I've had an idea for a while now and have been trying to find info, but haven't had any luck so far. Maybe I'm not asking the almighty google the right questions...
My idea is to neck down a 300wm to a "7mm" (.284) projo. I checked our process records at work (i work for Sierra Bullets) and the 7mm 175 mk exceeds the 200gr 30 cal in both oal and bearing surface, and the 180s are a step up from the 175s in both dimensions. Jacket thickness is about the same between the 7 and 30s as well. With the slightly smaller dia and longer length = potential for higher coefficiency, right?
I ran the numbers and with a mv of 3400 fps(i think this is achievable or at least close to it) zeroing at 3 would put me at about 4.5 mils at 1k while being just under 2100fps. Now the testers downstairs said 3400fps might be starting to push the limits a little bit. But "might be starting to push the limits a little bit" is a far cry from an "oh hell no". I figured poly rifling would probably offer some insurance for keeping the bullet from ripping itself apart.
So what do you guys think? Is this a reasonable idea/project? If this has been done before could you please provide links?
Any thoughts or input would be great. Thanks in advance.
My idea is to neck down a 300wm to a "7mm" (.284) projo. I checked our process records at work (i work for Sierra Bullets) and the 7mm 175 mk exceeds the 200gr 30 cal in both oal and bearing surface, and the 180s are a step up from the 175s in both dimensions. Jacket thickness is about the same between the 7 and 30s as well. With the slightly smaller dia and longer length = potential for higher coefficiency, right?
I ran the numbers and with a mv of 3400 fps(i think this is achievable or at least close to it) zeroing at 3 would put me at about 4.5 mils at 1k while being just under 2100fps. Now the testers downstairs said 3400fps might be starting to push the limits a little bit. But "might be starting to push the limits a little bit" is a far cry from an "oh hell no". I figured poly rifling would probably offer some insurance for keeping the bullet from ripping itself apart.
So what do you guys think? Is this a reasonable idea/project? If this has been done before could you please provide links?
Any thoughts or input would be great. Thanks in advance.
