Gen5 Glock heat issues

[TCinVA]

There is, in my opinion, an additional concern on the Gen5 Glock pistols...or at least on my Gen5 G17: Heat.

My Gen5 gun heats up quite a bit faster than any other pistol I've used except for the P7 family of pistols from H&K. It also seems to hold on to that heat more readily. ARay gave me a good suggestion to try and quantify it, so I did a little back-to-back shooting with the Gen5 G17 and a Gen4 G34.

Gen5 G17 -
Slide temp: 83.3 degrees F (direct from the holster)
Aimpoint housing temperature: 81.1 F

After 100 rounds (5 yard roundup some bullseye)
Slide Temp: 116.3 F
Aimpoint housing temperature: 92.4 F

After 150 rounds (slightly more rapid bullseye work)
Slide temp: 130.6
Aimpoint housing temperature: 97.8 F

After 3 magazines, rapid fire
Slide temp: 158.9 F
Aimpoint housing temp 110.6 F

Gen4 G34 -
Slide temp: 80.2 F

After 100 rounds (same COF)
Slide temp: 92.2 F

After 150 (same COF)
Slide temp: 98.3 F

After 3 magazines, rapid fire
Slide temp: 114.4 F

Now I wouldn't say this is a statistically valid test because sample of one and I made a general effort at keeping the pace of fire the same but didn't absolutely guarantee it. What is useful from that data, however, is quantifying what I was feeling with actual numbers. The Gen5 G17 is, in fact, getting quite hot. When the slide read 158 degrees that was just below the ejection port...the place I put my trigger finger into register. The muzzle end of the slide was over 170 degrees. I plan to do another hopefully more valid test in the relatively near future where I fire 6 magazines through a Gen3 17 and my Gen5 17 as fast as possible, record the total time, and record the temperatures on the guns before and after at specified points.

I suspect the new finish on the Gen5 guns...an ion-bonded "diamond like coating"...is partially responsible for the heat phenomenon I'm experiencing. There may also be some change in the metallurgy of the gun's components that was made necessary by the finish change. I can't say because I'm not a materials engineer.

Most germane to this discussion, though, is that the heat is working into the housing of the ACRO and elevating the temperature of the optic, too. It gets noticeably warm. The temperature readings I was taking off the optic show that it's getting at or above 100 degrees, at least on my gun.

That is something of a concern regarding battery life because temperature negatively impacts the life of these coin batteries:

http://data.energizer.com/pdfs/lithiumcoin_appman.pdf

As you can see on the graph presented on page 4 of that document, battery life at 40 Celsius (which is 104 degrees F...a temperature that the housing on the Aimpoint is reaching on my gun) is cut by about 40% if the battery operates in that range continuously. That data is for a 2032 battery, but it's probably safe to assume that a CR1225 battery does not have any better performance in that regard than a 2032.

It's hard to say how much heat is actually reaching the battery as the optic is heating up or how long it stays in the zone where it could potentially impact battery output in the ACRO.

My opinion based on what I've observed is that if you notice that the ACRO on your gun is warm to the touch after shooting some rounds through it, factor your shooting volume into your battery change strategy. For me, if I have another range day like I did a couple of weeks ago in the Givens class where I fired about 800 rounds in a single day, I'm going to assume my battery got hot enough to drain some life and I'll replace it a little bit sooner. Or, as cheap as the batteries are, maybe right after that range day and then keep with the same 30 day replacement cycle even with the new battery. I blow about 5 batteries worth of value on a single cup of Starbucks at work so it's not a deal breaker.

If you are routinely shooting enough rounds to put heat into the optic or you are regularly exposing it to situations where the optic's temperature can get above 100 degrees for prolonged periods of time go for more frequent battery replacement than the 30 days I'm trying out.

Hopefully all of that makes sense.

[David S.]

Ceramic MOS plates. Done.

[Tokarev]

Just wondering but is the interior of the slide in close proximity to the exterior of barrel all the way along? I don't have a G17 in front of me but, from what I remember, the inside of the slide is fairly open and away from the exterior of the barrel.

[Zman001]

Im no expert on thermodynamics, but i think ita unfair to compare a G17 and a G34, thich has more surface area to deal with heat, like how some Thompsons had barrel fins to help dissipate heat

[JonInWA]

Im no expert on thermodynamics, but i think ita unfair to compare a G17 and a G34, thich has more surface area to deal with heat, like how some Thompsons had barrel fins to help dissipate heat

Not to derail the original post query too much, but did the barrel fins on the Thompson actually work? A number of things on the Thompson were discarded as the exigencies of war intruded on production, necessitating simplified manufacture, quicker and in greater numbers production, such as the finned barrels, Blish lock, and muzzle compensator.

In my Gen 3 and Gen4 Glocks, I've never really perceived excess heat, but probably the most I've fired them continuously and relatively quickly would be in the GSSF 4-string Glock The Plates stages (especially it I'm shooting the same Glock in that stage for multiple divisions).

As I recall from my Glock Armorers' Course, I believe the polymer frames on the Gen5 guns is thicker, too. It'll be interesting to see how this heat accumulation/retention plays out in terms of platform durability and reliability over both continuous firing and higher accumulated round counts.

Best, Jon

[JTQ]

Im no expert on thermodynamics, but i think ita unfair to compare a G17 and a G34,...

Nor am I, but the Gen 4 G34 also has the big open port on the slide to dissipate heat and in this case, the G34 is not wearing an optic, like the G17 is, that is also capable of retaining heat.

[JonInWA]

Nor am I, but the Gen 4 G34 also has the big open port on the slide to dissipate heat and in this case, the G34 is not wearing an optic, like the G17 is, that is also capable of retaining heat.

That's certainly an interesting secondary, and probably initially unintended quality of the G34's slide window cut-out, particularly on the Gen5 pistols. Originally it was provided on G34 and G35s to allow for the slide's weight to be roughly similar to the un-windowded slides of the G17 and G22, allowing the same RSA to be used.

Best, Jon

[modrecoil]

Completely agree about Gen 5 getting hotter. I took the first day of the Advanced Recoil Management class with Paul Sharp in FPF over the weekend. Ran a G34.5 with an RDS. It's a high-round class and heat is expected but the G34 warmed up quicker and hotter than anticipated to a point where my training partner was burning himself during hands-on coaching drills. I wore a strong side JW IWB 3 holster and it became quite uncomfortable despite a completely covered barrel and a compression undershirt. RDS became unusually warm but performed fine.

No measurements were done. Completely anecdotal and subjective but I've run different generations of Glocks in many high-round classes over the years and the heat output was unusual.

[GJM]

How about comparing a Gen 3, 4 and 5 Glock 17, so we have the same slide configuration as a starting off point?

[UNM1136]

How about comparing a Gen 3, 4 and 5 Glock 17, so we have the same slide configuration as a starting off point?

And weigh them...

pat