9x21 data in 9mm Luger - Safe to use?

[IM_Lugger]

OK I know 9x21 is basically the same as 9mm Luger, with the the major (only?) difference being 9mm's case is 2mm shorter. COL is the same right? what about pressure? is it also about 35K PSI?

I'm wondering if I can use 9x21 data in 9mm Luger; I found an interesting powder - VihtaVuory 3N38 but they only have load data for 147gr bullet, but they do have load data for 9x21 using 115gr and 123gr.

so can I use that date for 9mm? I don't see why not...

 

[9x21kid]

9x21

Your title says "YOU HAVE NO LIFE" Use 9x21 load data for 9mm and you WILL get your wish.

 

[Andy]

From the published loads I've seen, you could use starting loads for 9x21 as a max load for the 9mm Luger.

 

[IM_Lugger]

9x21 kid 1985 posts later you will have no life either btw do you reload for 9x21? can you think of anything that would make this dengerous?

Accoring to VihtaVuory guide the loads and velocities of 9mm and 9x21 are almost the same. Since the major (only?) difference is the 9x21's case is 2mm longer, but COL is still the same;

a little drawing I did;

 

[SandRoad]

the 9x21 was first developed in Italy to get around their rule that no civilian guns could be chambered using a military cartridge. So they took the 9mm and made the case 2mm longer. The same was used in IPSC when they initially banned the 9mm loaded to major. The 9x21 got around the IPSC rule.

In this case the COL is the same, BUT if you were to take a longer 9x21 load worked up to max pressure and reduce the COL to 9mm specs, then you are asking for trouble.

When you are at max loads with fast burning powder, a couple of mm less OAL can raise pressures thousands of PSI.

I plugged a sample into the QuickLoad program so you can get an idea of what a change of a couple of mm does. I don't have the data for 3N38 so I used 3N37 which is a quicker burning powder.

9x21
147gr TMG
5.4 gr 3N37

OAL 1.18 inch (30mm)
34,000 psi

Now seat the bullet 2mm deeper

OAL 1.100 in (28mm)
60,950 psi

SAAMI Maximum Average Pressures (psi)

9mm.......................35,000
9mm +p...................38,500
9mm min proof load....52,000
9mm max proof load...55,000

 

[ElmerFudd]

IM_Lugger, I think your best answer will come from the powder manufacture. That being said, I think you are right and that it would be safe. Start at the same starting loads and work up, as always.

With the same bullets, the OAL is the same. The powder volume is the same. The only difference is the tension on the bullet from the additional contact between the bullet and the extra case length. Would that extra case length cause more resistance than the barrel rifling of the 9mm? I don't think it would. But I am not a ballistician, I just play one on CGN.

The 9x21 came out because of Italian laws (and other countries) that made the military 9x19 illegal for civilians.


Fudd

 

[IM_Lugger]

In this case the COL is the same, BUT if you were to take a longer 9x21 load worked up to max pressure and reduce the COL to 9mm specs, then you are asking for trouble.

but that's the thing COL of 9mm and 9x21 is the same! so I wouldn't be compressing the load (the illustration I did shows it).

3N38 is slower so I think it should produce lower pressures than 3N37.

I will try to contact the manufacturer and see what they have to say, hopefully I can find someone to talk to who knows something about this...

 

[9x21kid]

9x21

NO, The COL is longer in the 9x21.
Yes, In Italy it was developed to get around the law, In North America it was to make MAJOR, So the cartridge overall length is longer to accomadate MORE powder. Higher pressure/greater velocity., Low end/starter 9x21 loads are like 9mm +p+.
It would be like saying 9x23 is similar in size to .38 super, So therefore I can use 9x23 load data, It doesn't work like that.
The Kid.

 

[Andy]

I'm wondering if I can use 9x21 data in 9mm Luger; I found an interesting powder - VihtaVuory 3N38 but they only have load data for 147gr bullet, but they do have load data for 9x21 using 115gr and 123gr.

so can I use that date for 9mm? I don't see why not...

No you can't.

There is no SAAMI spec for 9x21, so you don't know what you're getting with the 9x21 load data. Again, from the load data I've seen, the 9x21 is loaded hotter than the 9x19 (9mm Luger). By hotter, that means more powder and more pressure, so the COL is irrelevant - there's more powder in a 9x21. A few posts back I noted that published starting data for the 9x21 fell within the working range for the 9mm Luger, hence my suggestion that you use 9x21 starting loads.

If that's still not good enough for you, keep asking, or just load as you wish.

 

[9x21kid]

9x21

Andy is Right in the fact you DO NOT use the same load data, However Do not make statements if you do not know the FACTS.
facts.
9x21 is a longer case, to get more powder in than a 9mm case.

9x21 case is thicker and stronger than a 9mm case to handle higher pressure.

OAL of the cartridge IS LONGER allowing you to put more powder in the case, This allowed compitition shooters like ROB LEATHAM safely make MAJOR.

Otherwise, If you lived outside of ITALY there would be NO reason to switch from 9mm to 9X21 If the overall cartridge length was the same., You would still have a 9mm in a longer case.

There is REAL LOAD DATA on the internet, Some by powder manufactures, You can even go to Rob Leatham's web site. It would appear that the talk on this site is by people who THINK they know something about 9x21.
Which is why I rarely look at these groups.
I have been using it for 15 years and have had 1911"s, SIG 220, RUGER SP101,RUGER SPEED SIX, UZI (factory) MARLIN CAMP CARBINE, RUGER CARBINE, SIG 228, BROWNING BARRACUDA, To name a few in 9X21.

So do your research for LOAD DATA, Do not get it from a talk forum, There are too many experts on the 9x21 who have never used it.

 

[IM_Lugger]

The 9x21 load data I was talking about is from VihtaVuory load guide, NOT from some internet forum.

They have only one published load for 9mm (147gr bullet) and two loads for 9x21 (115 and 123gr)...

BTW COL for 9x21 loads I'm talking about is 1.161” which is LESS than max COL for 9mm Luger. So COL is not a problem...

Also their 9x21 loads using other powders (3N37, N350) for 115, 124 and 147gr bullets are only 0.2-0.3gr higher than their 9mm Luger load, but so is the COL my 0.5mm (still with in max OAL of 9mm)!

Here are the 3N38 laods;

9mmP 147gr XTP/ 6.3-6.9gr / OAL 1.142"

9x21 115gr FMJ / 7.6- 9.4gr / OAL 1.161"
9x21 123gr FMJ / 7.1 -8.2gr / OAL 1.161"

I think I should be OK to use starting 9x21 loads (which are a bit lower than max loads and not that far away from heavier 9mm bullet load).

 

[IM_Lugger]

9x21 case is thicker and stronger than a 9mm case to handle higher pressure.

I didn't know that... Do you have the data comparing 9mm and 9x21 cases? I know I can use my LEE 9mm dies to load 9x21, so I think there wouldn't be a significant difference in wall thikness between the two rounds...