I know all you reloaders take care when handling your components and I`am sure some of us have made mistakes but let me tell you of my most recent one.... I`ve always used (from day one) Remington
7 1/2 small rifle primers when loading a 454 cartridge. They come in a orange and green box as do their 1 1/2 small pistol primers. I mistook the 1 1/2`s for the 7 1/2`s and loaded 31.0grs of H-110 over the small pistol primer using 260gr partition`s and 265gr Swift`s. At 25yds they grouped good, however, at 100yds the groups opened up. I know I`am not the best handgun shot but I also know I could have done better. Anyway I have about 60 rounds of 454 that I have to pull because of my mistake. Would the use of a small pistol primer under all that H-110 cause erratic groups??

H-110 is somewhat hard to ignite, so that could be your problem.

It could, James, but I've never noticed it at 'hunting' distances. I seldom run 'mag' primers with 110/296 unless I'm going where the temp is extremely cold and I've only experienced one squib where the primer didn't fully ignite the charge. However, I very seldom load .454's preferring a hot .45 Colt load.

I experienced several squibs when I first started reloading for my 454 using small rifle primers under 31.0gr of H110 (was not getting full ignition of the powder). I have since switched to CCI450's and have had no issues since (over 2000 rounds). Don't know if that helps but I run mag primers in all my loads for the 454 and the 500JRH. I have not noticed any pressure issues or other case problems using the mag primers in Starline brass (some of it on the 5th reload). Good Luck and stay safe.

Good info James!

I haven't loaded for the 454 with H-110, but I have for 45LC, 44 Mag and 445SM and found it to be quite temperamental and always found mag primers best. H-110 produces great velocities though! Over the summer I began experimenting with No.11FS (3 lbs. worth) and found it to be right up there velocity wise with H-110/W296 and giving me much better ES/SD readings across the chrono. . .also doesn't have the muzzle or cylinder flash and burns clean. I put 100 rounds (50 44Mag and 50 445SM) in a cooler of ice for several hours and only took three rounds out at a time to shoot. . .there was only a 22 fps drop in velocity with the same marginal variance in ES/SD. Accuracy was on par with H-110/W296 loads as well. My favorite for these two cartridges is still good o'le IMR4227! It's not as fast nor clean burning as the others mentioned, but the consistency and accuracy are impeccable! ! !

WHAT IS NO. 11FS?

No.11FS is a somewhat new powder from Accurate. I think it is a great powder for magnum wheel gun shooters.