Load data for 10mm PLEASE

[RickCoop]

Hello All
I am planning on reloading some 10mm for a Glock 20. This gun has a stock barrel and a 6" Glock hunter barrel. My problem is that load data seems to be all over the place. I have data from the following sources:

Lyman 49th
180 Gr JHP
Unique 5.8 start - 6.7 max
Power Pistol 7.2 start - 8.0 max

The following data is from the One Book One Caliber Series

Hornaday 180 Gr FMJ FP
Unique 5.8 start - 7.1 max
Power Pistol 6.8 start - 8.4 max

Sierra 180 Gr JHP
Unique 5.6 start - 6.3 max

Speer 180 Gr TMJ-FN
Unique 7.2 start - 8.0 max

Alliant Powder
180 Gr GDHP
Unique 8.0 Max

I am trying to develop a load for around 1100 - 1150 FPS using X-Treme 180 GR Copper coated RN FP. All of these above loads are 1.250 -1.260" OAL

Can anyone advise me on what they are doing? This is a new load for me and I'm not used to such wild swings in load data. I load 9mm, 45ACP, 38 Special, 357 Magnum and 40 S&W. None of these have variables like this. As you can guess, I have Power Pistol and Unique to load with for this project. I'm looking for some help if you have experience with this caliber.
Thanks
Rick

[Mike / Tx]

I would love to tell you what to do, but unfortunately I load mine with AA-9 and the 180gr Gold Dot and am about 300'ish above where our wanting to be.

I can tell you that 5.0grs of Unique shoots awesome in my 45 with 180gr bullets, and in reality that ain't a whole lot of difference with Unique.

To stat with load the bullets so they pass the plunk test just as you would with any other auto. Then once you have that, start with the start load and work up looking for accuracy and don't sweat the velocity unless you start getting leading. If your loading plated you should be loading with cast data to begin with and that might be a bit different than what you have posted. Look for the same weight of cast bullet in the Lyman manual and work from there.

[reddog81]

You're basically looking for a top end 40 S&W load. You can use max 40 S&W data or minimum 10mm data and you'll be pretty close to what you're looking for.

I use 6.2 behind a lead 180 grain powder coated bullet. It's accurate and works well in my Delta Elite and Glock model 20.

[Nick_C_S]

I can maybe help a little . . .

I have a G20sf. I don't have a 6" conversion barrel. I do use a stock length Lone Wolf usually; otherwise, the stock barrel.

I load more X-treme 180 FP's than any other bullet (I go jacketed for the hot stuff). My OAL is 1.255" +.000/-.005.

With that bullet, I load with AA#5, and HS-6, per the Speer #14 manual, and their data seems to be right on the mark. I have never used Unique for 10mm however (I have Unique; just never put it in the 10).

So with that said, I wouldn't hesitate trusting Speer's data.

I don't know how long you've been loading, but these seeming contradictions are more or less common. Sometimes you gotta not over think it and proceed. Experience comes onto play here. From my experience (32 years) I've come to trust the Speer manual - it's never let me down. And when I first got started (long before the interweb), the Speer manual is all I had - or needed, so it turned out.

[pctechdude]

Hs6 is good for what you want, so is autocomp or ramshot silhouette. Power pistol is good, but the fireball that comes out is massive, so any lower light shooting will damn near blind you!

I prefer be-86 (flash suppressed power pistol). With 180gr fmj, I use 8.4gr and they move out around 1200fps from the Glock 20. A good in between load that isn't quite full power, but not watered down either.

The biggest thing with the 10mm is not going too light with rounds as switching between full house and watered down 10's just makes it an expensive 40.

Sent from my XT1585 using Tapatalk

[T. O'Heir]

"...data seems to be all over the place..." That's typical of all manuals. Manuals reflect conditions, using the exact components and equipment listed, on the day of the tests only. Any data in any manual will be safe to use, but look at the publication date too. A simple change of powder lot will change the results, but not as much as a change of barrel length.
Usually best to go with the powder maker's data. Pick the powder you want to use(or can get easily) and go from there.
Alliant gives 8.4 as max for Power Pistol and a 190 grain jacketed bullet. 9.3 for a jacketed 180. Max loads for the 180 are running 1,296 fps with a 5" barrel. Your 6" will gives lightly higher velocities with the same loads. Reduce the Alliant site max loads by 10% for the start loads.
You must work up the load anyway. And accuracy is far more important than velocity.
You won't get 1100 - 1150 FPS using Unique unless the accuracy is good with max loads. That'd be 1138 fps with a 5" barrel.

[Clark]

Per my experiments, the most power that can be got out of a 10mm pistol is with 200 gr bullets, a throated 40sw barrel with case support to the case web, 800X powder individually weighed and triple compressed loads with the loaded ammo with highly compressed powder resized to drop in the chamber. The recoil spring assembly should be at least 40 pounds at the rear.



Here is a recoil spring assembly I made for my Glock 20.

But nobody seems to want to buy a 40sw barrel and throat it.
Nobody wants to measure 800X.
Nobody wants to triple compress powder charges.
Nobody wants to resized loaded ammo.
Few have the grip to chamber a round with a 40 pound spring assembly.
Nobody wants to get kicked that hard by recoil.

So the compromise is probably going to be aftermarket 10mm barrel with case support, aftermarket recoil springs, 200 gr bullets, power pistol, and work up until the recoil hurts too much.