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Automag 3 and S&B ammo

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ltkatze View Drop Down
Baby Auto Mag
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ltkatze Quote  Post ReplyReply Direct Link To This Post Topic: Automag 3 and S&B ammo
    Posted: 04 Aug 2022 at 4:10am
I have posted this elsewhere first but not too many people own these guns. Hopefully someone here can help more.

I've only ever used my own reloads in this gun, but a friend asked to play with it recently so I took it out to shoot... He brought a box of S&B factory ammo to use (nice guy, wish more people were like this)

It turned out to be a bit of an adventure because of a combination of 1) the chamber in my gun may be oversize - at least compared to that on a carbine 2) S&B ammo is smaller at the mouth than other ammo - I had this confirmed by other people measuring - S&B generally seems at least 4 thou smaller than other manufacturers.

But here's the story of my adventure:

FTF on second round, primer had a firing pin imprint on it... he finished the magazine and I wanted to see if the FTF round would fire, I put a few more rounds in the mag and the FTF round on top... let the slide go forward... pull the trigger - nothing, wait the few seconds, repeat... well, it fired after a few tries... didn't feel any different except the casing didn't eject... and the primer was gone... and there were some serious signs of overpressure... (case head smooshed)

Well... time for some pictures to tell the tale and why I think there is a problem with the chamber that I never noticed before...

Put a rod in the barrel and hammer out the casing... except the a part of the casing is still in there... (case head separation alright)

Ok, let's see if I can extract the rest of it _carefullly_ with my field expedient broken case extractor aka a tap - worked well

Except is that the rest of the bullet jacket still there? Look carefully at the mouth of the case, zoom in...

Yup (after taking the tap out) - and the remnants of the primer... that were somehow in the case...

I'm thoroughly impressed with how strong the gun is - no signs of damage whatsoever... I'm very lucky - things could have gone much worse, I know. But none of my past experience led me to expect anything of this sort... But how could this happen? By the looks of the case mouth, could it be jammed past where it's supposed to be in the chamber?

Ok, let's try some plunk tests with this ammo. Most of the time it looks just fine:

But occasionally

This shouldn't happen, right? Just on the off chance I pulled out the carbine - nope, can't do that.

So... here's what I think happened.

Cartridge got picked up from the mag, but instead of the extractor jumping over the rim it pushes it into the chamber because the chamber is just too big, huge out of spec headspace results. 30carb headspaces on the case mouth, right? And in this case (ha!) the cartridge got pushed past that point...
FTF, of course, because the firing pin doesn't quite reach the primer. At this time the bullet is jammed into the rifling - you can see marks on the jacket that got left behind.
I keep cocking the hammer and trying to fire until eventually the primer has enough abuse and goes...
Out of spec headspace + bullet in the rifling - overpressure. The primer is blown, the case is torn in half as it's pushed back to the boltface, but the bullet is still jammed in the rifling so the core gets blown forward with most of the jacket...

If this were a new gun, I'd call this a warranty issue, but for lack of an ouija board, AMT is quite out of reach for any claims :) Anyone with an automag III, could you try the plunk test in yours and see if you have the same issue? If you have factory S&B please use that - i.e. did they just ream _all_ chambers generously and I never saw this before with reloaded ammo? Or is S&B generally small? I can only replicate this with the S&B factory, not with my reloads from a Lee die... I don't have a headspace gauge...

Does anyone know where I can get a spare barrel? :)

Day 2 of my investigation:

I asked around and was able to get some old surplus...

So what do you know! No problems whatsoever, and when I measure at the mouth (Mitutoyo dial caliper - quality ;) )

S&B is smaller by .004" compared to surplus. Ouch! (.334 being max spec, I believe, .332 on surplus and .328 on S&B)I've now had other people confirm this about the S&B ammo - this is not a problem in a carbine, but at least my Automag doesn't like it... dangerously so...

So fair warning, NOT ALL FACTORY ammo is SAFE in these pistols!!!

With all of this said, has anyone else had problems with S&B ammo in their automag 3? Can anyone test / measure?
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Luc V. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Luc V. Quote  Post ReplyReply Direct Link To This Post Posted: 04 Aug 2022 at 2:17pm
Hi, thanks for the heads up on the ammunition from Sellier &Bellot.

I have no .30M1 ammunition on hand to try the "plunge test", but a similar thing happend to a friend of mine with his 45-70 Gov't.
When he shot those factory ammo from Sellier & Bellot, the top of the case was shared off from 8 out 10 cartridges. The (extreme heavy) crimp on the case was totaly ripped off and gone along with bullet down the bore...

Now, I'm curious to know if you have some S&B .30M1 cartridges left, can you pull off a bullet? I would like to see if S&B use some sort of crimp on those bullets also. If so, you should see sort of a cannelure on the bullet, or the rear section of that bullet should be smaller as the rest of the bullet.
Hard to tell from the pictures, but it looks as the remains of that bullet-jacket is about the length of where the bullet sits inside the case.

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ltkatze View Drop Down
Baby Auto Mag
Baby Auto Mag

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Post Options Post Options   Thanks (0) Thanks(0)   Quote ltkatze Quote  Post ReplyReply Direct Link To This Post Posted: 04 Aug 2022 at 5:03pm
Have most of the box left - we couldn't shoot any more with some of the casing stuck in the chamber...

Picture below - a cannelure is indeed there. Also the bullet has lead exposed on the bottom - it is FMJ - and this contributed to how the core got blown forward...

There was maybe 1/32" of the jacket still in the case - it was hanginng on by a thread. The bulge in the jacket where it expanded into the chamber right before where the rifling started is what held it in place I think? And then forward of that bulge you can see the rifling marks on the remaining jacket... What looks like the jacket is actually the casing where it went past that little step in the chamber that it would headspace on and then fireformed to it.

red arrow is where the case ends and jacket begins
purple is the end of the chamber - jacket bulged and fireformed to it
green is where the case would normally headspace but went past the 'step' and fireformed to it

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jw4570 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jw4570 Quote  Post ReplyReply Direct Link To This Post Posted: 05 Aug 2022 at 2:53am
I've always done well with S&B ammo, but thanks for the heads up.  I don't think I have any for 30 carbine.  I have a good bit of 30 carbine remade with military brass and pull down military bullets.  I have some of those left, but when they run out, I will suffer sticker shock I'm sure.

One nice thing is the 44 Automag and 30 carbine both do well with WW296 powder.

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Baby Auto Mag
Baby Auto Mag

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Post Options Post Options   Thanks (0) Thanks(0)   Quote mefly2321 Quote  Post ReplyReply Direct Link To This Post Posted: 05 Oct 2022 at 10:06pm
How is your chamber - after using the tap on broken case?
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