darrindlh
Well-Known Member
Would creating a 40 degree shoulder and blowing out case taper on my 300 weatherby improve on performance? Even 100-150fps?
Darrin
Darrin
Last edited:
Curious question
- Thread starter darrindlh
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While I'm uncertain, without blowing out case taper, I don't think simply changing from the radiused shoulder to an "improved" shoulder would gain you enough case capacity to gain that much speed. That is a significant gain.
Some cartridges gain that much by "AI-ing", but not all. Most add more freebore in the AI process and remove case taper, increasing case capacity in multiple areas. Weatherby already has a lot of freebore and about .020" body taper. The steeper shoulders also help with case stretch, but tend to "hide" pressure.
Do as you wish, there is no wrong thing to do, just know that you may or may not get the desired velocity gain. Let us know what you decide.
Some cartridges gain that much by "AI-ing", but not all. Most add more freebore in the AI process and remove case taper, increasing case capacity in multiple areas. Weatherby already has a lot of freebore and about .020" body taper. The steeper shoulders also help with case stretch, but tend to "hide" pressure.
Do as you wish, there is no wrong thing to do, just know that you may or may not get the desired velocity gain. Let us know what you decide.
darrindlh
Well-Known Member
Oh yes gotcha , i would blow out case taper as well. I just think there is so much neck space on the case that I could increase volume.
Darrin
QuietTexan
Well-Known Member
No need to try to rework the Weatherby, what you want is already available - the 300 RUM. 110.2gns og H2O capacity vs the 300 Wby at 100.4gns.
No sure what your plans for process was, but a rebarrel to 300 RUM plus dies is almost certainly cheaper than getting a custom reamer made based on the Wby, trying to punch it out, getting dies etc, and at the end of the day still having a factory barrel on the rifle.
No sure what your plans for process was, but a rebarrel to 300 RUM plus dies is almost certainly cheaper than getting a custom reamer made based on the Wby, trying to punch it out, getting dies etc, and at the end of the day still having a factory barrel on the rifle.
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darrindlh
Well-Known Member
QuietTexan
Well-Known Member
Probably still less than the RUM because of the belt and resulting narrower case walls. Seems like it's basically a Gibbs treatment (short neck and steep shoulders) just on a 375 H&H case. So functionally analogous to a 300 Win Mag Improved.
If you have the case mocked up, what does it hold in terms of water weight?
If you have the case mocked up, what does it hold in terms of water weight?
darrindlh
Well-Known Member
I was able to hold 106 grns of h20 in my 300 weatherby improved case. My original 300 weatherby held 100 grns of h20. This is way more case capacity than a 300 win mag. Waiting for dies to be made.
Darrin
Still less than the RUM
memtb
Well-Known Member
Just my opinion for what it's worth…..No! Certainly not enough to justify the expense!
Though, judging from your photograph…..ya just might get some significant gains! memtb
darrindlh
Well-Known Member
i agree with you. The rum is an amazing round! I just have never wanted to own one.
It will be interesting to see. The weatherby necks are so long and have so much space.
Darrin
Calvin45
Well-Known Member
I like the long weatherby necks! When you're running the kind of freebore they are, I think the long neck helps ensure concentricity before the ogive hits the lands.
darrindlh
Well-Known Member
I agree with you. I also like how much surface area the necks will grab the bullet when seated to the neck junction
