Well as the title states, I am sick and tired of the short life of metal halide lamps, as well as their tendency to "explode" in the fixtures.  Doesn't matter what brand bulb I am using, I've tried GE, Philips, and Sylvania.  They all blow up and only last 10,000-12,000 hours if I am lucky.  I'm lucky if we get 12,000 hours of them, and about 5 times out of 10, they end up blowing up in the wall packs leaving glass everywhere and having to sweep it out and use needle nose pliers to get the base out.  What gives!?  I am seriously considering seeing if I can replace the guts in a few of the troublesome RAB wall packs around my church building that has them with 150 watt HPS.  Won't be as bright as the 175 watt MH but that's ok with me.  These are hard to get to fixtures and I would prefer to not have to re-lamp them every 9-12 months. 

http://www.rabweb.com/productLine.php?productLine=WP2C

I would recommend that u get Horizontal Burning MH lamps.  It because the lamp arc bowed upward to
The tube wall causing the arc tube to bubble up
And two 12,000 hours is usually the rated life time for
mH lamps my best advice take that average life if that lamps and replace them at 8 or 9000 hours before
They have a chance to blow up  or the first fail rule
to group relamp them.

I suppose it is all about the M57 probe start 175W. These have quite large arctube, so the explosion is quite energetic.
There are three options to deal with the explosions:
- One was mentioned by Funkybulb and it is in fact in line with general recommendation of most lamp makers for group relamping: Relamp after 2/3..3/4 of the rated median life. If you don't mind cleaning the glass from single fixture after that period, you may extend this till the first lamp fails.
- Use "Open fixture" rated lamps. These are designed so, the failure is not able to desintegrate the outer. But I don't know, if these are available in the M57 format you are using.
- Convert the fixtures to pulse start and use ceramic MH (M102 150W would be the equivalent in lumen output). The ceramic run at way lower pressure, so the eventual explosion is most frequently contained within the outer. And furthermore the EOL failure mode of ceramics is inherently more peaceful: The halides corrode the arctube on one place, till it leak, so without any explosion or so. If you want to stick with QMH (cheaper, cooler CCT), the "open rated" are readily available on the market. I would even recommend that option anyway, because the side effect of the protective quartz shroud around the arctube is longer lamp life (it charges positively and keep the sodium ions further away from the arctube quartz wall, so slow down it's degradation)
And yet another advantage of the M102 is, you can use S56 150W 100V HPS lamp in there, if you wish.

Thanks for the info.  The bulbs sit horizontally in the fixture. 

This is what I am using.

http://www.lightingsupply.com/m175-u-med.aspx

It is 4000K, so I would go for an M102 /942 CMH. Same lumens, same color temperature, CRI above 90...
E.g. Philips
or some cheaper QMH
or Osram/Sylvania 3000K QMH

I think the lamp you need is the MP175/U/med protected version, although it will probably be an imported bulb. Also, make sure that the fixtures are designed for M57 or M107 (probe start) lamps, and not pulse start lamps.

And as DetroitTwoStroke remind me, when going to pulse start, you will have to change the ballasts to M102 (or equivalent). Although if I remember well, both ballasts feed the same 1.8A current, so adding an superimposed ignitor may be sufficient...

@DTS: Based on the lamp type he is using, I assume the fixtures are now equipped with the M57...

Deleted.

175w medium base is a hard size to deal with, and rarely have a long life when burned horizontally. The arc tubes in these lamps are so crammed in there, I am not surprised they run hot & ultimately explode. In general, 175w metal halide lamps seem to fail earlier than any other wattage. There doesn't seem to be a ceramic arc tube lamp made in that size.

If these have pulse start ballasts, use a EYE 175w Moon Pulse (mercury) lamp.

If it is probe-start, it will be almost impossible to find a standard 175w mercury lamp with a medium base. I used to have one but gave it to someone who has one of these 175w MH fixtures. EYE lighting has discontinued their 175w medium base mercury lamp, probably because it was rarely purchased; you might be able to get it directly from EYE via special order (and probably only with a large quantity & high price). You probably can't fit a mogul base lamp + medium-to-mogul adapter in the fixture, but if you can, and you use a NOS Westinghouse Lifeguard lamp, you'll never need to change the lamp again.

Otherwise, I hate to say it, it's either you change the ballast (150w pulse-start MH with ceramic lamp would be a good choice if you need good colour) or the fixture (LED is in vogue, but you didn't hear it from me). If you go with HPS, don't use off-brand Chinese lamps or you'll be changing them every year or two...don't ask me how I know.

Thanks folks, Great info here I do appreciate it.  I'm going to try to talk the facilities maintenance group to re-ballast and re-lamp these for 150 watt High Pressure Sodium.  Something tested and true and lasts 20,000+ hours.  The color is not so important for this building, the exterrior color of the building is brown/tan brick.  I'll get a photo of it tomorrow.  I think it would look spectacular with HPS 150 watt in those type of RAB Wall packs.  I'll get you some photos so you can see what I am talking about.  I will say this much though, I use a Metal Halide 175 watt for a fixture that shines up on the flag pole at one of my buildings and the white color it puts onto the flag at night is absolutely fantastic.  It makes my heart beat with pride with I see the flag in the wind with the white light on it.  I'll get a photo of that too.  I just put up a new bigger flag today and man.. what a great way to ring in 2014! 

As arcblue mentioned, if you convert to HPS be sure to stay away from Chinese lamps - they tend to cycle early in life which is stressful to the ignitor. I would use Sylvania, GE, or EYE lamps.
Also, 100 watt HPS provides about the same lumens as the 175 MH, so you would be able to save some energy by going to HPS.

I would suggest staying away from L.E.D. since the installations I've seen do not perform well - many have early failures and/or provide less light than advertised.

All halides should really be re-lamped at 10,000 hours anyway, but yes, they will last longer in a vertical position, all ours at work do.

As arcblue mentioned, if you convert to HPS be sure to stay away from Chinese lamps - they tend to cycle early in life which is stressful to the ignitor. I would use Sylvania, GE, or EYE lamps.
Also, 100 watt HPS provides about the same lumens as the 175 MH, so you would be able to save some energy by going to HPS.

I would suggest staying away from L.E.D. since the installations I've seen do not perform well - many have early failures and/or provide less light than advertised.

Thanks.  I am very loyal to GE and Sylvania Lamps and won't use any other brand in outdoor fixtures.  I am also loyal to Magnatek and and Advanced ballast brands as well.   

You said they are RAB wallpacks.  If they are the medium series non-cutoff wallpacks, you could always replace the medium sockets with mogul sockets, than use either open rated 175w MH bulbs, or 175w mercury vapor bulbs.  

I maintain canopy type 175w medium base MH fixtures in a parking garage, and I try to test different brand lamps every group relamping. There are 200 some fixtures and all use the medium base M57 lamp. The best results ive gotten to date are actually from Ushio lamps. They were approx. $8 more per lamp compared to Sylvania but easily maintained color and output 20% longer. Ill also make a note that not a single Ushio lamp failed in a rupture, whereas Sylvania and Philips lamps exploded at EOL as much as 10% of the group. Color uniformity from lamp to lamp in the Ushio lamps was the best of them all too. Im unsure of the chemistry they use but lamps were also a crisper white and not so yellow as the other brands too, all are rated 4000K, even the Ushio. I will never use a different brand again for a 175w medium base halide