Hornady 9mm 124gr conflicting data

[tcanthonyii]

Found that at some point I bought some 124gr JHP Hornady bullets and I was going to load them up today. Pulled the Hornady manual and looked at what powder would work well. I have some Unique so perfect. It says 4.0-5.0 gr. for the heck of it I pull my Lee manual and it says 5.1-5.8! How can their be so much discrepancy? I'm think I'll start with the hornady manual but why on earth would there be so much difference, especially with Lee, they are usually on the VERY cautious side.

Anyone loading more than the Hornady manual?

 

[Sunray]

Lee does no testing of any loads themselves. They use the powder maker's data. However, all manuals will be different as they reflect the conditions of the day of the tests and with the particular firearm used. Hornady must have been using something other than a 4" pistol.
Alliant gives 5.8 as the max, out of a 4" barrel. Reduce by 10% for the start load.

 

[Dudedog]

Don't have data for that bullet but
Lyman shows 4.5 to 5.0 with a 125 JHP,
Alliant 2014 shows 5.8 Max with a Gold Dot HP,
Alliant 2009 shows 4.9 max FMJ, 5.5 max lead.
Alliant 1995 shows 6.0 max lead, 6.2 max FMJ (note older data is higher)
Alliant 2000 is the same as the 1995 data, Alliant 2002 data is the same as the 2009 data.



I am sure this helps eliminate the confusion.
4.3 and 4.6 both worked for me with MBC 125 lead cones, did not try going higher than 4.6.

 

[Hungry1]

Speer 14 shows 5.2-5.8 Unique for a similar bullet from a 4" barrel.

I've found that the Hornady 9 has conservative data.

 

[vaalpens]

The differences are also due to the construction of the bullets and the COL. The link below has some Hornady XTP data with Unique loads which I think is low, but it could be due to the COL. Maybe the bullet is just seated deeper, thus a lower charge. You will see they lists different bullet types with a big difference in powder charge.

http://www.realguns.com/loads/9mm+P.htm

 

[climbnjump]

The differences are also due to the construction of the bullets and the COL.

More directly, it is the depth to which the bullet is seated in the case and hence usable case volume that counts. And of course, bullet construction, geometry and COL directly influence seating depth.

For small volume cases such as the 9mm, seemingly small changes in bullet seating depth can lead to larger than expected changes in pressure.

The result of this is that you cannot safely compare MAX load data from one source to another without also knowing the differences in bullet seating depth.

For example:

• For the 124 gr XTP, Hornady lists a MAX of 5.0 gr of Unique, with a COL of 1.060.
  
• For the 124 gr Gold Dot HP Speer lists a MAX of 5.8 gr of Unique, with a COL of 1.120.
  
• The length of the XTP is .576 and the length of the GDHP is .570 so the resulting difference in seating depth is about .066.
• That translates into about a 20% difference in usable case volume between the two loads.

So perhaps the MAX charge in the Hornady data is lower than the Speer data because the Hornady load has 20% less case volume.

Most reloaders already know this, but perhaps it bears repeating: EVEN IF both bullets have the SAME WEIGHT, a powder charge that is safe with one bullet at a defined COL might result in a kaboom (or a squib) when applied to a different bullet at a different COL.

 

[tcanthonyii]

Well I stuck with hornady data. Loaded up a few at 4.7 and a few at 5.0. 4.7 were EXTREMLY ACCURATE. 5.0 opened up a bit but not much. Much more recoil than I was anticipating. I've been shooting a mid 115gr load for long...

Thanks again for the help.

 

[1KPerDay]

I personally haven't been too impressed with the Hornady manual. Once in a while they have the EXACT combo you're looking for but Lee and Lyman have much wider varieties of projectiles and powders.

 

[Toprudder]

As Sunray said, the Lee manual is just a collection of the powder manufacturer's load data, but with important information missing (such as primers used, barrel length, etc). I hardly bother referring to it anymore, I just go the powder manufacturer's website so I am sure to get the latest, COMPLETE, information. About the only value-added thing the Lee manual includes is the volume for a load (for those that use dippers).

Hornady obviously only lists data for THEIR projectiles, same thing with Speer. But I find in many instances that the chrono results from my loads more closely resembles the data from either Speer or Hornady.

Lyman is a good reference, but I find their data to be somewhat limited in projectiles tested.

Having data available from multiple sources is a good thing. I like correlating data.

 

[zeke]

Hornady's pistol data with unique is distinctly differing than some other manuals in several calibers. IMO it is a bit light. Am guessing they had a fast batch of unique, or they just wouldn't compress it.

 

[tcanthonyii]

That crests a question for me. Is it ok to compress unique? Seems like you would have to to load it up past 5grains in 9mm

 

[Toprudder]

When there is difference in the load data, look at the COL listed for each. More often than not, the shorter COL will have a lower charge listed.

 

[Dudedog]

Sorry left out OALs
Lyman shows 4.5 to 5.0 with a 125 JHP, 1.075 OAL
Alliant 2014 shows 5.8 Max with a Gold Dot HP, 1.120 OAL
Alliant 2009 shows 4.9 max FMJ, 5.5 max lead. 1.120 OAL
Alliant 1995 shows 6.0 max lead, 6.2 max FMJ (note older data is higher OAl longer) 1.150

 

[Rule3]

Hodnady manual data is usually much lower than Hodgdon data also. I use more Hodgdon(IMR,WIN) powders.

Hornady data does work fine when using their bullets and COL.

 

[Mad Chemist]

4 grains of Unique is very low for the 124gr XTP. I have worked it up to 5.9gr out of a G19. Recoil was stout but not punishing. Brass and primers were fine. 4.0 is too low to start IMO.

4.0 gr Unique used to be my target load for 147gr Rainier plated HP.

Cross reference multiple sources and pick a reasonable starting point.

 

[zeke]

IMO it is alright to reasonably compress unique in 9mm. 4.0 grains, especially with a 124 xtp is on the low side, 6.0 is on the upper end with 124 xtp.

Unique is an excellent powder for 9mm. Am guessing some don't like it for progressive presses because it spills out. If using a manual powder measure, can do the old rap a tap tap to settle it.

When manuals are showing the same max charges with unique as with 231, something's up.