Re: 30-P1 on a 17?
KYS, so, we are very close on this topic..
Most manufacturers acknowledge that cans can shoot under-bored calibers. There is nothing really uncommon about it, nor is there anything inherently wrong with a vast majority of calibers. Most have done this through their use of their cans. In many instances it can make a very real difference and provide fair to good suppression.
My points are as follows:
1. .17 is not among the calibers that suppress well (as in hardly at all) through a .30. At some point, it is important that folks begin to realize where the line is. I personally think, with a .30 can, even in XL (300 winmag, with either larger chambers, an extra baffle, or in my case both) the line for .30 underbore is at 260. In other words, I think the .223 (already a very difficult round to suppress, is poorly served by sending it through a .30 can.
2. 9mm through a .45 can will suppress. Some cans more than others. Having said that no well designed .45 can suppresses a 9mm as well as a well designed 9mm can. The reason is rear gas jet chase, that which follows the projectile right out the bore.
A few companies, not many, suggest that their .45 cans suppress 9mm as well as SOME 9mm cans. That is true, but it takes a junk can to make that possible. I have heard and continue to hear with great regularity the cans mentioned in this thread. No .45 can mentioned in this thread suppresses as well as a good quality dedicated 9mm.
3. dB readings and sound attenuation. As you and I both know and have written about regularly, dB without duration and frequency is essentially devoid of meaning when it comes to suppress values. Having said that, it is true that dB attenuation when comparing blast in the dB range of crowned muzzle vs muzzle with brake is difficult to determine in the 1-2 dB range. But, as we both know, when we drop the dBs down in pressure to the much lower register of a well suppressed round, 2 dB is very clearly distinguishable, and three is figgin' huge. Its the lower pressure register that is the key, that is where human hearing can detect remarkably small shift.
So, with that, I think I've laid out my position here and this poor guy gets some real data. Best.
2.