Sps pantera-mags dropping under recoil

[Jfitz427]

Hey guys,

 

So I just go out on the range with my new SPS and as the title says the mags keep dropping on me. I’ve had this happen in the past with a sig938 and the fix was to put a heavier mag release spring. Is that what’s most likely going on here? Or could it be these crappy mags? I’m gonna buy some new gen 2 sti mags soon. Should have done it already but i was hoping these would atleast function. I can’t imagine this would be caused by mags, and not the mag release. Judging by the mag release button, it’s a weak spring. 

 

So so what do you think? Mag release spring or mags themselves?  

[perttime]

Is any part of your hand on, or near, the release when you shoot?

Some photos make the button on the Pantera look pretty big.

[Jfitz427]

I don’t think so, plus I’m a lefty, so unlike righty’s, the button isn’t in a problematic spot for us. I looked closely at my hand and there’s really no way. 

[Jfitz427]

Anyone else. Couldn’t get 2 shots of today without the mag dropping. Yesterday was basically just as bad, but I was able to get though one full mag without it dropping. The quality of these SPS mags is pretty bad. At first I could only get 3 rounds in a mag, I couldn’t figure out what was going on, then I noticed the follower was sticking out the hole on the shoulder where the mag tapers out. So now when I load it when I get to the 4th round I have to stick something in the hole while I load the round to prevent the follower form getting stuck in hole. Ordering some gen 2 sti mags tonight 

Edited September 24, 2018 by Jfitz427

[Rader1812]

Had this issued with a "tuned" mag catch. I'd buy a new mag catch and see if that works. Take the mag catch out and inspect the lip that holds the magazine in place.

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[blaze190]

Yep I had some problem with my sps 40 out of the box. The mag catch was cheap and not catching right. I replaced mine with one from Dawson precision and never had another problem.

[Hi-Power Jack]

That problem developed on one of my TruBor's when it was about 8 years old.

 

Turns out just had to replace the mag catch spring - solved the problem      

[Absocold]

Shoot it right handed and see if the problem goes away. If it does, get a smaller button, reshape the button or adjust your grip.

 

If it's still dropping mags right handed, stretch out the old catch spring to temporarily give it more oompf and see if it goes away - if so, get a new spring - if not, get a new catch and spring.

[Jfitz427]

On 9/27/2018 at 1:08 AM, Absocold said:

Shoot it right handed and see if the problem goes away. If it does, get a smaller button, reshape the button or adjust your grip.

 

If it's still dropping mags right handed, stretch out the old catch spring to temporarily give it more oompf and see if it goes away - if so, get a new spring - if not, get a new catch and spring.

I think it was the mags themselves causing the problem. They’re so short. I bought some new sti mags 140mm and you can really feel and hear the click when you seat them, very positive engagement. But I also changed to a heavier mag release spring. But I believe the problem was the mags themselves and the gun ran flawlessly with the new mags. So I tried loading up the factory mags to see if it was indeed the spring, and they still dropped under recoil, whilr the new 140s ran great. To me it looks like the front of the baseplates ars hitting the magwell and not fully seating in the gun. 

 

I dont underatand how a company can send mags that don’t work with the gun. If it didn’t have a magwell they’d probably work great. But it seems like there’s a lot of people who didn’t have problems with factory mags, so idk. I’d like to be able to atleast use these for practice though. 

 

Now the question is do I buy 2 more gen 2 sti mags, then have to change out the guts and baseplates to get them to hold 20 rounds. Or do I just buy some MBX mags and not have to change anything. 

[Jfitz427]

On 9/26/2018 at 2:15 PM, blaze190 said:

Yep I had some problem with my sps 40 out of the box. The mag catch was cheap and not catching right. I replaced mine with one from Dawson precision and never had another problem.

Maybe I’ll pick up a new catch from Dawson. Cause I’d really like these to work atleast for practice. But so far with the sti 140s the gun runs great. 

[blaze190]

When I tried STI's in mine before installing the new mag catch mine did the same thing. Then I tried a known good mag catch from a friends STI and it fixed my problem. If you are hitting the mag well with the shorter mag base plate then you may have an issue with that too.

[Matt1911]

If you're hitting the magwell and the mags aren't seating properly, try chamfering the base pads to get them to seat. 

[Jfitz427]

On 10/1/2018 at 6:07 PM, Matt1911 said:

If you're hitting the magwell and the mags aren't seating properly, try chamfering the base pads to get them to seat. 

That’s exactly what I did and they work fine now. But now I have 2 sti and 2 mbx mags, so these are basically just for dry fire now. Idk why they would send mags that don’t work. But on the other hand tons of other people have bought one of these and not had any problems. So idk. 

[Scrmblr]

On 9/23/2018 at 10:47 PM, Rader1812 said:

Had this issued with a "tuned" mag catch. I'd buy a new mag catch and see if that works. Take the mag catch out and inspect the lip that holds the magazine in place.

Sent from my Pixel using Tapatalk
 

It happens eventually with all mag catches. Metal mags + metal mag catch = erosion of engagement surface. Since modifying the mag catch hole in the mag, is likely to irreparable damage the mag. A stronger spring may help, but eventually you'll need a new mag catch. It's a cheaper option than two new mags...

[kalaikanui]

Hummm, Just picked up a new SPS Pantera and it ran so good out of the box at the range; I shot it in a match the next day with the two factory 18 round mags. The rig ran flawlessly throughout the match (thank God the round count on the stages didn't exceed 30). I just order MBX mags for it, maybe I better get a mag catch just in case.

[Jfitz427]

5 hours ago, kalaikanui said:

Hummm, Just picked up a new SPS Pantera and it ran so good out of the box at the range; I shot it in a match the next day with the two factory 18 round mags. The rig ran flawlessly throughout the match (thank God the round count on the stages didn't exceed 30). I just order MBX mags for it, maybe I better get a mag catch just in case.

I’m not really sure what the problem was that first day. But 4000rds later the gun has been absolutely flawless. I think the mag catch was just a little to big for the hole on the mags. And it looked like the basepads was hitting the magwell just a little bit. Is yours a 40? Cause the factory mags are 16rds. I added Dawson IPSC basepads for, and taran ultra thin followers and got them up to 18rds. I use them for practice and stuff but they’ve been 100% reliable. Then I got 2 mbx mags, also been 100%. And 2 sti gen 2 mags with grams guts and Dawson basepads and they also have been 100%. Those are my favorite and going forward I’ll only be buying the sti gen 2s. Mbx ars great for 9, because the short overall length can be a pain to get to run 100% reliably, so they’re worth the extra money. But 40s super easy to get to feed and run reliably. So the sti work great and I prefer them.  I’d pick up a Dawson mag catch just to prevent over insertion. Don’t want to break an ejector. I also got one of the Brazos drop in trigger groups, really what they are is extreme engineering parts which are top notch. All tool steel machines bar stock parts. Drop in 1.5lb crips trigger pull now. Not that the stock trigger wasn’t good. Mine was around 2.5lbs. But I just wanted to make sure those critical parts were high quality steel. 

Edited February 5, 2019 by Jfitz427

[funflyr]

I use the STI mags in mine without any issue.