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Posted: 3/19/2005 11:35:39 AM EDT
| What is TMJ, I saw it on some Speer Lawman .45 auto, 230gr T.M.J. in the shot gun news…or to make sure I never ask a dumb question like this again, could some one point me to a site that has ever bullet abbreviation known to man.h.gif |
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Speer precision chemically plates their bullets in copper, rather than the traditional swagging of the bullet into a copper jacket. The result is the bottom of the plated bullet has no exposed lead rather than having an exposed base like traditional bullets. Thus, the term TOTAL Metal Jacket. TMJ:  FMJ: 
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I think that the process of plating the copper makes a pretty strong chemical/molecular bond between the lead/copper. I dont think it will shed at standard velocities. There usually is no real bond in a regular FMJ as the lead is just shoved into the copper cup and held in place by friction and/or the jacket is crimped in the rear to hold it in. Of course, bonded FMJ or HP bullets are another matter as their name implies. I shoot the new Blazer Brass all the time and it has a plated lead bullet. It seems that it is full power, and the accuracy is pretty darn good. Of course, A-merc uses a plated bullet too, but they cant get anything right and their ammo is real poo... 
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I may have spoken too soon. While I am correct, it seems Speer has copyrighted TMJ. They also appear to want it to mean, "Totally Metal Jacket." Well that's just "totally awesome" of them. They have also copyrighted "Lawman," so they might be changing the long known meaning of that too. The Brothers of the Shield might not approve though... |
I've shot bullets listed as TCFMJ, or Truncated Cone Full Metal Jacket. Fiocchi's 142gr .357mag uses this. It sure likes to go through stuff. I shot some ballistic-resistant, laminated polycarbonate panels which were 1.75" thick, which was rated for .357mag. I think it was called "hy-gard" or something of that sort. It's the higher-end stuff you might find in a med. sized bank, not a check cashing kiosk/stop n' rob. It punched right through it!  It stopped FMJ from 9mm, .45acp, and .38spl. about halfway through. .380acp bounced right off and left little dents. I still have some of the pics, I could post them some day if you guys want to see em'.
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