I'll IM you a response.

Our heavier cans are cans like the M4SDK.  Sage Dynamics ran the M4SDK harder than anyone else I can think of.  He put 500 rounds through the M4SDK in 5 minutes on a 10.5" barreled upper.  That really looked heinous and a bit dangerous to me, but the can made it through that and he is still running the can and that was maybe 2015?  I think that's a good example of something the can can take, but not a good example of something someone should esteem as something safe or smart to do.

The DL5 I did run in testing 4-28 round mags full auto, followed by 28 rounds a minute for 9 minutes (13 mags at 28 a recon basic load in 11minutes 20 seconds, when the par time I had established for it was 9minutes 40 seconds).  I had ~4 failures to eject on my 11.5" gun, a couple mags after the full auto portion- the 4 FTE's sprinkled infrequently throughout the remainder. I think those were to excessive extractor tension in the weakened high temperature state of the ejector spring.  The whole gun was too hot to hold after the first 4 magazines.

I probably should have pulled the rubber insert and just run the spring and O-ring and then the balance of the extraction and ejection forces would have worked better together.  The FTE's were all stovepipes with a fresh round mostly in the chamber and the rifle was very hot, so I didn't want to look in the ejection port for concern I might have a cookoff and shoot myself with a case head because I know one guy who shot himself through the hand that way clearing an M249, and have heard of people killed that way.  So more or less blind malf clearance ended up putting me about 1 minute 40 seconds behind schedule for my objective time.  

The can was cooling during the 28 rounds per minute part of the test, so it has a good rate of cooling.  It did glow through 4 baffles in daylight on the fourth mag of full auto and I don't think that is a good temperature range, so I would recommend more like 2 mags of full auto followed by the at or less than 28 rounds a minute as that keeps you from peaking into the 1600F+ range which is not good.  In our experience 1200F and below is a good temperature range to run cans at or below.

I know a guy who was in Marine Recon in the Falujah offensive and he said he nearly got through his 13 mag basic load in 4 hours of combat running a longer 14.5" barrel that would be lower pressure and temperature, and that's 1.5 rounds per minute sustained.  This is a critical point to make.  That was considered the most intense urban combat since Hue City in Vietnam in 1968.  People get far too rapped around the axle on durability and cans get far heavier than they need to be for practical and optimal use.

Food for thought is this note from the KAC M4QD SS-NT4 manual that appears in two places in the relatively brief manual:

"WARNING
Firing should be limited to: semiautomatic or burst fire except in emergencies.  Never subject the model QD suppressor to more than 90 rounds of continuous automatic fire. If this limit is reached, allow the unit to cool before resuming fire if the tactical situation permits.  Up to 15 rounds per minute of continual fire is acceptable.  Extraordinary full automatic firing will cause premature loss of performance."

The same can is being supplied on a contract that specifies 36 rounds a minute for 16 minutes 40 seconds without failure.  So recommendations, and torture tests will differ.

The Note makes a lot of sense.  The Sustained ROF for the M4 carbine is 12-15 rounds per minute.  The can appropriate for the M4 carbine should not need to exceed this ROF, because that's abusing the gun, and territory where the companion product shouldn't need to go logically speaking. I bet I would have had zero malfs in my test if I ran 12-15 rounds per minute, because my rifle would have been able to deal with that level of heat appropriately.  Obviously there are things like the Army's M4A1 skilled paratrooper (something like that) Rapid rate of fire for 0-300 meter combat, which is something like 46 rounds per minute.  There are a whole bunch of different rates of fire, but applying those is intended to be within the amounts of permissible time, which I'm assuming is only maybe 2 or 3 minutes for that rate of fire.  Maybe I would know what exactly it is if I had the corresponding TM that broke that out. These are essentially various guidelines intended to inform war fighters of the operational parameters the service branches feel are maximum thresholds for equipment and also at times guides for regulating the application of effective fire.

Conversations of rates of fire seem to be kind of a rabbit hole where the longer you think about the problem the more durable you want the can to be, regardless of any real world need for it to be so.  

I can take a Recce 5 out and shoot 196 rounds on a 14.5" gun in about 3 minutes and the can never glows in daylight in that amount of time, and takes that like a champ.  If we strictly convert for weight, you could probably run about 150 rounds in the same time with an Explorr can.  At the point at which you reach 1200F, the Explorr can probably shoot more rounds per minute than the Recce 5 because it will cool faster. So there are pros and cons to being heavy. There is a major benefit to being tubeless in that the thermal pathway of all parts to the outside is clear and relatively short.  Tube over cans transfer heat a little less optimally in terms of speed.  

This is stuff that goes for all cans.  The more high performance the silencer, often that means it heats toward the higher end of the spectrum.  Every round you fire creates heat at approximately 7-15 degrees per round (more when cold, less when hot).  You can only shed heat efficiently when the can gets hot, because it takes a temperature gradient that is high to create cooling speed- the gradient is the space between ambient air and the temperature of the can.  That might be 550F+ per minute at a constant 1200F can temperature, with a 90degree ambient atomosphere, on a really excellent can like these are for cooling speed.  The heavier the can you shoot, in general the slower they heat, and the slower they cool because they have more mass to cool, and generally similar surface area to cool it with.  The more mass at temperature, the more stored heat to cool.  As the can cools, the gradient is getting smaller, and the cooling speed is reducing with the diminished gradient.  So down at 250F, a can might have 70F per minute of cooling speed.


27 seconds into this video, you see a Surefire on a 14.5" gun executing a 60 or 90 round full auto dump (I can't tell which mag), and you can see the tube is glowing hotter and hotter in the daylight, that's a force that eventually will blow out the tube if the cyclic rate of fire were to theoretically continue because heat would continue to stack at that staggering speed with nowhere to go.  The tube can't hold pressure beyond a certain temperature and glowing in daylight is like 1500F.   That glow populating rapidly in a localized area, is the tube heating much faster than it can move the heat around or cool off. The parts under the tube are going to be even hotter and in a surefire they are insulated by the outer tube that they kind of float underneath with a space of ~.030" of air in the middle.
Pretty much nobody has a problem with the Surefire, because pretty much nobody shoots over a hundred rounds at cyclic with a Surefire. Again these conversations go to irrational places.

The baffle upgrades are great on both if you shoot .300blk subsonic. If you don’t, the recce 5 is the only one worth the money.  

Its like a new can for closer to the cost of the stamp. Thanks for your business and for the kind words.

It's fine

I don't have pictures but at Cola warrior PA hosted at the Geissele range, my M16 became the king of the show at the open range time...

It has an Explorr 224 on it. I had to dump bottles of water on it and the barrel every few minutes. It got abused.

The mk1 rifles used in the test are bone stock.  They do have our proprietary buffer, our over the beach receiver extension and stock, and our barrels- those parts are standard on those guns.  But they do run unsuppressed like all quality di guns.

If we were to do R&D, on a gun that had an adjustable gas block we would be cheating ourselves and our cans would fail to perform optimally on customers guns.

We do all our development on our own quality, di guns, because that allows our performance to correlate to customer firearms in the field.  

The mic placement debate is more or less moot when we compare the other cans to the same standard.  

Happy fourth of July everyone.

Thinking out loud here.

Hasn't griffin shown videos of their cans getting beaten too?

Trademark law says you can’t advertise for sale, an item using the name of another registered trademark in the same industry space / USPTO classification.  Pepsi for example can’t copy and sell coca cola using the same label on the can.  They also can’t put pepsi in a coca cola brand can and sell that as their product, because that would cause market confusion that would harm coca cola which has protected itself with a registered trademark, which is a protection they purchased from the federal government’s USPTO.

So for another example, IF Sierra 5 is a registered mark for the 013 class (I believe thats the class for firearms but I admittedly am not involved in registering our marks, which other people at the company and lawyers who represent us are involved in), THEN we can’t sell a firearm grip for example, and call it a Sierra 5 grip without potential legal problems.  But that wouldn’t stop General Motors from calling their next truck a sierra 5, or even registering that mark in whatever class passenger trucks fall into. Sony could probably also register it as the name of their next pair of ear buds in whatever class that would be.

I am not causing confusion by calling another brand product by its brand and trade name.  That is written on the side of the unit.  Thats just a fact.  There is nothing confusing about stating facts.


What you’re saying is sort of like people might be in legal trouble for saying that red can of soft drink is a coca cola.

Thanks, I also believe that multiple data points are helpful in terms of letting customers check an independent or distributor review, or compare one testing protocol to another.  

This will reduce the ability of any one authority to influence reality because for example TBAC could test one of these products tomorrow, and many companies have similar equipment for testing. Multiple testing sources increase the data accuracy.

Testing will also influence companies to care about performance and to do real development work.

Behind the scenes it is obvious some entities in the distribution or even dealer pipelines have desires to increase sales momentum of one company or another. Sometimes that is evident also in the form of working to reduce sales of another brand.  Sometimes the root issues can be as simple as ego or desire for market control.  The reasons for sales bias can also be relationship reasons.  Sometimes it can be more direct like x company wined and dined us and we like them more than y company, or they support dealer sales with regional reps.  The size of a product line or the presence of dealer sales support can influence bias. Reasons that may have nothing to do with the product being great or not so great for the end user customers and that’s a place where company testing can help show people something that isn’t sales bias.

When people assume manufacturers are biased, there is some lack of perspective in that there can be bias in sales or distribution or in independent testing as well. None of the areas is immune from that.

With that said, will you share your Pulse template or, at a minimum, your settings?  That way we can all be on the same page from the HBK Pulse perspective.