I see lots of threads about using hardcast bullets for hunting or protection when deep penetration is desired. What about FMJ bullets? Will they give the same penetration and performance? The main difference is some hardcast bullet designs have a flatter nose with sharper edges.
I am handloading some 200gr XTPs for hog and deer hunting this year and some of the boar are large. I am just wondering if a FMJ will work as well as a hardcast against the big hogs.
I like the 200 Grain XTP's, and I load them to 1240 fps in my firearm. I do cast my own Speer 200 TC SWC's and they tend to cut a cleaner hole because of the SWC until they encounter bones to deform the nose...
Shooting targets and milk jugs with FMJ tells me what I need to know. They punch smaller than diameter holes in tissue, which means it will take longer for the target to exsanguinate. Unless you get a solid CNS hit, they aren't like to stop a threat fast enough.
SWC and WFN designs on the other hand punch full diameter holes in tissue. Lots more bleed, which means lots faster incapacitation. FMJ are great for plinking, and perhaps for small game. But if there is a need to stop a threat, I want either an expanding round, or a WFN/SWC design.
I've been thinking the same thing about using FMJs for hunting. I've looked at a lot of manufacturers' bullets paying particular attention to the size of the meplat. Conventional wisdom seems to be the bigger the meplat, the bigger the wound channel. I read Elmer Keith finally settled on a 70% meplat diameter with a BHN of 15 for his lead bullets. He apparently liked them for a balance between accuracy and performance on game.
Both Beartooth and Double Tap have larger meplats than Keith's design and I haven't found any FMJ manufacturer that offers a comparable meplat to theirs. There are some close to the Keith's in the 60%+ range but I'm concerned the BHN of the lead in them will be too soft, which means it will flatten somewhat on impact rather than simply cutting a close to caliber size hole all the way through the animal and exiting.
So, if I can over simplify and generalize bullet performance, Hornady XTPs penetrate in inches and hardcast lead bullets penetrate in feet. Some folks have reported the faster you drive the XTPs, the less they seem to penetrate. I think that is simply because they are an expanding bullet and higher velocity makes them fully open inside the animal sooner. So, penetration is affected. How much of a difference in penetration between the fast and the slow XTP? I have no idea but I doubt the difference is much and it could probably be measured in inches and not feet.
Mind you, I've not done any 10mm penetration testing myself, I'm just parroting the excellent work done by folks on this site and others. It's all a matter of what type of performance you want. The XTPs seem to easily penetrate 18-20 inches (maybe more in some cases) and the hardcast will give you complete pass throughs. So, you'll have to choose what type of performance you want on those angry tuskers.