Plunk test + XDm issues

[DanK3Pos]

If you have some ammo that passes the plunk test, measure the case mouth diameter and compare it to the ammo that doesn’t pass the plunk test.
FWIW, I have to load Zero 230gr FMJ to less than1.230” COL or less for a HK45 while some other bullets have room to spare at 1.260”. The Zeros have a “fat” ogive and I’ve heard that some Springfields have short leades.

If you load longer, what is the problem? Do they not drop in and out, or do they just not spin?

 

[DanK3Pos]

An easy way to determine the issue is to take a magic marker (in a nice color) and color the entire cartridge from top to bottom. Then do a plunk test, and a drop out and look for any missing coloring. If there is, put it on the side and color another one, plunk that one and then rotate and drop it out and look for missing color. Now you can compare the two and see where there is rubbing. You have to remember, you not just looking at the bullet, but at seating and at the cartridge and how the bullet affects the cartridge. Good luck and let us know what you find. And while your are at it, some 9mm info might also help us trouble shoot. I by the way also shoot a 9mm XDM with no problems.

I should have thought of that. I've done that when gunsmithing.

 

[DanK3Pos]

You may need to apply a little more taper crimp. I've had to do this on several guns with tight chambers.

I will have to take a look at that. I set crimp based on the case gauge and they fell out of the chamber with that crimp, too. I don't remember what the case mouth measured after crimp, though.

 

[rfwobbly]

I set crimp based on the case gauge and they fell out of the chamber with that crimp, too. I don't remember what the case mouth measured after crimp, though.

Friend, you're not supposed to remember it. You're supposed to write it down in your notebook.

 

[jmorris]

When did "spin" become part of a plunk test??. If they drop in and fall out then go shoot them

The only time I would spin would be using a case gauge, if they don’t drop in/out of them, often putting the case in backwards and giving it a twist would iron out the bur on the rim, will make it gauge OK. The plunk test still needs to be done when setting up the dies to make sure the bullet will clear the lead but after that I prefer the casegauge as barrels don’t check the rim like a case gauge will.



I used barrels until I had a malfunction at a match, that cost me a win. I had plunked every round so I had thought they were good to go. A fellow competitor grabbed his case gauge from his range bag and showed me that my round would not case gauge. My barrel had let the defect pass but the breechface did not. That was the day I ordered my first case gauge, I had been happily reloading for more than two decades without them before then.

 

[Trent]

I used barrels until I had a malfunction at a match, that cost me a win. I had plunked every round so I had thought they were good to go. A fellow competitor grabbed his case gauge from his range bag and showed me that my round would not case gauge. My barrel had let the defect pass but the breechface did not. That was the day I ordered my first case gauge, I had been happily reloading for more than two decades without them before then.

I had the exact thing happen with an XD; the rounds cleared the plunk test but would not reliably chamber because the angle of feed was too strong; the nose jammed in to the top of the cylinder and wedged. Slightly longer, they slid in just fine, but too short on that bullet profile and they just wedged right in.

This was pretty common on a lot of brands of 1911's, and feed ramp polishing so they would more reliably feed hollowpoints became a norm. It doesn't take the removal (honing) of very much material to significantly alter the feed angle, to get hollowpoints to chamber reliably in stubborn 1911's; although if you take too much case bulging becomes an issue.

The feed angle of XD's is very severe, compared to many other manufacturers (Glock, S&W, H&K, etc). They are a damn sight trickier to work with in non-round bullet shapes, or with some of the more aggressive hollowpoint bullets (a.k.a. flying ashtrays). While remaining perfectly reliable with round nose and not-too-aggressive hollowpoints.

The honing feed ramp trick probably wouldn't work in XD's as well as some 1911's because the case web is already unsupported to quite a degree. I wouldn't want to hone more material to make it feed easier, like old time 1911's as it would support even less.

 

[NMexJim]

Although SAAMI and CIP include the throat in chamber specifications, there are a lot of short ones and a lot of what you might call "full figured bullets." Some USPSA shooters match the gun to the load and have their CZs rethroated to take the bullet and length they want.

I prefer 200 grain .45s but not all my guns will feed the usual semiwadcutter and coated cast 200 gr roundnose are not common items, less so in the panicdemic. Plated bullets are more expensive, apparently marked up more than cast.

So I bought a sample pack of 200 gr roundnose flatpoint, with crimp groove for revolver and lever action use. After I got the OAL adjusted to suit (shorter than recommended by the vendor) they fed in my automatics; so I ordered more.
This batch feeds as well, but takes a lot of help in the loading. OAL is more variable and a lot of them tight in the gauge, some total rejects. The Lee CFC straightens them out but it is either an extra step or, if installed on the progressive, more effort on the handle.

So I splurged on some plated bullets and will get some of the 230 coated bullets I had found satisfactory before even though not the original John Browning choice.

If by "full-figured" you mean the shank is too long, then that's the one! Long shank, little stubby, flat nose. PITA!

 

[higgite]

If you load longer, what is the problem? Do they not drop in and out, or do they just not spin?

They fail "my" plunk test if they don't drop out under their own weight.
I don't spin the cartridge in the chamber, but I what I do is.... once the cartridge drops out under it's own weight, I turn the barrel upside down and "reverse plunk" it with my finger while I clock the barrel a few degrees between plunks. It takes maybe 5 seconds to make a full revolution when you get used to it. If I can't make a full revolution without the round sticking in the chamber, I seat the bullet .001" deeper and try again. When I get a full revolution without the round sticking, I call that the max COL for that bullet in that pistol and seat my reloads .010-.015" shorter than max. It's overkill to squeeze the last couple of thousandths out of it, but it's a hobby, I have time, and it works for me. ymmv

 

[Alex G]

Looking for some input on this one. I have a .45acp and a 9mm Springfield XDm and I reload for both. I'm having problems with my loads and the plunk test in those two barrels. My 9mm loads do fine in my CZ SP-01 and my .45acp loads do fine in my Dan Wesson 1911. They plunk in, they spin, and they drop out.

On both XDm's, the rounds plunk in, -will not- spin, but do drop out. I've read that this is an indication that the bullet is into the lands. I've come to think this is not what is happening with these two barrels. I was loading Zero 230gr. FMJs this weekend, OAL was 1.26". I ran them in all the way to 1.20" and the loaded round would still not spin in the barrel. I think the chamber is tight at the mouth of the cartridge, so the case not the bullet is what prevents the loaded round from spinning.

Anyone else have this issue? Any ideas how I can test this theory?

I had something similar happen with 9mm and Brazos 124 grain rn projectiles. Took the barrel that had the shortest/tightest chamber and kept seating deeper till it would plunk and turn. Definitely started low and worked up to ensure no overpressure, but all was well just be extremely careful with adjusting the OAL.


squatch reloading did an excellent video loading with coated bullets that don’t plunk well (and one of my learning sources when I had plunk test issues.)

 

[sparkyv]

I have taken several double takes on that barrel on the left. Fools me every time!

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