Ruger PC9 load

Nature Boy said:

RMR 124g FMJ ... 4.0g HP38, OAL 1.150

... they weren’t as accurate as my Berry’s plated 115g ... 5.0g HP38, OAL 1.130

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No wonder, you are at start charge for 124 gr load data while at max charge for 115 gr load data.

• 124 gr Berry's HBRN-TP W231/HP-38 COL 1.150" Start 3.9 gr (920 fps) 27,400 PSI - Max 4.4 gr (1,037 fps) 31,900 PSI
  
• 125 gr Sierra FMJ W231/HP-38 COL 1.090" Start 4.4 gr (1,009 fps) 24,600 CUP - Max 4.8 gr (1,088 fps) 28,800 CUP

You are using plated load data when you should be using jacketed load data for RMR jacketed bullet (Most jacketed/plated bullets vary by 1.0 gr and I interchange load data for 124 gr and 125 gr bullets) - http://www.hodgdonreloading.com/data/pistol

BTW, I use 124 gr FMJ/RN with 4.3 gr W231/HP-38 at 1.135" OAL for lighter target load.

Since you are using 1.150" OAL, you will need to bump up the powder charge more. If 4.3 gr of HP-38 shoots better at 1.150", try 1.135" and see if group size decreases.

Yes.

My typical load development uses longest working OAL for powder work up. But once accurate powder charge is identified (including lighter target load), I then incrementally decrease the OAL (usually by .005") to see if accuracy improves. For 9mm FMJ/RN bullets which have shorter bullet base (Especially 115 gr FMJ/RN), shorter OAL like 1.125"-1.135" tend to produce greater accuracy than longer 1.150"-1.160" OAL, particularly at lower/start charges.

And my guess is using RMR 124 gr FMJ, 4.3 gr of HP-38 will produce greater accuracy at 1.135" than 1.150".

We recently discussed virtues of using longer working OAL vs neck tension on this thread where I mentioned for 9mm, exception is shorter OAL improves neck tension (and possibly bullet setback) - https://www.thehighroad.org/index.php?threads/oal-impact-on-headspacing.859637/#post-11304448

BTW, are your finished rounds experiencing any bullet setback at 1.150" after chambered from the magazine?

Nature Boy said:

Unknown. Didn’t check

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When I got some inconsistent range test data that made me scratch my head, one of many things I checked was bullet setback.

Think about it. If you use mixed range brass, it's not the consistency of "finished OAL" that produces accuracy rather "chambered OAL" after any bullet setback.

This prompted me to do a myth busting thread on neck tension and bullet setback - https://www.thehighroad.org/index.p...neck-tension-and-bullet-setback.830072/page-4

Now, I prefer to conduct range testing with loads (OAL and brass, especially for 9mm) that won't produce bullet setback for greater consistency in testing.

I agree that bumping the load should help. I use 4.3 gr HP-38 under 124 gr plated bullets and that was my standard load with the COAL varying by nose shape (1.140 for RN). That said, I've recently changed most of my standard loading to 147 gr bullets and my Ruger PC really likes them as does my SR9 and my Shield 2.0. I like both Longshot and CFE Pistol (even better) for the heavier bullets.

What you should do is get a chrono and as many factory rounds as you can and see if someone else can do better.
I did a small amount of testing on mine on 3 diff 115gr factory rounds, and 2 were not accurate and 1 was very accurate. And the very accurate was the slowest of the 3. Go figure.

My go to load for a 124 grain bullet is 4.3 grains of W231/hp38. 3.9 grains is minimal...

I like HP38 (favorite for .45)but it never seemed to work as well for me in 9mm as some other powders.
Maybe try some Sport Pistol or WSF
I agree bumping up the charge should help.

Why don't you do a load work up to see what your gun likes instead of pulling numbers out of the air and see if they work.

Blue68f100 said:

Why don't you do a load work up to see what your gun likes

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That actually maybe a good suggestion for this reason.

I found blowback action of PCC don't always translate the accuracy generated from locked breech action of pistols.

When I was developing carbine loads for blowback action (which quickly lose chamber pressure as soon as bolt starts to move back from the chamber), I found faster burning powders did better and resulted in less soot on case.

And that may be the reason why faster burning Promo (Red Dot burn rate per Alliant) produced smaller 50 yard groups than slower burning powders (Around BE-86 burn rate) because case mouth/neck sealed with the chamber and pressure built quicker before the bolt moved back.

Here's comparison 50 yard Promo vs W231/HP-38 groups showing smaller Promo core group size



And here's 100 yard Promo group (HP-38 group was larger)

Nature Boy said:

4.3g HP38 and an OAL of 1.140 tightened it up

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Nice.

Nature Boy said:

When I bought this carbine I said I wasn’t going to chase the accuracy genie. It’s just a fun gun and minute of milk jug is good enough.

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Yes, pistol caliber carbines are sure fun for plinking.

If you are just looking for minute of milk jug at plinking distances, any decent pistol loads will do, like 115 gr FMJ/RN with 4.8 gr W231/HP-38 at 1.130" (I noticed you are using 5.0 gr) or 115 gr FMJ/RN with 4.0-4.2 gr Promo at 1.125" - my current general purpose range practice/training drill load.

LiveLife said:

Nice.


Yes, pistol caliber carbines are sure fun for plinking.

If you are just looking for minute of milk jug at plinking distances, any decent pistol loads will do, like 115 gr FMJ/RN with 4.8 gr W231/HP-38 at 1.130" (I noticed you are using 5.0 gr) or 115 gr FMJ/RN with 4.0-4.2 gr Promo at 1.125" - my current general purpose range practice/training drill load.

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They certainly are! I shoot more 9mm now than I ever have just due to my AR9. Thank god for progressive presses and inexpensive HiTek coated bullets.

@Nature Boy You could also try some 147s with 3-3.2gr of TiteGroup or something comparable in that burn rate for powder. My AR9 will pull about a 2" group at 50 yards with that load, and is still subsonic from a 10.5" barrel.

Nature Boy said:

I have 8lbs of HP38 that I’d prefer to use. I’m not much of a pistolero so that’s going to last a while, however, this Ruger ppsh, er PC9 might put a good dent in it

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I hear you. I have about 14# of TiteGroup on hand, which at 3.2gr of powder per 9mm load, will last me about a lifetime