SAAMI and how it relates to ammo

[Intercooler]

Unless I am reading wrong, SAAMI is a Org unless I am mistaking. The only member I see on that list is Double Tap which would be bound to such standards and perhaps why their ammo isn't what it was (and stays in SAAMI). As a note Cor-Bon is on the list and also probably within the SAAMI guidelines. Buffalo Bore, Underwood and a few others loading at max SAAMI or a little over aren't under the same umbrella.

List: http://www.saami.org/member_companies/index.cfm

10mm SAAMI specs: http://www.saami.org/specifications_...essureData.pdf

   It's in the end up to the user, owner of said firearm. The way I see it is their really is no governing the level of the ammo unless you are listed as SAAMI. Garrett Cartridge and some others I am sure are in the same boat but not bound.

[REDLINE]

That's the way I've always understood it.  100% optional.  The benefit of being a SAAMI member (in my mind) is simply showing your willingness to follow a good set of guidelines, kind of like being ISOwhatever certified.

One thing I would add is SAAMI doesn't push for loads to be on the Lite end of the spectrum.  They have pressure guidelines that in no way are geared toward Lite loads per se.

There are many reasons waaaaaaaaay outside of being a SAAMI member or not, that a manufacturer won't try to compete with an Underwood premium 10mm load.

[Intercooler]

   They are still pretty generous but when I look at my actual Double Tap and Cor-Bon results I would say they are in those guidelines. When Double Tap went mainstream Midway, etc... they probably had to make the downgrade change for the standard. That picture is pretty clear now to me.

[REDLINE]

Yeah, Double Tap went through not only growing pains, but also a learning curve.  Seems to me they must have had close to a half dozen or so price raises over time, and also it seemed to me they couldn't start cutting corners fast enough, whether is was going to a lower cost bullet, or switching to different powders where they could decrease the amount of powder they were using per round.  The problem with switching powders was that their velocity levels went even lower, and since the powder (whatever it was/is) was not the best match for 10mm Auto the pressure levels stayed relatively high.  It was a lose-lose situation for shooters, just so in my estimation the company could save a few pennies.

[Intercooler]

  Unless I am reading the specs wrong here is what they have for 10mm but they don't have all the grain weights which leaves it TBD:

155gr@1410 FPS   Underwood is currently 1475 FPS. Double Tap 1302 FPS on a 1475 rating, Cor-Bon 1280 FPS and PBR is targeting 1400 FPS for their initial release.

170gr@1320 FPS Doesn't apply as nobody is making this.

175gr@1275 FPS This is close enough to the 180's. Underwood is 1295 FPS currently, Double Tap is 1290 FPS, Buffalo Bore is 1333 FPS, Cor-Bon 1194 FPS and PBR Ammo is 1317 FPS.

200gr@1150 FPS Underwood is currently about 1260 FPS from reports, PBR Ammo is 1240 FPS, Buffalo Bore is 1180 FPS, Cor-Bon 1082 FPS and Double Tap is 1156 FPS.

Pretty easy to see Double Tap and Cor-Bon are trying to hit or be below those SAAMI specs.

  I compiled all this and a bunch of data and sent to Kevin to review with some suggested specs going forward:

135@ 1500 FPS (Reduction here because I think they are a little higher)
155@1400 FPS (Reduction here because I think they are a little higher)
165@1350 FPS (I think these are 1400 currently but has been a while)
180@1275 FPS (Generally there)
200@1200 FPS (Easily done because it was the older loading)
220@1150 FPS (No huge adjustment)

   Don't know if he will want to do those but I tried.

[REDLINE]

Yes and no.

That chart ( http://www.saami.org/specifications_and_information/VelocityPressureData.pdf ) is nothing but a list of chronographed velocities of various factory loads from ammunition manufacturers who voluntarily signed up with SAAMI.  The data in the chart in no way reflects what pressure (in PSI or CUP) the listed rounds were loaded to.  It's simply a list of factory loads that fall somewhere between a pressure level under SAAMI maximum pressure specifications to a pressure level up to maximum SAAMI pressure specifications.  The chart is really useless unless one simply wants to see examples of actual velocity of 20some year old loads for the various factory loads listed.

For example, the 10mm loads listed as 175 STHP in the chart is simply the original Winchester 10mm 175gr SilverTip load.  The one listed as 200 SXT is simply the ancient Winchester 10mm 200gr SXT load.  SAAMI isn't showing us what pressure level they achieved.  They're simply showing us they fell somewhere within SAAMI guidelines for 10mm Auto which is anywhere between zero (obviously they have to be over zero PSI or the bullet wouldn't leave the barrel) and a maximum average of 37,500 PSI.  None of the listed loads hit 37,500 PSI, let alone an average of 37,500 PSI.  In the day, the Winchester 175gr SilverTip was pretty much the option for the hottest 10mm load available, probably reaching around 33,000 PSI depending on a host of factors (chamber dimension differences between different platforms, temperature, charge weight accuracy,...).

I pulled two 10mm Winchester 175gr SilverTips to see what was inside.  The powder looks sort of like Longshot too me, but could very well be something different, as I really don't know.  Whatever the powder is, the charge weight in one was 8.9 grains, and the other was 9.1 grains.  Both had a cartridge overall length of 1.252".  Anyway, that's a range of .3 grains of powder which is generally plenty to vary pressure and velocity to some extent.
I posted that info here - http://10mm-firearms.com/factory-10mm-ammo-pull-downs/disected-hornady-155gr-180gr-win-silvertip-175gr-blazer-200gr-and-dt-135gr/

On another note, keep in mind that a specific velocity does not equal a specific pressure level.  It would be normal, all else being equal, to have 5 different powders reach a certain velocity level for a given 10mm bullet load, but all 5 would range in pressure level to some extent.


To elaborate, lets say you wanted a 10mm load with a 180gr Gold Dot bullet to achieve 1250 FPS from a 5" barrel. On top of that you are going to keep the following parameters the same:  COAL - 1.250, Primer - Winchester Large Pistol, and Crimp - .423".  Lastly you don't want any averaging more than an average of 37,500 PSI (SAAMI 10mm Auto specification for Maximum Average Pressure) and absolutely none hitting beyond 38,700 PSI (SAAMI 10mm Auto specification for Maximum Probable Lot Mean).  At this point we still need smokeless powder to get the job done.

All of the following powders will get you there:
Accurate No.7
Accurate No.9
Alliant Power Pistol
Alliant 2400
IMR 800-X
Hodgdon Longshot
Hodgdon Lil-Gun
Ramshot Silhouette
Ramshot Enforcer
VihtaVuori 3N38
VihtaVuori N105
and more.....

The question simply then becomes;  Which powder did it the most efficiently which is generally going to be a combination of: accuracy, most velocity at lowest pressure, clean burning, cost effectiveness for the task of said ammo,.....depending what the shooter is actual trying to achieve.  Either way, between all the different powders reaching the velocity goal, generally none will be doing it at the same pressure as another.  Some may end up being really close in which case you might just pick the one with best accuracy and cleanest burning, but overall there will be some amount of pressure spread between the different powders.


As for the Double Tap 180gr (whichever bullet) velocity you mentioned, the 1290 FPS you posted is quite high for them from a full size Glock G20 (4.6" barrel).  From glocks on YouTube I've seen them average from 1149-1169 FPS (depending on the 180gr bullet being used).  1290 FPS is more what I expect from Winchester's 175gr SilverTip load.

[Intercooler]

    The Shadow has some data he may want to share on the pressures.

[The_Shadow]

Many of the powder manufactures either still do or use to, post pressure values with the corresponding powder charge used with a particular test using a particular bullet weight and make.  I like to study this data specifically for the pressure values.

Most of these are lower than the pressure set buy SAAMI because they have no idea what guns or conditions of the guns people will be using to load for.  However this does show that you might could step up a charge of powder based on it's specific performance and pressures if you feel froggy!  But thinking before leaping is a must!

The Winchester 175 ST's I pulled down, had powder which was smaller grains than LS, BTW I tested them @ 1229 fps from today's test. A charge of 9.0 grains of LongShot will drive that much faster based on test with 180 gr bullets where 9.4 will yield 1300+.

Somewhere I posted a chart of the older Winchester 10mm data which showed Win 540 powders being used by hand loaders at that time frame that produced near the values of the 175 SilverTips.  But I'll post that data here to help and please notice the pressures vs. values...

[REDLINE]

Here is the newest data by some powder manufacturers showing more given pressure levels for various 10mm Auto loads to compare to your Winchester data below:

Accurate Powder's data showing loads with No.5, No.7, & No.9 (see page 7);
http://www.accuratepowder.com/wp-content/uploads/2011/01/accurate_load_data_3.5.pdf

Hodgdon's data which of course includes Winchester and IMR powders along with their own brand name;
http://data.hodgdon.com/cartridge_load.asp

Ramshot Powders' data showing loads with Silhouette (see page 6);
http://www.ramshot.com/wp-content/uploads/2010/09/ramshot_handgun_rifle.pdf


Neither Alliant or VihtaVuori show pressure levels with the load data they offer.

[The_Shadow]

Ah but if you send me an e-mail address I can send you some data from Alliant that will show you pressure values...

But what they are doing now is a general statement that the pressures do NOT exceed SAAMI standards for a given cartridge.  Which is a BIG let down to the handloaders who study this data looking at how much room is left for those seeking top performance. 

[sqlbullet]

It is worth noting that while many mfg's do or used to include pressure data with the load data, and that while the pressure data may indicate headroom for increased loads, there can be a variety of reasons why a given load was noted at max well below SAAMI pressure MAX.

Don't know why means exactly that.  We don't know why.

It could be that the powder has a known sensitivity to temperature, or moisture content, and that while the loads tested in the lab were well below, the mfg has data indicating that in Arizona heat the pressure may well be MUCH higher.  Or that if the can is left open in deep south humidity for a few hours, the increased moisture content could cause a pressure spike.

It could be that above that load level pressure reading became erratic and unpredictable.

It could be that above that level, the increased pressure triggered a change in burn characteristic that caused a big spike in pressure above SAAMI spec.

It could be the  funding for testing ran out at the end of year and therefore that was the highest load they did test.

But venturing beyond IS asking for trouble.  Some of us (myself included) have done so.  But those of us that venture a little beyond do so having spend years reading handloading manuals, handloading magazines, and books about internal ballistics.  We "intelligently" do stupid things

At the end of the day, if you are going to venture beyond published load data, do so only after having checked lots of variable besides seeing if there is some headroom left in the book for pressure.

[REDLINE]

Thanks, I already have it, but so far I've not taken interest in loading with any Alliant powders anyway.

I know you didn't bring it up, but as for VihtaVuori Powder I had brought up not having current pressure info for;  With them it's hard to even care being that the loads they show for 10mm Auto in their load data are at best weak anyway.

I've studied all the data plenty, and it's gotten to a point where I'm not sure I even trust all the numbers floating around out there by THE MANUFACTURERS, and at the very least not in terms of real world pressure values. 

For example;  From Accurate Powder for 10mm Auto claims;
Hornady 200gr XTP + Win LP primer + COL of 1.250" + 12.5gr of No.9 = 37,000 PSI

There is nothing anyone can tell me that will lead me to believe there is ANY truth to that load hitting 37,000 PSI using any normal standardized test equipment.  Personally I believe it to be an outright lie.  The only way I would even consider believing it is if a batch were sent to SAAMI themselves to document the pressure levels on.  I would be highly surprised if that load even hits 35,000 PSI.  Other's opinions may vary.

Aside from questioning what I take away from the published data, some of it is so weak as to almost be considered useless anyway.

I wish a 3rd party or two would test all common loads available (at least premium rounds) on the same overall equipment and publish their results.  I know it will never happen, but it would be awesome if it did.

[REDLINE]

It is worth noting that while many mfg's do or used to include pressure data with the load data, and that while the pressure data may indicate headroom for increased loads, there can be a variety of reasons why a given load was noted at max well below SAAMI pressure MAX.

To add to your list, it makes me think of how some shotshell powders work great in handgun cartridges, while others simply will not work.  What I would give to go on a major powder manufacturer plant tour side by side with one or two of their lab nerds!!!!!