Barrel bedding question.

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   Gents, I have noticed a minor increase in the group size since refitting the woodwork to my 2nd No8.Comparing it to the 1st No8; I have noticed a difference of  fit of the Upper Hand guard; also 1st No 8 shoots slightly tighter groups.
The 1st No8 has a good clearance between the upper hand guard and the barrel, allowing it to be flexed upwards without touching the upper guard. It is touching the lower front which is as per the manual, but I have not checked the poundage (should be 3-5lbs)
The 2nd No8 has no clearance around the upper hand guard, the barrel appears sandwiched between the lower and upper and no flex can be felt. I believe this may be causing the problem by not allowing the barrel to resonate naturally when fired.
(I have also read that these can be a floating barrel, although the manual states 3-5 lbs upward pressure)

I would appreciate advice from knowledgeable people prior to modifying the wood.

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Zed Members Profile Send Private Message Find Members Posts Add to Buddy List Special Member Donating Member Joined: May 01 2012 Location: France Status: Offline Points: 6460	Post Options Post Reply Quote Zed Report Post Thanks(0) Quote Reply Topic: Barrel bedding question. Posted: April 22 2013 at 4:29am
	Gents, I have noticed a minor increase in the group size since refitting the woodwork to my 2nd No8. Comparing it to the 1st No8; I have noticed a difference of fit of the Upper Hand guard; also 1st No 8 shoots slightly tighter groups. The 1st No8 has a good clearance between the upper hand guard and the barrel, allowing it to be flexed upwards without touching the upper guard. It is touching the lower front which is as per the manual, but I have not checked the poundage (should be 3-5lbs) The 2nd No8 has no clearance around the upper hand guard, the barrel appears sandwiched between the lower and upper and no flex can be felt. I believe this may be causing the problem by not allowing the barrel to resonate naturally when fired. (I have also read that these can be a floating barrel, although the manual states 3-5 lbs upward pressure) I would appreciate advice from knowledgeable people prior to modifying the wood.
	It's nice to be important, but it's more important to be nice!

Shamu Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 20510	Post Options Post Reply Quote Shamu Report Post Thanks(0) Quote Reply Posted: April 22 2013 at 5:26am
	The full length wood on the No4's definitely likes a slight upward pressure, but at the muzzle, not part way down. The accurizing sequence for them was Knoxx first, tip pressure second & middle pressure as a last fine tune if needed. I often wondered if the shorter wood (& different bedding needed) wasn't possibly responsible for the ahem alleged wandering zero of the No5? Unfortunately I don't know how well this translates over to the different barrel of the trainers. Can you pull the handguard & shooot for group to see what difference is there?
	Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)

Zed Members Profile Send Private Message Find Members Posts Add to Buddy List Special Member Donating Member Joined: May 01 2012 Location: France Status: Offline Points: 6460	Post Options Post Reply Quote Zed Report Post Thanks(0) Quote Reply Posted: April 23 2013 at 3:32am
	I have thought about testing by swapping the upper handguard in the first instance, then without the upper guard, then with adjusting the front packing under the barrel. I have found a suitable spring balance to test the pull off weight, so it should be an interesting and hopefully fruitful experiment. As a side note, my No4 mk1/2 does not appear to be bedded at the front, which is I believe part of the "Fultons" treatment.
	It's nice to be important, but it's more important to be nice!

LilysDad Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: March 22 2013 Location: IL, USA Status: Offline Points: 183	Post Options Post Reply Quote LilysDad Report Post Thanks(0) Quote Reply Posted: April 28 2013 at 8:37am
	How does one measure the lbs. of pressure at the front spring?

Shamu Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Logo Designer / Donating Member Joined: April 25 2007 Location: MD, USA. Status: Offline Points: 20510	Post Options Post Reply Quote Shamu Report Post Thanks(0) Quote Reply Posted: April 28 2013 at 9:27pm
	I use a trigger pull gauge. Just hook it into the muzzle, secure the rifle & pull up till it just moves the metal from the wood. The pressure will be where the indicator of the trigger pressure gauge is.
	Don't shoot till you see the whites of their thighs. (Unofficial motto of the Royal Air Force)