No4 Mk2 still shooting low

[faz]

Hi folks back from the range, as suggested by Peter I took some Brittish surplus ammo
headstamp GB 45, some Greek headstamp HXP 69 and yet again PPU.
The weather was overcast no wind and about 10 degrees (quite nice realy). Findings were interesting at 200yds with 5 rounds Brit had to raise the sights to 300 to find the bull, next 5 rounds Greek sights still at 300 I had the correct elevation but widage was about 6" left (still no wind)
OK so back to 300yds in go 10 rounds Greek first shot low up go the sights to 400 second slightly low up more clicks to 450 got it correct elevation slightly left but kept going for the group the remainder around 5". Next the Brit first just a bit high down one click back on, this provided a 6" group but still just left. Next the PPU exactly the same group as the Brit.
MMM now I am confused taking into account myself and not bench resting I would of expected to see a bigger variation.
Ok got some Greek ammo left and it's nearly time to head back home,I load up and it starts to drizzle now got some wind around 10mph from the 11 oclock shot as fast as the butt man can score barrel now warming up sights still at 1 click down from 450 shots start to rise and my last 3 rounds end up 12" high.
It looks like my rifle needs to be hot before it shoots in the right place, she is still fitted with the -.030 foresight.
Has anybody got any ideas on this?

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[Thunderbox]

Check that the barrel is free to move UP slightly in the forend, without any sticking or asymmetry in the movement.

[faz]

Yes the barrel is free floating in all directions, could the bedding in the lower foregrip near the chamber be too high?

[Peter Laidler]

Next suggestion from Peter. The fore-end shouldn't be fully floating. It should have a muzzle bearing.

[faz]

Hello peter you have got me now what is a muzzle bearing? when taking the wood off there is nothing on mine at the muzzle end topor bottom

[Patrick Chadwick]

Faz, a basic question: what hold are you using? If you are using the 6 o'clock hold, a possible answer follows below!

I have a No. 4 Mk2 that shoots perfectly, but with the sight ladder adjusted up about 100. I.e. 200 for targets at 100 meters. There is absolutely nothing wrong with the rifle whatsoever. In fact, it appears to have been bedded/preloaded "According To Laidler". But according to previous correspondence on this topic with Peter, it appears likely that the rifle was zeroed with a "tin-hat" type of target (for those unfortunate people who do not know what that is, it is a target bull that looks like a black semicircle - the bottom half of the black is missing, and the whole thing is supposed to be reminiscent of a helmet peeping over a parapet.

In other words, a rifle that has been zeroed in this fashion has been zeroed for POI = POA. If you now use the 6 o'clock hold on a full round black, then you are in fact aiming low by precisely half the diameter of the black. Hence the sight correction. Which would be about 0.030" at 100 yards for an 8" black. Is that your case? Then don't worry, just use it as is, and be glad that the No. 4 has such a good vertical adjustment!

Of course, if you are in fact aiming dead center, then I haven't a clue....

Patrick

[faz]

hello Patrick this is now getting realy complicated. I am aiming dead centre.
But I kow what targets you are refuring to. Back an age ago at 25yds we used to use a No 29 target in the sevice and the rifles we had at this range had a POI at POA right bang in the center sight set at 200.

[Baal]

Hello peter you have got me now what is a muzzle bearing? when taking the wood off there is nothing on mine at the muzzle end topor bottom

It shouldn't be free floating at the muzzle. The muzzle should be seated against the wood for 2 or 3 inches, requiring between 2 & 7 pounds of up pressure to lift it off.

[faz]

We may be getting to the bottom of this. The muzzle is not touching any part of the wood and has about 3mm travel downwards 4mm side to side ond 6mm upwards. The only pressure required to move the barrel is overcoming the barrel length, which takes us back to Peter's suggestion of a muzzle bearing of which I don't know what this is

[Nickjc]

There are others sooooo much more knowledgeable than I on this topic bubfrom what I have learned is that the muzzle of the barrel must rest on the very end of the forestock and they shall be touching each other. The required amount of force to liftNthe muzzle off the forend is as staed above


The muzzle should have an audible snap back down to the forend when pulled up etc

if IM wrong someone will chime in! But this is what I've read and have been told