Automag III light primer strikes
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Category: Auto Mag Pistol
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URL: http://www.amtguns.info/forum_posts.asp?TID=3009
Printed Date: 27 Mar 2026 at 1:04am
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Topic: Automag III light primer strikes
Posted By: Pantera Mike
Subject: Automag III light primer strikes
Date Posted: 18 Jul 2025 at 2:28am
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All, I was exercising my new-ish to me Automag III today. Obligatory photo:  It proved to cycle and eject perfectly, and was reasonably accurate. However my shooting was adversely affected by the fact that I suffered an almost 50% rate of failure to ignite. Half the time my hammer drop was met with a distressing ‘click’ rather than a resounding boom and a rewarding fireball. In almost all cases, thumbing the hammer back and trying again resulted in successful ignition, although it frequently took multiple attempts. In the end I was left with three rounds from a box of 50 that resolutely refused to discharge. I’ve only fired it three or four times, with a variety of ammunition including factory ammo, my reloads (some of them quite old), and some other reloads from unknown and perhaps dubious sources. Nothing seems to have made a difference. It has a pretty consistent 50% failure rate. The primers all show pretty solid firing pin marks. I’m wondering if the hammer spring is simply weak and needs replacing, or if I should switch to using small magnum pistol primers instead of the standard small rifle primers? I’ve checked Wolff and can’t find springs for the Automag III there. If I wanted to change it, where would I source one? Does it use a standard 1911 spring, or is it something esoteric? Thanks in advance for any advice you may have to share. PS Shameless plug here—my magazine loading tool worked flawlessly all day.  |
Replies:
Posted By: Luc V.
Date Posted: 18 Jul 2025 at 7:50am
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Hi Mike, That is a more common problem with the AMT III. If you reload switch to pistol primers and big chance the problem could be solved. (That is what I do, as some others here) However, sometimes the hammerstrut CAN be bent, and that slows down the speed of the hammer. Springs are exclusively made for the III, IV and V series. I have no idea if something else will fit as a replacement.
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Posted By: Rumore
Date Posted: 18 Jul 2025 at 4:13pm
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Light strikes are a frequent problem with the III, IV, and V guns. Your strut is most likely bent and the spring is collapsed into an "S" shape. In my experience, replacing the strut won't fix the problem if your spring is collapsed. Tony ------------- Run it up, until you blow it up, then back it down a bit. |
Posted By: Pantera Mike
Date Posted: 18 Jul 2025 at 6:06pm
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Thanks guys—the gun was dismantled at time of purchase to reveal an un-bent strut. It was purportedly a new, unfired gun. Where do replacement springs come from for these things? Mike
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Posted By: OneWay
Date Posted: 18 Jul 2025 at 9:37pm
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Read through the thread on this forum https://www.amtguns.info/topic2898.html and you will know all about the III's quirks. It's pretty easy to bend a strut. There is a source of an apparently usable replacement spring buried in there. I picked one up for a spare but can not confirm it for function. Red Line Plus makes a superb strut replacement. Good Luck (Welcome to the exclusive FIRE DRAGON Club  )------------- The Older I Get The More "Keep It Simple Stupid" Means To Me "DENNY CRANE!" |
Posted By: Luvz2Shoot
Date Posted: 19 Jul 2025 at 3:55am
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I have run into this exact issue myself, and am going to follow this thread (and the thread that OneWay posted, above). Long ago I read somewhere that the 30 Carbine ammo was made for the M1, so they made the ammo with rifle primers. As you might know, rifle primers are "harder" than pistol primers. Hence possibly why not getting the BOOM (and flames) that you'd expect with every round? No primer ignition? Have you loaded any rounds with pistol primers and tried those? I've also read that pistol primers are a hair shorter than rifle primers. If you do load some rounds with pistol primers, watch the depth you seat the primers. I'd love to know what you find. I haven't needed to load any 30 carbine yet, but when I do, at least I'll learn from you.  Also, as we all know, the "quality" wasn't always the best with the cast frames. I have vowed that the next time I tear mine apart to clean it that I am going to "polish" the spring area, and the firing pin area with some crocus paper wrapped around something and attached to a hand drill (not a dremel tool). Maybe, just maybe, there is a small burr that is causing the firing pin to not float freely after a hammer stike? As for springs....??? You/me/us/we can measure the spring next time it's apart. Spring diameter, ID, OD, length, etc. I've used Century Spring in the past. They have a nice "filter" to help narrow down a suitable sub replacement spring. ( https://www.centuryspring.com/shop/316-compression-springs ). I am sure there are other spring manufacturers, Century Spring is the one that I am familiar with. ------------- If you were happy and you knew it, would you clap your hands? |
Posted By: Luc V.
Date Posted: 19 Jul 2025 at 10:58am
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Hi John, I checked my spare springs and I have two left. I did the lazy way taking the measurements, so if you can use this to make replacements please do! I see the springs do shorten when used, old vs new, about one coil shorter:  Some numbers, I used US settings instead of my usual metric system to make it easy on you... Not compressed OAL:  Wire thickness:  O.D.  I.D.  |
Posted By: Luc V.
Date Posted: 19 Jul 2025 at 11:06am
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I liked the idea of Tony and Eric said, to use the double spring setup. That should solve the problem with the bent hammerstruts. The power of the extra spring should also help to hit the primer harder.
I looked in my supply of springs but don't have anything able to use. It's a tiny hole to put an extra spring inside the original...  Just an example how it should look, original on top, below two random springs:  |
Posted By: OneWay
Date Posted: 19 Jul 2025 at 7:46pm
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I suspect that the absence of a Hammer Spring Bushing shown in RedLinePlus' tutorial
has a lot to do with mis-alignment (drag and stress increase of the
strut/hammer spring union) affecting hammer drop.  ------------- The Older I Get The More "Keep It Simple Stupid" Means To Me "DENNY CRANE!" |
Posted By: Yellow
Date Posted: 21 Jul 2025 at 12:16pm
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I saw that too in his manual, but I have 3 AMiii’s, and none of them have this part. Also the exploded view of the pistol doesn’t show the hammer spring bushing. Interarms has mainsprings if you need a new one.
If your hammerstrut is bent, you can easily make one yourself. I made a replacement hammerstrut from a piece of sheetsteel, not hardened whatsoever, and it works great. Rifle primers shouldn’t be a problem. I use fiocchi small rifle primers and all three pistols work fine with them, even with bent struts and slightly shortened hammersprings (from use). @Pantera Mike: i see you have two different magazines, or at least followers. Did you notice that? Any difference in feeding? I have 5 mags and they all look like the one at the bottom of your picture. I think the one above it is actually a 9mm magnum magazine.
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Posted By: Pantera Mike
Date Posted: 27 Jul 2025 at 5:08am
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Wow, excellent eye! As a matter of fact my oddball magazine is slightly longer front-to-back and doesn’t fit properly in the gun, requiring considerable force to both insert and remove from the frame. I assumed it was just another example of legendary AMT quality control. It does function, although I seem to recall having some issues which are almost certainly confined to this magazine. My gun came with two magazines and I bought a third from a forum member. It turns out he has a 9mm Win Mag gun and got his magazines mixed up. There was a 30 magazine in the box with his 9mm gun, and I got his 9mm magazine by mistake. A trade is underway and soon all will be right with the world. Thanks for notiicing and speaking up!
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Posted By: Pantera Mike
Date Posted: 29 Nov 2025 at 6:10am
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Minor update—a couple of days ago I put a crowbar in my wallet and sprung for a box of factory 30 Carbine ammo, to use as a diagnostic tool. I may have damaged the firing pin hole in hundreds of rounds of brass during my last reloading cycle (long story I won’t bore you with here) which perhaps may have accounted for my issues. I will try to get to the range next week to test it out and will report back.
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Posted By: AMT addict
Date Posted: 30 Nov 2025 at 5:03pm
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Can you clarify? You might of damaged the flash hole between primer pocket and powder in your brass or damaged firing pin hole of the gun? I feel like you are talking about on your brass but read it several times and just wasn't sure.
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Posted By: Pantera Mike
Date Posted: 30 Nov 2025 at 5:46pm
I was trying to take a shortcut in my reloading process and using a RCBS lube die instead of lubing cases by hand. The decapping pin kept getting caught on the edge of the primer hole and I broke several pins. I now think I damaged a bunch of cases in the process and I think maybe the primers aren’t seating properly leading to misfires. I’m also getting misfires in my M1 carbine which never happened before. I have squillions of pieces of 30 M1 brass, most of them loaded at the moment. As I use the rounds, I am going to carefully resize and deprime them the old-fashioned way and will discard any that are anything other than perfect.
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AMT addict wrote:Posted By: Luvz2Shoot
Date Posted: 01 Dec 2025 at 1:46am
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What dies are you using? RCBS? I ask because I was snapping pins in one of my RCBS dies. I think it was for a 308. Doesn't make a difference..... I called RCBS and mentioned that I kept snapping pins because they didn't seem to be lining up with the primer hole. (Sounds very similar to what you may be going through). RCBS sent me a new decap unit and a bag of 10 pins for free. The customer service is amazing! Maybe give them a call and see what they say? Who knows, they may send you new replacement parts. It really does sound like it's off center ever so slightly. Peace, my friend! ------------- If you were happy and you knew it, would you clap your hands? |
Posted By: Pantera Mike
Date Posted: 01 Dec 2025 at 6:40pm
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Thanks for the advice! I was actually trying to use a RCBS lube die (a dedicated die for lubing small bottleneck cases like .223) in an application it wasn’t designed for. Totally my fault. But you’re right about RCBS!
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Posted By: Pantera Mike
Date Posted: 04 Dec 2025 at 2:19am
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I promised an update ASAP. I finally had a free day today and even though the winds were howling, I was determined to conduct an experiment using factory ammo (it happened to be Aguila), and I’m happy to report it ran like a train with not one single misfire. So the good news is, there’s nothing wrong with my gun. The bad news is, my reloads suck. I don’t know how many cases I damaged, but it’s a bunch. I will slowly shoot them, gritting my teeth at the inevitable misfires, and then after resizing and decapping I will carefully inspect each of them and likely throw away hundreds of them. 🤬 But under the circumstances this news is good!
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Posted By: Pantera Mike
Date Posted: 04 Dec 2025 at 2:23am
Obligatory photo: PS and a shameless plug—my magazine loader tool (still available on ebay) works fantastic too!
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Posted By: AMT addict
Date Posted: 04 Dec 2025 at 4:40pm
It doesn't sound like you will be 30 carbine brass poor if you have to trash some but you might give my thought a try before you trash them. Take say 10 of the rounds that you either have to rehammer to fire or just will not fire. Pull them apart if you have to, process them. If you do not see any clear damage that looks like a concern, load them again with small pistol primers and look in your load data book for 30 carbine in the pistol section. Load up 8 to 10 and run a mag worth through your flame thrower and see if you have 100% fire rate. Then inspect primers and see if they show any concern. I know this would not help with your rifle miss fires but it might bring a  to your face if it saves you from throwing brass out.
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Posted By: Pantera Mike
Date Posted: 04 Dec 2025 at 10:32pm
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Thanks! Yes I will break down all my misfires and process all the cases at the same time as the ones that worked. I will save the good ones and toss the bad ones, even if they happened to work okay. I’ve probably got well more than a thousand pieces of brass (most loaded at the moment) so even if I wrecked half of them through my own buffoonery, I will still have plenty.
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