Quote Originally Posted by ireload2 View Post
Hi Patrick,
I have engineering reference books for steels. I just don't know which steel to use. The calculations for the stretch and compression are very simple and only require the modulus of elasticity which is basically the same for all steels. The calculations are so simple any one that disputes them could easily makes the same calculations and provide his own results for discussion.

I have calculated the average load/sq in for the #4 receiver. Since I do not know what steel is used I do not know if the loads approach the yield point of the steels. With very high test pressures it appears that the right receiver rail can approach yield stresses. That occurs at 85ksi and higher. However that is based on an assumption of the steel used. Without knowing the tensile and yield strengths of the alloy any results will remain disputed.

My measurements for the area of the right wall give .1582 Sq inches.
The area of the left wall is .2838 sq inches.
Both receiver walls added have a total area of .442 sq inches.
This data can be used to determine the stress in the steel per sq inch.
From the stress calculation your result can be compared to the physical properties of the steel at various chamber pressures.
From comparing the areas of the two rails you can see the tendency of the #4 receiver to bend with each shot. Since there are two locking lugs if you assume you apply the same load to each rail the right rail will stretch almost twice as far as the left rail. When this happens the receiver bends.
The *spreading of the receiver or action on the Enfield is most likely caused by excess bolt thrust causing the action to spread apart. If you put a small screw through the No.4 where the rear sight retaining pin goes and tighten a nut on the end of the screw you can bind the bolt or cause the action to close up.(*Newtons third law)