Dose anyone have any experience with this powder? Since I live in the Peoples Republic of California its lead free time. I'm not looking for data as it is for a 243 Win w 62gr VG , 55gr BTLF and Barnes 85gr Tsx. Hodgdon has the load data. for the gun and the 3 bullets. I am mainly looking for things like consistence. Is it consistent from starting load to max? Dose it have to be run heavy to be consistent . Dose it prefer standard or mag primers? If you have used it with Hodgon load data how close were the fps to to the data? Is it dirty? If so was it on the low end ? high end? or with all loads.? If you used a cromo was extreme spread smaller as the load was increased? Did the extreme spread go up as you got near the max load? Thanks, any thing would help PS start low and work up

Back when the Enduron powders first appeared a few years ago, Hodgdon assigned me to write an article on IMR4166 for their 2015 Annual Manual. I checked out their data and handloaded for nine rifles chambered in the .204 Ruger, .223 Rem., 5.56 NATO, .243 Winchester, .257 Roberts, .308 Winchester,.303 British, 8x57 Mauser, and .45-70.

Their data for the .303, 8x57 and .45-70 was all much lower-pressure than for the more modern rounds, and in fact the .45-70 data was for trapdoor Springfields. around 20,000 PSI--and in fact was shot in an H&H reproduction Officer's Model trapdoor. All the loads were consistent and accurate, as well as clean-burning--though there might have been a few unburned kernels in the .45-70 loads, just as there are with IMR4895 at trapdoor pressures. All the Enduron powders contain a decoppering agent, and it worked fine too.

They're also temp-resistant, and I tested that as well in both heat and cold. 4166 passed that test too.

My overall conclusion was that IMR4166 is an excellent powder, and just about as flexible as either IMR4895 or H4895, with a very similar burn-rate.

at M.D's advice I tried 4166 4451 and 4955. 4166 is my go to powder now for 80 grain barnes out of the 257 Roberts and 110 barnes out of the 7-08. I'll check my notes but I'm pretty sure 4166 worked well with my 30-30 and 223 also. I would think your 243 with the bullet weights you want to run, would be a great candidate for 4166.