Question For The Reloading GURU's

[WheelGunMan]

I was going thru my reloads the other night with the anticipation of getting a little range time in. I ran across a box of 50 count 9mm 124 grain FMJ loaded with 5.8 gr of Hodgdon HS-6 and another box of 124 gr FMJ loaded with 6.8 gr of HS-6 that I had made up last summer. When I seen the difference a red flag went up, so I consulted my manuals and the Hodgdon website and came up with a maximum load of 6.6 gr of HS-6. I recall somewhere seeing that 6.8 gr number in some reload manual somewhere but for the life of me cannot find it. Now I'm wondering if I need to start pulling bullets apart. Thoughts please.

 

[NMexJim]

Been there, done that. Pulled the bullets and slept deeply that night.

My 11th edition Hornady lists 124 gr FMJ w/ HS6 as 5.9 max and 1050 FPS.
Sierra 124 FMJ says 6.6 HS6 max at 1150
Speer 124 TMJ 6.7 max at 1059

Suggest you pull several (or more) of each and check bullet and powder weights just for giggles. Maybe 6.8 was typo.

 

[WestKentucky]

.2 over doesn’t sound like much, but that’s somewhere around 3% overloaded which can easily mean a 10% or greater pressure spike. Read books and look for loads listed that high.

 

[P Flados]

Hodgdon does have a 6.8 gr HS-6 load under a Sierra 125 FMJ in their on-line tool.

However, when not using exact components, the most important detail to get right for a round like this is proper bullet seating depth. Pressures go up real fast if you seat deeper than they did in the reference load.

I have Quickload and use it a lot to quickly tell me the seating depth for a published load when I can get an exact match on the bullet.

When I plugged in the Hodgdon load details (using Quickload bullet: 0.355, 125, Sierra FMJ RN 8120) to find seating depth I was surprised to note that Quickload says the load is way overpressure at the Hodgdon OAL. I had to reduce seating depth to 0.195" to get pressure down to the max for standard 9mm. For 9mm +P pressure, the seating depth can be up to 0.210".

If you know your bullet length, you can figure the seating depth using: 1.125" for the case length plus the bullet length minus your OAL.

 

[BigBore44]

My first thought was Hogdon’s site. If they say it’s safe, it’s close to a manual load, and the OAL is right, I wouldn’t be concerned. It’s their powder after all. Manuals are notorious for listing “Max” loads that are not truly Max. It’s a “lawyer approved” thing.

 

[kcofohio]

What bullets and, yes the difference in seating depth is a key.

I don't have access to my Lyman's right now. But could it be the one you got your data from?

 

[jmorris]

+1 on the what bullet question but my books show higher charge weights with 124/125 grain bullets. That said, I don’t start at the top either, so I’d try the lightest ones first and maybe a few in between before I pulled and started over.

 

[WheelGunMan]

What bullets and, yes the difference in seating depth is a key.

I don't have access to my Lyman's right now. But could it be the one you got your data from?

It's a 124 grain FMJ from RMR

 

[GW Staar]

If it were me with the question....I'd answer the question whether it's a typo or not first. 5.8 is really easy to write 6.8.

Pull ONE, and measure the powder.....then you'll know. Better than pulling all of them......

 

[GeoDudeFlorida]

What bullets and, yes the difference in seating depth is a key.

I don't have access to my Lyman's right now. But could it be the one you got your data from?

Lyman's is even more conservative:
125gr. Sierra JHP, #8125, for HS6: start --> 5.8gr - 949fps @ 23,800CUP / max. - 6.6gr. - 1080fps @ 30,400CUP

I agree with the pull one, measure, verify, then decide recommendation. I've been known to typo loads when entering them into my labeling software. That's why I double-check labels but nobody's perfect.

 

[Mark_Mark]

I got 6-9 baggies of 9mm loose ammo. from range and matches. I’ll pull them all, dump the powder and reuse the components (expect powder)

 

[kcofohio]

It's a 124 grain FMJ from RMR

I forgot to ask, but your cartridge OAL?

And your bullet length?

FWIW, Hornady's 124 gr. XTP length .603", Sierra's 125 gr FMJ (TM) .581" and JhP (SM) .554".
Per JBM bullet length list ;
http://www.jbmballistics.com/ballistics/lengths/lengths.shtml

 

[243winxb]

SAAMI average MAXIMUM working pressure is 33,000 CUP. Sierra data at 6.8 gr for a 125 gr fmj is 27,000 CUP . COL 1.090"
These are standard pressures, NOT +P The +P pressure is not listed by SAAMI, but should be higher pressure.

Should you shoot the 6.8 ammo. Your call. But always best to work up to maximum, slowly.

 

[kalielkslayer]

No doubt if you look long enough you could find a manual that shows the load being safe.

6.8 grains HS6 isn’t much more than I use (6.5) with 124 grain bullets. But I load them long, 1.150. The Hornady book has COL ranging from 1.050 to 1.150 depending on the bullet. Even at 1.150, it functions well (feeds/ejects) in the 5 guns I tested it in. My SD was in single digits in my gun but I didn’t really test it for Accuracy.

But my Hornady 7th shows max at 5.9. My Lyman’s is downstairs but I believe it’s well over 6.5.

Funny thing is when I started working up that load, I started at 5.8 grains and posted it on here. Several people jumped on and said it was below min? The Hornady 7th lists 5.1 as a min.

Pulling and weighing a few to ensure it isn’t a typo is a great idea.

 

[WheelGunMan]

I forgot to ask, but your cartridge OAL?

And your bullet length?

FWIW, Hornady's 124 gr. XTP length .603", Sierra's 125 gr FMJ (TM) .581" and JhP (SM) .554".
Per JBM bullet length list ;
http://www.jbmballistics.com/ballistics/lengths/lengths.shtml

Cartridge OAL: 1.145"

Case Length: .745

Headstamp: F C

Bullet Length: .5925

 

[Ranger99]

. . . But always best to work up to maximum, slowly.

Absolutely ^ ^ ^ always. Every time

 

[kcofohio]

Your bullet is .0115" longer than Sierra's FMJ. Hodgdon's COL is .055" shorter than your cartridge. Hodgdon has .0435" less case capacity left.

If you have any RMRs that are not loaded, if it were me, using your cartridge OAL, I'd load up some at 6.4 gr. (Hodgdon's start load) and some at 6.6 gr. Test them, if they're okay, shoot the 6.8 gr.

 

[Ranger99]

This thread is one of the reasons why the
man that taught me how to reload also
taught me to keep explicit written records
of every minute detail of what I do and
use when I load ammunition
The most important step in the process IMO

 

[kcofohio]

This thread is one of the reasons why the
man that taught me how to reload also
taught me to keep explicit written records
of every minute detail of what I do and
use when I load ammunition
The most important step in the process IMO

It took me a bit to realize that. I should know my memory was never what it use to be.

 

[AgPilot]

This thread is one of the reasons why the
man that taught me how to reload also
taught me to keep explicit written records
of every minute detail of what I do and
use when I load ammunition
The most important step in the process IMO

I would forget My name if I didn’t write it down!

 

[WheelGunMan]

Thanks all for the input. I've decided to error on the side of caution and pull the bullets and start anew. I'm going out of town for a month and was going to take these with me, but now I'm putting them aside until my return. I have other reloads that are tried and true that I'll take along to shoot. Thanks again for the sound advice.