Usually the shift is in the axial direction, so with some judicious tapping from the base or dome end you might succeed to move it slightly back in place.  But it is in practice difficult to make thibgs tighter.  It is equally likely that you make it even looser. 

I would not worry about it.  If they are older lamps they will have been rigorously vibration-tested during development and can more than stand the slight loosening of clamp points, it’s not detrimental in any way.  And it lets you learn another characteristic of different lamp brands - how they sound!

Some colleagues at GE who handled the different HID lamps every day used to swear that they could identify any competitor brand lamp with their eyes shut, just from the unique pinging noises that they made while being handled or due to thermal expansion when running up!  Almost anyone in the UK who has handled a GEC lamp will know what I mean, those had much stiffer frame alloys of nickel plated steel and quite loose top dimple supports, and produced a totally different sound than any other brand.

The problem is that the vast majority of home users seem to be entirely satisfied with this extreme short life. LED filament lamps became so cheap as a throwaway item, like old incandescent bulbs.  Almost nobody keeps the receipts and files a complaint when they fail after more than about 3 months - so the manufacturers seem to be cutting costs further and further to identify the sweet spot where profits are highest, before the cost of poor quality begins to grow too high.

A few years ago one big brand became famous in Europe for its basic range sold in cheap stores - these barely lasted 500-1000 hours despite their reduced 6000h claim.  That really was too short, and presumably attracted a lot of criticism because they seem to have been dropped now, only the claimed 15,000 hour range continues.

The only way this will change is if consumers start sending a signal to manufacturers that life is too short, by making formal complaints.  So I would urge you to take back all your failed lamps to wherever you bought them and demand free replacements.  Only a relatively small number of people have to do this before it is noted, and this really does make a difference.

In terms of finding a better lamp, I am not so familiar with the USA ranges but suspect you would do better to try a brand that serves mainly the wholesale and professional markets than retail-focussed.  Here in Europe I can genuinely say that the lamps from my company Sylvania do genuinely achieve their full rated life, I see the actual lifetest results both free-burning as well as at maximum rated ambient temperature.  We have to, because our focus is mainly on lamps for industrial and commercial applications with only a very small retail presence, and the big customers really do complain as soon as they detect early failures.  We also rate the life not only at 25C, but have a tough internal requirement that a certain minimum life must also be achieved at maximum rated ambient temperature, because that’s how lamps are so often used.

In all these designs I hardly ever come across actual filament failures these days, it is almost always the driver or the connection points that fail.  The drivers were radically simplified a couple of years ago with just 3-4 components, and so much power in the control IC’s that they simply run too close to their thermal limits.  It is very common now for the IC junction temperature to be running close to 150C even before you install the lamp in a fixture.  We try to leave a little more headroom to compensate for that.  In the 120V lamps I can imagine the problems are worse because current is doubled for a given power rating, and driver heat losses increase with the square of the current.

What you could also try is to buy the more efficient ~200lm/W 50k hour lamps.  These achieve their high efficacy partly due to the drivers which are typically over 99% efficient.  Those run considerably cooler, and naturally have longer life. 

I don't think there was ever any motivation to make such small MV lamp.
The 50W were already a challenge - very high temperature to keep the arc voltage high enough with just a short electrode gap in order to maintain somewhat reasonable arc loading, not enough power to maintain that temperature already at the 50W (needed vacuum outer, special heat reflective coating on arctube end seals,...), so rather high cost offering barely any efficacy benefit. You may be able to get something from skipping the starting probe, so allowing to make the seal assembly smaller and dissipating less heat, but then you would need some HV ignitor.
With lower power that would become way worse, so much that a simpler long life incandescent would perform nearly the same (efficacy, lifetime), with the way better light quality as a benefit, all at fraction of the cost.

The HPS was at least seriously considered because of the efficacy benefit, still did not make it till high volume production.

MH made it because the efficacy and light quality (thanks to the CMH), allowing them to compete with halogens for the high end display spotlight market where the high purchase price was offset by the lower energy consumption (because it uses to run 16+ hours/day) and way lower heat generation (giving more flexibility to the display arrangement).
Well, someone considers MH as an evolution of MV (it uses similar buffer gas, evaporated mercury, just with some additives), so by that metrics these small MHs are in fact those "small MV's"...

With halogen lamps like any incandescents, small variation in power leads to huge variation in life. (Near the rated power, not in very dimmed states where the halogen cycle may do some villekulla). So just a little not too noticable dimming may resolve your lamp life problem



Failing other lamp formats, car headlights (H7 etc) are also halogen, fairly good performance and quality for what they are, and i dont think are banned anywhere

They have shorter rated life than "home" halogens, but if the other halogens you can use are of bad quality, a car lamp may outlast them even at full power

Same dimming vs. life consideration applies. You could run the lamps with a plain transformer or a switching power supply. The "metal mesh box" type ones have a small pot to calibrate the voltage, essentially a dimmer for your application

24V (truck) lamps are a little higher power than 12V ones for the same lamp format



With LEDs i have not seen any integrated luminaires that are even remotely acceptable

With screw in lamps there are 2000K-ish filaments (probably ordinary 2700K filaments inside, but the glass has a golden color to it). Those do reduce the blue light content to nearly none, they have fairly pleasant light, but fairly dim

Lamp life : The big names are not really avaliable in my area. I have had mostly good life with Eurolux (a local brand name which you probably dont have there anyway, they are "the better ones of the made in China" sort of lot), but not without some hit and miss too

In one case i have replaced the same lamp in the same socket 4 times in 4 successive days (each one of the first three lasted less than an hour cumulatively), the 4th one (which looks identical) lasted 7 years so far and keeps going...

Sure. I have two reserved at this point, if anyone else is interested.

I'm interested in the 100W PSMH can lights from the auditorium.

Indeed, but strangely the Navion isn't...

ITT/American Electric ballast. They had this choke style ballast with aluminum windings in the 70's, 80's and 90s.

Verdeons actually are discontinued now.

I’m not sure either. Not sure if this helps, but I have been using Ecosmart lamps as of late, though they are just regular ones, most being 2700K, one 3000K, and two 5000K.

I have a 2700K snowcone from 2020 that is has just about five years of use in a table lamp, used about three hours a day, but after that generation they made them even lighter, which I don’t like. They still had weight then that gave somewhat of an assurance on how quality would be but now they feel light as a feather unfortunately. I have two other snowcones in use, a 2700K in a closet light (installed in 2023 I think), and 5000K in a garage light (installed in 2022 I think) and those have been working good.

Their filament lamps have been good to me as well. I know you said you tried them but I’m not sure if you tried the ones I used (regular ones). I have some 2700K 60w (closet light) and 100w equivs (floor lamp) installed in December of 2023 and they have been going strong no issues. Along with a 100w equiv 3000K (installed in mid 2023 I believe, room light) and a pair of 5000K versions (outside lights that are D2D, Oct 2023 and Aug 2025). The October 2023 one is a notable one as before that, I was installing Feit filament LEDs and literally the longest I got one of those in those outside lights was a year and a half, no joke, and started getting those in 2018 (dumb I know).

As @HomeBrewLamps says, sourcing older LED lamps might be your way to go. I have 2700K 65w equiv GE BR30s and Feit BR30s from 2018 (kitchen), another from 2021 (kitchen sink), and Feit G25 40w and Great Value 40w equiv (2018, most of the GVs had failed over the years except two, bathroom), and the best ones, a pair of Feit Electric 85w equiv BR30s in 5000K, that have run D2D since January 2019 with no issues. I haven’t had failures from the lamps mentioned above except for the GVs. The only mass failures I had were with the Feit A19 60w and 100w equiv filament LEDs. The longest I got from one of those was I think three years, in a garage opener light out of all places. People trash on Feit but I have great experiences with some of their older LED lamps.

Home Depot is closer to where I live so that’s been where I’ve been getting my LED lamps lol. Can’t say anything about the other brands.