My brother was returning from the All Guard Sniper team tryouts and he had to wait till Monday to return the rifle when our Armory was open.
That made a good opportunity to shoot so we went out this weekend and shot two rifles- an M110 and my bolt rifle which is a modified FNSPR-A1.
The m110 had the KAC can and was firing M852 Match (168grain Lake City), the FN had my Scout thread mount and was firing HSM M118LR Equivalent.
Today the Scout sounded better which may have had something to do with my bolt gun projecting noise downrange or something. I fired it without ear protection and it didn't ring my ears and didn't seem to be louder than my experience of various 5.56 Ar silencers. The M110 silencer is technically better- it meters better, but I think the gas operated rifle makes it hard to discern that it is better in the vicinity of the firer so much as down range which probably sounds better. The M110 silencer had a detectable longer sound signature on this occasion. We had four people present and that was the consensus opinion. The Scout/bolt gun combo seemed to be higher frequency- shorter duration. The perceived higher frequency and shorter duration of sound seemed to be the only difference we could perceive in the sound. The meter would probably say the M110 was 4DB more efficient. We've metered them once before, however today I did have my TAB SAS cover on my silencer and people have remarked that those covers do improve human ear perceived sound on different occasions. Perhaps they remove tube resonance or the .6" overlap of the front of the tube helps move sound down range? At any rate we've had more than one shooter tell us cans sound better with TAB SAS covers, and this seems to support that.
I had Peltor's new ACH's on and kept remarking that my rifle was just barely moving around, but still moving around as I tried to steady for a shot- so the new thicker ear gels made the problem so small that I didn't connect the dots- the ear pro was putting my pulse into the stock from my temple as usual, just not as bad as usual. Not diagnosing that sooner was my mistake and so this 3 round group represents about where my performance was limited by my electronic ear pro. It's pretty obvious that the suppressor has very little impact on external ballistics.
The trigger on the FN bolt gun I modified and it is pretty slick. I also Devcon bedded this rifle and gave it a 10 rd internal box magazine. This 6/10ths' MOA 200 meter group I fired with my Scout silencer/FN combo using 175grain HSM ammo. It's just about 1.1" at 200meters. This was fired with the pulse in my stock from my ear pro.
Something to remember is that the FN SPR A1 is guaranteed under 1MOA so this group even with that pulse is 40% better than the factory spec. accuracy expectation of the weapon.
I'm fairly certain the rifle would probably do somewhere between 1/3MOA and .5MOA [.5"-1" group] at that distance, it seemed to be putting my rounds pretty much where my trigger broke. I was just having a little trouble with pulse from my head through my peltor ear protection into the stock. I have a Leupold M3 knob with 1MOA elevation so POI was either high or low- I really wasn't concerned with POI as much as with just grouping three rounds on paper to demonstrate the Scout doesn't negatively effect accuracy in any way that I am able to measure. Recoil obviously is mitigated which for the bolt gun makes the difference between an eventual sore shoulder and a reticle constantly bucking off target, and no shooter fatigue with the reticle basically sitting flat through the firing cycle.
We ran out of LC M852 match for the 110, and I pulled my right ear cup off after isolating that pulse issue.
Using the 110 SASS at the same distance, I put 5 rounds of HSM 118 equivalent into a 1.75" group ~.9MOA. That was my only group of the day with the rifle. The M110 is a hell of a gun for what it is- gas operated semi-automatic. I noticed the Rail system on the gun had a lot of flex. I think Daniel Defense probably makes rail systems that are significantly more rigid than the URX. The 110 is very long and unwieldy, especially when the silencer is mounted, and pretty heavy, but that helps it when fired from a rest. On another occasion I've engaged Larue sniper targets (reduced silhouettes) from 110-620meters UKD and it's possible to engage 5-6 targets successfully with one round per target in ~45 seconds, because the minimal muzzle rise enables the shooter to spot most of his own rounds and estimate dope to the next target based on the last closer target engaged to the effect that it minimizes need for calls from the spotter.
To the rifles credit my brother made a first round UKD cold bore shot at 387 meters on a 6" round plate with this rifle. That's pretty outstanding performance and he'll probably be taking that rifle to some competitions this year.
