Mire arrière

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Mire arrière

Message  Alain Roy le Jeu 2 Déc 2010 - 17:35

Bonjour,

Voici un courriel que j'ai recu aujourd'hui, concernent la mire arrière.

Photos: http://cid-6d0afdc1a79e1cdc.office.live.com/browse.aspx/Forum%20de%20tir?uc=12

> Objet : Daisy Rear Sight Bulletin 1 Dec 2010

> > This is an information bulletin on the Daisy rear sight.

> > Commencing in 2011, all Daisy sights (new & rebuilds) leaving the Repair & Overhaul program at Connaught Ranges will have the following added to the rear sight.

> > A plastic spacer and 2 each #4 size washers will be added to the sight package. See the attached sight jpgs A thru E.

> > The plastic spacer is cut from 3/16 inch plastic tubing and prevents the user from over tightening the eyepiece against the sight back plate. See jpgs F & G. When the eyepiece is screwed in too tight against the back plate it does not allow the sight block to move up and down or left and right freely.

The user continues to put > "> blinders> "> on the eyepiece and continues to screw the eyepiece in too tight. This is wrong. Eventually an ovalization of the plastic sight block threaded hole occurs when the stainless elevation screw is forced to move a locked in sight block.. See jpg J which shows the ovalization of a sight block hole. Eventually this results in a sloppy sight with loose play and irregular movement on the sight adjustment. The user must be taught that the eyepiece must be free to move up & down and left & right. Anything that discourages this movement is detrimental to sight accuracy and repeatability.

> > The use of blinders held in by the eyepiece should be discouraged by the users. If the user insists on a blinder attached to the rear sight, then I suggest the use of the back plate screw. Other alternatives could include the use of a taped over safety glasses, eye patches or the use of velcro on the sight back plate and the blinder.. > > The purpose of the 2 #4 flat washers to prevent the > "> butterfly effect> "> of the sight dovetail. See washerB.jpg for this effect. The over tightening of the flat head screws can actually weaken the strength of the dovetail grip. In those rare cases of the flat washers that prevent proper tightening on an under sized receiver, the user can easily remove the washers.

> > Please feel free to pass on this information bulletin to all interested personnel.

> > For further information, please feel free to contact the following.

> > > MWO Richard Hem
> WO Peter Austin
> D Cdts
> Connaught Ranges
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Alain Roy
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Date d'inscription : 17/10/2007
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