I'm thinking about buying a Gemtech suppressor for my HK91 and also putting it on my PSS for fun.  If I were to buy a .300 Whisper upper for my Colt, would the same suppressor work?  I had assumed that the bullet diameters were the same, but I'm not positive.

.308 dia. on both.

I was thinking about putting a bi-lock attached Gemtech TPR-S on my HK-91 and contacted Gemtech about it.

The started by saying that the HK-91 barrel is very thin and the heavy silencer would play havoc with accuracy as the barrel heated up.

They also said something about the HK threads being at some kind of an angle and the gun would have to be sent to them to have the bi-lock attached.

I gave up the idea at that point. Too much hastle.

I do have three other of their suppressors (M4-96D, Talon-SD, and Hornet) and sent two uppers to them to have have the bi-locks put on since one was on a 11.5" Commando and that's the only way they would warrant the M4-96D on it. Work was top notch and mounting charge was $25 plus shipping.

You should contact them to see if you get the same response on the HK-91 as I did.

Quoted: The started by saying that the HK-91 barrel is very thin and the heavy silencer would play havoc with accuracy as the barrel heated up.

There is a barrel stabilizer that you can get for the 91...about the angle, I have no clue.

I'll repeat what several others have noted: the bullet diameter should be fine, and you might have a problem with varying threads between the rifles and the can.  One more thing: make sure that can is threaded exactly square to - and in line with - the rifle bore.  If it ain't square, you will quickly have (non-suppressed) problems.  

Quoted: Quoted: The started by saying that the HK-91 barrel is very thin and the heavy silencer would play havoc with accuracy as the barrel heated up. There is a barrel stabilizer that you can get for the 91...about the angle, I have no clue.

Yea, I have one on mine.

albums.photopoint.com/j/View?u=258760&a=10577068&p=56095340

I've talked to Doc Dater about this at length a couple of times...since I'd love to have a suppressor on my 91.  He told me the same thing.    He undoubtedly knows his shit...but AWC told me the Thundertrap would work fine, and it's even heavier than the TPR-S.  I don't know....maybe I'll just suppress my shorty and be done with it.  I have fired a .300 Whisper upper with SSK's can on it, and it is impressively quiet, and does cycle.  What a pain in the ASS it must be to load those rounds, though.

QS
resident suppressor nut