to put a LOT of rounds through it after cleaning it, if there's one thing .22lr's do not like, it's cleaning. Expect to put 50+ rounds through it before you can take grouping ability seriously in terms of pattern. Whilst doing so, and after, obviously check your screws. Shoot it without the moderator and see how it groups, if it groups well after being re-fouled, moderator was/is your issue. Is this a muzze can PH? if so, do you still have your iron sights? if so, shoot it without the scope and see if you get tight groups, if so, it's the scope. This will cost you an hour or two of range time but you can rest assured that going through this very simple process you'll find the issue. I can almost guarantee you it's not the brno that's the cause/ie. barrel.

to be honest, I am baffled by those who cut off their iron sights, but that's a whole 'nother story.

 

[ejg]

Bedding a 22 is not a bad thing either. Action screws will stay tight then.
edi

 

[finnbear270]

Was this rifle shooting good groups before you stripped the moderator, or did you strip & clean because groups de graded? ... a clipped baffle will wreck groups, so will loose scope mounts action screws etc.

 

[bewsher500]

What happened between shooting and not shooting? I suspect something had to have happened for it to just fail

if it was mine:

Remove scope, swap for a known good one - (this happened to me and it was the scope!)

STOP CLEANING IT! - the more you clean it the more you will start chasing issues that are possibly just the barrel settling down after cleaning!

swap the moderator for a known good one or remove completely.
For what they cost its not worth trying to fettle

obviously check the rest of the rifle out for loose things and damage but they dont just fail over night without help usually

 

[VSS]

Thanks for the replies so far.

Muir - my cleaning regime is pretty much what you've recommended to me in the past, i.e., leave it alone! However, I've noticed that accuracy drops off a bit after about 400 rounds, and it benefits from a quick pull through at this point. Initially I just assumed that this was one of those drop offs, but when the pull through failed to sort it I gave the barrel a slightly more thorough clean. Nothing too drastic though.

Usually it takes about 15 rounds to settle it down again after cleaning, but I've put about 200 through it since and no sign of it settling down yet!

I don't think the barrel is floated - at least, I can't slide a piece of paper between wood and metal as I can on my .243, and never have been able to.

Have checked tightness of all screws, and all seem to be ok.

Am pretty sure it's not the 'scope, as it grouped ok (ish) without the mod.

Which means it's probably the mod or something associated with it (e.g., thread etc).

I didn't reassemble the stack of baffles using an alignment tool, because until a few days ago (when someone else asked me the same question) I didn't know there was such a thing! I used a knitting needle, which I think was a tip I picked up off the SD. The last time I took it apart and reassembled it was 4 years ago, and it's been faultless ever since (until this episode) so I don't think there was a problem with my reassembly.
Finnbear - I stripped the mod because the groups had de-graded, not the other way around.

 

[VSS]

Oops, accidentally clicked "post" before I finished typing...


Klenchblaize - I was in the middle of a batch of ammo when this happened, so I was able to continue using rounds from the same batch while I tried to sort it out. Until they ran out. However, I had enough left over to show that it wasn't a batch change that was responsible for the inaccuracy.

So, for some reason a round has clipped one of the baffles. Why would this happen all of a sudden? Particularly as it was one of the middle ones. Mod out of alignment due to damaged screw thread? Surely I would have to clout it pretty hard to damage it enough for that to have happened? Don't recall hitting it particularly badly on anything at any time.
Perhaps a duff round did the damage, and now the grouping is being thrown out by the damage?
Also, why should such an apparently minor ding on a baffle have such a dire effect?

And what can I do about it? could I knock out the dent in that baffle? Or how about I remove that baffle altogether, then add a few ordinary steel washers of the right dimensions at the end of the stack before screwing the lid on. There's already a washer either side of the spring that keeps them all squashed together, so another washer or two shouldn't make much difference? At least be removing the dinged baffle I would take out the irregularity.

 

[10.9]

Sounds like a baffle in the mod has been out of line , maybe cased by all the crud in there. The bullets may be clipping it, causing you groups to open up, as said before , try shooting with the mod off and see if you can group as before. Not sure if you can add washers to replace the damaged baffle.
All rifles are different , my old anschutz grouping would drop of big style after about 2000 rds , and would only take 20 or so to be shot in again, but it had shot more than 100,000 rds.

 

[bewsher500]

Bin the mod
it will never be the same and will always be a source of questions with dinged baffles

there are better cheaper lighter mods out there you can walk in and buy over the ciunter


you say it grouped ok without the mod.
do you mean OK? Or as it was before with no issues?

what is your scope and do you have a known spare you could try?

you want to eliminate variable not just speculate

free floating is unlikely to be the problem
are you using a bipod though?

 

[VSS]

Bewsher - when I say it was "ok" without the mod: I fired two 5-shot groups, and in both cases got 4 shots very tightly spaced (or touching), and one a bit wide of the mark. I thought this was probably good enough to rule out the scope.
I was shooting prone, off bipod - this is my usual position.

When you say there are better "off the shelf " mods that I could buy, what had you got in mind specifically? I have tried a couple of other mods on the 22 over the past couple of years, but the P-H has always given the best performance.

The thing that's really worrying me though, is WHY should a round have suddenly clipped the mod after several years of faultless performance?

 

[User00003]

could've been one of the baffles that shook a bit loose, may not have anything to do with the rifle or the ammo

Bewsher - when I say it was "ok" without the mod: I fired two 5-shot groups, and in both cases got 4 shots very tightly spaced (or touching), and one a bit wide of the mark. I thought this was probably good enough to rule out the scope.
I was shooting prone, off bipod - this is my usual position.

When you say there are better "off the shelf " mods that I could buy, what had you got in mind specifically? I have tried a couple of other mods on the 22 over the past couple of years, but the P-H has always given the best performance.

The thing that's really worrying me though, is WHY should a round have suddenly clipped the mod after several years of faultless performance?