no4 sporter butt fitment

Today I took the no4 7.62 out with some chinese factory ammo that has served me well in the past. Same thing as my handloads.. shoots a nice tight group of 3 or so and then starts stringing vertically.
During cleaning I noted that there was movement somewhere in the butt. After a while I found it roatated slightly, no other movement. There is also a gap on one side of where the butt goes into the socket and not the other.
https://www.milsurps.com/images/impo.../no4butt-1.jpg

When I got home I took the butt off and the started to look at why it was moving. My first thought was that I didn't do it up tight enough... it was tight .. very tight. So I took it off and then pushed the butt into the socket and it fitted fine.... fine until I did it up and then the gap appeared and it rotated.

The butt is a sportco effort so it should be as good as it gets for a mass production butt.

https://www.milsurps.com/images/impo...no4butt2-1.jpg

Where do I go from here?
I wonder if the hole the butt screw goes into is straight. In the 5 minutes I spent with it's donor rifle it seemed to fit ok, there was certainly no movement.
I thought about trying to pack it out but if it fits okay without doing the butt screw up I don't know how this will help.

Any ideas? I really don't want to put the original back on as this fits me a lot better and works a lot better with the scope.

https://www.milsurps.com/images/impo.../no4_308-1.jpg

Others who actually know what they're talking about will chime in later. But first, have you used this rifle before with the original butt stock and not had this problem?

From what I understand, a loose butt stock will result in horizontal stringing, not vertical. Since your fore stock is cut down the barrel might not have the needed support, which will result in vertical stringing.

Anyways, knowledgeable guys will be by in a bit.... How's the weather?

Hi Baal,
I did use the rifle with the original butt though I didn't really get serious about trying it out. The original butt fits fine so it's definitely something to do with this one but I am not sure what. The barrel is free floating, I assume that this was all done when it was a target rifle. It is not a cut down milsurp stock, there are no markings what so ever on it.

The weather is okay, we are heading into summer so it's warmish and humid .. once summer arrives it'll bloody hot but dry. I like cold weather, but not so fond of how cold it gets up there :)

XA-Coupe, me want XC coupe.
So I presume you are in OZ. I have a sportco and Parker Hale wood set if you are looking for a replacement set a replacment set.
Myles

Hi Myles .. ADR 27A makes the XC a lumbering brute which uses amazing amounts of petrol !

I'll see how I go for sorting this out before resorting to buying things but thanks for letting me know, I'll certainly keep it in mind. Perhaps you can PM me some pics of the wood? Never know what else may crop up !

I can see the problem straight away.................... Butts are manufactured with the male part of the butt socket very slightly tapered and yours ain't! The result is that while on a normal military type butt, the tapered part of the butt tightens up in the socket as the stock bolt it tightened, yours isn't, so it can't tighten up. Simple as that. So as soon as the front part bottoms out, that's as far as it goes and if it's loose, it stays loose!

Some later No8 rifles had the same problem. Next question....................

You could just follow any glass bedding instructions but with the butt to the butt socket instead of the action to the wood. I've done this on one of 2 rifles and it worked perfectly. If it were an original military rifle I'd patch the tennon in timber and re fit it, but with a sporter/target rifle the epoxy filler/bedding compound would work fine and be easy and quick.

No cost you pay the postage or if your in brissy come pick them up.

I will try to take a photo of the sportco.

Quote:

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Originally Posted by Peter Laidler

I can see the problem straight away.................... Butts are manufactured with the male part of the butt socket very slightly tapered and yours ain't! The result is that while on a normal military type butt, the tapered part of the butt tightens up in the socket as the stock bolt it tightened, yours isn't, so it can't tighten up. Simple as that. So as soon as the front part bottoms out, that's as far as it goes and if it's loose, it stays loose!

Some later No8 rifles had the same problem. Next question....................

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Hi Peter.

Is it possible to indicate where it should be tapered?

The n1m3* 48 GRI I have has a slight space in the same area. I am wondering if the butt fitment can be corrected

thanks for the info!

As Peter points out the butt is aftermarket and not inletted (machined for the purist) to military specifications. Firstly check for the presence of the flat bearing washer by inserting a magnet or long screw driver in the long mounting hole. It's got to be there to achieve and maintain the torque from tighting the stock bolt. Secondly use "Devcon" or "Accuglas" and bed the stock to the butt socket. It's been done to many target rifles. I've got a couple done this way. Your rifle needs a secure butt if you want any degree of reliable shooting. You may want to bed the forend while your at it. A new stock set will have the same issues so why not correct the issues with yours. Hope this helps. Ron

The whole piece that fits into the butt socket should be slightly tapered NickCJ and should tighten up into the socket when the stock bolt is tightened. When it's done up so that it what we Armourers technically describe as 'xxxxing tight', there should be a slight gap of, say .020" or so between the remainder of the wood and the rim or rear edge of the butt socket. This is to ensure that when the butt is a) tight and b) is test fired on the rest with the recoil set to hard, the rim of the butt socket doesn't slice or chip away a chunk of the wood.

Hope that's answered it all.

These commercial butt makers just sling a butt on the copy lathe to get the pattern but ignore these important bits.

Just another very minor points chaps................ I don't ever remember accubed or epoxy fillers or plastic wood being a feature of our woodworking lessons during my apprenticeship or being in use in our workshops. They MIGHT have been, but if they were, I was probably off or asleep when they were. If you have a loose butt, as we did on the No8's, then cut a 1" long x 3/8" deep approx. dovetail out of the top, cut a hardwood patch and file to an oversize fit, glue and cramp/clamp in place. THEN when it's dry and solid. drill and peg THEN rasp and file so that you return to a good tight fit. That's the Armourers way. There are other methods......................

Quote:

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Originally Posted by Peter Laidler

Hope that's answered it all.

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perfectly...I'll check the 'armory' and pull it out and take a closer look at it and see what type of measurement i have !

thank you once again.....

I have to thank everyone for their input, particularly Bearclaw and Peter.

I'll add a picture of the original and sporter butts together. From some angles the sporter butt had no taper and others, a large taper. I wonder if it was 'fitted' to the previous rifle.
https://www.milsurps.com/images/impo...no4butt4-1.jpg

Peter, you mention cutting a dovetail in the wood, do you have a picture of such a repair that I can look at and understand the exact details? As much as the devcon/epoxy idea appeals, I would like to try doing it the 'correct' way first. I am hankering for a 303 sporter in the future and want to figure out how to correct any problems. I will buy something sporterised, not bubba-ize it !

I haven't got a picture of how we repaired ours and with the backlog of articles and other stuff (nagging wife, 2 always skint kids, VW golf with broken timing belt etc etc) I won't get round to it for ages.......................

But you can see how I picked the fault up straight away, after having seen and fitted about a zillion of them in the past...................

I would be very surprised if with your skill and experience if you didn't pick it up !! :)
I will figure it out ... I am a visual person and like to see something to get the idea.
Understand about priorities so no sweat there, thanks for your help.

so, I fixed it tonight after putting a new to me butt on and finding out it moved too. This made me go and find the original butt which pulled up really tight. So I got the washer off the spare bolt and put that on ... voila, tighter than a fish's butt at 40 fathoms. It seems that the sporter butts get the hole drilled to a less exacting standard. No idea if it will make any difference to the accuracy but I can at least rule it out. I have also changed scope which may or may help. Suppose I should have waited to try it out before changing scopes but the screwdriver was handy.
Extra thanks to Bearclaw too.