Lee 9mm data error?

spacecoast · April 10, 2010, 06:18 PM

I've been collecting load data for a number of different rounds - .380, 9mm, .38, .357, .45 and one trend I have seen is that the FMJ rounds tend to require more powder than Lead for a given bullet mass. This I believe I have read is because the lead is easier to get out of the barrel.

This data comes from my Lee 9mm Luger reloading dies instruction page -

115 gr. Jacketed bullet - 4.0 (min) to 4.4 gr. (max) of Accurate #2, OAL of 1.10" and velocity of 1092

115 gr. Lead bullet - 4.4 (min) to 4.9 gr. (max) of Accurate #2, OAL of 1.10" and velocity of 1146

Yes, the velocity on the lead bullet is slightly higher, but it seems the lead min and max powder amounts should be lower than the FMJ. Has anyone else noticed this apparent discrepancy? Is there another explanation?

armoredman · April 10, 2010, 06:27 PM

Hmm, I'd have to look at my load data I put together for LRN I have cast at home, but I use the 124gr Lee cast, (great bullet), only 115s I used someone gave me.
AA#7 works better for me in 9mm, but I have loaded #2, as well.

draggon · April 11, 2010, 03:35 AM

I haven't bothered checking those figures out in the Lee book BUT you need to keep in mind that Lee does NOT load test any of the data he reproduces in the book or his die tables.

Lee merely cuts and pastes data (with consent) from others data so what you are reading represents data from different guns, different conditions, different powder lots etc.

Nothing wrong with that provided you acknowledge that is what you are doing (as Lee does).

The book is useful as a source of multiple different data bases, most of which list maximum loads available but you cannot use it to compare individual component changes which is what you were doing in your question.

vladan · April 11, 2010, 11:56 AM

lead bullets are usually slightly larger diameter - .356-.357 in 9mm and should have LOWER max charge than jacketed bullets. My AA manual says 115g LRN will have min 4.6g and max 5.2g of AA2 loaded to 1.100 COL, jacketed nosler JPH have min 4.7g and max 5.2g loaded to 1.095 COL. on 124g bullets it is more pronounced, lead is min 4.0g to max 4.6g while jacketed is 4.2g to 4.7g of AA2
Well, either way it looks like you are safe with LEE max loads anyway

spacecoast · April 11, 2010, 04:57 PM

Thanks vladan, those numbers agree with the Accurate web site. I think the Lee JHP data is just mistaken. I've been using 4.8 grains of A#2 and a 115 gr. Berry's plated bullet (OAL of 1.15") with good results. Trying to reconcile the published data from various sources can be challenging.

BTW, where do you do most of your shooting? I'm on the east coast of C Fla and shoot outdoors at Fellsmere most of the time.

IllinoisCoyoteHunter · April 11, 2010, 05:01 PM

Quote:

lead bullets are usually slightly larger diameter - .356-.357 in 9mm and should have LOWER max charge than jacketed bullets.

Correct on the larger diameter, but you must also remember that lead bullets generally run at a lower pressure than jacketed. It is much easier to swage down a lead bullet than a jacketed bullet, thus you will run lower pressures with the lead. So this data does not surprise me at all. I often load my lead bullets using jacketed data.

dwhite · April 12, 2010, 03:30 PM

I just looked at these loads and compared the pressures. The Jacketed bullet runs about 4K psi higher than the lead bullet. This accounts for the heavier charge weight. The lead bullet slides through the barrel easier than the copper jacketed slug. Copper has a higher friction coefficient.

All the Best,
D. White

spacecoast · April 12, 2010, 03:45 PM

dwhite -

That's consistent with published data for other calibers, my original question was about the Lee data sheet showing a reduced load for the Jacketed bullet vs. the Lead bullet.

April 10, 2010, 06:18 PM	#1
spacecoast Senior Member Join Date: October 14, 2009 Location: Sunshine and Keystone States Posts: 4,461	Lee 9mm data error? I've been collecting load data for a number of different rounds - .380, 9mm, .38, .357, .45 and one trend I have seen is that the FMJ rounds tend to require more powder than Lead for a given bullet mass. This I believe I have read is because the lead is easier to get out of the barrel. This data comes from my Lee 9mm Luger reloading dies instruction page - 115 gr. Jacketed bullet - 4.0 (min) to 4.4 gr. (max) of Accurate #2, OAL of 1.10" and velocity of 1092 115 gr. Lead bullet - 4.4 (min) to 4.9 gr. (max) of Accurate #2, OAL of 1.10" and velocity of 1146 Yes, the velocity on the lead bullet is slightly higher, but it seems the lead min and max powder amounts should be lower than the FMJ. Has anyone else noticed this apparent discrepancy? Is there another explanation?

April 10, 2010, 06:27 PM	#2
armoredman Senior Member Join Date: May 22, 2007 Location: Arizona Posts: 5,299	Hmm, I'd have to look at my load data I put together for LRN I have cast at home, but I use the 124gr Lee cast, (great bullet), only 115s I used someone gave me. AA#7 works better for me in 9mm, but I have loaded #2, as well.

April 11, 2010, 03:35 AM	#3
draggon Member Join Date: April 16, 2009 Posts: 96	I haven't bothered checking those figures out in the Lee book BUT you need to keep in mind that Lee does NOT load test any of the data he reproduces in the book or his die tables. Lee merely cuts and pastes data (with consent) from others data so what you are reading represents data from different guns, different conditions, different powder lots etc. Nothing wrong with that provided you acknowledge that is what you are doing (as Lee does). The book is useful as a source of multiple different data bases, most of which list maximum loads available but you cannot use it to compare individual component changes which is what you were doing in your question.

April 11, 2010, 11:56 AM	#4
vladan Senior Member Join Date: March 14, 2010 Location: Central Florida Posts: 813	lead bullets are usually slightly larger diameter - .356-.357 in 9mm and should have LOWER max charge than jacketed bullets. My AA manual says 115g LRN will have min 4.6g and max 5.2g of AA2 loaded to 1.100 COL, jacketed nosler JPH have min 4.7g and max 5.2g loaded to 1.095 COL. on 124g bullets it is more pronounced, lead is min 4.0g to max 4.6g while jacketed is 4.2g to 4.7g of AA2 Well, either way it looks like you are safe with LEE max loads anyway

April 11, 2010, 04:57 PM	#5
spacecoast Senior Member Join Date: October 14, 2009 Location: Sunshine and Keystone States Posts: 4,461	Thanks vladan, those numbers agree with the Accurate web site. I think the Lee JHP data is just mistaken. I've been using 4.8 grains of A#2 and a 115 gr. Berry's plated bullet (OAL of 1.15") with good results. Trying to reconcile the published data from various sources can be challenging. BTW, where do you do most of your shooting? I'm on the east coast of C Fla and shoot outdoors at Fellsmere most of the time.

April 12, 2010, 03:30 PM	#7
dwhite Senior Member Join Date: September 2, 2007 Location: Wake County, N. Carolina Posts: 379	I just looked at these loads and compared the pressures. The Jacketed bullet runs about 4K psi higher than the lead bullet. This accounts for the heavier charge weight. The lead bullet slides through the barrel easier than the copper jacketed slug. Copper has a higher friction coefficient. All the Best, D. White Last edited by dwhite; April 12, 2010 at 03:33 PM. Reason: Noun/verb conflict affecting space time continuum.

April 12, 2010, 03:45 PM	#8
spacecoast Senior Member Join Date: October 14, 2009 Location: Sunshine and Keystone States Posts: 4,461	dwhite - That's consistent with published data for other calibers, my original question was about the Lee data sheet showing a reduced load for the Jacketed bullet vs. the Lead bullet.