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Posted: 9/5/2011 8:53:00 AM EDT
First I hope everyone is having a great holiday, hopefully some of you got it off. I didn't, I have to go to work later 
Anyways, I just finished the last of my Rainier 9mm, so I'm going to start in on my lead I picked up. It's Missouri Bullet Co. .356 115gr 9mm RN. When I reference my Lymans 49th Ed. it says to start with 5.0gr of Unique for a 90gr lead bullet. Then for a 120gr bullet (no 115gr listed) it says start with 4.0gr of Unique. I am relatively new to this so maybe there's something I just don't know yet, but why would the heavier bullet have a lighter start charge weight? Also, what OAL should I use do you think? If the pictures of the bullets are actually accurate that they use above each bullet listed, the 90gr looks similar to the 115gr that I have and it shows a 1.045 OAL. Thanks as always for your help and information. It's greatly appreciated!! |
| You would be safe using the start load for the 120 grain bullet. A heavier bullet uses a lighter charge. If you look at your manual, I think you will find that is nearly always true. The exception is lead and jacketed. Jacket bullets can nearly always use a heavier charge than a lead bullet of comparable weight. |
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Another reason the charge is smaller with a heavier bullet is the heavier (probably longer) bullet takes up more of the case volume when seated to the same COAL as a lighter (probably shorter) bullet. Less case volume means higher pressure, so a lower powder charge is called for.
This does not apply if you ever compare lead vs 100% copper bullets. |
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Quoted:
First I hope everyone is having a great holiday, hopefully some of you got it off. I didn't, I have to go to work later
Anyways, I just finished the last of my Rainier 9mm, so I'm going to start in on my lead I picked up. It's Missouri Bullet Co. .356 115gr 9mm RN. When I reference my Lymans 49th Ed. it says to start with 5.0gr of Unique for a 90gr lead bullet. Then for a 120gr bullet (no 115gr listed) it says start with 4.0gr of Unique. I am relatively new to this so maybe there's something I just don't know yet, but why would the heavier bullet have a lighter start charge weight? Also, what OAL should I use do you think? If the pictures of the bullets are actually accurate that they use above each bullet listed, the 90gr looks similar to the 115gr that I have and it shows a 1.045 OAL. Thanks as always for your help and information. It's greatly appreciated!! In 9mm with a cast 115 gr RN, I have used the 4.0 gr Unique load. I use an OAL of 1.03. Light load that cycled perfect. I have also used 5.0 grs of Unique with a 122 gr cast FP. OAL of 1.065. Both of these loads shot fine through my CZ 85. I have settled on Clays for my cast bullet loads in 9mm, but Unique is not a bad choice. I also used Lyman 49 and Hornady 8 to compare lead bullet loads. |
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Ok I think I'm going to use the 4.0gr charge of Unique. I wasn't sure though on seating depth so I started at 1.07 and took the barrel out of my pistol and checked to see how a factory round set and then tried the dummy round I made and they sit nearly exactly the same.
So I should be good to go with that right? |
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Quoted:
Thanks dryflash I appreciate it! So is 115gr kind of an oddball size or something? Or just not as common/popular as the 90 and 120gr? 124 and 147 gr bullets are the most popular in 9mm. I just punch paper with mine and use 115 gr bullets when I can because they are cheaper than 124 gr. |
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