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Posted: 10/15/2010 3:05:51 PM EDT
| I keep thinking this means they are plated, what exactly does it mean? |
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Means that they have a gas check on the bottom of the jacket so that the entire bullet is jacketed. Normally you have an exposed lead base on a jacketed bullet - supposedly this keeps the hot gases from vaporizing some of the lead off the bottom of the core and making it airborne. They are a nightmare to smelt down after digging them out of the backstop because the seal is so tight that you have to actually puncture them to get the molten lead to flow out.
Sarg |
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Quoted:
Means that they have a gas check on the bottom of the jacket so that the entire bullet is jacketed. Normally you have an exposed lead base on a jacketed bullet - supposedly this keeps the hot gases from vaporizing some of the lead off the bottom of the core and making it airborne. They are a nightmare to smelt down after digging them out of the backstop because the seal is so tight that you have to actually puncture them to get the molten lead to flow out. Sarg Doesnt this mean they are plated though? |
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While all three posts sound good, they are all wrong. TMJ does stand for Total Metal Jacket but it's a euphemism for plated. Quoted: Means that they have a gas check on the bottom of the jacket so that the entire bullet is jacketed. Normally you have an exposed lead base on a jacketed bullet - supposedly this keeps the hot gases from vaporizing some of the lead off the bottom of the core and making it airborne. They are a nightmare to smelt down after digging them out of the backstop because the seal is so tight that you have to actually puncture them to get the molten lead to flow out. Sarg No, they don't have a gas check added to a FMJ. The lead core is plated which completely covers the lead bullet core unless a second strike punches through the plating. That's why Berry's 38/357 HP bullets have a plated HP while Berry's HPs show bare lead. Quoted: No, they're jacketed. Plating is a very thin coating, as you know; these are actually jacketed. They're just like regular FMJ bullets, except that the base is also covered. No exposed lead. Again, they are not jacketed bullets, they are plated. Plated bullets have a thin (about .006"-.006") copper platting applied to the bullet shaped lead core. FMJ bullets start as a thicker copper cup (about .0625") and a piece of lead is swaged into it forming the final FMJ bullet. That's why the rear of a FMJ is open; it's where the lead was pressed in. Quoted: The Speer TMJ is plated, but the thickness of the plating is way more then say Berry's or other vendors.....Some companies have a CMJ ie Montana Gold which is the brass jacketed bullet with a copper base plate.... 3rs post error - no, surprisingly Speer Gold Dots plated HP bullets have the same plating thickness as the Berry's and Rainiers. The HP is punched after plating piercing through the plating. Montana Gold's newest offering; their CMJ bullet is also just a plated lead core they call a 'Complete Metal Jacket.' It's the same as the Rainier, Berry's, X-Treme, and Speer Gold Dots plated bullets. I've sectioned Rainier, Berry's, X-Treme, and Speer Gold Dots and the plating on all of them was about the same thickness. Here is a picture comparing the plating thickness of a Berry's and Rainier 200 grn 45acp bullets I sectioned a few years ago. It's the same, .007" thick.  |
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Thanks for the reply.
Are These the plated gold dots, or are the good expanding hollow points found in defensive ammo? Thanks. |
| Somewhere on The Firing Line, I saw a post from Jay at Berrys about this subject. He said that TMJs have MUCH thicker plating than his bullets (he didn't address gold dots). The thicker the plating, the harder the bullet will be overall. It looks like Speer uses much harder lead cores too (their "unicore" technology). All told, it seems like you can load Speer TMJs like jacketed, and I've never seen anything in any manual that says otherwise. |
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