Load Data - Warning

[The_Shadow]

I have seen and read where there has been some issues in the 9mm reloadings and yes the use of the 9mm Mak FCD die does help with bringing the lowest part of the cases back down to size.  Especially guys who are shooting competition and are looking for the best reliability of feeding without stoppages.

Why are they not getting sized?  The use of a carbide sizer die has a radiused opening and the thickness of the top of shell holder occupy the space. The older steel dies used less radius so they actually reached down a little more toward the extractor ring cut.

The pressures for +P and +P+ do add to some extra expansion in combination of loose chambers and yes those with excessive feed ramp bevels.

Here is some pressure info that is 9mm specific;

9mm Plus Pressure Plus by Charles E. Petty
Basicly..... Is it worth it to beat the snot out of your firearm for a little extra?



The current SAAMI (Sporting Arms and Ammunition Manufacturing Institute) standard for 9mm Luger ammunition specifies a maximum product average chamber pressure of 37,400 p.s.i., but, the +P+ loads exceed this by a substantial margin. A limit of 42,000 p.s.i. has been proposed for this ammunition. For comparison, proof load pressure (nominal average) is set at 49,800 p.s.i. Now the situation is even further confused, for Remington has begun to market +P 9mm Luger ammunition with a proposed pressure limit of 38,500 p.s.i. To clarify, +P ammunition is available for commercial sale while +P+ loads are not.
All of this raises the question of what the civilian shooter can use in his gun. Even though the ammunition manufacturers take pains to insure that special law enforcement loads do not circulate in civilian channels, it is unrealistic to expect that some will not "leak" out. The same is certainly true for M882 service ammunition, and it is important that the civilian shooter who encounters any of these loads be able to recognize them and understand that this ammunition is different. M882 NATO ammunition as loaded by Olin Corp. (Winchester) and formerly loaded by Federal is currently specified to drive a 124 grain FMJ bullet at 375 meters per second (1230 f.p.s.), which puts it in nearly the same league as the various +P+ loads.

Winchester requires purchasers of +P+ ammunition to sign a release which states in part: "The 9mm 115 grain +P+ cartridges covered in this purchase order are specially loaded to achieve higher velocity. Therefore, the pressure level is higher than standard 9mm Luger cartridges. Individual cartridges may achieve pressure which may approach or exceed the proof load pressure a particular pistol may have been subjected to in factory proofing.
This cartridge is not recommended for use in any aluminum frame and/or cylinder pistols and may cause damage to modern steel pistols because of the higher pressures.

"THESE CARTRIDGES SHOULD BE USED IN MODERN PISTOLS ONLY. CHECK THE CONDITION OF THE PISTOL OFTEN. IF DOUBT EXISTS AS TO THE USE OF THESE CARTRIDGES IN YOUR PISTOL, CONSULT THE PISTOL MANUFACTURER." The demand for +P+ loadings has caused some consternation among firearm and ammunition manufacturers and there has been some finger pointing both ways. So, in an effort to clarify the situation, all of the major manufacturers and importers of the popular "wondernines" were queried about their position on the use of NATO and +P+ ammunition in their products. This is something of a hot potato as far as the firearms manufacturers are concerned, and most were understandably cautious or did not reply at all.

A Smith & Wesson spokesman indicated that S&W was not in favor of using +P+ ammunition, although it was studying the subject. This presents an interesting paradox, for the Illinois State Police, one of the first agencies to ask for +P+ loadings, is a major user of S&W

While increasing bullet velocity increases energy, it is questionable whether this is really meaningful in practical terms. A 200 f.p.s. increase in velocity (about what you get going from standard to +P+ 9mm ammunition) does not guarantee significantly better results in actual shooting situations. When you consider that this gain, roughly 15%, is accomplished at an increase in pressure that could be as much as 33%, it makes me wonder if it is all worthwhile.

[murphypat96]

Case head expansion is unique to each gun and should be tracked when working up max loads.  Any sudden change in case head measurement should be treated as an indicator of excessive pressure, and the next lower charge should be considered maximum for your gun.

--Mitch

For me a G20 is the platform (bone stock for now).

What do you use for a baseline measurement when you start out not knowing what pressure any given factory loaded round is at in the first place?  I suppose a book load of listed pressure value would be a good place to start for a baseline case head measurement?

I fire a couple of factory loads that perform how I like. I measure the case bulge and record that and other relevant data. This is my baseline for my gun. I have used this method safely in .40 for many years.

Sent from my SHIELD Tablet K1 using Tapatalk

[BillinOregon]

I'll be interested to measure case head expansion of rounds fired through the KKM barrel, noted for a tight chamber.

[The_Shadow]

If I recall those using the KKM had 0.4280" chambers, you can measure the chamber to see.  The area at the feed ramp will be larger and this is where you will see over expansion and SMILES develop on the casings if the pressures are too high...

Factory Glock barrels are usually 0.4340" inside the chamber, anything more measured on a fired case is over expansion.

If you slide comes out of battery too soon you could see expansion larger than the chamber size as the casing is being pulled out of the chamber and increasing unsupported areas...

[BillinOregon]

Shadow, thanks for the comments. As I recall, I may want to play with a stronger recoil spring weight to retard the barrel from coming out of battery "too soon."

[rualert]

     Hello everyone, I will do an intro later but stumbled on this thread while looking for decent load data for my 10mm. I ma most likely the outlier here as I generally shoot 10mm from a 14" barreled Contender that seems to like 180-200 grain bullets at book max where they typically suggest strongly not to use these loads in semi autos. I cannot speak as to why my specific Contender prefers these loads in the name of accuracy, but I'm betting that having all that extra barrel to use every bit of powder and build the velocity has a great deal to do with it. One additional note, you are now making me want to pick up a decent 10mm semi auto for perhaps primary carry duty, and move my 45 to back up.  Nice thread, even if I'm a bit late to the party, glad I found the forum.

Casey

[sqlbullet]

Welcome aboard Casey!

I completely agree with your assessment that you need a semi-auto 10mm for primary EDC.   

[The_Shadow]

Casey, welcome to the forum!  I have some TC (only) 10mm data that someone shared with me...

Most of the data shown is equal to what I have seen in other manuals over the years with the exception being 2400 being shown about 1 grain higher.  Although the standard 10mm Auto data for 2400 was shown at 36,000 psi.
The velocity due to the 14" Barrel length is up there over the standard 5" barrel data.
Thompson Center Contender ONLY Data


Best regards!   

[gandog56]

Well, goodie! That manual uses my Blue Dot powder I use for my 10mm reloads.

[tommac919]

I'll be interested to measure case head expansion of rounds fired through the KKM barrel, noted for a tight chamber.

My G20 cases come out at .432-.433 for most of my loads
While my Sig 220/10mm cases are in the .426-.427 range for same loads.

It comes down to the chamber size, and all of the after-market barrels are much tighter then the stock Glock

[Mike_Fontenot]

It comes down to the chamber size, and all of the after-market barrels are much tighter then the stock Glock

Do the aftermarket barrels shoot as reliably as the stock barrel?  I've always guessed that the well-known glock reliability stems at least partially from their loose chamber fit.

[tommac919]

I have no issue with the glock stock barrel ( don't own an after-market )... For me with both my reloads ( Xtreme heavy plated 180s & Blue Dot ) and factory Win Stips / Sig V crowns there is better accuracy than I can do... tested both in a sighting rest and at 50ft have very small  5 shot groups of aprox <2"

Only issue is the brass being worked hard due to chamber

[The_Shadow]

It comes down to the chamber size, and all of the after-market barrels are much tighter then the stock Glock

Do the aftermarket barrels shoot as reliably as the stock barrel?  I've always guessed that the well-known glock reliability stems at least partially from their loose chamber fit.

Yes some of the aftermarket barrels can shoot tighter groups than the factory Glock barrels. especially with lead alloy bullets.
The Factory Glock barrel with the looser chamber tends to be more forgiving with respect to the feeding, especially with reloaded ammo where small discrepancies to correct resized and properly crimped cartridges that may not pass a cartridge case gauge.  The tighter chambers of the aftermarket barrels will show that the cartridge out of spec will show this quickly...

Because of bulging (AKA Glock Bulge but it also happens in other firearms as well) very low on the cartridge case just above the extractor cut, is why I started pass through sizing all of my 10mm and 40S&W brass.  By performing the pass through all of my finished rounds will pass the cartridge case gauge and feed reliably in all of my barrel chambers...