Yep, it's why I changed them in the first place. O.E. was just too light for my taste. Pretty much every accurizing smith out there that does TC's will first change out the hammer springs both on inlines as well as sidelocks. The O.E. springs work well enough but to most they just aren't strong enough for heavy loads which you found out the hard way.

ok, I just wanted to check before i broke something , that stout sucker is in the lock and works so we will see in the morning if it fixed the reset problem .
Last

sent a pm to guy got spring from he said sorry that one is for a tc flintlock i get you the right one in the mail . learn something every day, but on right track now.

I occasionally get the hammer to reset to havecock when my load exceeds 90 gr of 777. Should I be worried and replace the spring?

txhunter
If you have a 50-cal sidelock, it's manual probably states 100 grain charges and 90gr. 777FF puts you right there at the max. 777 is more powerful than Pyrodex or typical blackpowder.

If exceeding 90 grains - or even staying at 90, whenever the hammer repeatedly reverts to half-cock, that means replace the spring and inspect the nipple for an oversized hole. Lastly, store the ML with the hammer closed and that will add years to the spring's life-span.

Thanks. I have generally used 90-95 gr powder ffg 777 or pyrodex select. Will see what happens next time I shoot it.

When operating properly that spring wouldn't cause that much blowback with only 90-95 grains.... even 777FFF. I would change it...... new nipple too.