Model 1 Sales 300 whisper upper function problems

[TerroristHunter]

Just put together my M1S barrel on a CMMG upper with an Adams Arms Piston kit. Haven't tried the AA1680, but H110 and Reloader 7 haven't cycled yet. After drilling out my barrel to the same size as the gas block hole (.155) it will at least eject. I have also cut 1/4 off of the buffer spring (and stretched it out), and removed one of the weights from my buffer. The Adams Arms is a heavy Bolt carrier, but there is an option of just installing a key on a regular carrier. (Maybe chrome lightweight) Will keep you posted...

[TerroristHunter]

By the way, M1S will turn the barrel down to install a pistol position gas block, but it costs an extra $100.00

[mak91]

I got a m1s 300 whisper barrel back in 2004. Did the same thing, drilled out the port, cut the buffer spring, tried a bunch of different loads with Reloader7, Accurate 9, and Hodgdon335. Got some loads to cycle most of the time but never got 100% reliability. I also wanted to shoot some non subsonic loads some time and this setup would not work for the higher pressures. I finally figured out something to try, a double gas port configuration. I had tp555 make me a custom gas block. The adjustable gas block has 3 settings, off, pistol gas port and carbine gas port. In pistol gas port position the carbine port is blocked and gas only flows back to the bolt from the pistol port, same goes for the carbine port position, gas only flows from the carbine port to the bolt, the pistol port is blocked. This gives me the best of both worlds. Since I had already drilled out the carbine port to a larger size trying to get it to work in the original configuration I now have to use an adjustable gas tube to get the pressure right.

[Artful]

Pretty trick - what did that set you back?

[mak91]

I did all the work my self except for the gas block. For the block I had tp555 make me a prototype off the block he was already making. I am not sure what he would charge to do this work or for the block. IM or email him, real nice guy to work with......

[worksalot]

I will just throw this out...do with it as you please. I ordered my model 1 sales barrel a few months ago and did a lot of shooting getting ready for a hog hunt. Here is what I have found to work on my upper.Let me start by sayingit took about 50 rounds and a lot of lube to break every thing in, it was very tight to start with.I have the 16 inch barrel with the gas port in carbine location the port size is what ever it came from model 1 as. This is what works for me. h110 or n110 or win296 for super sonic loads from 110gr to 150gr all function fine no problems. Subsonics, I am using accurate 1680 with the standard carbine spring and buffer in my vltor stock. I tried using the n110,h110 and 296 for subs but they would not cycle unless i used the lightened buffer and special whisper spring that i ordered from model 1 when i ordered my barrel. I didn't want to switch buffers and springs to change from subs to supers so i found a powder that made the subsonics function in the supersonic configuration. I have seen a lot of negative stuff about the model 1 sales uppers but mine has been great. They need to be shot abit and lubed to break in but after that just work with your powders. It is asking alot of a semi auto to function with full house loads and then sub loads using the same powder because your pressures are way different. So give it a powder that has a slower curve to operate with the subs. just my 2 cents worth but i have put about 500rnds down range with my whisper in the last 2 1/2 months and love it...

[worksalot]

I will just throw this out...do with it as you please. I ordered my model 1 sales barrel a few months ago and did a lot of shooting getting ready for a hog hunt. Here is what I have found to work on my upper.Let me start by sayingit took about 50 rounds and a lot of lube to break every thing in, it was very tight to start with.I have the 16 inch barrel with the gas port in carbine location the port size is what ever it came from model 1 as. This is what works for me. h110 or n110 or win296 for super sonic loads from 110gr to 150gr all function fine no problems. Subsonics, I am using accurate 1680 with the standard carbine spring and buffer in my vltor stock. I tried using the n110,h110 and 296 for subs but they would not cycle unless i used the lightened buffer and special whisper spring that i ordered from model 1 when i ordered my barrel. I didn't want to switch buffers and springs to change from subs to supers so i found a powder that made the subsonics function in the supersonic configuration. I have seen a lot of negative stuff about the model 1 sales uppers but mine has been great. They need to be shot abit and lubed to break in but after that just work with your powders. It is asking alot of a semi auto to function with full house loads and then sub loads using the same powder because your pressures are way different. So give it a powder that has a slower curve to operate with the subs. just my 2 cents worth but i have put about 500rnds down range with my whisper in the last 2 1/2 months and love it...

[sten668]

Hey Worksalot, great news you have for me. I have just started shooting my MS1 config. I am hoping I can find a sub load for the 3000 175gn FMJs that I have. 1680 is on my list to try. H110 works fine with super sonic loads. What bullet/powder combo are you using? The dream would be to get my 225 cast loads to cycle while subsonic... they maybe will have to be bolt gun only fodder.
good shooting
Marv

[worksalot]

This load works in my rifle and is safe but each rifle is not the same and what is safe in mine may not be safe in yours.......now that i have that out of the way. I use 11gr 1680 under 208gr amax bullet 1000-1030 fps . They cycle mine and lock the bolt back on the last round. Hope that gives you something to work with.