how short is too short (.22lr barrel)

[Bewsher500]

I have a sako quad and acquired a 15" barrel and spare synth stock

previously it worked a charm, hole on hole or close to it at 50yds

 

The crown and thread job was a bit ropey so I had it recut and in chasing my dream of a very short pointy rifle I had an inch and a bit nipped off so the threads were just longer than the stock

The crown and threading job I had done is first class, have had work done on centrefires by the same person and they all perform well

 

took it out last night for the first time to zero it and it wouldn't group for toffee!

picture below to demonstrate just how bad!

the three triangular shaped groups are the .22lr (little circular ones at .17m2 at 50/100)

for contrast the sticker on the lower right is one of 5 shots plinking off sticks at 60 yds with the 14-15" barrel

4 inside an inch, 3 at around 1/2", off a proper rest it was mostly touching with some around about

 

barrel hasn't been deep cleaned (other than to remove swarf/solvent from cut/thread job)

ammo is the same

mod is the same

scope is the same, (all tight)

 

bottom target wasn't the most solid rest but no worse than off sticks (shots to the left were first ones to zero and the scope was adjusted)

middle target was two groups prone off a solid rest. first group left and scope adjusted to move POI right

 

is it now too short? or am i missing something here

I am conscious that the twist rate of 1:16.5" means it now only has roughly 3/4 of a twist as opposed to nearly one full twist with a 15"

 

 

[deershooter]

Try it without the mod

 

Deershooter

[keg]

Had my quad shortened to 16" and it's fine.

[Bewsher500]

Try it without the mod

 

Deershooter

 

 

I know what you mean but if it only groups with the mod then its pointless having it!

there is no clipping of baffles (stripped the mod to check)

previous shots with the same mod and an extra 1-2" of barrel were spot on

[Berettacocker]

Doesn't matter if the crown job looked ropey because it shot well previously. Maybe it's ropey now? Take it back to gunsmith get him to check it over. Try different rounds that might work? Good luck

[Bewsher500]

looks perfect, as have all other crowns I have had done by them

crown is concentric and perfectly smooth, no obvious angle to any gas marks
clean edge to all lands
done the cotton bud test, can't get anything to snag

micro rifling looks clear as far down muzzle as I can see
mod mounts perfectly, no snagging
shoulders on barrel square and sight through barrel with and without mod shows no obstruction

very odd

have a ammo test to do now to see if is just a flavour thing with the changed barrel harmonics
have some:
Eley subs
RWS subs
Win subs
CCI segs


will see how they fair.

will try a group without mod to check first and maybe foul up the barrel a bit

 

 

[fortune]

It could be that you have taken the barrel out of it's harmonic sweet spot. I think that is why a previous post said about "try it without the mod". I know that you want to use the mod but it is an experiment. This would show whether the weight transfer is affecting it. Alternatively as an experiment you could add a bit of down weight by wrapping an amount of lead sheet around the barrel or getting a cable tie and fitting it around the barrel and fore end. I had this with my 223 and it was all over the place. I had to completely re-bed the whole lot in glass. At one time there was a sort of adjustable weight that you could fit that was dial adjusted to find a sweet spot on the harmonics. I was even contemplating machining up an adjustable sleeve to get the desired result but sorted it out before this was needed.

[welshwarrior]

Interesting normally makes them shoot sweeter but as above you may now have to play about. Try different ammo first I had a Ruger that change it's preferred diet from Eley to CCI once shortened.

 

Is the barrel free floated full length at present if it is try a pressure point to see if thing improve.

[Bewsher500]

poxy placcy stock so any pressure point is likely to be variable

 

its a sporter barrel in a varmint stock so more clearance than parking in London

mod is a Aluminium Wiehrach one. be very surprised if it throw the harmonics off enough to produce such variety

 

harmonics is one thing, adding a mod will shift POI but to create such a variable POI is not likely to be just harmonics

 

very weird

[turbo33]

poxy placcy stock so any pressure point is likely to be variable

 

its a sporter barrel in a varmint stock so more clearance than parking in London

mod is a Aluminium Wiehrach one. be very surprised if it throw the harmonics off enough to produce such variety

 

harmonics is one thing, adding a mod will shift POI but to create such a variable POI is not likely to be just harmonics

 

very weird

 

 

The Anschutz 1417 only has a 14" barrel, and although its a different rifle, I can't think the length is the problem. The only thing that's changed is the engineering, so that has to be suspect no 1, no matter how good it looks. The other thought is, I wasn't aware Weihrauch did a silencer for rimfire Its not the one for the HW100 is it? If so, it only has some plastic curlers, stainless washers and felt inside, and defo not designed for rimfire. If it is that one, it will without doubt, be blown to bits inside and the rounds will be hitting all the jumble on their way through. If you won't try it without the mod, Can you try another one? Although, I would, as the others have suggested, try without the mod, as it will guide you to either the engineering or mod being at fault in one go

[welshwarrior]

Lengths not an issue I've got a Brno at 14" had several rifles at 12.5" all shot well.

 

Intrigued why it won't shoot.

 

Have removed everything then reassembled checking bedding into stock mounts scope all going on right and tight. Barrel in correctly no left swaff etc. I'd then be tempted to scrub the barrel so your starting from a known point.

[theshootist]

This is good advice, clean the barrel and put at least two boxes through it. If it still doesn't perform take it back and ask him if he can eliminate the barrel work as a factor.

[Bewsher500]

I wasn't aware Weihrauch did a silencer for rimfire Its not the one for the HW100 is it? If so, it only has some plastic curlers, stainless washers and felt inside, and defo not designed for rimfire. If it is that one, it will without doubt, be blown to bits inside and the rounds will be hitting all the jumble on their way through. If you won't try it without the mod, Can you try another one? Although, I would, as the others have suggested, try without the mod, as it will guide you to either the engineering or mod being at fault in one go

 

designed or not...it is super light, works a charm, is utterly silent, click, whizz, smack

I stripped it this morning

comes apart easily still

washers are slightly coated with residue, curlers are intact, felt is a bit dirty, otherwise as expected

probably had 500= rounds through it. if it dies I will buy another

 

It is my on ticket "rimfire moderator - no specific markings"!!

 

 

will try without mod after cleaning barrel

run half a box of win subs, some RWS, CCI and Eley and report back

 

have removed and refitted barrel several times to make sure it is tight

action screws tight

just wondering if the scope has somehow decided to go mental on me

[kent]

A .22 lr will shoot very, very well in a small handgun. Velocity is only marginally effected at 10". You problem is in the crown, threading job from what I see.

As mentioned remove the moderator and try again as that removes both a moderator fault and thread concentricity to the bore. Then you need to look at the crown (there is also the factor that some ram the centre of the lathe into the bore after cutting a crown to thread it and actually damage or flare it, it not even required or recomended if you have the right kit)

[turbo33]

 

designed or not...it is super light, works a charm, is utterly silent, click, whizz, smack

I stripped it this morning

comes apart easily still

washers are slightly coated with residue, curlers are intact, felt is a bit dirty, otherwise as expected

probably had 500= rounds through it. if it dies I will buy another

 

It is my on ticket "rimfire moderator - no specific markings"!!

 

 

will try without mod after cleaning barrel

run half a box of win subs, some RWS, CCI and Eley and report back

 

have removed and refitted barrel several times to make sure it is tight

action screws tight

just wondering if the scope has somehow decided to go mental on me

 

Doesn't mean a thing other than its on your ticket, and that's what is usually written by the supplier.

 

Scope seems fine with the .17m2 barrel, so as said before, the suspect is the only other change, the engineering. I agree with Kent, the crown looks horrible. My first 455 HMR had a crown that looked like that, and the grouping was as bad.

This is a pic of the replacement rifle, a 452. Both the 22lr and the HMR have identical crowns, and they are absolute pinholers. And this is a super macro pic.

Edited June 11, 2014 by turbo33

[Bewsher500]

 

Doesn't mean a thing other than its on your ticket, and that's what is usually written by the supplier.

 

, the crown looks horrible.

 

It means everything when it is attached to a section 1 Firearm

sticking any moderator on a firearm without authority is an offence

 

just so we are clear here...no offence...literally

 

but back on topic

the photo doesn't do it justice, its an 11 degree flat crown rather than the convex version you have in your picture

its actually very smooth

no centre was used in the bore.

no swarf or snaggy bits, cotton bud test.

its concentric, or at least as concentric as I can test without sticking it back on a lathe (its actually much more concentric than the previous one!

no witness marks on any of the baffles or muzzle of the moderator

 

doing my head in but I am hoping to sort before the weekend

[silverhawk]

Change the ammo.I had my barrel taken down and it wouldn't group with the ammo I had so I tried some different brands and it groups great now

[Bewsher500]

yeah that is my hope

have 5 kinds now

[kent]

You say it shot very well before it was shortened, now it don't (that's a no brainer) and it aint due to the shorter barrel I promise you that! I have yet to see a RF that was that ammo fussy but remember its the same tube as before, it shouldn't have changed what it likes if all is good

[kennym]

No offence to the OP but you ask for advice then don't seem to want to listern

Just an observation

Have a free shot if you wish but to avoid a slanging match I'll say no more

[Bewsher500]

OK point taken but tell me what is wrong with the crown? (other than "it looks sh1 t")

 

because as it stands I can't fault it

it is an identical crown in size and shape to my .222, also done by the same person, who also did my .243 and .300Win Mag.

Its not some micky mouse job by someone with a new hobby lathe

 

 

I agree that this is the only change of any significance (short of any process that removes swarf and lubricant from the process) and other than the shortening, but without an obvious issue just saying "its the crown" doesn't help me

 

if it was off centre

not perpendicular,

jagged

used a centre steady and screwed up the rifling...then yes I would be right there saying to the person who did it, "please fix this"

 

 

the rifling is crisp

all lands end uniformly

the bore is central to the threads (measured)

the thread cut is square, (measured with a square)

Its rebated and their is no shadow of the mod in the bore when it is fitted

no baffles are touched in the mod by any shots

 

so what exactly am I supposed to say to the smith who did it?

Edited June 11, 2014 by Bewsher500

[fortune]

Your crown looks about the same as my 223, which shot really accurately without the mod but whan the mod was on the barrel it was all over the place. Firstly I put a cable tie around the barrel and the fore end and this put a bit of down tention on the barrel. the result was that the groups were a lot-lot smaller than without. As a result of this experiment I removed the tie and then glass bedded the barrel and action into the stock so that the whole lot was stabilised. Not all crowns are of a rounded shape. My Anschutz target rifle crown is flat and then a 45 degree bevel up to a second flat out to the edge of the barrel.

[turbo33]

No offence to the OP but you ask for advice then don't seem to want to listern

Just an observation

Have a free shot if you wish but to avoid a slanging match I'll say no more

 

Agreed Kennym, with that attitude its me out

[CharlieT]

Just a thought.

 

I read that the CZ .22lr switch barrel is choked and that their 16" one is itself choked and not just a 22" one cut down.

Now I don't know if the Sako barrel is choked, but if it was and such a barrel was cut down, is it possible, if the barrel happened to be a fraction "wide" where it was cut, for this to produce the results you are getting.

[Bewsher500]

 

Agreed Kennym, with that attitude its me out

 

Attitude?

What attitude?

I will entertain any explanation if they are rational. i agree that it needs testing in a variety of situations to eliminate any variables

the crown looks "horrible"

 

The other thought is, I wasn't aware Weihrauch did a silencer for rimfire Its not the one for the HW100 is it? If so, it only has some plastic curlers, stainless washers and felt inside, and defo not designed for rimfire. If it is that one, it will without doubt, be blown to bits inside and the rounds will be hitting all the jumble on their way through.

 

two points which I don't agree with, not because they were stupid ideas, but because they don't apply in this case

 

1) The crown looks perfect, that is my issue, if it looked "horrible" I wouldn;t have asked, it would be back in the workshop from whence it came

the photo might be pants but there is no visible issue with the crown or thread. I have measured it to within an inch of its life

if there is a problem with it it is one I can't measure with a micrometer or can't see with a magnifying glass.

There may well be something up with the crown....but its not visible

 

2) There is nothing wrong with the moderator, I used it before the barrel was shortened the last bit

It is "without doubt" not full of jumble and nothing is hitting anything...other than bullets all over the shop

 

I will happily try the barrel without the mod and full intend to

doesn't make the mod any worse than it was 2 weeks ago.

 

Not giving you or anyone else attitude,

Questioning my use of a Weihrach mod was valid,

Assuming it was the issue and my judgement on the matter is impaired was not

 

Just a thought.

 

I read that the CZ .22lr switch barrel is choked and that their 16" one is itself choked and not just a 22" one cut down.

Now I don't know if the Sako barrel is choked, but if it was and such a barrel was cut down, is it possible, if the barrel happened to be a fraction "wide" where it was cut, for this to produce the results you are getting.

 

This is interesting

if it was this length cut from the original factory length I can see that being a perfectly feasible reason for change

thing is I bought it at 15", it had already been cut down

 

I only took another couple of inches off it.

would the lack of choke not have been present when it was 15"?

 

out tomorrow to do some testing

Edited June 11, 2014 by Bewsher500