Hello
Got a question/dilemma I just wanted to throw out here..

I have some 10mm test rounds loaded up with BE-86, 180gr FMJ and new Starline brass to print groups, record chrono data and measure case bulges as I work up.
I want to do the same with CFE Pistol, but...

I'm looking at IMR and Alliant data for the .40 S&W with these two powders. 

With 155gr jacketed bullets;
Alliant shows 7.5grs of BE-86 as max
IMR shows 7.4grs of CFE Pistol as max   ( 7.8grs with a Berry bullet??)

With a little interpolation one can see that if, the charges were identical, with the jacketed bullets, the velocities would be virtually identical.
This proved to be the case in my own trials with a Rem 155gr JHP in the .40




Looking at 180gr data;

Alliant shows 6.3grs of BE-86 with one style bullet and 6.6grs of another. (funny how they don't compare directly with the rest of their powders..)

IMR shows 6.0grs of CFE Pistol with a jacketed bullet and 6.5grs with a Berry bullet.

In my own trials with 180gr FMJ bullets I got 1047fps with 6.6grs of BE-86 and with CFE Pistol I got 1030fps with 6.5grs.  Again, if the charges were identical, the velocities would be virtually identical. (Target #9 and #11)



BTW I will reshoot these with lower charges and see if the groups improve.


Now for 10mm 180gr Jacketed data;

Alliant shows 8.5grs of BE-86
IMR shows 7.6grs of CFE Pistol.

I shot 8.5grs of BE-86 and found case expansion to be minimal. Then shot 8.7 and 8.9grs with once fired cases to test the waters, but I didn't like the measurements I was getting so I'm going to start over with new components.






Also shot 7.6grs of CFE Pistol with a 180gr FMJ. Same components as above.  Just a weak FBI load..



So I say all that to ask this..  Why is the IMR load almost a whole grain lower than the Alliant load?  Does CFE Pistol behave so much differently in the 10mm than it does in the .40?
And, has anyone taken CFE Pistol up to max in trials yet?

Just trying to figure out where to start with CFE Pistol..

I would ask this of IMR but you know what kind of patented answer I would get..  Powder companies are not so forthcoming with information like they used to be.

Very nice reports RDub!  Yes ever since 10mm was developed we never saw Alliant and others, take the load data much above 35,500 - 36,000 PSI except for the Accurate Arm powders where they showed 37,000 & 37,500 PSI in their data.

I fault the powder makers like Alliant for not including pressure values like they did in the past.  Yes I know things can be different with different components.  However the pressure value was an important part of the equation to me!
Commend those companies that still provide the pressure values even if they don't test to the 37,500 PSI levels...

In a recent Pull-Down of the Sig FMJ Ammo had BE-86  8.8 grains, after I put them back together here was my test results

Glock 29   velocity     1178    case expansion    0.4315"
Glock 20   velocity   1250    case expansion    0.4315"
Glock 20   velocity   1260    case expansion    0.4315"
S&W 1006 velocity   1276    case expansion    0.4265"
S&W 1006 velocity   1286    case expansion    0.4270"

I need to load some more and test again to see how they compare.

Thanks Shadow
Well it's just going to boil down to shooting and taking measurements..

Since we're talking about pressure, has there been any consensus about how much PSI it takes for cases to start smiling in a factory Glock barrel?
40K, 45K.. Is 37.500 PSI on the ragged edge?

I would imagine it depends on the brass somewhat.. But say Starline brass, what most of us use, what is the red line?

When I'm miking cases, I don't see bulges measuring over .4346" that wasn't a smiley.  Just wondering how much PSI it takes to get there.

From the Glock factory chambers the brass will get to 0.4340" before I see SMILES.  So I kind of used that for the guideline.

In the past with Underwood loaded 135 over IMR800X 11.8 grains from my S&W 1006 which SMILED and blew the primer out.
Case Data: expansion measurements: Diameter 0.4325" - "Smiled", 0.4295" which exceeds the chamber 0.4285" primer blown out, no ejection, case stayed in the chamber but loose.