Test results for 9mm

[gamestalker]

Well, I loaded up some 115 gr. Gold Dots and 115 gr. XTP HPs. The G.D.s functioned absolutely as posted data listed @ 1200 fps. consistently with 5.9 grs. Longshot COAL of 1.125". The XTPs as well were charged with 5.9grs. of Longshot but were seated to 1.095" and delivered 1050 fps. very consistently. So I'm now trying decide which way to go with the XTPs to get the velocity up around the 1200 fps mark. If I seat a little bit deeper, say 1.070" will it likely improve velocity? Or should I try increasing the powder charge one tenth a grain first? As you can tell I'm not very 9mm experienced with modern powders and bullets. I stopped loading for the 9mm back in the 1980s when G.Ds, XTPs, and Longshot were yet to have been developed.

 

[traveling1253]

Hodgdon shows 6.0 as max for 115gr so it should be safe to bump it up another tenth from where you are.

 

[CZ57]

One tenth of a grain isn't going to get you 150 FPS. If it were me, I would lengthen the XTP load to 1.125" also and then increase the charge-weight .1 grains until you get to 1200 FPS. Yes, lengthening the case will reduce pressure and your current load of 5.9 will most likely drop in velocity slightly. It will also give you increased combustion area so that a higher charge-weight will gain velocity at lower pressure than using 1.095". I don't know what the pressure rating of the load is but with Longshot you should be able to get 1200 FPS without +P pressure. Keep in mind that the bearing surface of the XTP is greater than that of the Gold Dot. Different jacket material as well. Vihta Vouri uses a OCL of 1.142"/29mm with the 115 gr. XTP and Longshot is used by the comp. boys that make major power factor using the Montana Gold bullet and Longshot.

 

[gamestalker]

Wow, thanks for the advice. The estimated pressure for 6.0 grains of Longshot with the 115 gr. is over 30,000 so I've still got a little room to work. All of the brass and primers from yesterday's test firing looked excellent and even appeared to be quite low. Based on tha,t I'm going to go with your suggestions and see how we do. I'll keep you informed and may ask for some more suggestions depending on the results. But I would bet you've got me going in the right direction here.
Thanks again!

 

[CZ57]

Be sure to look for signs of excessive pressure along the way. I don't expect any since your load is now at 30,000. Is that in PSI or in CUP? The SAAMI limit for 9mm is 33,000 CUP/35,000 PSI so you have some wiggle room. Less if the pressure was in CUP. Also, you don't mention the pistol you're using and its barrel length.

 

[noylj]

Is the goal a 135+ power factor or just to reach 1200fps?
Watch for flattened primers.

 

[918v]

If you want magnum velocity out of your 9mm safely, then get some Power Pistol. Long Shot is for hotrodding the 40.