Load Data from Powder Manual vs Bullet Manufacturer Manual

[lobo]

I'm loading Hornady's 165 gr Inter-Lock SP in my .300 WSM (Tikka T3) over 64.5 grains of H4350. Hornady's newest manual shows a max of 67.5 grains. Hornady puts all their bullets of the same weight into one.

I recently obtained Hodgdon's 2023 manual. While looking through it, I looked at the .300 WSM data. The new Hodgdon manual shows Hornady's 165 grain GMX with a max of 62 grains compressed of H4350.

Pretty big difference between the two manuals. I know they're different bullets, but again, Hornady lumps all 165 grain bullets together in the manual.

I have used this load since 11-2021 with no signs of pressure.


This is the first time I have run into this problem.


Any advice?


Whose manual/data do you use? The manual for the bullet you're using or the manual for the powder that you're using? Is it better to use one over the other?

[lar4570]

Is the GMX a longer bullet than the interlock? That could account for the difference.

[lobo]

Sept 23, 2023 18:30:28 GMT -5 lar4570 said:

Is the GMX a longer bullet than the interlock? That could account for the difference.

I don't know. That is a good question though. Nosler puts all theirs together as well, not differentiating between type only grains, but they put an asterick to denote a difference in loading the E-Tip bullet.

I only have 15 of these cartridges left. I may just pull them to be safe.

Chris

[Fowler]

If you have been shooting them in your gun for years then they are safe in your gun. Nothing has changed with your load because someone printed something with different information in it of course.

Loading manuals are notoriously conservative due to lawyers and liabilities these days but also there is a lot of variables in chambers, barrels, powder lot variations that make working up load for your gun with your components the only true test.

I remember loading for a buddies Savage 7mm mag with 175gr Nosler Partitions. Looked at 3 manuals that had a fair bit of difference between their maxes and ended up taking my press to the range and loading on the line. We started at a mid point between the start and max load and worked up. We got to where we were I think 8gr over the book max with ZERO pressure signs, no case head expansion to speak of, no primer flattening or cratering, no sticky bolt. Just ran out of powder space for the powder we were using (might have been H4831). I do remember getting to the point where I didn’t want to pull the trigger anymore because the load freaking hurt to shoot at that point. But it also shot sun 1” groups so we sighted in at that point, I loaded the rest of the box of bullets for him and he hunted for the next 10 years out of that box of shells.

[lobo]

Sept 23, 2023 22:14:25 GMT -5 Fowler said:

If you have been shooting them in your gun for years then they are safe in your gun. Nothing has changed with your load because someone printed something with different information in it of course.

Loading manuals are notoriously conservative due to lawyers and liabilities these days but also there is a lot of variables in chambers, barrels, powder lot variations that make working up load for your gun with your components the only true test.

I remember loading for a buddies Savage 7mm mag with 175gr Nosler Partitions. Looked at 3 manuals that had a fair bit of difference between their maxes and ended up taking my press to the range and loading on the line. We started at a mid point between the start and max load and worked up. We got to where we were I think 8gr over the book max with ZERO pressure signs, no case head expansion to speak of, no primer flattening or cratering, no sticky bolt. Just ran out of powder space for the powder we were using (might have been H4831). I do remember getting to the point where I didn’t want to pull the trigger anymore because the load freaking hurt to shoot at that point. But it also shot sun 1” groups so we sighted in at that point, I loaded the rest of the box of bullets for him and he hunted for the next 10 years out of that box of shells.

Thank you sir. That's what I was thinking since there have been absolutely no pressure signs. Makes me feel better hearing it from someone else.


Chris

[bigbrowndog]

Disregard
Trapr

[gnappi]

Powder makers hands down.

[harold89]

I’ll use either, but if I can find the specific bullet, that’s where I start and generally begin in the middle. I don’t like starting at the bottom or the top. I also like to compare multiple sources, that could be multiple books/manuals, articles, data on the web, etc.

[lobo]

Sept 24, 2023 15:24:37 GMT -5 harold89 said:

I’ll use either, but if I can find the specific bullet, that’s where I start and generally begin in the middle. I don’t like starting at the bottom or the top. I also like to compare multiple sources, that could be multiple books/manuals, articles, data on the web, etc.

Thank you!