Saving My Summer Load

[DMW1116]

I have a box of 9mm 125 grain Acme cast bullets loaded up, maybe 150 rounds. I loaded these with 3 grains of W231 powder. At the time I loaded them they cycled reliably. Enter winter of 2021/2022. When it got colder these would not run my M&P9. I attributed this to the drop in temperature. Now that it's warming up, they still won't run reliably in the M&P9. Now, I admittedly downloaded this load to the point it wouldn't cycle the pistol, then went up one increment to the last one it cycled. Data came from the cast bullet section in my Blue Book of 9mm spiral bound booklet. There were some lower loads but I stopped at 2.9 grains.

In an attempt to avoid pulling and redoing 150 rounds, I decided to seat the bullets deeper to try to bring the pressure up a bit and run the M&P9. The original COAL was 1.125". I bumped down in 0.025" increments to 1.1", 1.075", & 1.05". Anyone see any issues with this?

 

[GeoDudeFlorida]

The only thing is, increasing the chamber pressure does not proportionately increase recoil impulse. W231 is a fast enough powder to be completely consumed by the time the bullet leaves the barrel so increases in chamber pressure spikes really won’t change case head thrust but may increase velocity of the projectile. Worth a try, for sure but if you start seeing signs of head bulging stop.

 

[edwardware]

I'm not sure it'll work, but it's a good idea. . . so long as you try a few before reseating all of them.

 

[DMW1116]

Yea I think I fooled myself when I made this load. I shot three test rounds and decided that was enough to tell what was going on. Clearly I was wrong. I have 3 batches of 10 at each new length.

I’d be ok if the rounds would either fire and function or be too weak to eject. I could still practice with that. The rounds currently fire then stove pipe the brass. I can’t even use them as a slide action pistol and every piece of brass is dinged at the mouth. I’d have to trim them to fix it and most are too short to trim enough to get rid of the dings and dents. On the up side I don’t have to chase brass. The ejection port catches 90% of them for me and the rest land at my feet.

 

[GooseGestapo]

Put them in a plastic bag and set them on the dashboard of your vehicle in the sun for 15min before you shoot them. That’ll warm them up without over doing it.
On cold mornings before PPC matches, we’d put the ammo on the dashboard and run the defrost on high to avoid squibs failing to cycle the actions.

 

[Walkalong]

Don’t get carried away shortening them.

 

[Blue68f100]

Don’t get carried away shortening them.

Right. A 0.030" reduction in OAL can over double the pressure with some powders on a 9mm.

 

[DMW1116]

I’m not going any shorter than I already have. I’ll have to check my notes for specifics but I loaded a test batch with Berrys using COAL from the cast section of my spiral Blue Book of 9mm. Those were in the 1.06” range. I’ll double check that this evening.

 

[Charlie98]

Yea I think I fooled myself when I made this load.

It's OK... I did the same thing when I started loading for my HiPower. The test batch worked great, and didn't fling brass into the next county... so I loaded 1000 of them. Ooops.

Right. A 0.030" reduction in OAL can over double the pressure with some powders on a 9mm.

I actually plugged his numbers into QuickLoad just to see.. he should be OK by a fair margin. Using the same HiPower I mentioned above, I got into stupid trouble not paying attention to my cartridge OAL at max load... cratering primers and beating my poor pistol. I probably exercise more care loading 9mm now than any other pistol cartridge... based on my previous experiences.

 

[DMW1116]

It's OK... I did the same thing when I started loading for my HiPower. The test batch worked great, and didn't fling brass into the next county... so I loaded 1000 of them. Ooops.



I actually plugged his numbers into QuickLoad just to see.. he should be OK by a fair margin. Using the same HiPower I mentioned above, I got into stupid trouble not paying attention to my cartridge OAL at max load... cratering primers and beating my poor pistol. I probably exercise more care loading 9mm now than any other pistol cartridge... based on my previous experiences.

That's reassuring. I thought I'd have a fair margin, but no way to know for sure. I was downloading these in an attempt to make a gallery load that was close to or right at hearing safe. The data I was using actually had powder charges lower than what I tried, but I know now they wouldn't run the gun. Kinda makes me want that 9mm revolver I saw.

 

[DMW1116]

I double checked my 50th Edition Lyman manual for cast data. The 120 grain round nose shows a minimum charge of 3 grains of W231 with a COAL of 1.065”. The 1.1” and 1.075” lengths are fine probably. I’ll watch the 1.05” ones but at the minimum charge I’d think those are fine too.

 

[rsrocket1]

Many years ago I ran around 20 Quickload calculations and entered the results into a spreadsheet to see what the effect of seat depth did to muzzle velocity and peak chamber pressure.
You can see that the MV (and essentially recoil) increases close to linearly with the increasing seat depth but the pressure goes up more exponentially.



Running your numbers from the OP gives a peak pressure around 12,700 psi with a MV of about 800 fps which is probably enough to burn cleanly but is about 1/3 max pressure for the round. If this is true, seating them to 1.05 increases your pressure to about 17,500 psi with a MV of about 850 which is still quite safe.

My 124g 9mm load is 4.5g W231 which gives me 1075 fps in my 4.25" M&P 9 but I regularly shoot 45ACP and 40 S&W so 9mm is already a light load.

 

[DMW1116]

These are the Acme green coated 125 grain bullets. Half the reason I load them is just for looks. The other half is for cost. The final half is they are surprisingly accurate. If they’re going that slow I may try to push them a little faster when I get some more. Then again that replicates my carry ammo which is a 147 grain XTP going around 900 from my pistol. I have about 100 left so I’ll see how they do before changing anything else.

 

[Kaldor]

These are the Acme green coated 125 grain bullets. Half the reason I load them is just for looks. The other half is for cost. The final half is they are surprisingly accurate. If they’re going that slow I may try to push them a little faster when I get some more. Then again that replicates my carry ammo which is a 147 grain XTP going around 900 from my pistol. I have about 100 left so I’ll see how they do before changing anything else.

Same reason I shoot the Acme 147s. I run Hornady 147 XTPs in my carry gun They move at 980ish FPS, same as my Acmes do. And they are cheap and accurate.

 

[Bill M.]

Simple. You need to buy a revolver to shoot these rounds in.

 

[kalielkslayer]

Your idea is exactly what I would have done.

Except I would have shortened 5 at 0.010, loaded a mag, walked outside and saw if they ejected and locked back the slide. If that didn’t happen another 0.010 and try again. That would be as short as I would go.

If it worked I’d say a big “WHEW!”

If it didn’t, I’d definitely learn from the experience.

I would also try another gun if you have one in 9mm.

 

[film495]

Many years ago I ran around 20 Quickload calculations and entered the results into a spreadsheet to see what the effect of seat depth did to muzzle velocity and peak chamber pressure.
You can see that the MV (and essentially recoil) increases close to linearly with the increasing seat depth but the pressure goes up more exponentially.

View attachment 1083278

Running your numbers from the OP gives a peak pressure around 12,700 psi with a MV of about 800 fps which is probably enough to burn cleanly but is about 1/3 max pressure for the round. If this is true, seating them to 1.05 increases your pressure to about 17,500 psi with a MV of about 850 which is still quite safe.

My 124g 9mm load is 4.5g W231 which gives me 1075 fps in my 4.25" M&P 9 but I regularly shoot 45ACP and 40 S&W so 9mm is already a light load.

this is an interesting data set on powder characteristics and pressure. looks like in this case, if I had to hazard a guess it seems the peak pressure as the bullet in this case is deeper, happens faster - but, the nrg transfer to the actual velocity is not increased at the same rate, so the curve is different. It doesn't necessarily create significantly more velocity as a result, you just start to get a spike, which is where problems happen if you end up too deep and the spike goes off the charts.

This is like the answer to the other thread on a carry round getting set back. This is the answer and the answer is that round is broken/damaged, lose it.

 

[Rule3]

Pull them and load them correctly

 

[epags]

Why not a lighter recoil spring, just for those loads?

 

[LiveLife]

9mm 125 grain Acme cast ... 3 grains of W231 ... COAL was 1.125". I bumped down in 0.025" increments to 1.1", 1.075", & 1.05". Anyone see any issues with this?

Don’t get carried away shortening them.

Due to case wall getting thicker, decreasing the COAL can improve neck tension to affect chamber pressure but to a point as 9mm is tapered case and after certain point, neck tension will start to decrease to where bullet will simply fall down into the case.

With most 124/125 gr Lead RN, I load them to 1.125" (MBC Hi-Tek SmallBall RN down to 1.05" due to nose profile) and use 3.5 - 3.8 gr of W231/HP-38 depending on OAL and they reliably cycle slides of my various pistols but that's as low as I go.

3.0 gr of W231/HP-38 for 125 gr lead bullet maybe too light of powder charge and as you found out, W231/HP-38 being temperature sensitive, will produce lower velocities in colder temperatures - https://www.thehighroad.org/index.p...temperature-sensitivity.817116/#post-10473222

avoid pulling and redoing 150 rounds,

If 3.0 gr loads with shorter OAL won't reliably cycle the slides, you can try warming up the rounds to increase muzzle velocity.

BTW, here is Speer lead load data for 125 gr Lead RN using longer 1.130" OAL - https://reloadingdata.speer.com/downloads/speer/reloading-pdfs/handgun/9mm_Luger_125.pdf

• 9mm 125 gr Lead RN W231 COL 1.130" Start 3.8 gr (911 fps) - Max 4.1 gr (982 fps)

Hodgdon lead load data for 125 gr Lead CN using 1.125" OAL - https://www.hodgdonreloading.com/reloading-data-center

• 9mm 125 gr Lead CN W231/HP-38 COL 1.125" Start 3.9 gr (1,009 fps) - Max 4.4 gr (1,086 fps)

And Oregon Trails Laser-Cast (24 BHN) lead load data for 125 gr Lead RN - https://oregontrailbullets.com/xcart/images/filemanager/uploads/otbc-load-manual.pdf

• 9mm 124 gr Lead RN W231 COL 1.130" Start 4.0 gr (1020 fps) - Max 4.4 gr (1094 fps)

 

[DMW1116]

That worked surprisingly well. All 30 rounds functioned no problem. The 1.075” length shot slightly better than the other 2. Brass dropped on the table or the ground just to my right. The point of impact for these is basically right where I’m aiming at 7-10 yards. Many loads and factory ammo shoot low. This doesn’t dissuade me from switching to cast for practice rounds, which I plan to do soon.

 

[LiveLife]

That worked surprisingly well. All 30 rounds functioned no problem

Nice.

The 1.075” length shot slightly better than the other 2

You maybe seeing the effects of neck tension improving as you approach 1.075" but tapered 9mm case starting to decrease neck tension as you seat deeper.

Brass dropped on the table or the ground just to my right.

Brass ejecting weakly indicates powder charge with the bullet seating depths may just be barely cycling the slide.

The point of impact for these is basically right where I’m aiming at 7-10 yards

You really won't be able to tell much difference in accuracy/group consistency until you go further out at 15 to 25 yards. For me, most pistols with decent ammo produce around 1" groups at 7-10 yards, 2" at 15 yards and 3" at 25 yards (With accurate loads producing 2" groups at 25 yards).

 

[GeoDudeFlorida]

That worked surprisingly well. All 30 rounds functioned no problem. The 1.075” length shot slightly better than the other 2. Brass dropped on the table or the ground just to my right. The point of impact for these is basically right where I’m aiming at 7-10 yards. Many loads and factory ammo shoot low. This doesn’t dissuade me from switching to cast for practice rounds, which I plan to do soon.

Excellent!

 

[DMW1116]

Well I went through and seated all the remaining bullets to 1.075 plus/minus. I don’t have as many left as I thought so next batch will be different.

I started with the minimum load from a Hodgden with a 125 conical nose bullet. When I order more I’ll go with the Lyman round nose data since that’s what this bullet is. I think the conical nose is longer and requires a longer seating. I’ll drop the COAL to 1.065 and probably run a test array.

 

[DMW1116]

I took my son with me to the range today and found I’ll need to seat to the listed 1.065” whenever I get more of these bullets. I had good function with no failures but my son had 4 or 5 failures to eject and a failure to fire. The cartridge fired but the slide didn’t come back enough to strip the next round but did eject the spent case. They all cycled 100% in my Shield for both of us.