Re: 338 LM Project
From what Mike has told me, the bbl under the carbon is still a shootable bbl, with out carbon. Unlike the Christianson Arms using the Shilen tube. I have only put on one ABS bbl in the 338 snipe-tac, it shoots just as good as my personal steel barreled rifle, and a lot less weight. Mike said it will take anything we can put into it, i think the brass will go way before any other signs develop, when testing the carbon bbl earlier this summer, i put some really hot loads through it, "proof tests on the action as well" there was no change that i could see in performance. Groups stayed sub .5 moa through out the loads. There was even one load, way to stiff, that put 3 shots into one hole. Bolt lift was very tight. But this is in no way a test of any sort that shows how a bbl is reacting during firing.
400gr bullets sound good too, i dont think it will change any bbl dynamics, your limited to a certain amount of chamber pressure no matter what bullet weight you use. Twist rate on the bbl may be a big factor, will a 10" stabilize the long bullet? or will the 9.2 be a better choice? The 11" tops out at 300grns, 350grn bullets will key hole in my rifle. What kind of speed do you think the 400gr bullet will go? 3100?
My Lawton bbl is 1.350 breech, tapers to 1.200 then straight tapers to .900 muzzel 33" long then add the brake to end up at 35" total. I fluted it my self, big heavy flutes, it removed a lot of weight. I am loading my rifle to 3350 on average with the 300mk, i have pushed it too 3520,with good accuracy, it will give you a good thump with these loads, hard on brass too. I like to say stay around 3400fps or under.
Yea the price is up there, but they have their use in special circumstances, much lighter than steel. I dont push them to customers, but if they ask, what is the lightest rig you can make then, its Ti action and carbon bbl and 100% carbon stock. If a guy wants a Ti action and steel bbl, i allways ask "why"? What is the purpose of a light Ti action on a heavy steel bbl? It takes me twice as long to build a Ti action vs steel, when you start adding the cost of a rifle with a Ti action the carbon bbl should be the only choice along with it.
As far as the flexing, i have no idea, only thing i can go by is the end results. Groups and the stated performance of the carbon bbl. It may be such a thing where the carbon may flex more, but not vibrate or the flex returns faster than steel. Look at it this way, a carbon golf shaft flexes more that steel does, but a steel shafted golf club will ocilate after the flexing occurs, a filiment carbon shaft flexes but, stops abruptly after impact, where the steel shaft vibrates all over the place. Carbon fiber Absorbs vibrations quickly, they are not transfered through the carbon like steel does. This may play a large role in the bbl dynamics as well, im not an expert on the phyisics in the carbon bbls, but do know quite a bit about the golf shaft industry, but that is another story.
Any bbl can be carbon wraped, Mike has a certain profile that has to be met, Lawton, Mike Rock and some others make the bbls to be sent to ABS to be wrapped. They undergo a test inpection before he starts the process, if it dont meet his requirements, the bbl goes back to who ever made it. Lawton makes the 408bbls to ABS specs and they are putting them on the Chey-Tac rifles, i ordered two of these contours for my next two projects.