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

**Dannix** · July 14th, 2010, 12:52 AM

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** · July 14th, 2010, 01:19 AM

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** · July 14th, 2010, 07:55 AM

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** · July 14th, 2010, 02:24 PM

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** · July 15th, 2010, 12:48 AM

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** · July 15th, 2010, 03:16 AM

Originally Posted by sleeper78

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.