9mm COL: Is 1.035" Too Short?

[ConcernedCitizen]

I need some opinions on a current project. I apologize for the long-winded explanation, but hope you will bear with me.

I'm loading 9mm using some 124-125 grain lead bullets that I got at a swap meet. I'm not sure of the manufacturer, but they are a truncated cone design similar to the ones offered by Penn or Dardas. They are not nearly as tapered as the ones offered by MBC. The lube is a brown color, but could be faded. They were loose in a tub when I got them, so I have no way to identify them.

I have successfully loaded some for an M&P-9 Pro at a COL of 1.060". The throat on the M&P seems to be at 1.080", so I figured this gave me a safe margin. I tried to load some for my XD-9 Tactical, but the throat on that one was around 1.050", so I held off as I wasn't comfortable loading that short for my first test.

Now I'm feeling adventurous, and want to create a load that will work in both the M&P-9 and the XD-9. The COL that drops freely out of the XD-9 is 1.035". I've seen numerous posts of people using a similar COL, including Walkalong, but was hoping someone could help validate my loads in combination with the COL.

My problem is twofold, based on the lack of available components. In addition to changing COL, I'm also changing over from Winchester SPP to Tula SPMP, as mentioned in this thread. I plan take chronograph readings for comparison, and will also take chronograph readings comparing the 1.060" COL to the 1.035" COL.

Here's the data I have so far:

9mm Luger
124 gr. Lead Truncated Cone
Winchester Small Pistol Primer
Mixed Brass
1.060" COL
Pistol: 5" M&P-9 Pro

3.7 grains Win. 231
Avg. Velocity: 995.5 fps
ES: 49.2
SD: 14.6

3.9 grains Win. 231
Avg. Velocity: 1036
ES: 54.6
SD: 16.3

4.1 grains Win. 231
Avg. Velocity: 1080
ES: 32.0
SD: 8.0

The 3.7 & 4.1 grain loads both shot very well at 10 yards. 3.7 grains does not meet IDPA power factor, so I was planning to settle on 4.0-4.1 grains after some more testing.

I plan to keep the load the same for the first test, with the exception of changing over to small pistol magnum primers. Would you feel safe starting at 3.7 grains again, or would you start at 3.5 grains to be safe? I will probably stop at 3.9 grains using the magnum primers, as 4.1 grains was already a bit over my desired velocity of 1050 fps.

I then plan to load the same batch, but changing the COL from 1.060" to 1.035". Do you feel 3.5-3.9 grains of Win 231 and a Tula small pistol magnum primer will be safe at this COL?

Would anyone with QuickLoad mind running a quick pressure check for me, based on the 1.035" COL?

Any and all opinions are welcome. I've tried to research and reason out my project as much as possible, but I'm sure there's something critical that I'm overlooking. The knowledge of this forum never ceases to amaze me, so I'm hoping you can either help set my mind at ease, or help stop me from making a grave mistake. Any help you can offer would be greatly appreciated. Thanks in advance!

 

[exbrit49]

I use the same LCN (Lead cone nose) that you described and have ALWAYS seated them at 1.085. They function very well in my Ruger.
I dont use the same powder, I use WST and push mine at just about 1075 fps.
Using WST and seating to 1.085 I am not compressing the powder.

Not sure why you would load them that far in to the case? I have shot my 1.085 through several friends pistols as well as my own and no feeding problems encounted in several thousand rounds.
Roger

 

[ConcernedCitizen]

The seating depth is due to the very short throat on the XD-9. I've had similar issues with Montana Gold and Precision Delta 124 grain JHPs. I have to load them at 1.100" for them to drop free.

This bullet profile has a long bearing surface and short nose. In order to seat the body of the bullet to where it doesn't contact the rifling, I have to be at least 1.040", which is still hit or miss. At 1.035", all rounds drop freely from the chamber.

This is the only pistol of mine that has this problem, but it also happens to be my favorite competition pistol. This will be the first time I've tried running lead through it, but I'm willing to experiment a bit, if it means I can shoot it more often for less money.

I've seen others use similar seating depths on occasion, and I'm fairly confident in the low to mid-level loads I am using. What I'm concerned with is the short COL in combination with switching over to magnum primers.

If anyone with QuickLoad would be willing to run the numbers, I would greatly appreciate it.

 

[Skulptor]

Sorry C.C., I'm rather new to reloading and learning myself so I don't have an answer. But, I am looking to learn more all the time and hense found this thread. I'm REALLY curious as to what you find out and will be watching this thread closely. The "too short" issue is something I am always interested in as I tend to stay away from it like the plague.
We DO have a wealth of knowledge on this forum and I also greatly appreciate it. Hopefully some guys can help out.
Good luck and please post if you experiment.
Be careful!!!

 

[kerreckt]

I have loaded 9mm to a length of 1.020 COL using 95 gr. FMJ and 4.9 gr of Titegroup. They chambered and fired with no problems in my Tanfoglio, SIG228 and Star model 30. This was an experiment to see how "short" would work. Typically, I don't load any shorter than 1.037 because there isn't a real need for me to load shorter. I usually look at my manuals and see how short they have listed for some of their loads and 1.020 was the shortest I saw. Hope this helps

 

[ConcernedCitizen]

Sorry I don't have chronograph data to share yet, but the weather has not been cooperating lately. Hopefully this weekend I'll be able to do some testing.

 

[Edarnold]

Your top load is certainly nowhere near maximum, judging by the velocities you achieved. Given that, and the fairly forgiving nature of 231, I can't see you getting in trouble with the deeper seating.

That said, the maker of your competition gun apparently is under the common delusion that everyone shoots 1908-style FJRN ammo, and cuts the leade according. We're it my gun, I be looking for a gunsmith to deepen the leade to accept your choice of bullets loaded to maximum 9x19 OAL. There's no real advantage to the short leade, and being able to use bullets like the Hornaday HAP, or the type of cast bullets you are trying out loaded to full length will lower your pressures and may improve reliability of feeding.

IMHO

 

[ConcernedCitizen]

I finally got some partial chronograph data yesterday. I ended up missing a few readings due to sun glare and cloud cover, as I wasn't using my IR skyscreens.

It was an interesting test. I compared both the Winchester small pistol primer to the Tula small pistol magnum primer, and also compared velocities between a 1.060" and 1.035" COL.

Here's a brief summary:

3.5 gr 231, 1.060", Tula: 942.3 avg.
3.5 gr 231, 1.035", Tula: 972.6 avg.

3.7 gr 231, 1.060", WSP: 995.5 avg.
3.7 gr 231, 1.060", Tula: 1002 avg.
3.7 gr 231, 1.035", Tula: 1026 avg.

3.9 gr 231, 1.060", WSP: 1036 avg.
3.9 gr 231, 1.060", Tula: 1039 avg. (Note: Only 2 shots recorded.)
3.9 gr 231, 1.035", Tula: 1050 avg.

These were all fired out of the same firearm, but the WSP primer data was from a few weeks ago. If I had planned ahead correctly, I would have made up another batch of ammo as a control group.

As it is, it appears that there is little difference between the Winchester and Tula primers, even though the Tula is a magnum primer. It definitely has a harder cup, though. They were much harder to seat, and I did have a few misfires. Most misfires went off on the second try, but I did have one take three tries before it fired. I'll definitely use these up for practice, and will keep the better primers for competition use.

I think I'll try more of the 3.7 grain load with the 1.035" COL. This shot well out of both pistols I tested it in, and it meets IDPA power factor. I had no feeding issues with the short COL, so I'd consider the experiment a success.

If anybody is willing to run this load through QuickLoad for me, I am still curious to see what the pressure is. Thanks!