So I want a hundo case gauge, but...

[olstyn]

...I recently found out that it's no good to me; rounds that failed to plunk in my guns' barrels passed in a friend's hundo. Does anybody know of a vaguely reasonable option, price-wise, for a custom gauge based on my chamber? Does such a thing even exist at any price, or am I doomed to gauge rounds one at a time as long as I keep shooting the same guns?

[jeep45238]

It'd probably be much easier in the end to ream the chamber of your barrel. Pretty common to perform on CZ's.

[busdriver]

No case gauge checks for OAL interference with the rifling leade, which is what your problem is. Just use the barrel when you're setting the seating depth.

[GuanoLoco]

What kind of gun? What bullet manufacturer/weight/profile? What OAL?

Are you familiar with the 'plunk test'?

[Odin Bravo One]

What is a "Hundo" case gauge?

[MPG]

What is a "Hundo" case gauge?

This - http://benstoegerproshop.com/case-gauges/

[LittleLebowski]

This - http://benstoegerproshop.com/case-gauges/

Sean, it allows you to case gauge a hundred rounds at a time and I think there's a way to load the rounds from it right into an ammo box.

[Hambo]

What are you doing that causes some percentage of rounds to not chamber?

[olstyn]

What kind of gun? What bullet manufacturer/weight/profile? What OAL?

Are you familiar with the 'plunk test'?

Walther P99 and P99c (the P99 has a *slightly* tighter chamber than the P99c, so I use its barrel when checking rounds), Montana Gold JHP and CMJ, 124 grain, 1.075" for the JHPs, 1.12 for the CMJs. Yes, I'm familiar with the plunk test - as I mentioned, some rounds that won't plunk in my barrels will pass in the hundo.

Edit: I'm planning a switch to coated bullets sometime in the next few months for cost reasons anyway, so maybe that'll change things, but I'm not counting on it.

[olstyn]

Sean, it allows you to case gauge a hundred rounds at a time and I think there's a way to load the rounds from it right into an ammo box.

Yup, it'd be more convenient/much faster to be able to use a hundo vs plunking each round in my barrel individually.

[Luke]

Have someone mill the bottom to make it shorter

[olstyn]

What are you doing that causes some percentage of rounds to not chamber?

Unsure, but it's usually 2% or less of rounds that fail to drop in and out freely. Any that fail to do that never get loaded into a magazine.

[olstyn]

Have someone mill the bottom to make it shorter

Mill the bottom of what, and how would that help?

[busdriver]

Yup, it'd be more convenient/much faster to be able to use a hundo vs plunking each round in my barrel individually.


Have someone mill the bottom to make it shorter

No case gauge will solve the OP's problem, all they check is the dimensions of the post loaded case and if the bullet is set straight. None of them account for rifling leade.

Bullets all have slightly different ogive shapes, and the leade is a different length on just about every chamber. So depending on where the rifling starts and the specific ogive shape, you'll get a different max COAL for a given bullet when you move it between barrels. You will also get some variation on OAL as you load. My guess is the OAL you're loading to is very close to the max that will fit in your barrel. What you need to do is determine max OAL that will plunk in your barrel, then take another .010 or so off that number to account for variation in loading, then use that number as your max.

Once you've done that, the leade is removed as a variable to worry about and you can use the hundo.

If you're loading for multiple guns, just load to the shortest OAL among your various guns.

Edit add: You need to do this for every bullet you intend to load, they are all different.

[olstyn]

Bullets all have slightly different ogive shapes, and the leade is a different length on just about every chamber. So depending on where the rifling starts and the specific ogive shape, you'll get a different max COAL for a given bullet when you move it between barrels. You will also get some variation on OAL as you load. My guess is the OAL you're loading to is very close to the max that will fit in your barrel. What you need to do is determine max OAL that will plunk in your barrel, then take another .010 or so off that number to account for variation in loading, then use that number as your max.

Yeah, been there, done that. Max OAL with the MG CMJ rounds is ~1.13" and I'm loading them to 1.12" but still some that fail in the barrel at 1.12" pass in the hundo.

[Hambo]

Unsure, but it's usually 2% or less of rounds that fail to drop in and out freely. Any that fail to do that never get loaded into a magazine.

When you gauge, them, correct? Do they chamber in your pistol or do you discard based on the gauge?

Assuming they don't, I'd want to know why because it would bug the crap out of me. Are you using cast bullets? Coated? Mixed brass? The only time I've had this problem is with 150gr SWC in 9mm. My OAL is as long as will chamber reliably. Finding that point given slight bullet/coating differences took a little work.

[busdriver]

Yeah, been there, done that. Max OAL with the MG CMJ rounds is ~1.13" and I'm loading them to 1.12" but still some that fail in the barrel at 1.12" pass in the hundo.

First, I'm assuming you've measured the failed rounds to verify the OAL to eliminate that variable. Like wise, try painting the bullet ogive with sharpie to see if it's rubbing. I doubt MG changed things on you, but making sure that isn't the problem means you can move on to other troubleshooting. If this is old hat to you, I apologize for the "no shit Sherlock" advice.

Now for the goofy: This may sound stupid but make sure your chamber is clean, sometimes gunk builds up in the corner at the end of the chamber where the front edge of the case seats. If a piece of brass is on the long end of acceptable, that gunk could prevent it from "plunking," although it would probably chamber fine. One way to clean that gunk out is to cut notches in end of a piece of brass to make an annular scraper. Or just use a pick of some sort to scrap it out.

The only other thing I can think of is your chamber is right at SAAMI min spec (or smaller) while the gauge is just a bit bigger. According to the manufacturor the shockbottle gauges are cut to the small side of SAAMI spec but not right at precisely min, so the chamber in your problem gun could be tighter and still be within spec. If that is the case, by far the easiest option would be to ream the chamber.

[olstyn]

When you gauge, them, correct? Do they chamber in your pistol or do you discard based on the gauge?

I'm using the gun's barrel as a gauge. I'm sure that some of the rounds that are right on the line in terms of dropping into the chamber, but not spinning freely/dropping back out would work, but I'd rather be safe, so they get pulled.


Assuming they don't, I'd want to know why because it would bug the crap out of me. Are you using cast bullets? Coated?

As stated earlier in the thread, Montana Gold jacketed (most recently, 124 grain CMJ), but probably switching to some sort of coated when I run out of the MGs.


Mixed brass?

Yes.

[GuanoLoco]

I've found that I have to seat 124's (like ACME 124 RN) down to 1.06" in my Stock 2 barrels, where I can load at 1.095 for Baypou 135's. Lighter bullets are shorter, but also are being loaded deeper and may cause more issues. The ACME 124 flat points (conical nose) don't run any different. I plan to get by barrels reamed (probably just throated) so I can load longer.

I'd suggest trying a different weights/profiles, like the Bayou round noses, and seeing if you could load longer.

BTW last night I did a large reloading session and I think I convinced myself that I am getting far fewer CG failures at a (Dillon) taper crimp of 0.378 vs. 0.379 (measuring tightest across multiple rounds) at the case mouth.

[olstyn]

First, I'm assuming you've measured the failed rounds to verify the OAL to eliminate that variable. Like wise, try painting the bullet ogive with sharpie to see if it's rubbing. I doubt MG changed things on you, but making sure that isn't the problem means you can move on to other troubleshooting. If this is old hat to you, I apologize for the "no shit Sherlock" advice.

It is old hat, but you can't know that, and it doesn't change the validity of the advice; if nothing else, a newbie reloader might read this thread and learn from it. To be honest, I don't recall whether I measured the most recent crop of failures, so since I haven't gotten around to pulling the bullets, I'll be sure to do that check sometime soon just to be sure. :)


Now for the goofy: This may sound stupid but make sure your chamber is clean, sometimes gunk builds up in the corner at the end of the chamber where the front edge of the case seats. If a piece of brass is on the long end of acceptable, that gunk could prevent it from "plunking," although it would probably chamber fine. One way to clean that gunk out is to cut notches in end of a piece of brass to make an annular scraper. Or just use a pick of some sort to scrap it out.

That's a reasonable idea. It *has* been a long time since I cleaned that gun. OTOH, I know it's a super tight/short chamber regardless of how clean it is, so it *probably* won't make a difference, but it can't hurt to be sure.


The only other thing I can think of is your chamber is right at SAAMI min spec (or smaller) while the gauge is just a bit bigger. According to the manufacturor the shockbottle gauges are cut to the small side of SAAMI spec but not right at precisely min, so the chamber in your problem gun could be tighter and still be within spec. If that is the case, by far the easiest option would be to ream the chamber.

Much like CZ, Walther chambers are typically on the tight end of the spectrum, so this is IMO the most likely scenario, unfortunately, which is why I started this thread in the first place.

[busdriver]

Much like CZ, Walther chambers are typically on the tight end of the spectrum, so this is IMO the most likely scenario, unfortunately, which is why I started this thread in the first place.

Only thing to add then: A reamer is ~$75, a gunsmith would probably charge you about the same. Reaming it yourself is fairly easy unless the barrel has been hardened. I tried to ream the throat on a nitrided barrel once and destroyed the reamer, while doing nothing to the barrel.

[GuanoLoco]

There is a strong probability that my Tanfo chambers are hard chromed; I am investigating getting a carbide throater. A regular reamer lightly applied appeared to get no traction at all, we backed offbefore damaging the reamer.

[Super77]

Some Walthers have a step in the distal end of the chamber where the ID is reduced a little. I wonder if that could occaisionally catch the edge of a case causing it to fail the plunk test when the force of the slide would have been enough to send the round hone. Not sure if the P99 series or CZs have the same thing but VP9s do. Just food for thought.

[busdriver]

Totally missed the stepped chamber possibility. Good catch.

[olstyn]

My P99 does have the stepped chamber, but I'm fairly certain that's not the issue on the rounds failing the plunk test; they're not sticking that far out of the chamber. (Based on the ring the step leaves around fired cases, it's 3/16 or maybe even 1/4 inch from the end of the chamber, which would be VERY noticeable when plunking completed rounds.) Good thought, though!