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advice on 9mm load (n320 under plated 124gr hp)


pharoh
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Cant find the answer on other forum so ill ask here.

I found a load that i think is just awesome for ipsc prod, but im kinda scared to use it (a bit)

Using eaa/tanfoglio stock 2 & 3 i came up with this load:

3.9gr of n320 oal of 1.055-1.058 1060-1070fps

Ive never loaded such short ammo in 9mm but thats as long as both barrels will take with hp's.

I'm using federal spp and i dont get alote of presure but i start seeing the breach face tool marks on the fired rounds. (no primer flow)

Would i be safe in using this? (with good brass of course)

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Best advice I can give is this link to the companies reloading data and say that seems a very short OAL. This is especially true when you see that vihtavuori recommends a 1.142 OAL. If you have a Speer or other reloading manual it should have the minimum OAL listed in it.

http://www.lapua.com...a/relodata/6/34

Questions:

Will it shoot commercial Round nose ammo that is a longer OAL? What bullet and bullet shape are you using to reload with? Have you tried different bullet shapes? like Truncated cone, round nose, etc.

Most people advocate loading on the longer side as opposed to the shorter one for many reasons, pressure and reliable feeding among them. As I always tell people when this type of question is asked, there is no "magic answer" because your gun is different than mine in what it "likes" so what may work great in yours may not work as well in mine and vice versa. Each gun is different. Also each bullet shape is different as to how long or short it can be loaded, and the throat of the barrel in your gun is different as to when it will engage the bullet in the rifling.

If there is someone near you with some experience reloading I would say to ask them and test out some different shaped bullets and different OAL's and see what works *in your gun.*

As always be safe and pay attention when you reload.

Edited by Classic_jon
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Tool marks, "primer flow", and similar things are no indication of pressure or even over pressure for that matter. The only way you can measure pressure is if you have a test barrel that can measure CUPS or PSI. You can attempt to measure relative pressure similar to what is describe here:

http://www.reloadingroom.com/index_files/Measure%20Pressure.htm

Other than that, if you are not bulging cases dramatically and nothing has blown up, then you are probably fine. Many will say that a short OAL can result in possible additional setback and causes a kaboom... however, based on testing like that which was done in this article:

Somewhat clouds that... however that is commercial ammo, which does not utilize off-the-shelf powder. N320 is a relatively fast powder, so I would ensure that you are using something like a U-Die and a proper crimp (proper meaning, not to much and not leaving the mouth belled) to prevent as much set-back as possible. I use a U-Die for everything, and I get 0% setback even after a dozen chamberings on the same round.

Based on MY experience with N320, if you are at 1060-1070 fps with a 124/125 gr bullet, you are probably not in danger of a kaboom, but you are probably close to max. I haven't seen many guns that will run a 124gr bullet using N320 over 1100 fps, except with tighter 5" barrels... like a Glock 34.

Shoot some rounds and inspect your brass good and if there are no indications of bulging at the base, then you should be fine.

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True true, thanks for the information

The brass condition to me looked normal, no bulging at the base. I find my on my dillon once i complete a round it has the coke bottle look to it a bit and u can see where the projectile stops so i should not get any setback. I tried to push the bullet in on my bench to check the tension of the case mouth and the oal doesnt change.

I think i should be good :-)

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  • 2 weeks later...
  • 3 weeks later...

have you checked to see if you are compressing the powder? Did you do the math? Shell length + bullet length - your OAL = bullet seat depth. 3.9gn of N320 will fill the shell all but, about 0.237. If your seating your bullet deeper then this, might not be a good thing. You can always get a Throater reamer and ream your barrel so that you can load to a longer OAL with HP.

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I shot a thousand or so 124 gr flatpoints at about the same OAL, with 3.8 gr of n320. I had no shooting problems, and made 130-132 pf consistently. I did find that they wouldn't always feed properly out of a crappy pro-mag magazine, but they worked fine with mec-gar and stock mags.

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  • 1 month later...

I know this thread is a few weeks old but I'm facing the same questions with my XDM 5.25 and MG 124 JHP's. My gun will not take an oal with these bullets past 1.122. I'm loading 4.0 gr of n320 with the JHP's, either WIN or R/P brass and CCI spp's . I just got these bullets and have been loading RN/FMJ's to VV recommended oal of 1.142 with no issues. I decided to work up some loads to see what the gun liked best so I loaded 10 at an oal of 1.120, 10 at 1.115 and 10 at 1.110. The gun ran all three oal's with out a single problem and the best grouping was with the ones loaded to 1.110. The cases don't show any signs of an issue but I'm new to reloading and this is my first time loading anything other than round nose bullets and safety is my first priority. I was thinking of bumping up the charge to 4.2 gr to see if the accuracy would be even better with a touch more speed. Without much load data to work with I just wanted to post this up to see if I'm pushing the safety limits or if I should be good to go.

I have done dozens of searches both here and on other forums and read dozens of posts, but I still want to be safe, so I post here for your feedback. Thanks in advance...

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When I was shooting lead the bullet I was using required me to load to 1.08 out of a G34 to work. Since switching to Extreme 124s back in Feb I can load 4.3g of N320 at 1.15 and make 130 PF with no issue .... Bullet shape is a big deal and does vary between manufacturers ... YMMV ...

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G6 Guy

4.2gn of N320 is at MAX or over! Try 3.8gn -3.9gn at 1.110" OAL it will be a good target load.

If your barrel will not take anything longer then 1.122 you should be loading a OAL of 0.010"-0.015" less then 1.122" !

Your bullet should not touch the rifling! you need some free space between the bullet & rifling. BAD things can happen when the bullet engages the rifling before it is fired. When you fire the round you can get a pressure spike. If this happens you could blow your gun up, if your lucky you will not get hurt!

This video will show you what I am talking about. don't let this happen to you.

Edited by CZ85Combat
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G6 Guy

4.2gn of N320 is at MAX or over! Try 3.8gn -3.9gn at 1.110" OAL it will be a good target load.

If your barrel will not take anything longer then 1.122 you should be loading a OAL of 0.010"-0.015" less then 1.122" !

Your bullet should not touch the rifling! you need some free space between the bullet & rifling. BAD things can happen when the bullet engages the rifling before it is fired. When you fire the round you can get a pressure spike. If this happens you could blow your gun up, if your lucky you will not get hurt!

This video will show you what I am talking about. don't let this happen to you.

CZ85Combat, Thanks for the input and at 1.110 I'm not near the rifling. Doing the plunk test with the barrel out of the gun the rounds just fall in and out. I can't even push them down and not be able to spin them freely so I think I'm ok there. I haven't loaded any up at 4.2, just stuck with what I knew worked which was 4.0 gr. It's just the short oal that worries me as I haven't ever had to load that short before. Like I said earlier, it will go to 1.120 without any problems but the accuracy was much better at 1.110. Your video is exactly what I want to avoid and I really appreciate the response.

Nimitz, thank you for your response as well. Bullets are just as different as each gun. What mine loves yours may hate etc....

Thanks again....

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I know this thread is a few weeks old but I'm facing the same questions with my XDM 5.25 and MG 124 JHP's. My gun will not take an oal with these bullets past 1.122....

I'm amazed! I shoot a 5.25 and use MG 124 JHP's. if I load anything over 1.095 and drop a loaded round in the chamber (Barrel removed) and turn it over it won't drop out. It seems everyone is able to load longer than me. Frustrating! I'm using 3.7 gr N320 with R-P cases. Not Chronographed yet.

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Your bullet should not touch the rifling! you need some free space between the bullet & rifling. BAD things can happen when the bullet engages the rifling before it is fired. When you fire the round you can get a pressure spike. If this happens you could blow your gun up, if your lucky you will not get hurt!

This video will show you what I am talking about. don't let this happen to you.

There is just about NO way that a cartridge loaded to minor PF with a bullet seated long into the rifling, caused a pistol to blow up because of excess pressure. If the cartridge caused the action to fire out of battery, then I suppose it could have been a contributing factor. However, just seating a bullet into the rifling will not raise the pressure enough to blow up a gun. We used to do this all of the time on certain loads for precision rifle. There is no doubt that it does raise the pressure some, but it's not going to cause an otherwise safe load to blow up a gun!

Mike

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You can not compare rifle powder (slow burning) to 9mm powder (very fast burning). I know long range rifle shooters do this all the time, but that is like apple & oranges. 9mm pistols are not built to take the pressure spike, 3X-4X the max psi. was that the cause in the video, I don't know. With the bullet seated in the rifling it can act as an obstruction, or as you stated firing out of battery.

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You can not compare rifle powder (slow burning) to 9mm powder (very fast burning). I know long range rifle shooters do this all the time, but that is like apple & oranges. 9mm pistols are not built to take the pressure spike, 3X-4X the max psi. was that the cause in the video, I don't know. With the bullet seated in the rifling it can act as an obstruction, or as you stated firing out of battery.

I have fired pistol bullets that were hard into the rifling, by accident. There was no sign of pressure high enough to cause concern, much less 3-4 times normal. If his were loaded long by accident, there would have been more case volume thereby helping to offset some of the increased pressure from being jammed into the rifling. After looking back at the video, it was obvious from the close up of the barrel that the pressure was high enough to rupture/crack the barrel. That being the case pretty much rules out an out of battery ignition, because with the back of the case blowing out, the pressure would have been vented before it would have gotten high enough to rupture the barrel. Whatever the cause, this looks like an over/double charge to me. It is obvious from the video that the previous round fired normally so there couldn't have been a squib or other barrel obstruction.

Anyway, I wouldn't scare new reloaders by showing this video, as an example of a bullet loaded a little long, regardless of what the people who produced the video though!

Mike

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That is a very short OAL, even WalyWorld ammo is 1.140. So the best advice I can give you is get a decent bullet. Yeah, try some Montana Gold or some Zeros in FMJ/CMJ. Round nose lets you go about another .020 in length. But what really matters is how much bullet butt is in the case.

Or

Pickup up a $40 manson head space reamer and deep throat it.

Bayou is my favorite for 9 minor. All of the benefits of Jacketed and none of the issues of plated.

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