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Posted: 11/6/2023 4:05:08 PM EDT
What's the latest on how often a person should switch rounds from one mag to another to give the spring a rest when using Pmag or aluminum GI mags equipped with stainless steel springs?
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AZ, USA
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Posted: 11/6/2023 4:20:05 PM EDT
[#1]
17-7ph has excellent stress-relaxation and creep properties. It is my opinion that you will never experience a time-dependent loss of spring free-length with this material in your lifetime.
Music wire is a different story. A maximally-stressed spring made from music wire will absolutely experience a loss of free-length and an attendant loss of developed loads. I don't think that merely unloading will rehabilitate it. I think you should get new springs if it has been loaded for more than 5 years (which is a completely arbitrary guess on my part). If we were living in a post-apocalyptic hellscape with no new springs to be had, I might say to cook it for 30min at 475F, and see how much length is regained, but since we're not, I won't. |
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Posted: 11/6/2023 4:22:19 PM EDT
[#2]
Someone will answer your question better than me, however, loading and unloading mags weaken the springs. I leave my range mags loaded and have for years (20 +). They have never failed me and these mags have never been changed out.
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Posted: 11/6/2023 4:50:30 PM EDT
[#3]
Quote HistoryOriginally Posted By brownbomber: 17-7ph has excellent stress-relaxation and creep properties. It is my opinion that you will never experience a time-dependent loss of spring free-length with this material in your lifetime. Music wire is a different story. A maximally-stressed spring made from music wire will absolutely experience a loss of free-length and an attendant loss of developed loads. I don't think that merely unloading will rehabilitate it. I think you should get new springs if it has been loaded for more than 5 years (which is a completely arbitrary guess on my part). If we were living in a post-apocalyptic hellscape with no new springs to be had, I might say to cook it for 30min at 475F, and see how much length is regained, but since we're not, I won't. YouTuber Paul Harrell showed springs losing their free-length after being loaded for 1, 2, or 3 years (I forget which). I don't recall which springs, though. I guess music wire isn't chrome silicon. |
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AZ, USA
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Posted: 11/6/2023 4:53:49 PM EDT
[#4]
Quote HistoryOriginally Posted By peacematu: YouTuber Paul Harrell showed springs losing their free-length after being loaded for 1, 2, or 3 years (I forget which). I don't recall which springs, though. I guess music wire isn't chrome silicon. Quote HistoryOriginally Posted By peacematu: Originally Posted By brownbomber: 17-7ph has excellent stress-relaxation and creep properties. It is my opinion that you will never experience a time-dependent loss of spring free-length with this material in your lifetime. Music wire is a different story. A maximally-stressed spring made from music wire will absolutely experience a loss of free-length and an attendant loss of developed loads. I don't think that merely unloading will rehabilitate it. I think you should get new springs if it has been loaded for more than 5 years (which is a completely arbitrary guess on my part). If we were living in a post-apocalyptic hellscape with no new springs to be had, I might say to cook it for 30min at 475F, and see how much length is regained, but since we're not, I won't. YouTuber Paul Harrell showed springs losing their free-length after being loaded for 1, 2, or 3 years (I forget which). I don't recall which springs, though. I guess music wire isn't chrome silicon. I bought some Wolff springs for my Glock 17 magazines and am going to leave them loaded for a yet-to-be-determined period of time, to see how much length they lose. I suspect they ate chrome-silicon, but Wolff doesn't disclose what they are. |
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AZ, USA
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Posted: 11/6/2023 4:55:11 PM EDT
[#5]
Quote HistoryOriginally Posted By Petro: Someone will answer your question better than me, however, loading and unloading mags weaken the springs. I leave my range mags loaded and have for years (20 +). They have never failed me and these mags have never been changed out. This is not true. The number of compression cycles that a magazine spring will experience is completely trivial from a cyclic fatigue standpoint, even magazines that you've been using for 20 years. |
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Posted: 11/6/2023 5:13:03 PM EDT
[#6]
Originally Posted By Petro: Someone will answer your question better than me, however, loading and unloading mags weaken the springs. I leave my range mags loaded and have for years (20 +). They have never failed me and these mags have never been changed out. Originally Posted By brownbomber: This is not true. The number of compression cycles that a magazine spring will experience is completely trivial from a cyclic fatigue standpoint, even magazines that you've been using for 20 years. I read the springs in Pmags are good for 500 cycles. I guess they mean they should be considered done for after that many cycles. |
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AZ, USA
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Posted: 11/6/2023 5:51:38 PM EDT
[#7]
Quote HistoryOriginally Posted By peacematu: I read the springs in Pmags are good for 500 cycles. I guess they mean they should be considered done for after that many cycles. Quote HistoryOriginally Posted By peacematu: Originally Posted By Petro: Someone will answer your question better than me, however, loading and unloading mags weaken the springs. I leave my range mags loaded and have for years (20 +). They have never failed me and these mags have never been changed out. Originally Posted By brownbomber: This is not true. The number of compression cycles that a magazine spring will experience is completely trivial from a cyclic fatigue standpoint, even magazines that you've been using for 20 years. I read the springs in Pmags are good for 500 cycles. I guess they mean they should be considered done for after that many cycles. That's 15,000 rounds out of one mag. I don't believe that 500 cycles on a spring (any spring) is anything other than a rounding error. But if in doubt, throw it out! |
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PA, USA
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Posted: 11/9/2023 9:13:39 AM EDT
[#8]
My springs get a break when I shoot the magazins
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FL, USA
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Posted: 1/22/2024 7:39:27 PM EDT
[#9]
Few years ago I found my old range bag containing loaded mags in my garage that I had forgotten about for about 8 or 9 years. The bag contained 2 Chip McCormic Shooting Star 45ACP 8 round mags each loaded with 8 rounds of factory ball ammo, 1 East German steel AK mag loaded with 30 rounds of Wolf steel ammo and 2 GI 20 round mag with aluminum follower loaded with 18 rounds of Winchester 223 FMJ ammo. I shot them all with no malfunction of any kind including rapid firing last few rounds. Then loaded each mag to full capacity and fired them again and no malfuction of any kind.
I also had a spare Glock 17 mag kept loaded with 17 rounds of SD ammo in my nightstand for over a year (I think close to 16 months). All the ammo fired out of my G34 without any problem. When I took the mag apart to clean it I did notice the spring with shorter than my other Glock 17 mags. |
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Posted: 1/24/2024 12:22:10 AM EDT
[#10]
Zero failures and keep them loaded to max.
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MI, USA
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Posted: 1/24/2024 12:43:30 AM EDT
[#11]
I have 8 gen 3 pmags that I bought in 2013. Loaded them with lake city m193 and put the covers on. Pulled them out 10yrs later and disassembled them to check the spring lengths vs new mags. The springs on the 10yrs loaded pmags were the same length as a brand new pmag.
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Posted: 1/24/2024 1:09:20 AM EDT
[#12]
Quote HistoryOriginally Posted By Redshift556: I have 8 gen 3 pmags that I bought in 2013. Loaded them with lake city m193 and put the covers on. Pulled them out 10yrs later and disassembled them to check the spring lengths vs new mags. The springs on the 10yrs loaded pmags were the same length as a brand new pmag. @Redshift556 I wouldn't have guessed this. I wonder if they used chrome silicon springs back in the day. |
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Posted: 1/24/2024 10:58:34 PM EDT
[#13]
I had some Bulgarian AK74 mag springs take a set. I think they were loaded 10 to 15 years. They still worked for the first 25 or so rounds before the follower ran out of lift.
AR mags ive had never had that problem. |
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AZ, USA
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Posted: 2/5/2024 3:34:49 PM EDT
[#14]
Quote HistoryOriginally Posted By peacematu: @Redshift556 I wouldn't have guessed this. I wonder if they used chrome silicon springs back in the day. Quote HistoryOriginally Posted By peacematu: Originally Posted By Redshift556: I have 8 gen 3 pmags that I bought in 2013. Loaded them with lake city m193 and put the covers on. Pulled them out 10yrs later and disassembled them to check the spring lengths vs new mags. The springs on the 10yrs loaded pmags were the same length as a brand new pmag. @Redshift556 I wouldn't have guessed this. I wonder if they used chrome silicon springs back in the day. The drawings dated 1971 (M16A1 factory blueprints) indicate magazine springs are to be 17-7PH. 17-7PH is, from a stress-relaxation perspective, superior to chrome-silicon, and chrome-silicon is superior to music wire. |
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Posted: 2/5/2024 4:52:04 PM EDT
[#15]
Quote HistoryOriginally Posted By brownbomber: The drawings dated 1971 (M16A1 factory blueprints) indicate magazine springs are to be 17-7PH. 17-7PH is, from a stress-relaxation perspective, superior to chrome-silicon, and chrome-silicon is superior to music wire. Quote HistoryOriginally Posted By brownbomber: Originally Posted By peacematu: Originally Posted By Redshift556: I have 8 gen 3 pmags that I bought in 2013. Loaded them with lake city m193 and put the covers on. Pulled them out 10yrs later and disassembled them to check the spring lengths vs new mags. The springs on the 10yrs loaded pmags were the same length as a brand new pmag. @Redshift556 I wouldn't have guessed this. I wonder if they used chrome silicon springs back in the day. The drawings dated 1971 (M16A1 factory blueprints) indicate magazine springs are to be 17-7PH. 17-7PH is, from a stress-relaxation perspective, superior to chrome-silicon, and chrome-silicon is superior to music wire. @brownbomber Is 17-7PH superior to chrome-silicon for firing many rounds through a mag? IOW, load up a mag, fire off all the rounds, load up, fire off all the rounds. I read mags of a Beretta 92/M9 were loaded and unloaded every day. They wore out the springs that way. |
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AZ, USA
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Posted: 2/5/2024 4:58:52 PM EDT
[#16]
Quote HistoryOriginally Posted By peacematu: @brownbomber Is 17-7PH superior to chrome-silicon for firing many rounds through a mag? IOW, load up a mag, fire off all the rounds, load up, fire off all the rounds. I read mags of a Beretta 92/M9 were loaded and unloaded every day. They wore out the springs that way. Quote HistoryOriginally Posted By peacematu: Originally Posted By brownbomber: Originally Posted By peacematu: Originally Posted By Redshift556: I have 8 gen 3 pmags that I bought in 2013. Loaded them with lake city m193 and put the covers on. Pulled them out 10yrs later and disassembled them to check the spring lengths vs new mags. The springs on the 10yrs loaded pmags were the same length as a brand new pmag. @Redshift556 I wouldn't have guessed this. I wonder if they used chrome silicon springs back in the day. The drawings dated 1971 (M16A1 factory blueprints) indicate magazine springs are to be 17-7PH. 17-7PH is, from a stress-relaxation perspective, superior to chrome-silicon, and chrome-silicon is superior to music wire. @brownbomber Is 17-7PH superior to chrome-silicon for firing many rounds through a mag? IOW, load up a mag, fire off all the rounds, load up, fire off all the rounds. I read mags of a Beretta 92/M9 were loaded and unloaded every day. They wore out the springs that way. I don't know the answer to either of those questions. You can get new springs for a Beretta mag (if you own one - I don't) and compress them repeatedly with a dowel - 10x, 100x, 1000x, 10000x. Measure them at each logarithm. I think you will find that the overwhelming majority of set occurs after 3 full compressions, and I'll bet that you won't notice any further shortening up to 1000 cycles. 10000 might be another story. Of course, I have no idea what the spring is made of. |
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Posted: 2/5/2024 8:33:29 PM EDT
[#17]
https://www.ar15.com/forums/ar-15/High_round_count_AR_M4_s__over_100_000_rounds__and_how_they_have_handled_on_our_range/118-677135/?
Originally Posted By HendersonDefense: • We shoot approximately 400,000 rounds down range each month and the numbers have actually gone up a bit< •USGI mags have outlasted all of the other brands. We use UGSI (Brownell's with tan follower) and on a mag for mag basis, they have outlasted Pmags and a few of the other mags that we get from mfg'ers with new weapons. |
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Posted: 2/8/2024 12:09:03 AM EDT
[#18]
I have some preban AR 30 round GI mags that have been sitting loaded with M193 since 2006.
I should get around to shooting them at some point. Just a few weeks ago I shot some ten round Pmags that were loaded in 2013 with no issues. I have a few Glock 22 mags that were loaded in 2006 as well. I ran several of those in 2018 without issue. I still have 2 of them loaded. I don’t have any concern about them working either. |
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CO, USA
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Posted: 2/21/2024 7:40:40 PM EDT
[#19]
What are the indicators if a magazine spring needs to be changed? I have some usgi mags from the 2006 or so era that exhibit some feeding issues when there are less than 10 rounds left. The bolt is overriding the round and the round comes out of the mag about half way but jams up as the bolt is on top of it.
All my mags have the magpul anti tilt flower already, so my next thought is the Springs are worn out. With another carbine that doesn't have m4 feed ramps, when only 10rds left in the mag, the round will just slam into the barrel extension and shove the bullet into the case. Feeding is fine when the mags are full in both cases. Do I need new springs? |
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AZ, USA
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Posted: 2/22/2024 1:14:07 PM EDT
[#20]
Quote HistoryOriginally Posted By DR2341: What are the indicators if a magazine spring needs to be changed? I have some usgi mags from the 2006 or so era that exhibit some feeding issues when there are less than 10 rounds left. The bolt is overriding the round and the round comes out of the mag about half way but jams up as the bolt is on top of it. All my mags have the magpul anti tilt flower already, so my next thought is the Springs are worn out. With another carbine that doesn't have m4 feed ramps, when only 10rds left in the mag, the round will just slam into the barrel extension and shove the bullet into the case. Feeding is fine when the mags are full in both cases. Do I need new springs? Sounds like you do. Make sure the new springs are 17-7ph stainless steel (which is the mil-spec). |
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Posted: 2/22/2024 6:42:06 PM EDT
[#21]
Quote HistoryOriginally Posted By brownbomber: Sounds like you do. Make sure the new springs are 17-7ph stainless steel (which is the mil-spec). Quote HistoryOriginally Posted By brownbomber: Originally Posted By DR2341: What are the indicators if a magazine spring needs to be changed? I have some usgi mags from the 2006 or so era that exhibit some feeding issues when there are less than 10 rounds left. The bolt is overriding the round and the round comes out of the mag about half way but jams up as the bolt is on top of it. All my mags have the magpul anti tilt flower already, so my next thought is the Springs are worn out. With another carbine that doesn't have m4 feed ramps, when only 10rds left in the mag, the round will just slam into the barrel extension and shove the bullet into the case. Feeding is fine when the mags are full in both cases. Do I need new springs? Sounds like you do. Make sure the new springs are 17-7ph stainless steel (which is the mil-spec). @brownbomber Magpul Pmags are mil-spec now. Do all Magpul Pmags use 17-7ph stainless steel springs, or just a certain one? Also, If a civilian buys that particular Pmag, does it have the 17-7ph springs, or does Magpul reserve them for the militay? I recall Pmags having stainless steel springs but I don't know whether they are also 17-7ph. |
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Posted: 2/22/2024 6:52:58 PM EDT
[#22]
I don’t “rest” the springs in my mags. I’m fairly certain it does nothing
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AZ, USA
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Posted: 2/22/2024 7:19:01 PM EDT
[#23]
Quote HistoryOriginally Posted By peacematu: @brownbomber Magpul Pmags are mil-spec now. Do all Magpul Pmags use 17-7ph stainless steel springs, or just a certain one? Also, If a civilian buys that particular Pmag, does it have the 17-7ph springs, or does Magpul reserve them for the militay? I recall Pmags having stainless steel springs but I don't know whether they are also 17-7ph. Quote HistoryOriginally Posted By peacematu: Originally Posted By brownbomber: Originally Posted By DR2341: What are the indicators if a magazine spring needs to be changed? I have some usgi mags from the 2006 or so era that exhibit some feeding issues when there are less than 10 rounds left. The bolt is overriding the round and the round comes out of the mag about half way but jams up as the bolt is on top of it. All my mags have the magpul anti tilt flower already, so my next thought is the Springs are worn out. With another carbine that doesn't have m4 feed ramps, when only 10rds left in the mag, the round will just slam into the barrel extension and shove the bullet into the case. Feeding is fine when the mags are full in both cases. Do I need new springs? Sounds like you do. Make sure the new springs are 17-7ph stainless steel (which is the mil-spec). @brownbomber Magpul Pmags are mil-spec now. Do all Magpul Pmags use 17-7ph stainless steel springs, or just a certain one? Also, If a civilian buys that particular Pmag, does it have the 17-7ph springs, or does Magpul reserve them for the militay? I recall Pmags having stainless steel springs but I don't know whether they are also 17-7ph. I believe all Magpul magazines use 17-7. Someone correct me if I'm wrong. I'm sure there are other manufacturers that use something other than 17-7 for the springs. |
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