I just finished my first SBR and I am still waiting on my suppressor. Basically I want to take it out and setup the rifle. I want it to be reliable and work both with the suppressor on or off. So I think I know what I am doing but let me know if you have any tips or can answer any of my questions.

Im going to shoot with the weakest ammo ill be using with this rifle which is probably American eagle 55gr 5.56. So ill adjust the gas block with this ammo and then once I find what seems perfect ill probably go one or two clicks further out depending on feel. The suppressor is going to add back pressure right? So in theory I should be able to just add the suppressor and not adjust anything? Wouldn't this add to the reliability?

I did learn a lot about all this a year and a half ago when I started this build but I cant recall if this is all correct or not.

Pictures because otherwise this post would be boring.

I make sure it runs and locks back unsuppressed with weakest loads. Then open two more clicks. Suppressor does add additional back pressure.

For an item used 100% suppressed I do the same but with suppressor on then add two clicks

SLR adj gas blocks

Just go to the range and close the gas block all the way, then open it up slowly until the gun locks open on the empty mag. Shoot one round at a time using an empty mag. Once it locks open, yeah go ahead and open it up just a little more just to be safe. Then try one round suppressed and see if it locks open on an empty mag. But yeah play around with it and see what setting runs best for ya for both suppressed and unsuppressed.

I forgot to mention I have the spring kit for the JP SCS. I was planing to start with the lightest spring weight and move from there. What should I be feeling for with the springs? Obviously the spring in the buffer tube is to manage the BCG both forward and backwards and you dont want to go to weak because it wont load a round. I think I am going to have to play a good bit with the spring kit to fine tune that. I am wondering if the springs will be more sensitive to the suppressor?

I pretty much do this but don't open the SLRs any more once I have reliable function unsuppressed since I almost always shoot suppressed (but want reliable function unsuppressed.)

I don't have experience with the springs.

JPK

I have a couple of questions regarding this, as I just acquired the SLR block for my 10.5 sbr.... first, do you guys bench the gun when you're doing the adjustments or do you stand and shoot it from the shoulder? If I'm going for reliability, should I go a step further and hold it off shoulder and "limp wrist" it, and then adjust until it stays open like that or is that overkill? Lastly, I have both T1 and T2 buffers.. which should I be using for this? I'm guessing T1, but just double checking. Thanks!

I have used standard H2 buffers in all of my SBR's without issues. For that matter, I have used standard H2 buffers in all of my AR's shooting suppressed or unsuppressed, and I've never had any issues swapping uppers between lowers either. The uppers I run with no issues on H2 and standard spring lowers include 16" 5.56, 10.5" 5.56, 16" 6.8 SPC, 11.5" 6.8 SPC, 10.5" 300BLK.

JPK

I have an SLR block on my 12.5 that I run suppressed.
The screw is seized all to hell and won't loosen up ever again but it is set where I like it and it works.

Feed the gas tube with pb blaster wait one minute and then use pliers. Or heat the gas block up and then use pliers. The nice thing about the slr block is the adjusting bolt sticks out pretty far. So you can grip the bolt no problem with tools.

My sbr is setup to only run suppressed with my SLR adj block. (I think I went 1 over lock back)

My 16" is 1 over unsuppressed, and I make no adjustments when I pop the suppressor on.

I'm currently using an 11.5" upper, SLR, saker k or saker 762 and a T2. Everything works well together. I tuned it shooting standing/shoulder fire. Tested hip shot, strong and weak side. No issues.

Do whatever makes you feel comfortable that's it's setup properly.