9 Major Mag Tuning

[Todd7446]

I've tried every keyword combination search I can think of, but can't find the information. Can anyone give me the "most recommended" feed lip dimensions for 9mm? I'm running 0.350-0.352" at the back and +0.005" at the front. They are running well, but trying to see if this is the optimum.

Also, I've "polished" the inside by letting the tubes go in the tumbler with walnut shell media for ~5 hours. Is it really worth building a mandrel and sanding/buffing/polishing more than this?

My combinations are:

140mm STI tubes, Grams follower & springs, Joey Hardy spacers, Dawson SNL bases = 22 reloadable.

170mm STI tubes, Grams follower & springs, Joey Hardy spacers, Dawson SNL bases = 28 reloadable.

Hear a lot of talk of TTI bases. Are they really that much better?

[Sarge]

Talk to Suchy . The guy knows everything about tuning mags

[BMartens]

I use .355" for the feed lips, easy to check with a loaded round. I polish the lips with red jeweler's rouge inside and out, anywhere a round makes contact. Polishing the inside of the tubes seems to help. I just use a 12 gauge shotgun mop and DuPont #7 auto polish and drill or drill press. Works on SVI/STI mags equally well.

[Jaxshooter]

The feed lip dimensions are on the STI website.

[sniper3]

^{Putting the mags in the tumbler ? Awesome idea, thanks Todd !}

[Glk21C]

A well known smith told me the proper feed lip dimension is the when the round that is at the top of a loaded magazine points at the top of the feed ramp.

[Todd7446]

Any chance of getting the link for the STI page? I've looked all over their site and can't find them.

Anyone have thoughts on TTI vs. Dawson SNL base pads?

Sent from my iPad using Tapatalk

[B_Seehawer]

You could just man up and shoot Supercomp

[Sudden Death]

Todd,

Base pads is not where it's at

[CocoBolo]

Have you considered sacrificing a Chicken? The only difference from 38SC to 9 is the spacer in the 9. I switched from 38SC to 9 and on the SVI mags did nothing. Over several years of many thousands of rounds I learned only two important things.

1. Replace the springs every year, or as need which ever comes first.

2. Load the mags one round down from maximum, yes, that last round is really hard on the spring and if you don't need it don't put it in there.

I have no idea what the dimensions are but if one don't work I make it the same size as the one that does.

If it is not broke don't fix it.

I throw mine in the tumbler over night a couple of times a year to get the powder residue and funkamongus out of them. They look a little better afterward.

Base pads, I save those for big sticks, if you need more rounds, big stick, little sticks are for classifiers, and weak hand shooting.

[Todd7446]

Sacrificed a chicken last night. It was delicious.

.38 Supercomp - because I like to hunt for my shells as much as hunting for powder.

Jeff - I know they're not magic. Call it the curse of being an engineer and an Open shooter...