Plunk test varies

[midatlantic]

I usually load 124 gn bullets for 9 mm But have some 147 blue bullets that I am loading for a CZ shadow. The case neck is .376 or .377 any tighter and the neck breaks the polymer coating.

 

The cartridges pass the plunk test in the barrel, but have to be pressed to fit the case gauge. I have not had a chance to go shoot them yet, but was looking for some thoughts. I’ve only loaded 30 or 40.  Should I pay attention to the case gauge? 

[ddc]

Try blackening several cases with black magic marker.

Insert in case gauge and rotate.

See where the interference is.

 

Your gauge may not have enough throat/leade for 147s at your chosen OAL.

Try loading a couple a bit shorter to see what happens.

 

Make sure your gauge is clean.

 

In the end the plunk test is the final decision maker although one of the 100 round checkers is very handy for batch checking a lot at time.

 

Edit to add:  Which gauge are you using? Can you beg/borrow/steal a different gauge?

 

Also: What OAL are you loading at?

Edited January 2, 2022 by ddc

[HOGRIDER]

@midatlantic:

 

While @ddchas provided excellent information, I'm too curious as to which bullet profile your loading?  And what max OAL are you plunking to?

 

https://czfirearms.us/index.php?topic=34225.msg189131#msg189131

 

For my S2 Orange, 1.120" was my max OAL for the Blue 147g FP; testing the new 147 RN profile required shorter, so I have stayed with the FPs.

 

[ddc]

If you should decide that your gauge checker is flagging perfectly usable rounds it is still possible that it can be a helpful tool.

 

You can develop a sense for how proud a round can be in your gauge and yet still be perfectly usable in your particular gun.

 

I put those in a practice bin but I can't recall the last time I put anything there that was a problem during practice.

Match loads take a little more consideration...

[verla]

Make sure your case gauge is clean- clean it with a brass bore brush that is just oversize for the hole. It might surprise you !

 

Also, make sure that the case and bullet are clean.

Edited January 3, 2022 by verla
additional thoughts

[Sinister4]

first off do as stated above and find out where on the gauge its binding, its usually the base/lower areas not the bullet itself

[midatlantic]

Thanks for all the advice. Finally got to the range today and 40 rounds went down to the tube without a hitch. I have a EGW chamber checker and I will go ahead and clean it as suggested above. If the result is any different afterwards as I load the next couple of hundred rounds will advise all

[Tunachaser]

Also check the adjustment of your sizing die.  I switched to a Lee u-die, there are numerous post on the why's of the U-die.

[Furrly]

I Would not be to worried if the rounds pass the plunk test and shot fine out of the pistol, certian case gauges have tighter tolerances then a barrel..

[Balakay]

I roll size and use a U-die for 9 mm major..  Everything fits perfectly in my Hundo gauge. In one of my open guns, anything that passes the gauge will plunk.  Unfortunately, I recently learned that that is not the case with my primary match gun. Same barrel type, same gunsmith.  Match ammo gets plunked individually in this barrel.  Rejects go into the practice bucket. 

 

Long story short, the gauge is only a guide.  If it doesn't plunk in YOUR barrel, problems arise 

[CenTX]

For an education on this read the ShockBottle 100 round case gauge FAQs. Very informative on case gauges and various issues.

 

https://www.shockbottle.com/faqs-1

 

[CZ85Combat]

On 1/4/2022 at 7:48 PM, midatlantic said:

 I have a EGW chamber checker .

There is your problem. The EGR guage will give false failures. It is ease to check, take an unload bullet and see if it will pass all the way through the EGW gauge. If the bullet will not pass through,  the gauge is not checking the brass it is checking OAL.

[Johnny_Chimpo]

On 1/2/2022 at 12:33 PM, midatlantic said:

The cartridges pass the plunk test in the barrel, but have to be pressed to fit the case gauge

 

If they fit the barrel, the gauge is irrelevant.  That should be obvious.