SHinck82

I know the M107 has irons on it but using any military standard round the irons aren't good beyond maybe 500m, the barrel and break get in the way. Those heavy 600gr rounds have some serous drop on them, also the M107 has a relatively short sight radius, 2.5ft I believe and they are standard hight for an M4 series rifle as well as being relatively close to the bore. Good luck with that though, not my first choice for shooting that far, but I think it's doable.

If you are in the Kansas City area check with Steve up at snapshots, I've had all of my triggers on my M&P's done by him and love them.

The Syrac fully adjustable gas block is simple to adjust. All you need to do to adjust is press in the ball detent lock and then adjust the hex screw in or out as needed. This gas is hands down the simplest full adjustable gas block I have ever used and due to it's built in locking system there is no need to worry about it adjusting on you without your knowledge, I will be running this block on every upper I build and recommending it everyone running an AR style gas system.

I donno much about those 2 triggers but CMMG does make some good stuff. if you are looking in the 3-3.5 pound trigger range I highly recommend the American Trigger Gold Trigger. I have one in My Black Rain .223 and one in my LaRue 7.66 OBR. They are pricy, about $280 each, but they have a single stage feel in a 2 stage trigger and a short reset. Geissele triggers aren't a bad option either, they run a bit cheaper also, closer to $200, but if what you have works for you, then use it.

I run on the theory if there's no precision targets out past 300m go with Montana Gold or Hornady 55 FMJBT, anything requiring a 4 MOA target or smaller beyond 300m the entire stage gets 75gr Hornady. There are better bullets out there but the Hornadys are cheap and shoot extremely well through my rifle.

I would highly recommend using an IR sensor type chrono like the M2, this will remove the light issue. I have used my M2 to great effect for getting loads developed and getting ballistics tables built. One thing to keep in mind though is that when you start talking longer distances that things such as pressure, humidity and numerous other factors can effect the drop of the round greatly. THe best thing you can do is find a place to verify your chats and do the old school method of the data book. Ballistics programs are great but having a data book is even better. With a .308 just a 2000ft change in elevation can be the difference between a hit and a miss at 1000 meters on a 20x40in target

It's a slide lock not a release, the M&P slide can be released by simply loading a magazine, if you use 125gr loads there's more than enough mass there to slide it in a bit harder and get the slide to go in to battery. It's faster than pulling back o the slide or looking for the slide lock

I shoot an 18' OBR, I have not had access to 1000m range I have however shot sub-moa out to 800m. With Berger 155.5 and 44.8gr of IMR 8208 you will be pushing 2800fps and stay supersonic out to just past 1000m. THe biggest suggestion I can make for making shots out that far is make sure you have clear scope and enough elevation adjustment in the turret or enough MOA built in to the rails or mounts.

Hornady rounds tend to shoot great, if you want cheap rounds try the 150 FMJBT. I've gotten great accuracy out of my rifle with them. I know they aren't in your manufactures specs but going lighter shouldn't show any negative performance.

You just need to find what works best with yur rifle, my OBR loves Hornady 150gr FMJs and Berger 155.5 fullbore rounds, 175 SMK rounds shoot sub-moa barely and honestly they are't coming out fast enough. My 155.5s preform better in the wind than the heavier rounds due to the fact that they can just get to the target faster even at 800m

I have an 18" OBR, I have gotten 1 moa or better with everything I have tried. Hornady 150 FMJs are shooting .5 MOA at 100-300M but I haven't shot them out past that. For long range stuff I use Berger 155.5 Fullbores, they aren't exactly cheap but I haven't shot anything that can touch them. I shot a 6 inch group out to 800m with it. I am using Reloader 15 on the Hornadys and IMR 82-8 for the Bergers. The OBR is a tac driver, you'll just need to make sure you trim your cases and back off a little bit at least a grain on your loads or your plunger will dent the head of the brass.

I have an 18' OBR and have been getting sub-moa groups out to 300m, I haven't shot them past that yet though.

The Hornady 150 FMJ is a great round for 3 gun. it's cheap and I can shot sub-moa groups at 300m with it. I use 44.9gr of reloader 15 with an OAL of 2.815

I haven't loaded any rounds that heavy with 8208 but it is the best shooting powder I have used in my OBR. Velocities are extremely consistent and groups are very tight. I generally use Berger 155.5 fullbore rounds with 8208. When I do it's 44.7gr through brass that has been previously fired.

I'm running an 18' OBR and while I'm not using 155 SMK I have loaded 150 SMK and Hornady 150 FMJBT as well as Berger 155.5 fullbores. My best long long range load is 155.5 fullbores using 44.7gr of IMR 8208 XBR loaded to 2.815 OAL. They are chronoing around 2750fps. If you are looking for something more for 3-gun I suggest the Hornady 150s, they are cheap and accurate I use 44.9gr of reloader 15 loaded to the same OAL and chrono at roughly 2760fps.