Load data diff. for same weight but diff. brand projectile

[Jakethefake]

I'm loading up a handful of Nosler 50gn I have left over from years ago for my 223. I'm using AR2208. I went to the adi website as I usually do for load data.
They have data for a Hornady 50gn soft point and a Speer 50gn soft point. The starting load for the Hornady is 24.0gn(for AR2208), but the starting load for the Speer is 26.5gn. What could be so different between the two projectiles that the starting weight would be so different? The maximum load for both is 27.5gns.
I checked my old Nick Harvey manual and he lists the same data as ADI does for the Hornady projectile, but doesn't specify a brand.
Where does that leave me and my Noslers? I'm guessing if I stay between 24.0gn and 27.5gn I should be safe? I did put 26.5gn in a case, and it looks too full, a compressed load I think, if not very close to it.

[bladeracer]

Load data only relates to the specific firearm and the cocktail of components used during the testing. It does not indicate what loads are safe in your firearm with ammo assembled your way. Load data only offers a rough guide of the area to start within. When I'm starting loading a cartridge I have no load data for, I load a round with a light bullet and test fire it. The velocity produced and any pressure signs occurring give me a good starting point to work either up or down from regarding bullet and charge weights.

[No1Mk3]

G'day Jakethefake,
Use data for the weight of projectile your using, all data, no matter which company, is predicated wholly and solely on the bullet weight regardless of manufacture and even style of bullet other than lead or jacketed. All bullet/powder manufacturers stay within SAAMI/CIP pressure limits for the specified cartridge when publishing load data, and most publish reduced data to keep their Liability insurers happy. Cheers.

[No1_49er]

The difference could be the subtle difference in the bearing surface area, which will be relevant to the ogive of each.

[marksman]

its more than likely that that is what they used at the time of testing?

get a copy of quickload, learn to use it properly to make loads for each individual chamber and throw your handbooks in the bin