full metal jacket vs complete metal jacket

[pcctex]

Montana Gold sells 9mm bullets in FMJ with the lead core visible at the base of the bullet, and CMJ with the entire bullet including the base jacketed.

What difference does it make?

Thanks in advance for any responses.

pcctex

 

[243winxb]

FMJ & Plated bullet difference.

http://www.frontierbullets.co.za/about.htm

The difference between Complete Metal Jacketed bullets and traditional Full Metal Jacketed bullets starts with the manufacturing process.

Full Metal Jacketed bullets are manufactured by means of pressing ("swaging") a lead core into a copper jacket while the jacket of a CMJ is electroplated onto the lead core, covering the core completely. Through the years this process has been refined continuously to improve core-bonding, smooth plating and other factors, resulting in a premier product. Among the many advantages of CMJ bullets is the fact that the lead core is completely covered with copper, eliminating the dangers of lead poisoning. The manufacturing process s more flexible, resulting in a product that is easier to customize for specialised use.

http://www.thehighroad.org/showpost.php?p=4783660&postcount=10 FMJ are best at maximum loadings. Plated are to be loaded to mid-range. The fully plated bullet might keep lead vapors low on indoor ranges. Plated bullets maybe less expensive$$. Some plated bullets have pure lead cores. Do not over crimp plated bullets, very light crimp only as the plating is thin.

 

[edSky]

Does one fly truer than the other? Can you get tighter groups from one? Thanks

 

[rcmodel]

In general, conventional jacketed bullets are more accurate then the cheaper plated bullets like Berry & Rainer.

All bets are off when you go to the premium plated bullets like Speer Gold-Dot & Unicore match bullets.

rcmodel

 

[saskboy]

I got hornady 150gr FMJ's and they are grouping .5'' at 100 yrds, anyone had any bad luck with these bullets at all?

 

[D. Manley]

full metal jacket vs complete metal jacket

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Montana Gold sells 9mm bullets in FMJ with the lead core visible at the base of the bullet, and CMJ with the entire bullet including the base jacketed.

What difference does it make?

Thanks in advance for any responses.

pcctex

Montana Gold's FMJ are made in the conventional jacketed manner that is, with the lead core exposed. Their bullets designated as "CMJ" are actually encapsulated which means, the core is seated into a copper base (similar to a gas check) before the outer jacket is swaged over both it and the core.

The difference is...no exposed lead and therefore, no atmospheric release of lead from the burning gasses when fired. Virtually all my shooting is at an indoor range and I only use encapsulated rounds or JHP's...after lengthly sessions, you can actually taste the difference when shooting anything with an exposed base. I find no difference in loading or accuracy using the encapsulated bullets when compared to FMJ. FWIW, if you check MG's pricing you'll find in most cases you can buy JHP's for about the same price as CMJ and I do find JHP's tend to group a bit better than RN...YMMV.

 

[Walkalong]

The difference to some is no lead exposed at the base for less lead in the air.