Thread: Time for a re crown?

I had a rifle bought from trademe, threaded with a can. Guy I bought it from said he'd taken it as a trade and hadn't fired it but the guy before him told him it grouped well.

Groups were all over the place, no consistency at all. Can was working loose and some shots were clipping, but even without can it was hopeless - similar badness to what yours is doing. Checked screws etc, turned out out someone had packed the rear scope ring up with cardboard! Took the cardboard out, tightened things up again. POI 18" low at 100m on max elevation. Signature-zee rings sorted that, sometimes it would group ok-ish and sometimes all over the show or right off the paper for no apparent reason.

Finally got a gunsmith to look at it, he cut off what was some rough as guts off-centre threading and recrowned it - straight away it shot half inch groups with 3 or 4 different loads.

If yours was shooting ok before it was threaded/crowned then I'd say thats the problem.

Whats your scope/rjng combo
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Originally Posted by horihunter

Did you try other loads? What velocity were you getting with factory sst loads? Es doesn't dictate group size unfortunately. Not uncommon to have single digit es loads that just won't group then have loads with ~40 that produce very tight groups.

Yes I've tried other loads, even ones that were shooting sub moa for the previous owner, thats why i'm a bit confused and can only put it down to it needing a re crown. I hear what yuour saying re the Es spread, I just assume that I could rule that out as a factor. I'm learning all the time about this reloading caper I don't know if I can trust the chrony setup I used to test the factory loads awhile ago - they were going around 2800fps and that was supeformance which doesn't seem right to me.

Originally Posted by GravelBen

Finally got a gunsmith to look at it, he cut off what was some rough as guts off-centre threading and recrowned it - straight away it shot half inch groups with 3 or 4 different loads.

If yours was shooting ok before it was threaded/crowned then I'd say thats the problem.

I hope this will be the case with mine as well. fingers crossed

Originally Posted by CreepingDeath

Whats your scope/rjng combo
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Bushnell elite 3200 4 - 12. Warne 1 inch steel rings. The scope Has had a hiding a couple of times from assing over so I would agree that this could be a factor and one I will need to rule out.


Thanks for the replies again guys.

I'd start with the simple stuff.

If the barrel was fully floated and action nicely bedded before the thread/crown job then I'd recheck that your barrel is still fully floated and the action has been refitted correctly.

Also check the scope mounts, rings etc are tight.

That should only cost time.

Cheers
Pete

I would do as p38 suggests and then take it to a decent smith. Seeing as how it's not performing as it was they must have changed something to take it off the boil. If everything else is ruled out then it only leaves the crown

Hey Pete,

Barrels still fully floated. I've checked the rings etc as well. I've had a very generous offer from a forum member to have a look and re crown it for me which is awesome and unbelievable. Failing that - I'll see if I can grab a scope a mates rifle as that should be the only other problem I can foresee. Whatever the end result is I'll post up weather the issues been fixed or not, but I'm fairly confident it will be after the new crown job.

Cheers,
Grant

Originally Posted by P38

...and the action has been refitted correctly....

Thats a good point - heard a story from a guy on another forum whose .17hm2 started shooting like absolute crap after he put a new stock on it. Turned out he'd forgotten the recoil lug when he put it back together!

I will be amazed if the crown is solely responsible for those groups.

Its more likely a combination of all the factors mentioned. Crown, average shooting, wonky reloads blah blah blah. It soon adds up to less than stellar results.

Average shooting - definitely a factor, wonky reloads - I was anal with the measurement of the powder this time (re check 3 x). I've got around 25 rounds left of this load before I'm changing pills so I'll get to restart again.