A friend of mine purchased a model 740 in 30-06 caliber several years ago and while sighting it in , on the first shot, with factory ammo, split the forearm. Fast forward to this afternoon, he took this rifle out with a new forearm & on the second shot the darn thing split again. Any thoughts as to why?

Hmm...I'm pretty sure those had a steel liner??? If it split with the liner in place, Id be very surprised. He was able to purchase an original?

Yes, replaced with an original and it does have the steel liner.

I checked with the owner; split the entire length of the forearm

Was the area of the barrel and forearm, where the gas is exhausted, blocked by anything? I did it once, and only once, with my left hand.

Ask him how much torque he put on the forearm retaining screw. Binding there, over tightening, or uneven bearing on the barrel, will cause what happened.

Yep.

"The earlier Model 740 rifles were quite sensitive to variations in the degree of tightness with which the fore-end screw was set up, and a spacing block had to be used.

In the later Model 740 rifles and in the new Model 742 this is accomplished by making the fore-end screw with 2 separate threaded portions, each thread having a different pitch. When the screw is tightened, the parts arc drawn together by the differential action of ¿he varying pitches, and the fore-end comes up tight with a small clearance remaining between its rear end and the front of the receiver."


Bev Fitchett's Guns Magazine » Firearms Assembly

quote:

Originally posted by dpcd:
Ask him how much torque he put on the forearm retaining screw. Binding there, over tightening, or uneven bearing on the barrel, will cause what happened.

One more thing; this forearm bears against the receiver and is pretty thin; over tightening cracks them, so I remember that Williams used to make a little aluminum block to go under the screw, which would allow the wood to float and not bear against the receiver. The stuff I remember from the 60s is scary.

Thanks everyone for the responses, Doug is going to take it over to Williams gun site co. And have them take care of it.