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Question for the reloading gurus (sorry, long post with lots of numbers, but I want to show the results):

I finally got to chrony the rounds I cooked up for my new (used) 9mm Open pistol. It's a customized STI Matchmaster. It has the stock 4.15" no-hole barrel and T2 comp. For this reason, I know it's a bit harder to make Major PF with the shorter barrel.

I loaded a progressive series using the following: 124gr Precision Delta JHP, Win SPP, Speer Nickel +P Brass, Loaded to COAL of 1.160. Powder is Winchester Auto Comp - I loaded rounds for each powder load: 7.0gr, 7.1gr, 7.2gr, 7.3gr, 7.4gr. Press: Hornady LNL AP (Go red!). I checked the weight of each powder load even though it's a progressive press to verify accurate powder weights.

Here are my velocity results (note - 1331 fps needed to make major with the 124gr bullets; actually 1330 since they are 124.3+gr bullets on the scale). I will skip 7.0gr because too many fell below 1330fps.

Location: Albuquerque, NM (Elevation ~5300 ft, 92 deg, sunny, clear). Chrony: ProChrono Digital ~10ft from barrel

7.1gr

-------

1375

1364

1352

1332

1394

1355

1332

1317 (only 1 missed major pf)

1340

1349

Avg: 1351fps (167.5 PF)

7.2gr

------

String 1 String 2

1350 1359

1346 1364

1364 1336

1335 1344

1346 1341

1339 1352

1349 1348

1325** 1345

1359 1390

1337 1337

(only 1 missed major PF)

Avg: 1345 Avg: 1351

PF 166.8 PF: 167.6

7.3gr

-------

String 1 String 2

1342 1353

1337 1350

1348 1366

1342 1357

1432(!) 1352

1330 1349

1361 1349

1345 1332

1330 1363

1349 1352

Avg:1343 Avg:1352

PF:166.5 PF:167.7

I think the 1432 was a misreading (or there must have been something about that round that I didn't catch, so it is left out of calculation)

7.4gr

------

1345

1356

1355

1364

1325**

1346

1317**

1344

1344

1360

Avg:1346

PF:166.9

(Interesting, 2 rounds didn't make PF even with a tad more powder. I wonder if I hit the plateau)

In none of these tests did the brass or primers show signs of increased case pressure. So based off of this, I am planning on loading 7.3gr of WAC. Now, on a couple of these rounds, I JUST made PF with a 1330fps. If I'd like to get a bit more cushion, what are the suggestions? I know because it is a shorter barrel that these same rounds would easily make major PF in a 5" barrel, but this thing transitions so nicely that I really want to shoot it!

Options (and I don't know if some of these would actually make any difference)

More powder?

Change the COAL?

Add a bit of crimp? (I am not adding any right now)

Something else I haven't thought of?

or

Just leave it! (the average of 3 should be fine, I am being too picky about this, etc.)

Thanks!

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Well, it is a shorty in 9. That's a tough combo. You need to get up to over 170 for a cushion as well as to work the comp. 166 isn't going to cut it. I have maxed out with WAC before. Velocity stopped climbing and groups blew out. But I must say I don't think it should have maxed out on you at only 166ish. Maybe you could try sticking a no shoot target on top of the screens of your chrono and retest? I always do just that with my PCD.

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Thanks for the suggestions. We put the plastic cover over the chrony and I was checking other rounds in this gun and my .40's and they all seemed accurate, so I think the numbers were fine. I could try to push the powder a bit more, but I am hesitant as it seems to have started to plateau. I will shorten the OAL a bit (I know I have a bit of room between the top of the powder and the bottom of the round).

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I can't locate HS6 and have a good amount of WAC. Anyone load over 7.5gr of WAC? All the recipes I can find max out at 7.5gr

I was 7.4 with a 121 bullet and got 174 PF. But that was with a full size gun. I run 7.8 with 115's but do not try that with a 124 in my opinion.

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I went with Blue Bullets (coated) 125gr

Made 170 Pf with 6.8 grs. WAC, Fed SRP, 1.170 COL

May be an option if you have a lot of WAC

Seems to be Ok with the coating

Hit a1000 rounds with it over the week end at a 208 round match.

Has some stuff in the comp that comes out with a rounded screw driver

Key thing for me is I've got the WAC as you do and the bullets are available

I've also shot Bayou's and SnS hytek coated out of my 38SC with good results

Got about 4000 rounds total of hyteck and blue bullet coated through the 2 guns with no problems to date

Shot in conditions from about 40degress to 85

Coated seem to need less powder to make PF

Just a thought for you to meditate on, not claiming its the answer you need

Edited by jcc7x7
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What OAL's are all of you running? The seller of the gun told me he used 1.130 with 7.4gr WAC and 115gr bullets. I wanted to give it a tad more hence I loaded to 1.160 with the 124gr. Maybe I'll make a progressive series where I load shorter to 1.155, then 1.150, and maybe 1.145. I check the brass after each string so I should be able to ID any signs of excessive case pressure.

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What OAL's are all of you running? The seller of the gun told me he used 1.130 with 7.4gr WAC and 115gr bullets. I wanted to give it a tad more hence I loaded to 1.160 with the 124gr. Maybe I'll make a progressive series where I load shorter to 1.155, then 1.150, and maybe 1.145. I check the brass after each string so I should be able to ID any signs of excessive case pressure.

While your doing all of that put a target down range so you can kill two birds with one stone. Put an aiming point on it and take dead aim every shot through the chrono. You will find the adjustments you make to the loads will affect accuracy, group size, etc.

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I have a Freedom Gunworks 9mm Open Gun with 5 " KKM barrel, 3 poppel holes, and Cheely Comp. My load is 7.1 grs. AutoComp, Precision Delta 124gr JHP, OAL 1.165 and making 173 PF.

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You seem to have inconsistent chrono data ... :surprise:

I would do a few things a little differently, and see what results you get:

1. Set your powder charge for 7.3 gr and leave it = let the powder flow thru your reloader - don't measure each charge

2. get a larger sample size thru the chrono - try 25 rounds

3. If I can get 25 rounds thru the chrono so that they ALL make PF, I'm happy

BTW, are you planning on shooting major competitions? If you are, then I'd also try to get that PF

up a little bit above 167, if you can. If NOT, I'd leave it at 7.3 gr and work on reliability and accuracy. :cheers:

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Thx for the suggestion. I plan to eventually shoot b level 2 matches with it. I set my powder drop to 7.3gr and have loaded about 20 rounds each at OAL from 1.140 to 1.150 to see if there is any difference too.

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I'll throw in a few things I've experienced with this same type of load.

I had two guns, one with a 24 in 1 twist barrel, and one with a 32 in 1 twist. It's been a while so forgive me if I have something wrong in the barrel specs and also can't remember which was which.

Anyways, both are shorties with no holes. I was shooting 7.3 of WAC in one of them and when I got the other one it was super hot. With the same load I was at 185pf. All this was with 124gr and I ran them short... maybe 1.15 or so. (long story as to why I got Round Noses running that short.. don't do it)

So, I tell that story as maybe you'll find the rifle twist might have something to do with you loading up that combo but getting short on PF.

I've since re-barreled the "slow gun" and was shooting 7.3grains of WAC on the 124 rounds for a long time in both guns and making 170pf no sweat. I believe I still ran them very short and while I think I may have been compressed, I never blew anything up. So maybe you'll be fine getting into the 7.6 territory. Load a few up, and then unload them and see if the powder falls out. It won't if you compressed it even a little bit. (I've done that too)

And one more thing. I've never personally seen an appreciable change from .1 gr change in powder. I always load in .2 increments and find that .2 gr changes nets me about 50fps (averaged out) with all other things unchanged.

I don't know if I helped or just spewed, but there you go.

oh, now I shoot 7.6gr WAC OR 8.3gr HS-6 with 115gr JHP's and run 170PF consistently in both guns with 1.125 OAL.

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