.243 suddenly not grouping

[rtaylor]

I checked zero on my .243 this evening and was shocked to find it isn't shooting on anymore. I checked zero a couple of weeks ago and it was less than 3/4" at 75 yards (my usual deer range).

 

But tonight it was shooting about 6" low on the first shot and a couple inches right. Then the next two shots were even lower, fairly vertically in line but about 1-2" below each other. I put a few more through and they were doing the same thing.

 

The only thing I can think of is ether my scope has been knocked in travelling, but wouldn't this just change zero but keep the grouping. Or more worryingly the screw cut has some how been knocked. When I screw the mod on it does't seem to be screwing in straight and the nylon bush at the bottom is very gently touching the barrel (I have now drilled this out so it isn't touching anymore). I can't recall it getting knocked at all and it would have had to be something fairly bad to knock the mod out of alignment.

 

I have changed my bullets to PPI but when I checked zero the other week it seemed to be shooting nicely with them.

 

I am going to try my mod on my mates rifle to see if I can rule that out, and maybe try his mod on my gun.

 

Sorry it's a bit long winded but any thoughts?

 

 

 

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It was shooting something like the above but about 5 or 6" between the top shot and the bottom.

Edited July 12, 2013 by rtaylor

[CharlieT]

I bet it's the ammo.

[rimmie]

Have you just cleaned it ? Might need some fouling shots. Or on the other hand it might need a clean ?

[Beretta28g]

Whats it had done cleaning wise?

 

If youre having problems, take it right back to clean and go from there, a good scrub.

[rtaylor]

It hasn't been cleaned and I did think about giving it a good scrub and checking again. If it still won't group after a clean I'll try some different bullets which I know do work.

[Frenchieboy]

I assume that you have checked all of the mounting screws for tightness and that you have checked that there is no clipping on the moderator! If so I would start with giving it a good scouring and start from fresh with an ammunition that you know your barrel shoots tight groups with. If no joy after this, and looking at the pattern of the shots that you have described I would be thinking about the problem being in the scope. Out of interest what scope is it?

Edited July 13, 2013 by Frenchieboy

[wymberley]

Is the barrel free of the fore end?

[rtaylor]

It's a Simmons white tail. I will double check all the mounting screws but can't think where they would have come loose. I'll check the mod for clipping. I bedded the action in and free floated the barrel, I've put maybe 20-30 good grouping rounds through since then.

I'll strip it down and have a look this afternoon.

[Underdog]

just shoot a few rounds without the mod!

 

U.

[Redgum]

Trouble when things like this start happening many worry the barrels worn out but in most cases its not. As said above, clean your barrel with a good copper solvent, etc, ,plenty of instruction on the net. Give it a real good clean, check the barrel isnt touching stock if its designed not to touch. I have had similar problems in the past, my rifle didnt like ppu ammo and I was never confident it was consistant. I have a WTC on my .22lr and had a similar problem earlier in the year, all my centrefire scopes have adjustable focus (whatever its called) that don't have a locking ring, the WTC does so when I adjusted the focus on the end, the eye box ( changing eye sight with age) was wobbling about as I hadnt relocked it up. It made a hell of a differance at 60yds with a rifle that is lazer accurate normally. If things are still not consistant then use another scope, checking all the mounts and rings in doing so. If still no joy then have a gunsmith have a look at the thread/crown. As for mod rubbing on the barrel, most barrels are not perfectly round and if the rear bush is a bit tight it will touch somewhere. Both my 243 and 308 have marks from the mod but these are my fault, the unf thread is quite loose until the mod is tight, if you don't hold it square while tightening it will touch.

[delburt0]

Look very carefully at the end of the mod magnifying glass would be helpfull see if there's a paint missing from the round fowling the mod

[tharsus]

Check everything is tight, mod, scope, stock screws and try again with different rounds, i stopped using prvi because they were very inconsistent, one box great, next lot shotgun.

[casts_by_fly]

Sounds like a loose screw, either action or scope mount. If they are stringing up and down but not left to right it would imply to me that the scope is sliding back to front.

 

Rick

[crossy 666]

just shoot a few rounds without the mod!

 

U.

That what i was thinking

[rtaylor]

Checked all the action screws, scope screws and the mod. They are all fine, nothing loose and no marks on the mod.

 

I've given the barrel a really good clean, so I'll give it a few shots and fingers crossed that is all it needed.

[malantone]

I`ll lay odds it`s the ammo

[tedster]

Aye, if the spread was left to right, instead of vertically, I'd look at a cause with the rifle.

It isn't so I'd blame the ammo.