I have an AMT .45 Backup pistol that used to be an every day carry. It got to where it wouldn't feed the cartridge, though. I have noticed that as the round tries to chamber, the tip tilts downward and jams. I have two magazines and both do the same thing. I was thinking that I might need a new magazine spring, but I cannot find any. Does anyone know where I can find these springs or ... if this isn't the problem, what I can do to fix this? I've since replaced the gun with something else, but I really miss this little guy! Thanks.
Looking for Help with AMT Backup .45
- Thread starter theBob
- Start date
Aguila Blanca
Staff
It's Wolff, not Wolfe.Ed4032 said:
Wolff doesn't list any springs for the AMT Backup 45. They do list magazine springs for the Backup 380 -- I don't know if those will also fit the .45 magazines.
https://www.gunsprings.com/AMT/BACKUP .380/cID1/mID7/dID10
The magazine is probably similar in width and depth to a 1911 mag, so if no springs are available for the Backup, springs for compact a 1911 might work.
Springs can be designed for a specific follower design, so it might not be as easy as "1911 magazine spring"; can you post a pic or pics of the mag?
Springs can be designed for a specific follower design, so it might not be as easy as "1911 magazine spring"; can you post a pic or pics of the mag?
Here's a link which has pictures of an AMT Backup .45 and its mags:
https://www.d4guns.com/product/amt-backup-45-acp-2/
One old trick at diagnosing a mag spring problem is to:
-diassemble the mag;
-put a cartridge, live or dummy, underneath the mag spring (as a spacer);
-reassemble the mag with one cartridge underneath the spring;
then test fire to see if it helps or eliminates the feeding problem.
Examine the mags while you're at it and determine if the feed lips might be cracking at the rear of the mags. Also, try to measure the width of the feed-lips at the rear of the mag, for good measure (hopefully the feed-lips aren't beyond 0.390").
DO NOT consider trying to bend the feed-lips or stretch the mag springs (at this time).
This is what I'd do. I like the Glock30 suggestion as the Glock is still a current firearm with plenty of factory and aftermarket support, unlike a "vintage" or discontinued firearm (of which I've a few, too).
https://www.d4guns.com/product/amt-backup-45-acp-2/
One old trick at diagnosing a mag spring problem is to:
-diassemble the mag;
-put a cartridge, live or dummy, underneath the mag spring (as a spacer);
-reassemble the mag with one cartridge underneath the spring;
then test fire to see if it helps or eliminates the feeding problem.
Examine the mags while you're at it and determine if the feed lips might be cracking at the rear of the mags. Also, try to measure the width of the feed-lips at the rear of the mag, for good measure (hopefully the feed-lips aren't beyond 0.390").
DO NOT consider trying to bend the feed-lips or stretch the mag springs (at this time).
This is what I'd do. I like the Glock30 suggestion as the Glock is still a current firearm with plenty of factory and aftermarket support, unlike a "vintage" or discontinued firearm (of which I've a few, too).
Aguila Blanca
Staff
The magazines look a lot like shortened 1911 magazines. The follower isn't clearly shown, but looks like it might be a Devel-style follower. Springs for an Officers size 1911 might work if a couple of coils are clipped off the bottom. Wolff will have springs for Colt Officers ACP magazines.
I'm sorry y'all. I don't get notifications.
I contacted Wolff. They told me they didn't have these springs.
I bought a couple of 1911 springs (at the suggestion of someone else elsewhere) and they aren't anywhere near close.
I can post photos of the spring and magazine tomorrow.
Never heard of the round under the spring trick, but I can sure try it. I will take measurements tomorrow as well. I haven't stretched anything yet. I figured that it would need to be heated and treated, anyway, which is beyond my knowledge set, so...
I have another everyday carry - a Springfield XDS .45 - among others, but I would really like to get this gun functioning again. It's not sentimental, but I really do like it. The size, the weight... nothing else I've found compares to it.
I appreciate the replies. I'll get back tomorrow with follow up. Thanks!
I contacted Wolff. They told me they didn't have these springs.
I bought a couple of 1911 springs (at the suggestion of someone else elsewhere) and they aren't anywhere near close.
I can post photos of the spring and magazine tomorrow.
Never heard of the round under the spring trick, but I can sure try it. I will take measurements tomorrow as well. I haven't stretched anything yet. I figured that it would need to be heated and treated, anyway, which is beyond my knowledge set, so...
I have another everyday carry - a Springfield XDS .45 - among others, but I would really like to get this gun functioning again. It's not sentimental, but I really do like it. The size, the weight... nothing else I've found compares to it.
I appreciate the replies. I'll get back tomorrow with follow up. Thanks!
Bill DeShivs
New member
Of course 1911 springs won't work.
You have to cut them down to size.
You have to cut them down to size.
Aguila Blanca
Staff
See post #7 and #9theBob said:
Please post a photo of the follower, also.
This may be a consideration when you come to a fork in the road.
AMT set about to reverse engineer the 1911 and then investment cast the parts. Thats not bad, Ruger investment casts fine parts.
But when casting/molding parts, shrink when the part cools becomes important. You can make a pretty good guess,by using a different unit of measure to scale up the part. If you think you will get .010 shrink per inch,you can multiply all your dimensions by 1.010 and you may get pretty close.
But its a fickle process subject to a lot of variables.
AMT built a set of cast parts that would build a gun, but they may not interchange with other milspec or commercial parts. And where do we buy original AMT parts? Try exchanging a military or commercial magazine
catch with an AMT. You will get the idea.
I don't have the answer for your spring or follower. It might be changing to another follower will help. Or not.
There is the Glock recommended. Good guns but not every hand likes them. Shoot a S+W 45 Shield and compare.
AMT set about to reverse engineer the 1911 and then investment cast the parts. Thats not bad, Ruger investment casts fine parts.
But when casting/molding parts, shrink when the part cools becomes important. You can make a pretty good guess,by using a different unit of measure to scale up the part. If you think you will get .010 shrink per inch,you can multiply all your dimensions by 1.010 and you may get pretty close.
But its a fickle process subject to a lot of variables.
AMT built a set of cast parts that would build a gun, but they may not interchange with other milspec or commercial parts. And where do we buy original AMT parts? Try exchanging a military or commercial magazine
catch with an AMT. You will get the idea.
I don't have the answer for your spring or follower. It might be changing to another follower will help. Or not.
There is the Glock recommended. Good guns but not every hand likes them. Shoot a S+W 45 Shield and compare.
Bill DeShivs
New member
The AMT Backup is not a 1911 pattern gun.
Aguila Blanca
Staff
I initially thought they looked like Devel-style followers but after looking at the photos again, I'm now inclined to agree with you.RickB said:
In that case, Wolff springs for a Colt Officers ACP would be a good starting point. I think the AMT Backup mags are shorter than the Officers ACP magazines, so it might require clipping a coil or two or three off the bottom of the springs (as I suggested previously), but I think they can be made to work.
PolarFBear
New member
For theBOB
Can not address the spring issue. But I invite you to use the "search" function on the AMT DAO Backup 45. I've owned three of these. I agree, the AMT is a "special" firearm. I too really tried to like it. Just gave away my last magazine last month. As an alternative, as has been mentioned, is the Smith & Wesson 45. I really like it. You might also review the Kahr 45. I owned one but traded it away before I shot it. Both firearms are close in dimensions to the AMT 45. I will say, if I find another one at around $200 I'll try it again. I am a fool for the dang things. But, I will NEVER carry one as a trusted firearm. Good luck.
Can not address the spring issue. But I invite you to use the "search" function on the AMT DAO Backup 45. I've owned three of these. I agree, the AMT is a "special" firearm. I too really tried to like it. Just gave away my last magazine last month. As an alternative, as has been mentioned, is the Smith & Wesson 45. I really like it. You might also review the Kahr 45. I owned one but traded it away before I shot it. Both firearms are close in dimensions to the AMT 45. I will say, if I find another one at around $200 I'll try it again. I am a fool for the dang things. But, I will NEVER carry one as a trusted firearm. Good luck.
Aguila Blanca
Staff
At what point do we acknowledge that the OP (theBob) has already obtained a replacement pistol, and that he asked for advice on fixing his AMT Backup 45 magazines, NOT for suggestions on other firearms?
Indeed. Thank you
Here are the photos of the magazine, the original spring (the shorter one), the 1911 spring and the lip(?).
I knew that the spring would have to be cut, but the problem is that the 1911 spring is narrower than the AMT. It doesn't fit the magazine or the lip properly.
I tried the round under the spring trick and it did seem to chamber the round better.
Attachments
The lip?
Spring width might not matter; the follower should track up and down.
Since the follower is so similar to that in a 7-round 1911 mag, I'd trim the spring so it's two coils longer than the factory spring, and test it.
Are you sure the spring is oriented correctly in the last pic; usually the top coil is pushing up on the front of the follower, to counter any tendency for rounds to nose-dive.
Since the whole endeavor is an experiment, try it both ways.
This is a disassembled 6rd 1911 magazine.
Spring width might not matter; the follower should track up and down.
Since the follower is so similar to that in a 7-round 1911 mag, I'd trim the spring so it's two coils longer than the factory spring, and test it.
Are you sure the spring is oriented correctly in the last pic; usually the top coil is pushing up on the front of the follower, to counter any tendency for rounds to nose-dive.
Since the whole endeavor is an experiment, try it both ways.
This is a disassembled 6rd 1911 magazine.
Attachments
Last edited:
Aguila Blanca
Staff
I agree with Rick -- the spring in the last photo is oriented backward. The top half coil should parallel the feed lips and the follower.
And the follower is a GI-style (with a shortened rear leg, which probably contributes to the tipping), not a Devel style follower as I originally thought.
And the follower is a GI-style (with a shortened rear leg, which probably contributes to the tipping), not a Devel style follower as I originally thought.
Where did you get that longer spring? It's not correct. Here's the Ordnance Department blueprint of the M1911A1 magazine spring:theBob said:
