SAAMI Pressure for 9mm

[checkfeo]

Any of you old time re-loaders out there know what the SAAMI pressure on Winchester White box is? (9mm 115gr) Most everyone agrees that works the best in a Luger. Is it close to max pressure? (35,000 psi)

I load 147gr's for my Luger to about 25,500 psi. This is on the low side, or below, 25% max load, (according to QuickLoad) and I have no problems with FTF, FTE, or going to hold open.

I want to put in a new, "standard," Wolf main spring, but don't know if it will be too strong for my loads. (I know, try it) Since pressure is what makes the whole thing work, I'm thinking if I could get close to White Box pressure, I should be, "Good to Go."

Any Thoughts?

[Ron Smith]

I recall reading that U.S. Military 9mm ammo is to maintain an average test pressure of approx. 32,000 psi maxiumum, with milspec. set at 31,175 psi + or -.

Ron

[mrerick]

Actually, there were different versions of the mail recoil spring depending on the era of the Luger.

The Mauser period lugers used more coils than the WW-I period lugers.

Consult someone with experience on your particular Luger before replacing things.

Marc

[checkfeo]

I just installed the standard Wolf spring kit, (main, ejector, striker, trigger) on my 1916 DWM. All the springs were the same size except the striker, which was longer.

Does it matter, anyone know for sure?

The action is great with no jams, FTF, FTE, or Hold Open problems. Even the trigger feels crisp.

Total job was about 30 minutes and the only hard part was the main spring. Very strong, but easy enough after watching the video. Had to rest the frame on a door jam to be able to compress it.

So, I guess I answered my own question on the correct pressure of loads, as my 147gr 25,500 psi loads cycle just fine.

If anyone is interested (use at your own risk) I use Berry Plated 147gr RN over 3.6 gr of Accurate #2. Seat is 1.155 Crony puts them at just under 900 fps. Mild and safe for the 1916.

Thanks to Ron Smith for the input on the psi. After reading that I figured I was on the right track, (my load would be light) and Mrerick for the spring info. Same main that came out, but who knows, it could have been changed once already.

Thanks Tom

[unspellable]

SAAMI max average pressure for the 9 mm is 32,000 cup, not psi. That has nothing to do with the actual pressure of any factory load as it's an upper limit, not actual pressure.

Pressure has NO bearing on functioning. It's a recoil operated action, the impulse is what counts, not the pressure.

[Ron Smith]

"SAAMI max average pressure for the 9 mm is 32,000 cup, not psi. That has nothing to do with the actual pressure of any factory load as it's an upper limit, not actual pressure."

Oops! Thanks for catching that. It's what I meant, but not what I said. I must have been thinking of the tire pressure for my Jeep.

[checkfeo]

Call it what you like, CUP, PSI, PIEZO SAAMI CIP. It's all a way (although different way) to measure the chamber pressure of a firearm, and yes, there is a max. That was not my question.

We reload so we can control the speed, accuracy, and pressure (among other thing) in the bullets we shoot. We try to find the best load for that particular gun. If you find a good factory load, you may try to duplicate it. That was my question. Is white box a near max load, or near min load, or something in between?

I beg to differ, but the amount of pressure generated by a curtain load has everything to do with the cycle rate and function of any recoil or gas operated firearm. The higher the pressure, the faster the bullet goes and the harder and faster it cycles.

I don't know of anyway to measure, "impulse," I don't even know what that is referring to, or how to change it, but I do know and can change the amount of recoil by changing the amount of pressure.

Different ammo works better or worse because of different pressures, shapes, weights or lengths. Giving the correct impulse, recoil, if thats what you mean, but to say it works on impulse or by impulse is just not correct. It's Pressure.

[checkfeo]

If the recoil impulse is not strong enough to overcome the main spring tension, the action will not fully cycle (open) to eject the spent case (stove pipe) or load the next round.
If the recoil impulse is too strong, it overcomes the spring tension and slams the toggle against the stops, putting undo stress on the action.

The only way I know to correct either problem is to change the spring or change the pressure in the load. (change ammo)

[Ron Smith]

The best way to determine what you want to know is start with minimum load, working up a 10th of a grain of powder at a time, until it cycles the toggle properly.

Every gun has a different personality. You just need to find what makes them happy.

[tomaustin]

is there a direct conversion of this to psi, etc. ??

[checkfeo]

The actual pressures are identical, but the numbers are different, sort of like measuring your height in inches or meters, the same height but the numbers are different. Most times the cartridges have a higher PSI maximum than the CUP number for high pressure cartridges, but opposite for lower pressure loads.

So, you can use either number, PSI or CUP. You just have to know which one your using or talking about.

[checkfeo]

Amen, Ron Smith, you get it!

Start out with a light load and keep increasing the pressure until it cycles.

Thats called "Load Development" and thats how its done.

[sheepherder]

My $.02...

I doubt this is unused military ammo; it does not have the lacquer sealed primers...I have a box in front of me...

Usage: Target/Range
Application: Indoor & Outdoor Range, Plinking, Target, and Match

I would say that pretty much eliminates Police use as well...For issue, anyway...

Practice ammo??? Maybe...but I don't think (judging by my experience qualifying with DoD Police in the 80's & 90's) that any Police agency would practice or qualify with anything other than issue ammunition...the bullet strike would be different...

It looks to be just general use 9mm cartridges, not anywhere near +P.

BTW: My Speer Reloading Manual says 35,700 cup is the maximum industry working pressure...

[Sieger]

Hi All:

Ron Smith is absolutely correct above.

Pressure is irrevelant, function, however, is relavant!

From my well over 30 years of handloading for the Luger, here are the key elements, I have discovered, to making the Luger function, as well as, shoot accurately.

1) Cartridge OAL is key to proper feeding. Too short a cartridge and the pistol will jam all day long! A good place to start with your particular bullet is: round nose 29.8mm, truncated cone 29.0 mm (Hornady FMJFP is perfect at 28.7mm). These lengths are for 115 to 125 grain bullets. Personally, I shoot nothing lighter or heavier through my Lugers

2) Powder burning rate is key to accurate and consistant function. Try "Power Pistol" and "IMR SR 4756". For an excellent target load, with perfect function, Bullseye is tops!

3) Most accurate rounds are in the range of 900 to 1100 FPS. Anything much faster and you will be outrunning the rifling twist of the barrel. The WWI service round was 123 grs at 1,076 fps. My most accurate rounds are in this exact range.

Here are some of my most successful handloads for the Luger:

Using Winchester brass, Remington 1 1/2 primers and Hornady 124 gr. FMJFP bullets seated to 28.7mm,

Power Pistol- 5.4 grains (three shot clover leafs at 25 yards, all day long)

SR 4756- 5.5 grains (three shot clover leafs at 25 yards, all day long)

Bullseye- 3.7 grains (seven touching at 25 yards, slow but consistantly accurate, with perfect function)

HS-6- 6.2 grains (two or three touching [out of three] at 25 yards) Also functions perfectly and accurately in my L.P.-08. Very clean burning! This load is on the upper end of the accurate velocity range of a Luger.

If your Luger's recoil spring and magazine spring are in spec. the above loads should perform almost magic through your Luger.

On the other hand, the much vaulted Winchester White Box may function your Luger, but the bullets spray all over the target for me. According to Winchester's site, they are flying out the barrel at almost 1,200 fps, again, too fast for the rifling twist to accurately stabilize.

This has been my experience, what has been yours?

Sieger

[G43K98]

Thank you, Sieger, for the excellent data using jacketed bullets. Do you have any favorite loads for the 124 gr. round nose cast lead bullet?

Gerhard

[Sieger]

Originally Posted by G43K98

Thank you, Sieger, for the excellent data using jacketed bullets. Do you have any favorite loads for the 124 gr. round nose cast lead bullet?

Gerhard

Hi:

Just which lead bullet are you shooting?

With lead, I prefer the truncated cone 121 to 125 grainers.

Sieger

[HankB]

Pressure standards for most cartridges used to be measured in CUP - Copper Units of Pressure - which relied on measuring the deformation of a copper crusher that powder gasses had impinged upon, and comparing the measured amount of deformation with that found in a tareage table to determine pressure. (Shotguns used lead crushers to determine - you guessed it - lead units of pressure, or LUP.)

Current industry standard is to measure and list pressures in pounds per square inch (PSI) using piezo-electric transducers. The standard maximum average pressure for 9mm P is 35,000 PSI. The standard for "+P" is 38,500 PSI. There is no standard for "+P+" ammunition, but I have some from Remington and Winchester that is labeled "40,000 CUP."

What does 40,000 CUP correspond to in PSI? I don't know, but would guess it's close to 45,000 PSI. But that's ONLY a guess. Though CUP and PSI seem to roughly correspond to one another, there is no known universal formula for converting CUP to PSI.

Things are further complicated by the method of using piezo-electric transducers - I believe SAAMI and the European CIP do things a little bit differently.

[G43K98]

Although I've been reloading for 30+ years, recent Luger purchases created the need to reload 9mm for the first time. The bullets I picked up at a local gun store are lead 124 gr round nose, sized to .3555. The profile is similar to the Lyman #356637, except that it's missing the bevel base and is 124 gr rather than 147 gr. If they turn out to be unsuitable for the Luger, I'll give them to a friend for use in his Glock.

Some of my .45 ACP loading is for a 1912 vintage Colt Model 1911 U.S. Navy. For that I use a 200 gr bevel base semi-wadcutter (similar to the Lyman #452630) behind 6.5 grains SR 4756. According to the Lyman reloading manual, that should give about 675 fps muzzle velocity at 9,750 c.u.p. -- a nice gentle load for a 99 year old pistol that is accurate and cycles the action reliably. For shooting .45 ACP in modern pistols, I typically use 7.5 gr SR 4756 for 840 fps mv at 14,400 c.u.p. These loads are well below the max of 8.0 gr SR 4756, 933 fps mv, 16,700 c.u.p.

Gerhard

[Sieger]

Originally Posted by G43K98

Although I've been reloading for 30+ years, recent Luger purchases created the need to reload 9mm for the first time. The bullets I picked up at a local gun store are lead 124 gr round nose, sized to .3555. The profile is similar to the Lyman #356637, except that it's missing the bevel base and is 124 gr rather than 147 gr. If they turn out to be unsuitable for the Luger, I'll give them to a friend for use in his Glock. Gerhard

Hi:

I've done an internet search on your Lyman 356637 and the only 124 gr. bullet I can find is the 147 gr. in HP format. Also, the bullet I've found is a RNFP bullet. Since I haven't worked with this bullet, I can't comment on its suitability for the Luger.

Here, however, are some lead bullets I've had excellent experience with in the Luger:

Bushwhacker Bullets, LLC, Ron Roehrs, 417-681-0506, their 125 gr SWC, my cartridge OAL, 29.0mm.

Bear Creek Supply, Steve Miller, 209-874-4322, their 125 gr. Conical Round Nose Molly Coated, my cartridge OAL, 29.8mm.

My accuracy loads with these two are with Alliant's Power Pistol. For your accuracy load, start at about 4.8 grs. and work up, 1/10 of a grain at a time, to about 5.4 grs. or so, while keeping an eye out for your best group.

The SWCs are a bit expensive, but they are of excellent quality, and shoot extremely well. I like the perfectly round holes they cut in a target. Feeding is also perfect!

The Molly coated bullets are of excellent quaility and consistency, yet, are extremely affordable. These bullets are so slick that you can barely hold onto them long enough to get them seated, there is no leading, and clean-up is with only one or two Hoppes #9 soaked patches. My accuracy load with this bullet has cut the center out of a 25 yard X ring with 7 touching!! This is the best lead bullet shooting I've ever done with a Luger!

Some notes of caution when developing handloads for the Luger:

1) Though a Luger's groove diameter is 9.1mm or .358, the chamber and throat of a Luger will not permit bullets of a diameter greater than 3.56 to fully chamber. Larger diameter bullets will only partially chamber, either jamming the pistol or leading to a very, very dangerous situation whereby the pistol can be fired with the toggle not at full battery (fully closed)!!! Pay extra attention to the diameter of the bullets you are handloading and always check to make sure your handloads will fully chamber!!!

2) Luger chambers and throats will vary in diameter and length as well. After you have determined the proper cartridge OAL your pistol needs to feed cartridges properly through that highly slanted magazine, always check to make sure your handloads will, again, fully chamber. A handload too long for your pistol's throat will lead to the same highly dangerous situation described above, whereby the pistol can be fired with the toggle not fully at battery. If it takes more than the slightest index finger tap to fully chamber your handload, reject the component combination, and start over!!! Always check to make sure your handloads will fully chamber!!!

Please share your experiences with me after you have done your load development.

Thanks!!

Sieger

P.S. Remember, popular myth has it that the 9mm just won't shoot lead bullets accurately!?!

[Sieger]

Originally Posted by G43K98

Although I've been reloading for 30+ years, recent Luger purchases created the need to reload 9mm for the first time. The bullets I picked up at a local gun store are lead 124 gr round nose, sized to .3555. The profile is similar to the Lyman #356637, except that it's missing the bevel base and is 124 gr rather than 147 gr. If they turn out to be unsuitable for the Luger, I'll give them to a friend for use in his Glock.

Gerhard

Hi:

I've found, what appears, to be your bullet, Lyman's 356637, in Lyman's latest Cast Bullet Handbook.

The "flat" of the front of the bullet looks too wide to me to be able to properly feed through a Luger's magazine. The Luger "likes" truncated cone bullets with narrow "flats".

You might want to try either the Lyman 120 gr. #356402 or RCBS' #9mm-124-CN, as these should work perfectly.

Sieger