01-11-2017, 07:55 AM
Klem Wrote:Cycling
Suppressors increase the barrel pressure and hold it for longer. This will aid cycling in your 16"/mid length. Maybe even be to the point you have to tame it. A variable gas block will help here although in your setup its probably not critical. It does help wear on the gun to have no more port pressure than you need for reliable cycling. Heavier buffers also help but it's better to regulate this excess energy earlier.
Cleaning
A lot more spit and soot comes back around the case as it unlocks. Your receiver is going to get dirtier and if you are a left-hander it will spit in your face via the ejection port (I wear glasses when using suppressors although if you don't have them squinting and knowing its coming helps). If you re-load your cases will be dirtier so leave them longer in the tumbler or get an ultrasonic cleaner. Your suppressor will get dirty and caked too so need cleaning from time to time also - Regardless of whether they are permanently sealed or come apart. Watch for corrosion as suppressors attract moisture as they cool.
POI Shift
Your POI is likely to shift from when shooting non-suppressed. I have never known it not to having shot many suppressors over the years. Some shooters claim their POI does not change although I suspect for some it's more a boast about choosing 'quality' than truthfulness. A phenomenon called, 'Freebore boost' will increase your velocity up to 10fps with a suppressor attached and if this doesn't change your POI then there's something wrong with the laws of physics. You end up preferring to shoot with it on or off to save the hassle of re-zeroing all the time. If you shoot with and without a suppressor devices like the Kestrel permit you to have offset POI's for the same gun which makes dialling for long range easier.
Hearing Loss
If you are shooting volume like when load testing I recommend you still wear ear protection. Let's face it, after all the cost and effort you will be tempted to leave your ear-protection off but multiple impulses at a lower level will still damage your hearing. Workplace OSHA regulations limit noise to around 80db which is the sound of a kitchen blender or vacuum cleaner for all-day constant noise. While your suppressor will limit each impulse by around 30db the residual noise will still be above 100db. Too many shots over a period of time above 100db and you get permanent hearing loss, the same as if you fired it once without protection.
Baffle Strike
If it's a screw-on type without a locking mechanism be mindful to keep it screwed-up tight. Centrefire suppressors collect a lot of heat, especially semi-autos where you end up shooting volume fire that exceeds 1rd/min. The suppressor expands when heated. This will crack the bind at the thread from when you put it on cool. If you keep shooting they have a tendency walk down the thread when loose and it only takes a small amount of run-out caused by gravity to give you a baffle strike. An over-barrel suppressor with a tight fitting grommet or O ring helps but the risk is still there. There is only about 0.5mm clearance between the bullet and the baffles so be sure to check it regularly (e.g. suppressors for 6.5mm calibre tend to have 7.5mm baffle holes). Be careful touching the suppressor after volume fire, they get hot.
I don't see this in the 6.5 bullet range but some bullets will damage your suppressor. Lehigh for example, introduced a 30cal 'CQB' bullet with petals designed to fragment at low velocity on impact with flesh. At high rpm (1:7 twist barrels) the petals were coming apart exiting the but barrel within the suppressor. They now have a qualifier on their website about velocity and barrel twist. The point being, make sure your handloads are stable coming out of that barrel. - If they yaw too much then you risk baffle strike.
Great review Klem, thankyou!