Got "caught" checking only one mag

[sinbad339]

Well, I learned something new today, and thought it would be worth sharing.

I recently purchased a new Beretta PX4 Compact in 40 S&W, a new caliber for me so I purchased dies and components. I set up my seating die by progressively seating deeper until the round passed the plunk test in the barrel, then set the bullet just a bit deeper. This came out to an OAL of 1.151". I then checked for fit in the magazine, and it seemed fine. I loaded a total of 30 rounds, 10 each at three different charges of Power Pistol. I put about five or six of these rounds into the magazine as a double check, and everything checked fine.

I went to the range today to check these loads, shooting five of the first load out of one magazine, and they shot fine. I started to load rounds of the second load, and with the second round, the first would jam in the magazine; there was no spring pressure to hold the top round. I'll admit I was confused for a minute, as I was sure everyuthing was the same length +/- a few thousandths. then I tried these same rounds in the other magazine; they fit fine. In the end, I discovered that one magazine is goodwith this OAL (it must have been the one I checked originally), but the other magazine was smaller, and they would get stuck. So, I'll be checking all the magazines I have for a gun for new load workups going forward.

 

[kcofohio]

SAAMI specs has the 40 S&W max OAL as 1.135". Some load data will list at 1.0xx", but I have never seen published data over the 1.135".

 

[leadchucker]

Hmmm. Not surprising. The maximum OAL for the 40 S&W round is 1.135".

 

[sinbad339]

Well... color me embarrassed. It is right there in the manual; 1.135". I'll seat the next batch to that length, check everything, and I suspect I'll be good to go.

And thanks kcofohio and leadchucker, for being "highroad" with your replies. This was a real oversight (to put it mildly) on my part.

 

[thump_rrr]

Don't forget that depending on the nose of the bullet you may still not pass the plunk test at max OAL.

 

[kcofohio]

Well... color me embarrassed. It is right there in the manual; 1.135". I'll seat the next batch to that length, check everything, and I suspect I'll be good to go.

And thanks kcofohio and leadchucker, for being "highroad" with your replies. This was a real oversight (to put it mildly) on my part.

Hey, it happens. And it was caught.

 

[Rule3]

Please let us know what bullet(weight and profile like Flat nose or HP) and powder charge you are using also.

 

[judgedelta]

If I might suggest; loading a round nose at 1.135 and a flat point at the same length is going to be a whole lot different... You might plunk the cartridge with a flat point and make sure that it will spin in the chamber.

 

[redbone]

What do you mean by "plunk"?

 

[sinbad339]

The bullet is an RMR RNFP 165gr. I loaded 10 each at 6.6, 7.0, and 7.4 gr of Power Pistol. As stated in the OP, I did plunk test to get to my length of 1.151", and checked them in one of two magazines.

FWIW, I use Power Pistol in my 9mm loads (5.3gr under a 115gr X-treme RN plated bullet). Those loads are "flashy" as is expected with Power Pistol, but the .40 loads were even more flashy. I'm hoping to find some BE-86 when I get close to using up almost 2 more pounds of the Power Pistol.

 

[Sport45]

What do you mean by "plunk"?

It refers to using the barrel to gauge the cartridges. If they "plunk" in they are not oversize for the chamber. If they stick they generally need to be seated deeper as the bullet could be hanging up on the rifling.

 

[redbone]

Sport45: thanks.

 

[Patocazador]

I set my seating die to give me an OAL of 1.133" in my .40 S&W. However, spot checking afterwards showed variations up to 1.137" with bullets from the same box. (Speer 165 GD)

 

[ny32182]

Normally it just depends on the max length your specific magazine can accept, at least with RN bullets... which seems to be the case with yours.

My manuals say 1.125 for most round nose bullets, but for my shiny new Witness Limited I've been loading them to an average of 1.139". Max length the magazine can accept is 1.145". I'll get variations out to 1.142" or so. No issues so far. They will still fit in the chamber at much longer length (bullet is a Precision Delta 180gr FMJ RN in this case).

 

[Robert101]

I think we all make a minor mistakes every once in a while. I know I have in the past and will likely in the future. That being said this is why I tend to check and recheck the numerical settings and values a few times. At least you didn't load up hundreds to then find and error. I too use the same methodology for evaluating ammo in my gun prior to establishing the die settings (loading.)