CIP vs SAMMI

[DWalt]

Dwalt,

I believe the issue with the high-pressure loads for the M-9 was more a matter of damage from slide and frame battering rather than catastrophic failure of any component from pressure! Unless the barrel bulging you mention occurred in the chamber area I doubt that was a pressure issue either!

The only barrel bulging came from in-bore collision tests. We put bullets in the barrel at different distances from the muzzle, and even then there were sometime no bulges. A barrel bulge would tie up the slide. Heavy loads alone did not cause barrel bulging or any other structural damage. The M9 is tough. We were not attempting to test to pistol destruction. The program had another purpose related to testing ammunition rather than the durability of the M9.

 

[Nevada Ed]

In all my years of reloading I go by;

SAMMI, NATO then CIP for my data.

Just use care when in the top 96% of the data.

 

[AJ]

What brought this up is a load I was making for up. I am using 7.8 grains of Unique with a 230 cast RN bullet in .45 Colt. My Lyman CAST Bullet loading manual gives the low side as 7.4 grains and the high side as 9.3 grains. When I ran this through Quickload it gave me the 7.8 grain loading as a magenta colored loading which means it is on the higher end (using the SAMMI standards). When I used the CIP standards it give me a white colored loading which means on the lower end. So was curious.

I took the loading of 7.8 grains of Unique with the 230 RN Cast bullet to the range this morning. I was using my S&W 25-9 with a six inch barrel. I had some factory loads to shoot also. I tried my loads first and they seemed a tad warm, but not excessive. I tried the factory loads and they were much hotter. Accuracy was not bad, probably a three inch off hand group at 15 yards. Will start by going up and down a 1/10 grain to see if I can find a sweet spot for better accuracy.

 

[Oldy089]

I am not sure about SAMMI spec for pressure in firearms but CIP requires that weapons be tested to 125%(I think) over the approved pressure rating. That doesn't mean that they can shoot that all day long, but that they won't blow up at 125% pressure.

Use a reloading manual provided by the powder manufacturer and use components listed in that manual if you don't want to have to worry. Otherwise, do what all good reloaders do and WORK UP your loads from starting charges.

 

[AJ]

I am not sure about SAMMI spec for pressure in firearms but CIP requires that weapons be tested to 125%(I think) over the approved pressure rating. That doesn't mean that they can shoot that all day long, but that they won't blow up at 125% pressure.

Use a reloading manual provided by the powder manufacturer and use components listed in that manual if you don't want to have to worry. Otherwise, do what all good reloaders do and WORK UP your loads from starting charges.

If you had read my Post #11, you would have read that I was using a manual. I still had 1.5 grains until I reached the max loading of the Lyman Cast Bullets loading manual.

I have been loading for 50+ years. Just had a question between the SAAMI and CIP.

 

[stansdds]

My understanding is that it boils down to where the pressure transducer is placed. SAAMI places the transducer at the midpoint of the cartridge case, CIP places it very near the case mouth.

 

[mtgianni]

I use SAAMI. I think it recognizes older firearms whereas, CIP assumes modern firearms are in use.

The other reality is that I often use surplus powders and cast bullets without any listed data. I can still count to ten on my fingers.

 

[AJ]

I can still count to ten on my fingers.

Like I wrote, been reloading 50+n years. Have not blown up a gun or myself so far. I do not plan to do so. The older I get the more cautious I am.

 

[DWalt]

Ugeb

My understanding is that it boils down to where the pressure transducer is placed. SAAMI places the transducer at the midpoint of the cartridge case, CIP places it very near the case mouth.

Unless things have changed since I was involved with such things, the SAAMI method uses a conformal piezo gauge that does not involve drilling a hole in the case. The CIP method does. The NATO method has a.piezo gauge at the case mouth, no hole in the case involved with NATO either. For those who express a preference, I would sure like to hear you explain why. Why would anyone prefer a method they cannot use for any purpose?

 

[Krogen]

Lots of good information (and yes some conjecture too) in this thread. AJ poses a reasonable question. I've wondered the same thing in contemplating Quickload results. The same load, in an identically dimensioned cartridge in Quickload predicts identical pressures whether you select SAAMI or CIP. But the acceptable MAP is different for SAAMI or CIP. If your load is on the high margin, SAAMI criteria may show overpressure while CIP shows it's OK.

I don't consider Quickload as gospel; it's a predictive tool. I've had good velocity correlation between Quickload predictions and chronograph data in bottleneck rifle cartridges. Not so much in short pistol cartridges. It's also a case of GIGO. Initial predictions of .223 pressures were scaringly high even when inputting load book data. Only when I measured case capacity and entered that corrected information did Quickload make sense.

As I said, I have wondered the same thing as AJ does. But as he also said, he (and I) use databooks.

 

[Krogen]

While this doesn't answer the question of SAAMI or CIP being more accurate, it does provide an interesting read about these pressure test methods. Additionally, it addresses military test methods which contribute to the 5.56x45 vs. .223 Rem pressure arguments. Of course, this is Wikipedia, so take it all "with a grain of salt."

Small arms ammunition pressure testing - Wikipedia

 

[CH4]

In addition to chamber pressures, CIP defines the dimensions of the chamber, barrel and action distance of the weapon, dimensions, which differ from SAAMI.

 

[AJ]

CIP standard for 9x19 is 1,500 fps in a handgun max velocity...

That is great info and germane to the thread.

 

[WR Moore]

CIP standard for 9x19 is 1,500 fps in a handgun max velocity...

What weight of bullet and what are the specs on the test barrel?

 

[308 Scout]

well dont know about you, but valid data is valid data.

its like my box of barns 44 magnum ammo,, has the big CIP logo on it.. nothing about SAAMI on it...

CIP really is more closer to the original loading standards in a good number of cartridges. However the user is expected to be smart enough to know the proper ammunition to use.

for example, if the CIP standard for 357 magnum IS the original elmer level chamber pressure, the usser is expected to NOT use in alloy frame guns.

And then i have to ask the fellows, if you are scared of CIP chamber pressure, how do you feel about the Buffalo Bore chamber pressure?

I don't think SAAMI and CIP pressure standards are different because of the methods pressure is taken on the firearm, CIP standards simply allow for more pressure with some cartridges, others not.

For example, CIP MAP standards for the 45 ACP are 1300 bar or ~19,000 psi which is about 2000 psi lower than SAAMI for 45 ACP (non- +P). On the other hand, their MAP for the 357 Magnum is 3000 bar or ~43,500 psi vs. 35,000 psi per SAAMI standards. (On a side note, lest ye think foreign (European) revolvers chambered in .357 might be weak, they're proofed at 1.3x CIP standards which is almost 56,000 psi.) CIP standards for the .38 Special is 1500 bar or almost 22,000 psi vs. SAAMI which is 17,000 psi standard, 20,000 psi +P.
If one looks at the ballistics of factory ammunition loaded in Europe, it's quite obvious that much of it's loaded to higher pressures than over here, the .38 Special as load by S&B being a perfect example. But more than that, and as KittenPics alluded to, U.S. ammunition, some at least, is quite obviously loaded to less than SAAMI standards. If one doesn't believe it, just look at Buffalo Bore's non- +P offerings and compare their ballistics to the same ammunition as loaded over here by the Big 3 ammo companies.

 

[Model19man]

I don't think SAAMI or CIP either have bearing on what 45 Colt loads will do. Accuracy wise I find that 6 grains of Unique under a 250 grain Keith SWC works very well - for me. You need to find out what works for you with your guns. Don't exceed the pressure called out in the manual you own.