Today I decided to pick up a jar of H414 because I see it mentioned quite a bit. I figured it never hurts to try something new and my .257AI has not responded well with any powder other than IMR 4895. However I had not noticed till I looked in my old Speer reloading manual that magnum primers are suggested in almost all loads with this powder. So for those who use this powder do I need the magnum primers or not?

i always use mage primers with h414/win760 .. don't recall ever having gone with standards on those

It is a ball powder.
Try it at low light and see how you like the fireball.

I had lots of hangfires with H414 in a .243 with normal CCI LR primers. Switched to magnum primers and haven't experienced another.

I have used H414 in my 257AI and never used a magnum primmer. I also use it in a 30-06 and 22 Cheetah using a Federal 210 in all three. I never had any issues using the 210 primmer.

Good luck, Tony

No problems with H414 and Fed 210s in 30-06 here. I do use Fed 215s in my H414 375 H&H loads however.

I use H414 in 06 based wildcats using Rem 9 1/2 LR primers. Never had an issue and get very consistant velocities. I do step up to magnum primers in magnum cases.

My only experience with H414 was in a 7-08 using standard CCi primers. I hunted in WY in single diget temps w/o a problem. YMMV

I have used H-414 and use the regular primers from CCI and Winchester without and problems in quite a few calibers.

Same as plainsman... I use non mag primers even in cartridges like the 300 Win Mag... and under a charge of 83 grains of H 1000, and it still ignites the powder just fine...

so it will certainly ignite H 414 in an 06 or any thing smaller...

SR 4759 is right about ball powders and pyrotechnics in low light... especially impressive is H 335 for those huge fireballs..

I use Winchester's standard (WLR) primers with W-760. W-760 and H-414 are just different lots of the same powder. I haven't had a problem with it in the several cartridges I load with that power.
If you get a copy of Winchestr's load booklets, all the ones I have state that the standard WLR primer was used in all load work up and testing.
Pretty much says it all for me.
I did try WLRM (magnum primers) in a couple of loading and accuracy went to hell. naturally, YMMV.
Paul B.

w760 usually delivers better groups with a magnum primer. YMMV.