Do You Plunk Test???

[Carl N. Brown]

My limited semi-auto pistol cartridge reloading is for one Curio & Relic pistol I shoot in local club matches that have time limits*. I "plunk" test every round. If it doesn't fall in the chamber and fall out, the head gets marked with a magic marker and set aside as a fouler.

Factory ammo for carry in defensive guns gets plunked, too. I recently found a new factory round in 9mm Luger with an untrimmed neck that would not let the slide close to locked position. I suspect unfired semi-auto pistol cartridges left on the ground or in the disposal box at the range probably failed the plunk test.

Granted I am a low volume handloader compared others, but plunk testing ammo to be sure it will chamber seems logical.

__________
* black powder cartridge (10 rounds in 10 minutes slow fire and then rapid fire two stages of 5 round in 2 minutes) and vintage military (two 10 round in 10 minutes).
A cartridge that fails to chamber costs time and maybe points.

 

[Jim Watson]

Not every round, but to set up the press absolutely. SAAMI spec is exactly that, its a spec. That doesnt mean your chamber is SAAMI like a case gauge. Ive seen long, short, tight, loose chambers, so I always setup on the chamber.

I recently had a friend that stopped by, said he couldnt get his CZ to chamber his reloads and that he checked him on his gauge. Guess what? The chamber on the CZ is shorter than SAAMI, therefor his reloads wouldnt chamber because he setup using a SAAMI case gauge.

The usual fault in a 9mm seems to be the throat. The headspace dimension is usually ok but a lot of guns have short leades and a bullet of other than hardball profile will hit the lands. CZs are well known for short throats.

Chamber diameter is a common flaw in .45s. I had one that was brilliantly accurate but not a smooth feeder. FLG fed in a SAAMI reamer, an amazing amount of steel shavings came out, and the gun was reliable. Still accurate but not with the same best load.

If the advertising flack says "match grade barrel" and especially "minimum match chamber" you should be ready to apply special treatment like an undersize sizing die, a short OAL, or a proper reamer.

 

[Kaldor]

The usual fault in a 9mm seems to be the throat. The headspace dimension is usually ok but a lot of guns have short leades and a bullet of other than hardball profile will hit the lands. CZs are well known for short throats.

Chamber diameter is a common flaw in .45s. I had one that was brilliantly accurate but not a smooth feeder. FLG fed in a SAAMI reamer, an amazing amount of steel shavings came out, and the gun was reliable. Still accurate but not with the same best load.

If the advertising flack says "match grade barrel" and especially "minimum match chamber" you should be ready to apply special treatment like an undersize sizing die, a short OAL, or a proper reamer.

Thats about right! We bumped a few back 10 thou and that was the magic number, they dropped right in. Good thing he only had 20 or so loaded. Also gave him a few of my reloads to test out to verify as he cloned my load I have run for years.

 

[Louca]

If you have one that plunks but won’t case gauge, the base and rim are the most likely culprits.

I can confirm that; it's what I am seeing when the cartridge fails with the gauge check. I mostly see base problems. If it is a rim problem, I just toss them since most of the rims that fail are pretty beat up (hammered by the slide), after being fired many, many times.

 

[GeoDudeFlorida]

* black powder cartridge (10 rounds in 10 minutes slow fire and then rapid fire two stages of 5 round in 2 minutes) and vintage military (two 10 round in 10 minutes).
A cartridge that fails to chamber costs time and maybe points.

---
Yup. I know that feeling. My Maltby Enfield No. 4 Mk.1* would chamber anything - except a Lee Loader neck-sized reload, even from it's own chamber. I tried neck-sizing for the Maltby once and learned a hard lesson (in how to use a bullet puller). My restocked '43 Faz' was the same way but worse: full-length sized only. Even some boxed factory ammo had problems in that rifle. It was a five-groove some Enfield lore claimed were cut-down Bren machine gun barrels that didn't make inspection. The British waste nothing. I don't know about all that but it had a tight chamber and my best targets were from some nice hang-fire '55 ROF Radway Green. Great ammo when it went "bang".

The Fazakerley wore a TZ sight and was for modified rifle matches only. It wouldn't pass for as-issued. I used leather strop under the tip of the forearm to put just a wee bit of pressure up on the end of the barrel. Perfectly legal in British service rifle competitions - and it tightened the groups up by more than half - but the general consensus at my club of that time was, if it didn't leave the factory like that, then it was modified - so I mounted the TZ 44 and had at it in modified. That was years (decades?) ago when I hooked up with some former UK armorers online at Mark Bitting's old Enfield site (RIP Mark, you are missed, brother). I didn't compete for long - I was working 70 hour weeks - and never won more than a big grin in competition - and a lot of good conversation - the only prizes really worth having, IMO.

 

[Carl N. Brown]

I have an old sporterized .303 No 1 Mk III* (stamped BSA 1917) that works fine with reloads neck sized only with the Lee Loader ("mallets for all") method.
Sometimes guns are cranky individualists.

 

[Erief0g]

Only in the beginning to be sure the OAL I am working with will plunk ok.

That's it. Take a specific bullet from XYZ. Work out my max oal for my shortest lead barrel. Reduce oal to save margin to allow for some oal variance from progressive press. Done. That bullet doesn't need a plunk test again.

Now if you bring up case guage.. yes, always

 

[Spare Parts]

I now check every cartridge I reload or initial load into virgin brass.
Why you may wonder?
During a shooting session of .223 reloads in an AR15, I experienced a jam when chambering a reloaded round.

#MeToo. The 5.56 case jammed so hard into the chamber that two gunsmiths couldn't remove it. After abandoning all hope of salvaging the barrel, I hit it with a steel rod from the muzzle. Nothing. The projectile went into the case, and the case was still work-welded to the chamber. I hit it - HARD. Goggles, eye protection, gloves - full safety. No go.

Finally, as a service to posterity, I drilled alongside the primer, removed all powder, and sent the barrel to the landfill.

Since that event, I put all rounds in a case gauge. For pistol, I use the EGWguns gauge. For rifle, the Lyman. No. Jams. Ever.