Charge Adjustments Relative to Seating Depth

[Walkalong]

Mixed brass, 3.9 Grs N320, WSP primer, X-Treme 124 Gr HP @ 1.060 OAL. Runs > 1050 & < 1075 FPS from my 5" 1911 and shoots great. Super clean as well.

4.6 Grs N330 works with the X-Treme 124 Gr RN @ 1.130/1.135 OAL runs a hair faster.


3.8 Grs WST and the X-Treme 124 Gr HP @ 1.060 OAL gave me an average of 1051 on an 83 degree day. It would take another tenth or two to be sure all rounds are over 1050 FPS. Probably two. In my gun anyway, a Colt .38 Super with a Storm Lake 9MM barrel. My S&W 5" 1911 runs slower than the SL barrel.

I don't do the IDPA thing.

While these loads appear safe in my guns using my reloading technique, use them at your own risk.


I check all my sized 9MM brass with my Wilson case gauge. It it passes the gauge, I know it will fit in my tightest 9MM chamber, an EMP with a SAMMI minimum chamber. About 10% or so of range brass will fail the gauge, and after that only a few will fail from my reloads, except for the time I got a little too hot with a load. Whoops.....

 

[Potatohead]

^Nice pistol Walkalong.

As to the topic: with the little bit of experience I've gathered so far, it seems to me that with so many variables involved in handloading, it's almost "formula proof", as in, it's hard to find any formulas that you can apply to most situations.

 

[9mmepiphany]

Either I have a really slow barrel or I'm losing pressure somewhere.

It took 4.4grs of WST just to get to where your 3.8grs is clocking...granted I'm giving up .75" of barrel. I thought about going with 4.4grs, because they chrono with the longest barrel in that class...a 5" 1911.

I might use my EMP barrel for plunking...but it is such a pain (recoil spring compression spacer) to get it out of the slide...but I do have a Lyman gauge coming

 

[gamestalker]

The way it should be done is to work back up from the published start charge any time you decrease the OAL be .010" or more. This is especially important when working with high pressure cartridges such as 9mm, .40 cal. and such, but a good practice with any rimless pistol cartridge, or those that don't have a canelure to consistently seat too.

9mm can more than double in pressure with as little as .030" OAL reduction, and noticeably show pressure changes with as little as .010" OAL reduction. Speer # 10 stated that on a load that was producing a confirmed 28,000 cup, the pressures jumped to 62,000 cup when seated .030" deeper / shorter.

Also, auto loading cartridges will go red line pressure without much, if any indication that they are operating at excessive pressures. One could find their self in serious trouble before ever seeing any visible pressure signs with AL firearms. In other words, trying to read pressures with these type cartridges / firearms is very difficult, as none of the usual signs such as primer appearance, or difficult extraction is present. Chrony speeds and how far the brass flies are about all one has to go on in this respect. So that means we must work with published data, and seating depth as our primary tools to control and predict pressures, all else is a crap shoot.

GS

 

[1SOW]

9mmepiphany, with 9x19 " taper crimping plated/jacketted bullets isn't the solution to anything except FEEDING within SAAMI specs".

If that loaded bullet is less than .380" immediately below the casemouth, it should FEED IF the oal is correct for that chamber.

My CZs have a very short chambers, and JHPs, FPs and some concal nose bullets often have to be loaded shorter to seat on the casemouth.

While most don't seem to appreciate it, the "PUSH TEST" is virtually infallible for finding a 100% reliable OAL for a given bullet.

1. Find 3-4 SPENT unsized cases that have opened up enough so they will just allow you to just hand-seat a bullet enough to balance it in place.
2. Take the barrel out of the pistol your reloading for, and carefully insert that dummy rd into the chamber and slowly push it in until the case seats fully on the case mouth.
3. Turn the chamber down and slowly gently pull that dummy cartridge back out.
4. Measure it carefully.
5. Repeat with another spent unsized case. Do this until you get a pretty consistent length.

If that length was say 1.142", then subtract .010-.015 from the 1.142" That would give around 1.130" as the MAXIMUM USABLE OAL in that pistol with that bullet.

The .010-.015" subtracted, allows for any possible case, press or press operator variations and a little head space. The 1.142" was the length that contacted the rifling or the cone.
I promise you, it will fit your chamber every time with a taper crimp from .3765 to .3785.
The best possible 9mm case gage is your tightest chamber.

You can then load a few and plunk test if you like, and they WILL PLUNK every single loaded round using this method.

I only load 9mm. Have been doing so for a number of years. I shoot 1200+ average /month.
I have NEVER had a bullet loaded that wouldn't run in all three of my 9mm when using this test to determine max usable oal along with taper crimps to just close bell snug against the bullet/ .3765-.3785. I also suggest using the minimum belling you can get away with to retain maximum 'neck tension'.

 

[Walkalong]

Bottom line is to find your OAL that you are going to use. It needs to pass the plunk test (Or push test), and feeds 100% in your pistol. After that it is simply a matter of starting low and working up to 1050 plus FPS with your lot of WST, your scale, your load technique, your barrel etc.

WST should get the plated 124 Gr bullet to 1050ish safely, but without the data, we cannot be 100% sure. It's going to be up there around max for sure.

Anyone with Quickload out there that could help?

 

[LeftyTSGC]

I am no expert, but i have been following this thread. With all of the talk about OAL and Powder to adjust. I think you may have over looked a key item. You stated that you are thinking of changing your crimp from .380 to .378.

I think this is your entire problem from the start. here is why:

.355 (bullet diameter) + .011 (case wall) + .011 (case wall) = .377

If you have been loading your 9mm and making them all .380 then you probably have a setback and low pressure issue. Case wall thickness may vary but not by much.

I crimp all of my 9mm from .375-.378 and they all work and provide accurate and reliable shots.

if you get this figured out, then you can go about adjusting your powder loads and COAL based on type of bullet and powder.

FWIW,

 

[Potatohead]

I crimp all of my 9mm from .375-.378

+1
.3765 is usually what I end up settling on..

 

[Potatohead]

Pretty good post (#30) 1sow, never really thought about doing that.

 

[Walkalong]

I have never measured a "crimp" on a 9MM round. I adjust the die so that all of the bell is removed from the shortest cases, which means the longest cases get the case mouth moved in maybe .001 or .002. I use the knife edge of the calibers to run over the part where the bullet is seated until it comes off of the case. This will show you if there is any flare left. I never pay attention to what it is reading on the dial, just that it doesn't get bigger at the case mouth, and not more than one or two thousandths smaller.

If one is having to "crimp" (squeeze the round down more), to get it to chamber or feed, something else is wrong.

 

[9mmepiphany]

The .010-.015" subtracted, allows for any possible case, press or press operator variations and a little head space. The 1.142" was the length that contacted the rifling or the cone.
I promise you, it will fit your chamber every time with a taper crimp from .3765 to .3785.
The best possible 9mm case gage is your tightest chamber.

Thanks for the information...just never thought of it that way

Just came back from the garage and it was a very interesting exercise indeed. Unfortunately I'm not sure it is going to help me much.

The measurement came back at 1.244". Even taking away .015, I'm still at 1.239, which isn't going to fit in the magazine.

Would this be considered an oversized chamber?

 

[Walkalong]

The chamber is really just where the brass fits, then you have the throat and leade. They determine how long the round can be and still fit without the rifling interfering.

Whether you do the push test (Be careful you haven't jammed the bullet into the rifling), or the plunk test, this only gives you the max usable OAL for that barrel. It is not necessarily the length to load at, and might not even fit the mag. It is just the max that can chamber.

Sammi max for 9MM is 1.169, so I would guess many, if not most, mags would not accept rounds at 1.235.

I suggest loading some at 1.130 +/- OAL with 4.0 Grs WST and giving them a try. Then bump it up to where you need it.

I started with a 9x19mm reload at 1.150" and reduced the OAL, by .005", down to 1.130" and didn't see much change is velocity or pressure signs. What I did see is that my velocities between shots was more consistent as the OAL got shorter. I settled on loading to 1.140" and had some feeding issues, so thinking about going a bit shorter

Yep.

 

[9mmepiphany]

The Lee Factory Crimp die came in today along with the Lyman Case Gauge.

Dropping my loaded ammo, that had all fit in the chamber of my barrel, into the gauge was an eye opener. More than 10% failed.

I checked if I'd removed enough bell from my loaded rounds...yup they were still flared. Using the FCD, I got them flush...mic'd out at .377...and took out the Glock budges at the bottom of the cases too.

I'm hoping smoothing out the bell, removing the budge and pushing them down to 1.133"-.135" cures the feeding issue. I just took my already loaded ammo and didn't do that many, to see how it goes.

The Lyman expander will be here by week's end and I'll try belling less...I'll also lower the powder charge to 4.0 grs and press to 1.125"-1.130" to see how it effects my velocity.

Sidebar: I'm really liking the LNL's ability to switch dies in seconds. I yanked everything off the head and installed just the RCBS seating die and Lee FCD to run 50 rounds through...and the Hornady Die Locking Rings are so much nicer than the RCBS set screw or the Lee O-ring to lock in die body settings

 

[LiveLife]

9mmepiphany, I can send you some RMR 115/124 gr thick plated RN bullets.

 

[JRH6856]

the Hornady Die Locking Rings are so much nicer than the RCBS set screw or the Lee O-ring to lock in die body settings

Yes, I'm in the process of replacing the lock rings on all my dies with Hornady rings.

 

[Walkalong]

Dropping my loaded ammo, that had all fit in the chamber of my barrel, into the gauge was an eye opener. More than 10% failed.

Which is one reason why I gauge all my sized 9MM brass. Most 9MM chambers are pretty generous. My EMP chamber is not though, being at SAMMI minimum, and that was when I discovered what reloading range brass will do for you if you have a tight chambered gun. That is when I started gauging all sized brass and tossing those that did not pass. I don't care if an FCD will "fix" them or not, I take them out of the equation.

http://www.thehighroad.org/showpost.php?p=6225628&postcount=3