TMJ vs FMJ whats the difference?

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LibertyorDeath

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I am just wondering what the difference is between these two types of rounds and if the tmj would be ok with the glock thanks
 
Merch said:
Total Metal Jacket covers the back of the bullet, FMJ just covers the front. TMJ is fine in your Glock.
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Exactly.

Although I once bought some CCI aluminum cased 9mm that claimed it was TMJ, and after I pulled a bullet out to check just for S&G, I found out it wasn't.
 
Bullet terminology 101
TMJ= Total Metal Jacket. No lead is exposed. In fact it is a plated bullet. Beware of some manufacturers with insufficient plating thickness
FMJ= Full Metal Jacket A lead core is contained within an actual metal jacket but the base of the bullet remains uncovered, exposed to lead
CMJ= Complete Metal Jacket. Again a lead coreUusually) is fully cased within a metal jacket. As well, a metal disc is placed in the base, covering the lead so no lead is exposed.
All will work fine in a Glock. However if you are using a revolver at some point, and it requires a crimp, you do not want to use TMJ or plated bullets as they can separate from a tight crimp
Hope this helps
dB
 
With that information... taking for example Wolf ammunition from SFRC, why are TMJ cheaper than FMJ? I would think TMJ is a better alternative? Is it worth it to pay the extra ~22$ a case for FMJ or TMJ is just as fine?
 
I can see why plated is likely not in the same league, in terms of performance, but what's the diff on the business end between CMJ and FMJ, then? Do the two behave differently on impact or something?
 
"..."business end" is identical..." Not the identical at all. A plated bullet plating is 3.5 to 8 thou thick. Plating is not a jacket. Frontier's CMJ is electroplating.
An FMJ's jacket can be 30 to 92 thou thick. An FMJ's jacket is a separate piece that the lead gets put into.
"...difference between TMJ and CMJ?..." Different name for the same thing from different makers. Both use cast bullet data. An FMJ uses jacketed bullet data.
 
Another point to note. TMJ is a copyrighted name for Speer bullets. There are other makers out there using the name TMJ which are nowhere near the quality of the real TMJ. Unfortunately a lot of folks unknowingly refer to plated bullets now as TMJ which is wrong. Speer uses a much thicker plating and are double struck to ensure they are coincentric and maintain proper flight characteristics. Beware of folks claiming to have TMJ's when in fact they are NOT Speer. Also, CMJ is NOT a plated bullet. A true CMJ is in fact a jacketed bullet over a lead core with the base covered with a small disc of copper or brass. Plated bullets should be referred to as fully encapsulated but nobody wants to use the terminology.
Cheers
dB
 
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