What is the minimum seating depth of 124 Rem JHP 9mm

NoleMan · May 19, 2009, 07:23 PM

I'm using 124 grain Remington JHP bullets, and found that using 5.1 grains of Alliant Unique, mostly fills the casing. I performed a test where i flared the casing (without resizing...so the bullet would "fall" right into the casing), charged the casing, and gently let the bullet down to find where the bullet touches the powder. I then measured OverAll Length. What i found is 1.140 OAL, will keep my bullet off of the powder and won't compress the powder. My concern is, the bullet seems to be seated awfully high. I pushed the bullet down and pulled on the bullet, to see if would budge, but it seems to be holding steady. I did a calculation and found that approximately 30% of the bullet is seated.

What would you guys recommend as the MINIMUM amount of bullet that can be safely seated in a 9mm casing? Is there no minimum?

Shoney · May 19, 2009, 08:43 PM

The standard unit for seating depth on any bullet is not less than 1 diameter into the case. This is not an absolute, but is usually good advice to follow.

NoleMan · May 19, 2009, 09:06 PM

Quote:

The standard unit for seating depth on any bullet is not less than 1 diameter into the case. This is not an absolute, but is usually good advice to follow.

Maybe I'm missing something, but If I'm loading 9mm, that would mean I'd have to seat my bullet a MINIMUM of .355. The overall bullet length is .568. That surely can't be the case. If so, I would have a mere .213 inches of the bullet out of the casing. Where am I going wrong here?

D. Manley · May 19, 2009, 10:40 PM

1.14 is a little longer than *most* people load a JHP to but, if it runs through your mags and feeds OK, then it's no problem. Were it me, I'd drop it down to around 1.120 to 1.130. I'm not sure the "1 bullet diameter" thing holds true for pistol rounds, seems some bullets in some calibers would disappear into the case.

glokmunkee · May 20, 2009, 03:34 PM

Hello, were you not able to find a minimum OAL published for that powder? It is the compression of the powder that should concern you after your feed and function issues if any, are resloved. There is no universal minimum depth a bullet should be seated as powder burn rates vary... obviously. Most commercial 9mm round nose( I did say most I have in no way measured all of them) come in at 1.150" coal. ( again your concern is what is inside the case not the crown so that being said, be aware that the difference in a round nose and an hp can be as much as .045" in length so the actual depth would coincide at 1.105" coal, which should put the bullet inside the case at the same depth as a 1.150 rn., by your calculations provided that the bullet is.572" long, you should have .172" of bullet in your case which is not enough btw. you should try for the .190's .185-.195) So if you have no data and the round should feed into your gun, clock the 1.15's and work your way down. You will notice several different characterisitc changes in the way your gun handles them. The further you seat the bullet from the throat of the bore you will get a more snappy recoil. I seat my match bullets 1.135 using the round nose bullet but with tightgroup powder cause Im not looking for a fast bullet and it has a cushiony recoil and clocks in at around 127000 p/f. So first decide on the mission of the round your building, i.e test results, foundation data, match rounds, practice rounds.... whatever and experiment! Watch for pressure signs be safe and have fun. that is really what it should be about.... oh and I most sencilry appologize for any mosspellings and grammer punctiyations that aint currect!

putteral · May 20, 2009, 04:14 PM

I seat mine at 1.125 OAL only I use Hornady XTP'S instead.

NoleMan · May 22, 2009, 05:33 AM

Update: I loaded 10 rounds of 9mm with approx 5.1 grains of Unique, 124 grain Remington JHP & Federal small pistol primers. All ten casings showed zero signs of too much pressure. I ended up seating the bullet to create an overall length of 1.130, well under maximum spec. I don't think I'd go any shorter than this as it will compress the powder. Anyway, I shot five single rounds, in case i had a kaboom, and then loaded the magazine with the remaining five rounds. Out of this small sample size, I didn't have any FTFeed or FTE. Thank you all for your input on this!

glokmunkee · May 22, 2009, 06:11 AM

You dont have a chronograph?

NoleMan · May 22, 2009, 06:37 AM

Quote:

You dont have a chronograph?

Nope, sure don't. The first time I went out I used someones Chrono though. I plan on getting one in the future.

glokmunkee · May 22, 2009, 02:29 PM

I think you will be glad you did. I have the f1 master and it works for me. I like that I can put the display on th bench next to me.

olmossbak · May 22, 2009, 03:36 PM

and clocks in at around 127000 p/f.

Glockmunkee,

What is that measurement?

glokmunkee · May 23, 2009, 07:10 AM

Just the bullet weight times the velocity. ( some divide it by 1000 I think but i have seen it described both ways, i took the easiest... go figure)

It is supposed to level the playing field by providing a baseline ( 'power floor') to handloading bullets used in pistol matches. ( ipsc uspsa idpa) Simulates the recoil close to factory built ammo. I use it to compare different ammo and load to it. It helps simplify my recoil setups too.

glokmunkee · May 23, 2009, 07:25 AM

Quote:

by your calculations provided that the bullet is.572" long, you should have .172" of bullet in your case which is not enough btw.

My awsome skills of observation. :barf: That you already said the bullet was .568".

May 19, 2009, 07:23 PM	#1
NoleMan Member Join Date: March 13, 2009 Posts: 40	What is the minimum seating depth of 124 Rem JHP 9mm I'm using 124 grain Remington JHP bullets, and found that using 5.1 grains of Alliant Unique, mostly fills the casing. I performed a test where i flared the casing (without resizing...so the bullet would "fall" right into the casing), charged the casing, and gently let the bullet down to find where the bullet touches the powder. I then measured OverAll Length. What i found is 1.140 OAL, will keep my bullet off of the powder and won't compress the powder. My concern is, the bullet seems to be seated awfully high. I pushed the bullet down and pulled on the bullet, to see if would budge, but it seems to be holding steady. I did a calculation and found that approximately 30% of the bullet is seated. What would you guys recommend as the MINIMUM amount of bullet that can be safely seated in a 9mm casing? Is there no minimum?

May 19, 2009, 08:43 PM	#2
Shoney Senior Member Join Date: February 21, 2002 Location: Transplanted from Montana Posts: 2,311	The standard unit for seating depth on any bullet is not less than 1 diameter into the case. This is not an absolute, but is usually good advice to follow. __________________ I pledge allegiance to the Flag - - -, and to the Republic for which it stands….Our Forefathers were brilliant for giving us a Republic, not a democracy! Do you know the difference??? and WHY?http://www.wallbuilders.com/LIBissue...les.asp?id=111

May 19, 2009, 10:40 PM	#4
D. Manley Senior Member Join Date: July 13, 2008 Posts: 299	1.14 is a little longer than most people load a JHP to but, if it runs through your mags and feeds OK, then it's no problem. Were it me, I'd drop it down to around 1.120 to 1.130. I'm not sure the "1 bullet diameter" thing holds true for pistol rounds, seems some bullets in some calibers would disappear into the case. __________________ *"Old School" ain't all bad...*

May 20, 2009, 03:34 PM	#5
glokmunkee Member Join Date: April 25, 2009 Posts: 50	Hello, were you not able to find a minimum OAL published for that powder? It is the compression of the powder that should concern you after your feed and function issues if any, are resloved. There is no universal minimum depth a bullet should be seated as powder burn rates vary... obviously. Most commercial 9mm round nose( I did say most I have in no way measured all of them) come in at 1.150" coal. ( again your concern is what is inside the case not the crown so that being said, be aware that the difference in a round nose and an hp can be as much as .045" in length so the actual depth would coincide at 1.105" coal, which should put the bullet inside the case at the same depth as a 1.150 rn., by your calculations provided that the bullet is.572" long, you should have .172" of bullet in your case which is not enough btw. you should try for the .190's .185-.195) So if you have no data and the round should feed into your gun, clock the 1.15's and work your way down. You will notice several different characterisitc changes in the way your gun handles them. The further you seat the bullet from the throat of the bore you will get a more snappy recoil. I seat my match bullets 1.135 using the round nose bullet but with tightgroup powder cause Im not looking for a fast bullet and it has a cushiony recoil and clocks in at around 127000 p/f. So first decide on the mission of the round your building, i.e test results, foundation data, match rounds, practice rounds.... whatever and experiment! Watch for pressure signs be safe and have fun. that is really what it should be about.... oh and I most sencilry appologize for any mosspellings and grammer punctiyations that aint currect! __________________ Gimme Th'm Nannerz Last edited by glokmunkee; May 20, 2009 at 03:51 PM.

May 22, 2009, 06:11 AM	#8
glokmunkee Member Join Date: April 25, 2009 Posts: 50	You dont have a chronograph? __________________ Gimme Th'm Nannerz Last edited by glokmunkee; May 22, 2009 at 06:12 AM. Reason: i cant spell!

May 20, 2009, 04:14 PM	#6
putteral Senior Member Join Date: May 17, 2008 Location: Homosassa,Florida Posts: 206	I seat mine at 1.125 OAL only I use Hornady XTP'S instead.

May 22, 2009, 05:33 AM	#7
NoleMan Member Join Date: March 13, 2009 Posts: 40	Update: I loaded 10 rounds of 9mm with approx 5.1 grains of Unique, 124 grain Remington JHP & Federal small pistol primers. All ten casings showed zero signs of too much pressure. I ended up seating the bullet to create an overall length of 1.130, well under maximum spec. I don't think I'd go any shorter than this as it will compress the powder. Anyway, I shot five single rounds, in case i had a kaboom, and then loaded the magazine with the remaining five rounds. Out of this small sample size, I didn't have any FTFeed or FTE. Thank you all for your input on this!

May 22, 2009, 02:29 PM	#10
glokmunkee Member Join Date: April 25, 2009 Posts: 50	I think you will be glad you did. I have the f1 master and it works for me. I like that I can put the display on th bench next to me. __________________ Gimme Th'm Nannerz

May 22, 2009, 03:36 PM	#11
olmossbak Member Join Date: May 19, 2009 Location: NE Tenn Posts: 22	and clocks in at around 127000 p/f. Glockmunkee, What is that measurement?

May 23, 2009, 07:10 AM	#12
glokmunkee Member Join Date: April 25, 2009 Posts: 50	Power Factor Just the bullet weight times the velocity. ( some divide it by 1000 I think but i have seen it described both ways, i took the easiest... go figure) It is supposed to level the playing field by providing a baseline ( 'power floor') to handloading bullets used in pistol matches. ( ipsc uspsa idpa) Simulates the recoil close to factory built ammo. I use it to compare different ammo and load to it. It helps simplify my recoil setups too. __________________ Gimme Th'm Nannerz