With a tubular magazine the Lee factory crimp die is your friend.
If you want to blow up milk jugs or plink around the farm far more cost effective rounds are available. 55 grain charges and .45 bullets that don't grow on trees will reinforce this.
Your father gifted you the Guide gun because with full charges as listed in the "lever action only" section of current manuals will get your attention. Give it back to him.
300 and 405 grain factory stuff is mild mannered, if you reload using a whole bunch of gunpowder see below;
Invest in a Limb saver slip on for use on the bench and take it off when hunting.
If you do decide to keep it, invest in a good front sight and a ghost ring for the back to replace the factory issue sights.
400 grain Speer and 405 Remingtons are soft and punch big holes in deer sized animals. 400 hard cast punch holes all the way through meat targets.
