Just wondering if anyone has tried 5010 in a 375....I know it's too slow for high velocity but was wondering if it would work for practice loads???

While it is not 5010, I have used WC 870 in several calibers and it works well for practice loads, but ya burn a lot of powder to reach less than moderate velocities!
LouisB
Just an opinion of course!

Yes, 5010 will undoubtedly go "boom" if loaded in a .375 H & H. Maximum velocities (in expected proportion to maximum pressures) will be relatively low. I suspect you would find it very, very dirty due to a lot of unburned powder. Will it hurt anything? Not really. Just keep the case full or very close to it in order to avoid possible S.E.E. (secondary explosion effect).

But I would suggest trading that 5010 to some .50 Caliber or other magnum shooters and buy a better-matched powder for your .375.

I am a .50 caliber shooter......that's why I have 5010 on hand!

Well, that makes sense. I thought maybe you had a bunch of 5010 because like me, you found it cheap!