Hello all,
long time reader on the forums and i thought it was about time i made my own account. Especially as i have got a problem with my High Cap TM Thompson mags! I have a TM Thompson and I have used 7 TM High Caps for as long as i can remember (yes i know im a bad boy.) but now 4 of them just dont seem to push the rounds "up" the mag and when i let the release go on top of the mag about 10 bbs feed through while the others just roll out. And when this happens you have to fully wind the spring again just for the same ammount to push through again. I have taken 2 of them apart and the "big clock work spring" works perfectly fine as far as i can tell and while testing it with a friend outside the mag the mechanish seems to work perfectly as well. So i really am stumped. 
The only other thing i can think of atm is possible the ammo i am using (king arms polished 0.25 BB's) but they still work fine in the other 3 Mags.
Has anyone else had an problem with this? I did a quick search but could not find anything related to this.
Stuart
From experience I'd say that the bbs could be it. I had similar problems with M4 midcaps and excel .25g bbs. I blamed the mags, but after much agro found it was the bbs that were the problem, once I started using .20g excel they were fine! Daft thing was I was saving the .25g bbs specifically for use with the midcaps.
Have you just switched over to the KA .25g bbs?
I had brought the King Arms in Bulk with a mate a while back. Before i was using Excel and "Devil" BB's which i have had no problem with. I dont think it is the BB's as when i went to a friend of mine and we tried his ones ( i think they were excel) and still had the same problem.
My first thought was the spring.
However, if it works outside the mag, there could be some binding when it's inside that is causing the problem. It might just need lubrication.
WRT some failing and some not:
Different springs will weaken at differen rates. Also, if you're not careful, you could be using some mags more than others.
It may be that the faulty ones' springs have weakened to the point that friction in the mags' mechanisms are causing a problem with the heavier ammo.
The ones that are working now may not last much longer.
Hmmm... I'm not so sure the spring is that likely.
I've been running the same 190rnd tommy hicaps for about 5 years now. They are never unwound for storage and work fine even now.
The symptom you mention is actually quite similar to the one I had with my HP PPSH mag. i.e. 10 bbs and then a rewind needed. The solution there was that there was something catching on one of the gears in the mag. (The rewind knocked the mag mech enough to dislodge it.) And once that something had been filed away then the problem went away.
Now obviously these have worked before so it's not that simple, but you say they work fine when they mech isn't in the metal casing? Is it possible that something has started to catch on the gears? Perhaps a clean will help?
flog the tommy and buy a no4 enfield 
lol... yeah cos then you'll have no mag problems at all... yeah right... 
i dont.
i do want to start collecting a Brit load out but got to finish my American loadout first! i am going to clean all my broken mags and see if that helps, the amout of time i have dropped a mag on the floor and slammed a new one in might has mislodged something so i will take that into concideration too.
why use a high cap?
i used to have 6 low cap thompson mags in my USA impression, i hardley ever ran out of ammo before dying , no winding, no springs wizzing on overwind, no rattles from a half filled mag. low caps are better all round, unless you dont like changeing mags under fire (but thats half the fun in my opinion)
"Take that you rotton helping of strawberry flan!"
Joseph Porta to "strawberrys and cream", in the sven hassel book ,ogpu prison
why use a high cap?
i used to have 6 low cap thompson mags in my USA impression, i hardley ever ran out of ammo before dying , no winding, no springs wizzing on overwind, no rattles from a half filled mag. low caps are better all round, unless you dont like changeing mags under fire (but thats half the fun in my opinion)
Yes i totally agree but when u attend standard woodland skirmishes and your average player is carrying 3-4 AK High caps with 2400 rounds not to mention all the m249 clones kicking around atm 400 rounds just donest quite cut it. Especially when your attacking. On my milsim days i carry 560 rounds (5 king arms mags + 1 standard TM ) 
i know where your coming from, but i didnt like the high cap all the same my best ever open day out was with my thompson and low cap mags at shitefighter urban, (the battery factory)
low caps and black ammo, thompsons sights were spot on and so many teflon warriors franticly looking to see where the hits came from, my thompson was my best ever performing aeg, i wish i hadent sold it now.
"Take that you rotton helping of strawberry flan!"
Joseph Porta to "strawberrys and cream", in the sven hassel book ,ogpu prison
my thompson was my best ever performing aeg, i wish i hadent sold it now.
See, it was a mistake going to the "dark side"
two things to look at
1 debris in the mechanism
2 silicone spay them
and never leave them wound as the springs do weaken to the point of failure to push the bb's up.i doubt verry mutch its the weight of bb but it might be the make ,i never use anything other than excel ,aftrer trying other brands there is no substitute ,thats what 12 years experience has taught me.
armoury
m1a1 Thompson,sten mk2,mp40,stg44,sterling,mk2 bren gun,lee Enfield no4 mk1,Mauser Kar98, Walther ppk,smith and Weston m10 and Mauser m712
Give me a big enough hammer and a place to stand and I could fix the world.
i'll kill a man in a fair fight or if i think he's going to start a fair fight or over a woman or.......
a problem shared is a problem halved ,but an advantage shared is no advantage at all
if a job's not worth doing then its certainly not worth doing well
I had this problem with my new tommy mags. I opened it up carefully and found that the culprit was a tiny bit of rust on the axle of the smallest, and only steel, gear in the winding mech. It let me wind the mags fully and would sometimes turn a bit letting a few bbs through but not filling the tube or moving the bbs through the mag.
A little rub with sandpaper and a spray with silicone oil to stop it happening again and it's never missed a beat.
I figure the factories must be humid and seal a little moisture under the shrinkwrap letting this unprotected part rust up.
I noticed that there was no oil or grease in the mag as most of the parts are Nylon or polycarb to save friction.
As said before keep it lubed and debris free adn it should work fine.
