Lyman 9x19, 9x21 -- Why the difference?

[Dannix]

Lyman 49th Edition
9x19
147 gr. TMJ
1.115" OAL
Max: AA#7, 7.2gr, 1014 fps, 29k CUP

9x21
147 gr. TMJ
1.169" OAL
Max: AA#7, 9.2gr, 1228 fps, 33k CUP
The Lyman manual mentions the above 9x21 load is their only load within SAAMI spec that meets IPSC major requirements. But why isn't this load mentioned in the 9x19 section? The only difference between these guys is brass OAL, nothing else...right?

Just curious. I'm only plinking with 115grainers myself right now i.e. don't worry, not trying to blow myself up, at least not right now.

[sleeper78]

2 grains of powder, 214fps and 4k cup is a big difference. The 9x21 is a more powerful round than the 9x19. When working with fast burning pistol powders 2 grains difference can blow up a gun or even worse. Coupled with a 2mm length difference you are talking a huge difference. 9.2 grains in the 9x19 could and probably would make pressures well in excess of the 33k cup of that load in the 9x21. The bullet sits a lot farther into the 9x19 case than in the 9x21 thus leaving less space for powder. This translates into substantial pressure increases on ignition. Plus the loads you have listed are the max loads. They are to be approached with caution to begin with. Please do not try to use the 9x21 load in the 9x19 case it could be hazardous to you health.

[Tango Victor]

Please take Sleeper78's advice. If it's possible to get 9.2 gr. of AA#7 in a 9x19 case and still seat the bullet it would be very dangerous to fire in a 9x19 handgun. Maximum loads listed in the various maunuals should never be exceeded and listed OAL's should be adhered to. Failure to do either can result in excess pressures.

[Dannix]

I'm not sure we're talking about the same thing here. I'm talking about increasing a 9x19 cartirdge to full length, the same length for the 9x21's load data, 1.169" OAL

The dimensional drawing in the Lyman manual for 9x19 lists an OAL of 1.169". I read somewhere in passing though that manual reload data strongly bias towards shorter lengths for 9x19 as some cheaper guns do not allow for the full 1.169 OAL.

As for pressures, 9x19 @ 1.169" and 9x21 @ 1.169" -- with the same bullet, these would have essentially identical case capacities, right? Why wouldn't they?

[sleeper78]

Can you get a good crimp when making the 9x19s OAL longer? Can your 9x19 handle the extra 4k CUP. Will the CUP only be raised 4k when this change is made. Will your particular firearm function with the new OAL? If your firearm doesn't explode when this load is tried will it be able to function reliably while shooting the hotter loads. I can't answer these questions. More than likely you cannot either. If you can't answer these questions then you don't do it. It's not worth the risk.

[Dannix]

Can you get a good crimp when making the 9x19s OAL longer? Winchester lists 9x19 loads at 1.169. Can your 9x19 handle the extra 4k CUP. What do you see in your manuals? I see no difference in mine. The highest 9x19 load I see -- 33k. The highest 9x21 -- 33k. What is your source for the pressure difference? Will the CUP only be raised 4k when this change is made. Will your particular firearm function with the new OAL? Please see above. If your firearm doesn't explode when this load is tried will it be able to function reliably while shooting the hotter loads. I wouldn't try anything remotely "hot" 9x19 loads in an American 9x19. In a european gun designed to run 9mm Para and Nato in addition to Luger, yes albeit with the caveat that hot can be a subjective term.I can't answer these questions. More than likely you cannot either. If you can't answer these questions then you don't do it. It's not worth the risk.

With all do respect, it seems like you are posting without even the most simplistic research. Indeed your comment about 9x21 having "2mm length difference" and it implying "a huge difference" confirms such.

Now please, stop posting unless you're darn sure you know what you're saying. Please understand I will hold the highest respect for expertise you may and surely have in other sectors.

[WVBob]

The 9x21 comes from Spain where you can't have a firearm the same cal. as used by the Army. A lot of other countries do the same thing. When you reload, use loads for 9x19 and loads for 9x21. The loads for the 9x21 are made for a stronger gun. Look at some of the pocket 9MM to understand why. Firearms for the 9x21 are all larger.

[sleeper78]

With all do respect, it seems like you are posting without even the most simplistic research. Indeed your comment about 9x21 having "2mm length difference" and it implying "a huge difference" confirms such.

Now please, stop posting unless you're darn sure you know what you're saying. Please understand I will hold the highest respect for expertise you may and surely have in other sectors.

Well, since you seem to have ALL the answers why are you asking the questions? If you already know what you're talking about you obviously don't need us to tell you about this subject. I meant absolutely no disrespect when posting my last response. I was simply stating that you should be careful. I didn't have the answers to the questions that I posted and I stated that. You however, seem to have an answer to every single question that I posted. So, I will say this, since you can confidently answer every single one of those questions, in fact it was more than confidently, it was condescending and arrogant, so don't let me stop you. I never want to stand in the way of progress. And for all of your future reloading questions I will be sure to not answer and let someone else take care of it so I don't stand in your way.

PS: Any time you talk about adding 2 grains of fast burning pistol powder and shorting the case by 2mm you are risking the potential of increasing the pressures by a huge amount. Even the most simplistic research will tell you that. Since you accused me of doing no research I picked up my copy of Lyman's 49th. The 147grn tmj they used was a Speer bullet. So, who better to know about Speer bullets than Speer themselves. Out came the 13th edition Speer relosding manual.

Pg 441 states
"The 9mm case is rather small compared to other high-performance pistol cartridges. Propellant space is limited and any variation in capacity among brands may create wide variations in pressure, velocity and reliability."

Speer lists the 147grn tmj with a OAL of 1.130 and with AA#7 6.8 grns of powder for a velocity of 961fps. This is their max load. The Lyman 49th lists the load you referenced above as the max load.

It also states on Pg 346 " In this country, IPSC shooters have adopted this cartridge"
(the 9x21)
"to make major power requirements which can not be safely reached with the 9mm Luger. Even thought the 9x21 case is longer than the 9mm Luger, the same overall cartridge length was maintained to allow for the easy conversion of the 9mm Luger handguns. If this overall length is maintained, it is difficult to obtain major loads without exceeding the 33,ooo c.u.p S.A.A.M.I. pressure limit set for THE 9MM Luger firearms."

What this means is, even thought the OAL is the same the cartridge companies have a hard time loading this load safely. The case capacity of the 9x19 is smaller and therefore the internal pressures will be higher than the 9x21 all other things being equal. Any one who reloads can tell you that going 2 full grains of powder above max in a tiny pistol case is flirting with danger. Since I don't have a pressure barrel to actually test these loads and I assume (with the risk of being wrong and being chastised for it) that you don't either we just never can be sure of whats going on inside the case on ingnition. Just be careful.
<sarcasm> But I don't know what I'm talking about so don't listen to me <sarcasm>

[phill]

Nice try at trying to explain something to a person who just wants to argue his assumptions.
There are several pistol cases that differ only slightly from another but maybe capable of operating at drastically different pressure levels.

[Dannix]

WVBob, I know Glock did make a few 9x21s. I'll have to see if I can find if they designed it any different. You got any links to how 9x21s operate at a higher pressure level? The closest thing I've found is the imprecise blurb in the Lyman manual.

sleeper78, some if your information has been misinformation, some shows a lack of basic research. If you just want to learn along with me, awesome! Welcome aboard! Hopefully we'll both learn something.

phill, indeed your are correct. 45 Auto and 460 Rowland is probably one of the most acute examples I can think of. I'm not seeing any pressure differences between 9x19 and 9x21 in the manuals though. Got any info on differences? I'm not assuming there is not difference -- that's why I posted. I would like to know what they are. I'm also interested in why of the manuals lack of 9x19 1.169 OAL loads.