Flat base VS Boat tail load data. 30-06 125gr Nosler BT
- Thread starter Johnny_Zanni
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hometownhero
CGN Ultra frequent flyer
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As long as you use the same weight data you are good to go. Only exception is say 178gr bullet you can use the 175 or 180 data.
notsorichguy
CGN Ultra frequent flyer
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Start low......
If you are using published load data for the bullet you have, you can start in the middle and work up.
When you are using data for a different bullet of the same weight, always start at the bottom!
I have seen instances when data from one kind of bullet was used on a completely different bullet of the same weight. That fella started "in the middle". First shot; stiff bolt. Second shot; stiff bolt and the primer fell out of the case on the shooting bench. Third shot; stiff bolt. I'm still shocked that he fired the 2nd and 3rd rounds!
If you are using published load data for the bullet you have, you can start in the middle and work up.
When you are using data for a different bullet of the same weight, always start at the bottom!
I have seen instances when data from one kind of bullet was used on a completely different bullet of the same weight. That fella started "in the middle". First shot; stiff bolt. Second shot; stiff bolt and the primer fell out of the case on the shooting bench. Third shot; stiff bolt. I'm still shocked that he fired the 2nd and 3rd rounds!
That has a lot to do with the gun's bore, throat, and chamber dimensions as well. One should always start at the low end of book for this reason.
hometownhero
CGN Ultra frequent flyer
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- Toon Town, Sk
I find it funny how one books max in another books start.
notsorichguy
CGN Ultra frequent flyer
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- The city that rhymes with fun
It's all on how the bullet is constructed...... Jacket thickness, jacket composition and bullet core (lead or other).
No 2 bullets are exactly the same, this results in differing charge weights in load manuals.
I've found that Barnes bullets, for example, will make higher pressures vs traditional bullets with same powder charge. So even when dealing with same weight bullets and a known safe charge for your rifle, I'd still suggest taking at least a grain or two off and working up. I stopped at the first shot, after hammering the bolt open with my fist! LOL
I feel like most of the difference in pressure comes down to how different bullets seat in the case, and how much resistance they have in the lands-rifling.
I feel like most of the difference in pressure comes down to how different bullets seat in the case, and how much resistance they have in the lands-rifling.
I would agree with this except in many cases the load data that differs is for the exact same bullet. Compare Hornady to the Hodgdon website and you will find many examples of Honady's max being Hodgdon's start point. Makes for a lot of uncertainty. I always use a more conservative approach. After all it just means more time at the range and who's going to complain about that?
George
