300W Gas port size with 20" barrel

[kurtz]

If you can lay your hands on some Accurate 1680 powder I think you'll be happy with the results over the H110....the 1680 has a longer pressure curve which helps with cycling issues found with the more abrupt H110....the primer flattening should go away also....

the only buffer mods I have done is to drive the roll pin out, open the buffer and remove or add weight to see how it changed the cycling.....with the charge I'm running now I ended up being able to use a full weight rifle buffer....loads at or under 25gr of 1680 with a 125TNT I had to run a reduced weight buffer....

hope this helps,

[txjm]

I played with a little 1680. I ran out fire forming brass and have more on order. I was up to about 23G and started seeing pretty flat primers with the 125G noslers. I hope I can bump it up a little with the flat base sierras.
I opened the port up tonight. maybe that, different bullets and 1680 will do the trick. 22.5G of 1680 with the noslers would open the bolt enough for the case to hang in the ejection port, everything else either closed or hung on the edge of the barrel extension.
Thanks
Chip