| Matabele |
| (.300 member) |
| 08/04/17 09:26 PM |
Re: Building, regulating & engraving a DR with shoe lump barrels
|
Quote:
When you say that "It must be noted that the draw is in effect attempting to hold the barrels off the face and care needs to be taken to ensure good engagement with the draw (you can feel the barrels "picking up" on the draw if you close the barrels slowly and feel for the slight drag) but it cannot be excessive or it will bring the gun off the face"............I always assumed that the "face" was the breech face so therefore wouldn't the draw be moving the barrels towards the breech face ???
I think that, in Vic Venters book, with jointing a double rifle it said that the force had to be taken off the hinge pin or it may bulge actions at the hinge pin.......perhaps this is what the "draw" is doing when it fitted correctly in a double rifle. Venters does show the difference between the jointing of a shotgun and the jointing of a double rifle in the book.....the shotgun uses the hingepin as "bearing point" whereas the double rifle doesn't due to the greater pressures involved.
Not nit picking/arguing just testing my understanding of the principle.
Keep up with the great work and please keep us informed.
Hi there! No worries at all, happy to discuss these sorts of things. You are absolutely correct in that the draw will attempt to throw the barrels towards the breech face, however you must remember that when fitting detachable draws the gun is already perfectly jointed and "on the face". So excessive bearing on the draw will throw the barrels towards the breech face as mentioned and therefore disrupt the joint and the gun is then "off the face", holding a gun up to the light that is bearing too hard on the draw shows a wedge shaped chink of light as the barrel rounds are now hitting the breech face first. That is what I was alluding to.
With regards to double rifles and detachable draws I personally feel that pulling the action out of the hook is excessive, and the amount it is pulled out of the hook has perhaps been exaggerated (for purposes of explanation of the principle) in Vic's description. I have Vics book and read that section a number of times nad it has always intrigued me. In my opinion when fitting draws it is more a matter of a distribution of pressures and not so much a physical movement of the action out of the hook. To my mind it makes no sense to not use the 10 odd mm's of hardened pin in conjunction with a well fitted draw, this would seem to be much less prone to wear over time. And if a draw is used with excessive bearing when it does wear the gun will very rapidly come off the face to quite a degree, as the pin is now not able to provide support. Also consider that pulling the action out of the hook as the barrels engage the draw will lead to a very pronounced two stage feel on opening and closing the gun.
Of course when no detachable draws are used then you have no choice but to joint the gun down equally between the hook, circle and breech face...as Steve has done with his gun. History has shown the old vintage guns holding up remarkably well using this same system, so I do not feel a detachable draw with too much bearing offers any advantages in terms of strength and longevity of the gun, but certianly aids in tightening a gun back up when a rejoint is needed.
It must be said I have never built a double rifle (although I plan to) and don't presume to put words in anyones mouth...It's just simply my thoughts on the matter.