OCL Polonium Full Size and K Observations

[1168]

Since the sound suppression is reported "at the ear", it is correlated with back pressure, as over gassing increases ejection port noise.

Except in this case, the quietest, highest backpressure can was perceived to be quietest. And the loudest, lowest backpressure can was perceived to be loudest.

[Dutch110]

Thanks for the report.

These findings seem consistent with basic expectations.

Smaller Bore = more suppression (quieter) and higher back pressure.
Less baffles = lower suppression (louder) and lower back pressure.

More baffles = more suppression (quieter) and higher back pressure.
Larger bore = lower suppression (louder) and lower back pressure.

A theoretical Polo K30 would almost certainly come in a distant 4th on both lists.


Since the sound suppression is reported "at the ear", it is correlated with back pressure, as over gassing increases ejection port noise.


The most interesting comparison is between the 30 and the K.

Which is better, 5x30 cal baffles or 4x22 cal baffles ?

The 5x30 cal baffles appear to flow slightly better and have slightly lower back pressure, resulting in slightly better at ear performance.

The measured "at muzzle" numbers may be similar between the 30 and the 556K, but are likely to be reversed and favor the smaller bore.


This essentially sums up much of the conventional wisdom around suppressors on gas guns and that is:

"A full size 30 cal suppressor sounds about the same and is a little less gassy than a 556 K-can on the AR platform, at the expense of some added some weight and length, but gives flexibility to use with 30 cal."

Agreed. I would have been surprised if it had gone any other way because science. What was surprising to me was just how close the Polo 30 and the K were side by side. I think the deeper tone of the 30 was the differentiator to my ear. But I had to go back and forth between the two probably half a dozen times to be sure.

As a side, the full size Polo really is a bit obnoxious from a gas standpoint on the SBRs. And OCL will tell you its not the best can for shorter barrels. But when its on my 14.5 it settles down.

[HCrum87hc]

I have the full size Polo on my 12.5" upper, and it performs very well. While gassy, I didn't find it to be obnoxiously so. I'm running a BRT barrel, A5H3 buffer w/ green spring, and SOLGW charging handle to help mitigate gas/tune the gun a bit. Based on the PewScience results and reports from others, had the Polo K been available when I bought my full size, I'd have gotten the K. However, I'm not disappointed in the Polo at all.

[Dutch110]

I have the full size Polo on my 12.5" upper, and it performs very well. While gassy, I didn't find it to be obnoxiously so. I'm running a BRT barrel, A5H3 buffer w/ green spring, and SOLGW charging handle to help mitigate gas/tune the gun a bit. Based on the PewScience results and reports from others, had the Polo K been available when I bought my full size, I'd have gotten the K. However, I'm not disappointed in the Polo at all.

I think they are the best value out there right now. Once my 14.5 is back from getting pinned and welded I want to try the K on it just to see how it performs. Very similar set up. A5H2 with Sprinco green but using a Centurion barrel.

[BufordTJustice]

High BP cans can still be *very* competitive.

I run a Specwar 556 (non-K) on my Sionics 11.5" RGP SBR. Very very little port noise and zero gas to face. LMT E-BCG, Vltor A5 (BCM Mk2) H4 buffer, Tubbs AR10 flat wire spring, SLR Ti Sentry 7 AGB.

Less port noise than any HUX can and less GTF as well. Muzzle is muuuuuch quieter (smaller diameter, larger internal volume, more baffles).

Only tradeoff is it's a dedicated-suppressed setup without adjusting the gas block. A trade I'm willing to make.


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[1168]

High BP cans can still be *very* competitive.

I run a Specwar 556 (non-K) on my Sionics 11.5" RGP SBR. Very very little port noise and zero gas to face. LMT E-BCG, Vltor A5 (BCM Mk2) H4 buffer, Tubbs AR10 flat wire spring, SLR Ti Sentry 7 AGB.

Less port noise than any HUX can and less GTF as well. Muzzle is muuuuuch quieter (smaller diameter, larger internal volume, more baffles).

Only tradeoff is it's a dedicated-suppressed setup without adjusting the gas block. A trade I'm willing to make.


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Yeah, but the internet has convinced me that louder cans are somehow quieter.

/s

[BufordTJustice]

Yeah, but the internet has convinced me that louder cans are somehow quieter.

/s

UNpossible!


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[Dutch110]

[laughs in flow through]

[BufordTJustice]

[laughs in flow through]

[Whispers in HBP]




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[Dutch110]

🤣🤣🤣🤣🤣