I am having trouble with feeding
 

I have a newly built upper its accurate as heck but I am having trouble with failure to feed. any help with a good load for 16" I have a carbine length gas tube and gas port hole in barrel is .106" Thanks in aavance!:smile:

What load are you using?

What type of failure to feed are you having? Is the round not being picked up? Is the roung not fully chambering? Any further information would help determine your problem.

the rounds eject, bolt not coming back far enough to pick up next round from mag. I have tried switching to heavier buffer from AR57 and it shoots fine with 110 gr Vmax loads over "296" middle load from hornady manual. I put carbine buffer back in and still cant get it to function with heavier loads... Bolt doesnot lock open after any of my rounds.?

I had the same issue although my gun is shorter and has a pistol length gas system.

The remedy is more powder. You need a higher charge with the same bullet to get the BCG to go rearward enough to pick up the next round.

Keep in mind that the .300/.221 is much shorter than the .223 so it is easy to eject without a full cycle of the BCG.

Try going in .3 or .5 grain increments until you get reliable function. The only problem is that it may also be supersonic when that happens. That is the problem with the AR platform is that it needs to be stout enough to cycle the action, but slow enough to avoid the sonic crack. You may also have to play with some powders. Mine likes 8.5 grains of 2400 with 220 gr. Sierra Matchkings. I also tried it out and got it to work with lighter bullets (175 and 150) with 7.5 grains of 2400.

Last thing is since you have a carbine gas system, you may need to open the port up if you want subs that cycle.

Since you didn't list your twist, you may have better luck with lighter bullets if it isn't a 1 in 8.
________
Vapir Air One Vaporizer

Everything that buffetdestroyer said plus switching to a heavier buffer will just make things worse you need a lighter buffer if you are going to switch buffers.

Wolfe also makes a reduced power buffer spring that will help.

Thanks for the help

What powders are you using? I couldn't get H110 to function with the subsonic rounds, but I have been having better luck with AA 1680. It might be worth trying some different loads listed here to try some different burn rates.

:confused:I have tried AA#9, H110,w296 18.8 gr of 296 under 110gr Vmax feeds fine... I cant get it to feed with anything else.. . . I'm pretty darn confused. Ithink I need to go to a slower powder? The rifle shoots accurate just not feeding,ejects spent round, doesn't lock open after last round from mag. wont pick up next round...(short cycle)

I'm assuming you are shooting the 110 gr VMAX supersonic, right? I would try to get a hold of some Accurate Arms 1680 for the subsonic loadings a number of people here, including myself have had better luck with 1680 cycling the subsonics.