Strange Load data. WTF?
- Thread starter skhunter
- Start date
Yes, depending on COAL, bullet shape, construction, &c.
Just checked the site & my thoughts above still apply.
Sierra 300 gr. SPBT has a short bearing surface area, while 260 gr. Nosler Partition has a centre section of pure jacket material & a longer bearing surface.
Same goes for the homogenous Barnes bullet.
Just checked the site & my thoughts above still apply.
Sierra 300 gr. SPBT has a short bearing surface area, while 260 gr. Nosler Partition has a centre section of pure jacket material & a longer bearing surface.
Same goes for the homogenous Barnes bullet.
I think something doesn't add up.
For starters, usually a start load is 10% less than max, which fits with the 260 grain data, but the 300 grain data isn't even close, it's more like a 5% reduction for a start load.
I would quickly send them an e-mail asking for verification.
For starters, usually a start load is 10% less than max, which fits with the 260 grain data, but the 300 grain data isn't even close, it's more like a 5% reduction for a start load.
I would quickly send them an e-mail asking for verification.
Appears that the 300gr charges may have been crossed listed with 270 grain bullets, and vice versa. Misprints in manuals are rare, but they do happen on occasion.
Different bullet construction/materials do affect max charge for that weight. As does a manuals data from one manufacturer to another. Compare Barnes #1 to Hornady data, for example. Both are bullet makers. Data is quite different however. I've got old IMR published data here that lists 82 grains IMR4350 as max with 300gr. Too much for me or my gun.
FWIW, my Brno 601 .375hh likes 81gr's of H4350 with 270's, 79gr's. with the 300's. This particular rifle is long in the throat, OAL's are way long, 3.850".
Seated to nominal 3.60" OAL, a full 1/4" less, the pressure is more likely than not, to be somewhat higher than with a freebored throat.
Guess thats why common sense demands one work up for every gun that you load for.
Different bullet construction/materials do affect max charge for that weight. As does a manuals data from one manufacturer to another. Compare Barnes #1 to Hornady data, for example. Both are bullet makers. Data is quite different however. I've got old IMR published data here that lists 82 grains IMR4350 as max with 300gr. Too much for me or my gun.
FWIW, my Brno 601 .375hh likes 81gr's of H4350 with 270's, 79gr's. with the 300's. This particular rifle is long in the throat, OAL's are way long, 3.850".
Seated to nominal 3.60" OAL, a full 1/4" less, the pressure is more likely than not, to be somewhat higher than with a freebored throat.
Guess thats why common sense demands one work up for every gun that you load for.
So I phoned Hogdon today and the guy assures me that the data is correct, so I look at all the data and it still doesn't make sense to me. I think I will stay away from 4350 all together. 9gr difference in the staring load for 300gr bullets is scary for me.
250gr bullets, 78-83C H4350
71-79C IMR4350
260gr bullets, 70-78 H4350
71-78.6C IMR4350
270gr bullets, 69-75C H4350
69-76C IMR4350
300gr bullets, 77-81.5C H4350
68-76C IMR4350
250gr bullets, 78-83C H4350
71-79C IMR4350
260gr bullets, 70-78 H4350
71-78.6C IMR4350
270gr bullets, 69-75C H4350
69-76C IMR4350
300gr bullets, 77-81.5C H4350
68-76C IMR4350
back40sniper
CGN Regular
- Location
- South east Sask.
For a 270 grain bullet try RL-15 , Varget works good too just not quite as fast as RL-15. After that a lot of guys like W-760.
