929 Moon Clips .035 vs .040

[JDinAZ]

Howdy folks

Been reading a bit about various moon clips. Seems some of the 929 shooters prefer different thicknesses. Some run .035 and some run .040.

Have seen elsewhere that a few have to run .035 because the .040 creates an issue where the case head is held too tight against the blast shield. While some have to run the .040 to ensure a good primer strike every time.

I can see the primer strike thing due to light springs so the distance reduction of firing pin travel by a few thou could help. I can also see a potential difference in machining depth when the cylinder gets pocketed out to accept moon clips.

But is there any reason that .035 would not work for everyone, barring the light spring light strike thing.

ETA - which could be remedied with a extended firing pin or less main spring lightening to correct and light primer strikes

 

[Lou_the_welder]

I recently lost tension on a performance center installed power rib mainspring, and installed a cylinder and slide extended firing pin for my 929. To try and correct the light primer strikes. Only to have the extended firing pin jam itself on a primer and jam the cylinder shut until I got home to give it some light taps. (With the cylinder stop on the down position of course....)
So, that remedy will not always work.

I do use .035" (speedbeez?) Moonclips and haven't had the need to use anything else. The .035" work great on Winchester cases. But I would assume you would shorten the clearance you have on the recoil shield, using a thicker moonclip.

My 929 is 100% reliable with Winchester cases and Winchester primers. CCI primers will not fire reliably lately, but I have just replaced the mainspring. So, I may have fixed that issue. I sometimes load CCI's and getting anything softer right now is somewhat difficult.

:/

 

[Ignatz]

I'll give you my rundown on brass/moon clips from my wife and I shooting 929's weekly for years in USPSA matches.
We only shoot Federal, Blazer and Winchester 9mm cases.
The TK .040 moon clips hold the Federal and Blazer brass snug. but still rotate in the clip. Any of these Federal and Blazer cases that go in too tight, get set aside for a Ranch Product moon clip.
On my 929, I use the TK blue .035 moon clips with Winchester brass. Again, any Winchester brass that goes in too tight, gets put into a Ranch Products moon clip.
We use the different brass for consistency in loading the two different moon clips and most importantly, the fired moon clip leaves the 929 without a hangup. And standing at a shooting table leisurely firing a 929 and reloading is different from running with the 929 in odd positions.
We have three 929's. All have "about" 6.5 lb trigger pull actions. All have Apex firing pins and most importantly, only get fired with Federal small pistol primers. Year after year, all three 929's are 100% for not having a light hit primer, no matter if its a TK .040, .035 or a Ranch Product moon clip.
A 929 that fires a TK .040 moon clip and will not fire a TK .035 moon clip reliably....is a 929 problem. Assuming that the primer is fully seated in the case.... it goes back to the 929. There's more to doing an action job on a 929 than randomly changing springs.

 

[Pizza Bob]

I shoot a 929 for both ICORE and USPSA. I have been through the whole moon clip deal with my .38 Super and wasn't looking forward to it with my 929 when I acquired it.

Enter RIMZ moon clips. These are the EZ Moon Clips made of a reinforced polymer. So far they hold any brand of brass rigidly. They accomplish this by holding the cartridge in the clip not just by the extractor groove, but also by surrounding the case head. The clips look like a rebated S&W cylinder...

You can see the rebate in this picture.

I have never had a light strike nor have a had a round go flying when plucking a new clip off my 4-post moon clip holder on my belt.

Full disclosure - my 929 has been modified by Dave Olhasso and has an extended firing pin among many other modifications. It was set-up to run factory Federal ammo, but I have tried many other brands in the clip for test fitment and they all work equally well.

Before going through the frustration of trying to find a combo that works, save yourself some time and money and try the RIMZ clips first, you'll be glad you did.

Adios,

Pizza Bob

 

[JDinAZ]

Thanks for the info folks

Sounds like .035 is the perfect thickness based off the answers and looking at Saami specs for the rebate width under the rim of 9x19 and 9x23 both being .035 + .010

Seems like the cases vary in the rebate o.d. area .347 -.020 spec range even within cases produced by a single manufacturer. Probably just a difference betweens lot#s due to setting up the machines again for another run.



Does any kind of brass wear come into play when using the tight metal clips. I know the Rimz clips that were mentioned would not be able to create any brass wear due to them being reinforced polymer.



Ignatz - you mentioned some cases get set aside for use in Ranch Products clips. Is there a rough percentage of cases that don’t fit into the other clips you use.

 

[Ignatz]

If I had to guess a percentage, 5%. Because Winchester and Federal are so big, many head stamps are different and are probably made at different locations. Blazer brass (from what I'm told) is made by Federal and clips in the most consistent with the .040 TK moon clips.
You won't wear out brass from clipping in cases. If I clip one in and it doesn't spin freely, then its relegated to my Ranch Products moon clips.
Because of the "primer shortages", I recently put my 929 down for a rest and am shooting my 625 in the local USPSA matches. This way I'm using up Large pistol primers and letting my wife shoot the small primers. 6 shot major in a USPSA match is a fun break.

 

[AzShooter]

I had trouble loading the .040 moon clips. I stayed with .035 and Winchester brass. Never had a problem after two years and a lot of shooting.