SPR precision AR questions

[CRAMBONE]

I called myself searching the site looking for info. I got a lot from the 18" rifle gas thread but couldn't really find anything else. If there are other threads that match mine please link them. This rifle will be my first precision rig. I want it to be good to 600 yd, that's longer than anywhere I have to shoot currently. I'm doing an 18" because I want the rifle length gas system, more fun for the wife and kids to shoot all day.


Just ordered the lower for a SPR build I have been contemplating for a while, BCM with Geissele SSA-E trigger. I think I have settled on a barrel and am going to go with Rainier Arms ultramatch 18" with rifle gas system. I'm thinking of using a Vltor MUR w/o forward assist for the upper and a BCM bcg. I still have to decide on the stock, gas block, fore end, and suppressor. Would it be productive to go with a Switchblock or similar gas block? I do plan to shoot it suppressed and unsuppressed so I would think having the ability to control the amount of gas would be beneficial. And as far as suppressors, which is a good model to run on a precision rig? I'm looking at Silencer Co's stuff and like what I'm hearing about the Omega. Still lost with fore ends, I was thinking about a 15" KMR, but I have read they won't fit over a Switchblock. And let's not even start on optics or irons yet!

[rjacobs]

You're going to find a ton of opinions on your questions. The following is my opinion.

I run a Syrac adjustable on my SPR. I only am running adjustable because I am running a JP light weight carrier and silent captured spring system and wanted to be able to tune it for lowest recoil as well as full function. If I wasnt, I probably wouldnt have run an adjustable. Once I got it set I dont mess with it between suppressed and unsuppressed. Runs great either way. Could I dial it back a bit more for suppressed, probably, but it runs great either way so I havent messed with it.

I use a Vltor MUR without FA. good choice

I am running a Magpul Fixed rifle length stock. normally I am not a long stock guy, but this one just felt right. I couldnt get any carbine stocks out long enough to feel comfortable shooting prone.

Cans: end all be all of precision cans is Thunderbeast. Its what they are known for. They hold crazy tolerances.

15" rail is what you want for the rifle length gas. Im running a Giessele Mk4. It was on sale and its good quality. If I was building another one, I might go a different direction, not sure. Havent researched 15" rails in a while.

As far as optics go, I think you will find a lot of people recommending a 2.5-10x. I run the Vortex 2.5-10x32 FFP. Nightforce is also an option. Might be another couple out there now too.

[P2000]

https://www.m4carbine.net/archive/in.../t-109073.html

I went with vltor mur with fa, syrac adjustable, and surefire socom. I wanted a detachable can with a rock solid mounting system, and the socom fits the bill nicely. I only shoot suppressed, and have the gas choked off by 2-3 clicks which does make it shoot softly.

[Fatorangecat]

I have an SLR Adjustable gas block with a Vltor A5 buffer system on my precision rig and I love the combination. As for rails the Geissele SMRs are my favorite.

[CRAMBONE]

Thanks for the info guys. I'm almost at the point of pulling my hair trying to pick parts to go on this thing.

What made you guys decide on those gas blocks, the Syrac and SLR? And I'm assuming the rails fit over them?

[rjacobs]

What made you guys decide on those gas blocks, the Syrac and SLR? And I'm assuming the rails fit over them?

There was a reason, AT THE TIME(almost 2 years ago), that I went with Syrac over SLR. I cant remember what it was, but at the time, the Syrac was reported to be better than the SLR, which may or may not still be true(its probably not).

ETA: Looking at both websites now, it may have been as simple as Syrac offers an uncoated stainless gas block and SLR only offers coated gas blocks and I didnt want a black gas block on a stainless barrel. It may NOT have been a functional difference between the two, only aesthetic.

[Mr blasty]

Thanks for the info guys. I'm almost at the point of pulling my hair trying to pick parts to go on this thing.

What made you guys decide on those gas blocks, the Syrac and SLR? And I'm assuming the rails fit over them?

Both have a good reputation of being hard use capable gas blocks due to the self locking nature of the adjustment. There far less likely to self adjust compared to many of the companies out there.

Sent from my SM-G900T using Xparent BlueTapatalk 2

[P2000]

Thanks for the info guys. I'm almost at the point of pulling my hair trying to pick parts to go on this thing.

What made you guys decide on those gas blocks, the Syrac and SLR? And I'm assuming the rails fit over them?

At the time I hadn't heard of SLR. Not to say that would sway my mind anyhow. Yes, a non-clamp style Syrac will fit under a NSR or a KMR.

[Singlestack Wonder]

Go with a BCM SS410 barrel and BCM gasblock. No reason to have an adjustable gas block on an a 5.56 rifle. You will be very pleased with the BCM's barrel accuracy. While you at at it, go with a BCM upper receiver and BCG. It's never been proven that a Vltor MUR does anything better than a standard receiver. Great price and proven performance.

[Fatorangecat]

Go with a BCM SS410 barrel and BCM gasblock. No reason to have an adjustable gas block on an a 5.56 rifle. You will be very pleased with the BCM's barrel accuracy. While you at at it, go with a BCM upper receiver and BCG. It's never been proven that a Vltor MUR does anything better than a standard receiver. Great price and proven performance.

I agree that the BCM upper and BCG are good choices but I disagree about the gas block. Although a 5.56 is not a heavy recoiling weapon the reduction of felt recoil makes for a very smooth shooting rifle with very nice follow up shots.