SPS 9/38S 170mm Mag Tubes- What parts do you use and how many do you g

[RobE1010]

I have a couple SPS 9/38S 170mm mag tubes that I got awhile ago and have yet to assemble them for Open use. I am curious what combination of springs, followers and base pads people are using with these mag tubes and the number of rounds they are getting in either 9Major or 38Super/38SC. What springs and/or followers are you using along with base pads to be legal length and for best reliability/capacity?

I would prefer to use SV tubes but would like to give these a try for now as they wont cost me anything extra right now and I have them on hand. Thanks!

[mookman]

Hi there,

Sorry if this sounds negative , but I have been shooting a SPS open pistol for about three years, 9mm Major.

I had nothing but trouble with the SPS mags both 140 and 170. I tried all combinations of springs an followers,

mainly Arrondondo parts as thats really all we can get in Europe.

In the end I cut down stock followers and made plastic spacers from a water container !!!!

I now use STI mags and internals with spacers, these work all the time and give me 26 rounds the same as SPS.

I believe that Bevan Grams uses SPS mags but I think he reworks them a lot , I found that if I droped a semi full mag

the mags lips would change shape and all sorts of internal problems would occur.

I hope this helps, and if you can make them work please let me know as I have Ten mags both old and new sitting in a box going rusty...

Malcolm.

[CocoBolo]

I have one of those SPS Tubes after years of dinking with it, all I can say is it won't even make a good barney mag. Albiet I have not tried it with a spacer, maybe I'll give it one more shot.

I tried, Grams, STI, Arrendondo, and the other one with the really thin followers, I did get it to feed 38S at about 98% reliability, with 9 maj it would run once then next time couldn't make ready or up chuck and go salt shaker half way thru.

I'm not sorry to sound negative, it is what it is. The capacity isn't there either, I think 26 rounds with a +1 SNL pad, while my SVI will hold 30, 29 reloadable. My STI's hold 28 and are 100% reliable with Grams guts.

YMMV.

[Ace38super]

Maybe you will get some positive replies, but I also have a 170 that I dont use in competition, I settled on Grams spring and follower. I use it for practice and have no confidence in it at all. It is a nose dive waiting to happen.

[gng4life]

I have one of those SPS Tubes after years of dinking with it, all I can say is it won't even make a good barney mag. Albiet I have not tried it with a spacer, maybe I'll give it one more shot.

I tried, Grams, STI, Arrendondo, and the other one with the really thin followers, I did get it to feed 38S at about 98% reliability, with 9 maj it would run once then next time couldn't make ready or up chuck and go salt shaker half way thru.

I'm not sorry to sound negative, it is what it is. The capacity isn't there either, I think 26 rounds with a +1 SNL pad, while my SVI will hold 30, 29 reloadable. My STI's hold 28 and are 100% reliable with Grams guts.

YMMV.

+1...exactly my experience and the only reason I haven't sold them is because I don't want to push this off to some poor soul...

[Jaxshooter]

I had one that I gave away because it was a pain in the a**.

[ogiebb]

if you have the old school SPS mag tube (kinda copper in color) they will run well like an SV mag can even get 30 rounds reloadable... if its the newer one it would be kinda hard to make it run reliably.

[RobE1010]

Good to know. Thanks all for the replies, gents. No worries, no hurt feelings or negativity perceived. I was just curious if anyone else was using them for match use and if so, what they were experiencing and capacity they were getting. I have had good experience with the SPS tubes I've been using in my Limited gun for the last few years with no problem.

Otherwise, I currently have 1-170 and 3-140 SV tubes as well as 1-170 and 2-140 STI tubes reserved for my Open gun build. I plan to use TTI springs/followers/basepads for the SV tubes and Grams springs/followers and DP basepads for the STI tubes. I feel comfortable knowing I will get good capacity and reliability with those combos in either 9Major or 38S.

[Jeffrey Yao]

I have quite a few SPS mags (both 170 and 140) that were tuned by Bevin @ Grams Engineering and they never gave me any trouble in both 9mm and 38 Super if I keep them clean. Grams guts and 7mm pads are used with the tubes and I get easy 29+1 in 170 mags. You might want to give him a call and see if he can help with your SPS tubes.

[Spray_N_Prey]

I know you said 9/38 but I have 2 of them in 140mm 40 cal and one runs flawless w/ 20+1, the other would bind up at 18 and there would be about a 1/2 second delay going from the 18th round to the 17th round. I filed the inside of it where it hung up and guess I filed too much and went right through the mag. Now with a hole in it, it runs flawless Go figure.