Mag.Test !

[mismatch]

Greetings!

   Well, this is the test that I had promised on my mags that appeared to have a small defect near the business end of them.

   I first disassemble them completely, cleaned them with a degreasing solvent and applied the dye penetrant. Let the dye penetrate for approx. 45 min, wipe the dye off and sprayed the developer on them.

   The results are shown in the accompanying photos.  I do feel that there is a flaw in and where the weld ends near the feed lips of the mag.
  
    Whether this very small defect will propagate and lead to a failure to feed properly,  I couldn't honestly say........ but as I have mentioned before ,... I'd feel alot better if the dimple was at the bottom of the mag.

    I realize too that Rohrbaugh outsources these magazines, but,... I do believe that QC should take a better look at this situation.

    I also measured my two mags at the feed end and they check out at .325 & .326 respectively. The mags will be checked periodically for any changes,.... drastic changes that is!

    This test has absolutely no bearing on the quality of my R9, I love this gun and still feel VERY confident with it in my pocket,.........and the most wonderful thing about it, ...is that I can now keep my pants up!!  


http://tinypic.com/9iqouq.jpg     dye penetrant

http://tinypic.com/9iqqvr.jpg      developer

[theirishguard]

thanks mismatch for all your time and effort in looking at the mags. Maybe, R bros will look at this and talk with the mag folks and make changes. It appears like it's not a big deal, however, a change could improve things.   Regards, Tom

[mismatch]

Thanks Tom,

   And I agree,  I certainly didn't mean to make more problems for the Rohrbaugh factory.  I guess it's just one off those things, a mechanical engineer will look at the mechanics of everything he puts his eye to, a weldor will always critique the welds on everything he has a interest in, etc, etc, etc.

   I'm glad to be a part of this forum and share a common interest, .... I know that I've sure learned a lot from my fellow members, this forum is a wealth of firearm knowledge!!


  

[R9SCarry]

Fred - thx for going to all that trouble.  I am not overly surpised at your results after I gave it all some deeper thought.  These mags are made by CheckMate according to Eric, and overall they do seem very reasonably made.  They must have some good reason for the weld run direction.

I still tho would feel that the chances of significant crack propogation are more than slim.  I have not measured the upward force on top round of full mag - but just pressing feel around 10-12# might be close.  That upward force will naturally be producing two equal side-thust vectors on the lips so - there will be stress but IMO more than manageable.... too lazy to measure properly and do the math!

I just inspected the internal top weld surface in light of my E1e  and all looks good - such that I'd reckon that IF a crack did occur from the small crater then beneath that is (assuming good penetration which appears to be the case) effectively the mag wall material full gauge.

Under use, the stresses thru loading cycle will not add any significant extra similar stress - the fwd motion of the round being virtually sliding under existing mag spring pressure.

Good tho you brought this up - because we can all be a tad vigilant, just to keep an eye on it.  Thx again.

[sslater]

I just looked at my mags and found the same dimple at the top.  I agree with mismatch that if we had our druthers the weld should have gone in the other direction.  That would put the potential stress riser at the end of the mag which is supported by the base plate.
My old Firestar mags have the same sort of processing as the Rohrbaugh mags, but the two I have left appear to have been dressed at the top of the weld.  Very clean fabrication.
Several of my Ruger .22 Mark II (factory) mags have the same dimple at the top as the R9 mags, and have been trouble-free for many thousands of rounds.  Much smaller cartridge though.  

The only thing I can think of doing to the existing R9 mags is drill a small hole thru the dimple and carefully chamfer the inner and outer surfaces.  That eliminates the stress riser but may cause more trouble than it's worth.   I'm not going to be the one to do that, though.   :-/