Ream a chamber for 9maj

[newageroman]

Got ya, will curb expletives in future..
Was still hilarious sight.
My BEAST of a '78 bronco made it to the range too, for the first time hauling CZ's and all. It's currently in fastback mode (no top/tailgate or rear seat - just truk!). Washed him off in a couple of puddles on the way back. Too much fun!

[SoCal]

What did the 124's chrono at with 6.8 grs of Power pistol?

[George16]

My chrono results:

124 gr jhp Pd 9.72 gr AA7 @ 1.165-1.167” oal
- 1381
- 1378
- 1394
- 1380
- 1390
- 1380
- 1387
- 1387
- 1370
- 1356
- 1394 HI
- 1256 LO
- 1380 AVE
- 38 ES
- 10 SD
- 171.12 PF

115 Gr PD JHP with 10.43 Gr AA7 @ 1.165-1.167” OAL
- 1460
- 1452
- 1508
- 1460
- 1508 HI
- 1452 LO
- 1470 AVE
- 56 ES
- 25 SD
- 169.05 PF

ES and SD are high for the 115s so I’ll do another test tomorrow. I like the feel of the 124 though. The recoil is not as harsh compared to the 115s and the gun still shoot flat.

I’ll be using the 124 Gr JHP from PD with the AA7 with my Czechmate for open Major. Local Matches will start this Saturday with social distancing guidelines in place. Maximum number of shooters per squad will be 9 to abide by the less than 10 person group rule.

[Bossgobbler]

Now you will have to check and see if you are overpowering your comp. You will need to do another test.  This test will determine if you are using too much powder or too slow-burning powder. Set up a USPSA no-shoot target, hold the end of the comp 2"-3" from the target, and fire a shot. look at the hole, is the target torn from the muzzle blast? What you want is just a hole in the target and just a little powder burn. When you get your results we can work on the fix if you need one.

[Bossgobbler]

Two other thoughts.  #1. @ your OAL you have +/-0.005" clearance in your mags. At some point, you are going to get a FTF, when the rounds get stuck in the mag. Not if, when.

#2. @ 1.165" how much of the bullet is seated in the case?  About +/-0.150", Not much. At some point, you will have a bullet come out of the case in the mag. Hopefully, this does not happen in the middle of a stage run.

These are just some of the things that have happened in 20,000+ rounds through my Czechmate.

[Wobbly]

#1. @ your OAL you have +/-0.005" clearance in your mags. At some point, you are going to get a FTF, when the rounds get stuck in the mag. Not if, when.

This is true. The distance 0.005" is like 1.5 human hair diameters.  Hollow Point bullets may have sharp edges on the opening that can catch on the sheet metal edges of the mag. Because of all this, the longest I ever load is 1.160".

[George16]

Now you will have to check and see if you are overpowering your comp. You will need to do another test.  This test will determine if you are using too much powder or too slow-burning powder. Set up a USPSA no-shoot target, hold the end of the comp 2"-3" from the target, and fire a shot. look at the hole, is the target torn from the muzzle blast? What you want is just a hole in the target and just a little powder burn. When you get your results we can work on the fix if you need one.

Already did that. Thanks.

I didn’t have to reinvent the wheel with regards to the load. I’m also a member at the Enos forum and I got the loads from the 9mm/38 subforum. In fact, there’s a huge thread over there about the SWMP which is identical to AA7. There are shooters having problems with some lots of SWMP so I decided to use the AA7 instead.

As for the bullet coming out, I don’t see that happening with the 124’s. There’s more than .150” inside the case. With 115, it might happen but a lot of shooters don’t have problems loading certain bullets at 1.170”. So I think it depends mostly on the bullet you use. Besides, I tumble them immediately after reloading for about 5-10 minutes to get rid of the Dillon lube. No separated bullets after tumbling so I’m good to go.

With regards to the clearance in my mags, I measured my magazine’s lip width and its 1.2060”. So I have more than enough clearance for my ammo.

By the way, I’m not using the stock comp. It’s too heavy and makes the gun front heavy. I’m using a Durso aluminum comp weighing 1.5 oz compared to the 5.0 oz stock comp.

[Wobbly]

With regards to the clearance in my mags, I measured my magazine’s lip width and its 1.2060”. So I have more than enough clearance for my ammo. 

That would be true if the rounds stacked in the mag at 90° to the spring axis. But they don't. They're laid over at some slight angle, which kicks out the edge of the case rim, effectively making them longer. Just saying.

[George16]

With regards to the clearance in my mags, I measured my magazine’s lip width and its 1.2060”. So I have more than enough clearance for my ammo. 

That would be true if the rounds stacked in the mag at 90° to the spring axis. But they don't. They're laid over at some slight angle, which kicks out the edge of the case rim, effectively making them longer. Just saying.

With that in mind, the width of the mag also increases if measured at the same angle the rounds are stacked. Keep in mind that the follower has to be at the optimum angle and the magazine tube has to be able to stack the rounds almost on top of each other on the double stack to single stack transition (above the mag catch hole) or else you’ll have problems feeding. I have to squeeze my 26 round mag at this transition area to .735”, front feedlips to .375” and rear to .365” for proper feeding and prevent nosedives. This also enabled me to load 29 rounds using CZC spring and follower kit.

I have already shot over a thousand of these while practicing and so far no problems at all. I practice by setting up my targets to mimic a regular USPSA stage complete with reloading on the move since our bays are the same ones we shoot are matches at.

I’ll post a pic of a full mag after I get back home from the range. Thanks Wobbly.

[Bossgobbler]

" Durso aluminum comp " Been there done that.  At about 2,000 -3,000 rounds start looking for the start of cracks in the first chamber of the soft aluminum that he used for the comp.

[George16]

" Durso aluminum comp " Been there done that.  At about 2,000 -3,000 rounds start looking for the start of cracks in the first chamber of the soft aluminum that he used for the comp.

Hmm, that’s not good. I’ll definitely keep an eye on it. Thanks.

What comp are you using? I’m waiting for the review of the Sebo titanium comp before buying it. If the reviews are good, I’ll order one and install it on the other barrel.

[newageroman]

Didn't have a crhono, but here is alliants data sheet for power pistol:
https://www.alliantpowder.com/reloaders/powderlist.aspx?page=/reloaders/powderlist.aspx&type=1&powderid=8&cartridge=23
I used the speer GD as a guide and went lower to start and was using a longer COAL. Start low and work up...

By My calculations, 6.8 as suggested by Alliant only gets you ~143PF which is about halfway between Minor and MAJ.

26 round mag - holy crap that is awesome!I'm gonna save the mag tuning for later, but good to know.

[Bossgobbler]

 A guy on Enos posted a pic of the end of the comp blowing off. that is when I looked at mine. What do you know two small cracks. Went back to the factory comp. The Sebo titanium comp is out of stock already. I will get one if they make any more.

[newageroman]

OK, well, more to report I guess...
Went to the range today and tested 3 loads:
First was the highest load I shot last week 6.8, followed by 2 more groups 7.0 and 7.2 of Power Pistol.
They shot great, seems like they were noticeably more accurate than the blue bullets I had loaded previously.
I took the chorono, extra battery, and forgot the freaking tripod so that was a no go again....
I made a couple hundred of limited bullets using sport pistol while I was at it.

I did notice that the new batch using winchester primers did have a couple of soft strikes when the fed primers had none. Is to be expected, but here is the question now...
I see there is a tradeoff for using Federal primers in major. In minor you could get away with using them and the lightest springs and still get consistent strikes, but if we are talking 9maj loading do most guys use fed primers or S&B type (harder primers).

I'm not going to up any more loads until I get chrono results. comp should be here next week!

[Bossgobbler]

I have used Fed, Win, CCI, CCI(SRP), and S&B primers. In my Czechmate I don't have light strikes. I use the Stock hammer spring. I tried some lighter hammer springs one time, never again! My Czechmate like the stock spring and with a 1lb 14oz trigger pull no need to change. I am now using S&B primers with N350, 3N38 and Major pistol powders are what I have been using for the last 10,000 rounds.

Power pistol is on the very fast side for 9mm major loads. Close to N330 or N340