9mm Load Help

I highly doubt you'll get a squib load with just going out a bit on the COL. Hodgdon's data has always been good when I've used it, and the starting loads cycled my 9mm even when I went out on the COL like you describe.

ImjinScout said:

Hi All,

Need a little help with some 9mm and load data, I have been loading .40S&W for awhile and this is my first attempt at 9mm.

The question I have is I will be loading Rainer's 115gr RN, with HS-6 powder, Hodgon's site list 6.4gr to 6.9gr for LRN with a min COL of 1.100, and 6.7 to 7.0 for Spr. GDHP with a COL of 1.125.

What I am not sure on is, I would like to load these longer say from 1.35 to 1.50 as the same as the factory COL that I shoot and works well in my 9mm's. Should I still stay at the suggested starting load of 6.4gr and work up from there? The last thing I want is to load to light with a longer COL and end up with a squib load. I realize that the longer COL will reduce pressure and velocity, but I'm not sure how much. Thanks in advance for any help

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Imjinscout - I sure you just dropped a number in your indicated COL as there is no way a 9mm round that is 1.35 to 1.50 will chamber or fit in your mag. I'm sure you meant 1.135 to 1.15".

Both of these dimensions will be fine, and I'd also advise you to use the Hodgdon data for the LRN for your Rainiers.

I haven't used HS-6 yet, but I've read about it. You might want to use magnum primers, or small rifle primers if you have those already. (SPM primers are hotter than SR primers. Both of course are hotter than SP's)

Bell a dummy case, dump in barrel to make sure it goes into full battery. Mike the mouth. That is max taper crimp dimension. Slit another case lengthwise, inset a bullet, push into chamber to seat bullet at the lands. This is max col. Drop a few thousandths from these numbers and write it down. 9mm is a tapered case, the chamber may or may not be tapered. Load below max col or whatever works for the mag. Load midrange, shoot, smile or adjust powder.

Did you use a Magnum primer like suggested above? If not I highly suggest you do so. You will get much better ammo when using HS-6 with a magnum primer.

Using Mag primers w/ HS6 cut my SD's in half. The only problem w/ SPM primers is they are often not available at my local shop (like never unless I ordered them). For me, it seems HS6 likes to be loaded pretty hot.

I've never used Rainer bullets, so I have no idea what they are. The 2 loads you referenced are very different, although the charge spreads are similar. Often, data for lead and radical HP designs like the GD and XTP willl have odd COAL and charge weights. When possible, I try to find data using bullets close to the design/profile as the ones I'll be using.

ArchAngel what is the reason that you suggest mag primers? The primers that I have on hand our Federal Match SPP,

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There are a few Ball powders which are hard to ignite. The most common are HS-6, HS-7 and W296/H110. When lit with a magnum primer you get better powder ignition, a more complete powder burn and better SD numbers. Accuracy seems to be better with magnum primers too. I know there are reloaders who will tell you they use nothing but standard primers with HS-6 and they are just fine. I have a feeling they haven't done side-by-side tests with standard and magnum primers like I have so while their ammo is probably fine like they say it could be better.

I hope that explains it somewhat.

After reading and posting in this thread I went back and looked through my 9mm load book and found 25 shot group of 124 gr GD’s, 6.8gr HS6, standard Win SP primer gave SD = 21. Same load using Mag Win SP primers gave SD = 12. Average velocity was a little higher with Mag primers, but well within the ES of the standard primer loads. I did not lean the pistol back between shots so these SD would be consistent with normal range shooting.

I’ve noticed the same reduction in SD’s with other powders. One that comes to mind is IMR 4756 in .45acp with 230gr FMJ. Loaded with CCI 300 LP primers SD’s were >10; loaded with Win LP primers, SD’s were 8. FYI: 4756 in .45 produces a very smooth, accurate load. It’s a good powder that very few people use anymore (IME, it burns cleaner than it looks like it would).

That load should fill the case enough that position would be irrelevant. IIRC, and I believe I do.

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You’re probably right, but I do know there is enough room left for 0.4 gr of additional HS6.

As long as you are at, or above published SAAMI OAL for a particular bullet, the rest is about finding the OAL that fits your magazine, and feeds well through your firearm. It's when you start seating deeper than than the published data that pressures begin to rise. And with AL cartridges pressures can rise quite quickly and unpredictably high.