9mm MG 115gr FMJ : leading

[Art Yeo]

I bought 1,000 of the Montana Gold (MG) 115gr to try out on my pistols recently and have been pleased with its performance in terms of the shooting experience and accuracy.

However, the chore of cleaning is a different story. There were significant leading on all barrels across different manufacturers, so much so that the regular Hoppes #9 and bore brush cannot do the job. I had to resort to wrapping brush with ChoreBoy and intensive scrubbing.

N.B. : The MG FMJ bullets all have exposed lead at the base (bottom)

Details of the loads:

• Caliber: 9mm
  
• Alliant BullsEye : 4gr
  
• Bullet: MG 115gr FMJ
  

Any thots on why this can happen and how to fix it?

I'll be trying it out with (4.6gr and 5gr) of WST next.

Edited September 10, 2012 by Art Yeo

[Desmo412]

The simplest fix would be to buy the CMJ bullets next time you order from Montana Gold. They have a copper(?) disc covering the lead base. The price difference is negligible

[Sarge]

Yeah, go with the CMJ's. That bottom exposed lead will be covered with a copper disc of sorts. Only a few dollars a case difference.

Hard to believe they are leading that bad though. I shot a case of 3750 through my G34 with no leading at all but the gun stayed filthy! I was using cooler powders maybe. Not sure if the powder you are using is hot like Tite group and would leave lead in the bore. Just seems to me that the copper jacket should keep the bore clean.

[lcs]

Depending on which chart you look at, BullsEye powder is about 6th faster powder. Fast powders generate more heat--heat that melts the exposed lead base of the bullet.

Select a cooler burning powder and you will not melt as much lead or don't shoot exposed lead base bullets.

[Hi-Power Jack]

The simplest fix would be to buy the CMJ bullets from Montana Gold.

Or the 115 gr JHP's - they're also very good.

[Desmo412]

The simplest fix would be to buy the CMJ bullets from Montana Gold.

Or the 115 gr JHP's - they're also very good.

What he said. I run the 115 JHPs in my open gun....fantastic bullet

[ZombieHunter]

http://www.lasc.us/TaylorLeadingDefined.htm

Read the section titled: "Bore Leading, Entire Bore" - 2nd paragraph.

[kar45]

Depending on which chart you look at, BullsEye powder is about 6th faster powder. Fast powders generate more heat--heat that melts the exposed lead base of the bullet.

Select a cooler burning powder and you will not melt as much lead or don't shoot exposed lead base bullets.

I'm using 4.3 Bullseye with 115 FMJ(exposed lead base) Zeros with no leading whatsoever in two STI's. I doubt it's the powder.

[Tul9033]

Go JHP a much better bullet. The base will be more concentric than the either the CMJ or regular FMJ. The JHP is formed from the bottom up and the others top down.

[cecil]

I just ordered my Dillon 650 .. now i have to order bullets... was thinking about 124gr JHP to shoot in my Glock 19. ... anyone have feeding/jamming problems with the JHP bullets ??

[njd]

I just ordered my Dillon 650 .. now i have to order bullets... was thinking about 124gr JHP to shoot in my Glock 19. ... anyone have feeding/jamming problems with the JHP bullets ??

In my Glock 17 there is absolutely no problem at all with Montana Gold 124gr JHP. I have run them at COL's of 1.080" to 1.130". The longer ones have caused live-round-extraction problems with one AR barrel of mine but no problems in the Glock.