Originally Posted by
schnyd112
Good read, brings up some questions. I am no expert, but here is my rebuttal:
Bedding a wood stock, especially with devcon and metal pillars, takes the swelling out of the equation.
There is wood under the middle of the receiver and it is covered with a thin coat og epoxy. As that wood absorbs moisture it swells. The epoxy cannot contain the wood swelling and its elastic property lets it move back and forth following the wood movement. Not talking about waving in the wind movement here but a few thousandths of arch in the receiver will have a serious affect on the impact point. FURTHER, the distance between the mounting screws will change with the weather cause the wood grows in length when it gets wet. Wood has almost all it movement in the thickness dimension but it does grow in the long axis. Right? We are talking thousandths of an inch.
Heating and cooling of the action I think is minimal. We are heating the inside of the barrel, in front of any bedding material and ideally in a free floated chamber. This should take care of any swelling. As hot as my barrels have been, the action has never been hot. The difference between 0 and 100 degrees, ambient outside temperatures, is not going to swell any metal enough to make a difference.
Using my scientific kitchen range/oven to heat the action and a digital caliper to measure a Striker action we get the following: at @ 68 degrees the length of the action is 152.47mm. After heating it to 120 degrees that length grew to 152.56mm. Total growth is .09mm for a delta T of 52 degrees F. That seems to be .018mm growth for every 10 degrees. That is the T instability of the receiver at approx the mounting holes. That will probably only be a lot if you calculate the Impact point variance. Or just compare the groups if you start out with .25" groups. The thickness of the receiver must also have a bearing but that would only matter if the stock/epoxy is actually touching the receiver to move it. The idea to mount the rifle in a fixture and mount a caliper to measure the tip of the barrel movement is great. That can be done here as well to eval the changes in action temp.
If your action is completely floated on pillars, I think you are going to bend screws and break stocks. Like holding the gun tight to your shoulder to manage recoil, I think the action needs to be supported to keep from damaging itself or the hardware it's mounted in.
The recoil lug takes the recoil strain. Yes there is a shock in the stock and action but they are traveling together thanks to the lug. I agree that the mounting screws would snap under this pressure and certainly no epoxy would resist and certainly there would be variances between shots.
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