223 AI with 40 grain bullets

[couesaddict]

So last year I put together a little 223ai with an 18" brux 12 twist .050" freebore. Got it from bug holes with the bugnut setup for my Remington 700. I drug my feet getting components together until they were nearly nonexistent and didn't have a great stock in that burn rate so haven't done much past forming a couple hundred pieces of brass. It shoots extremely well with fireforming loads and equally as accurate in load development. My question is more related to velocity expectations. Read on some other forums of people getting some exceptional speeds with aa2015 powder with 40's and it just so happened that it was the first option in the range I was looking for to come available. In my pressure test today, 27 grains is top end for pressure at 3560ish fps and case is full to the base of the neck. This is with a magnetospeed that tracks with ballistic programs in my other rifles. It's fine and I'm not going to worry too much about it because I didn't build this one for light speed long range anyhow but thought I'd reach out to see if others thought this was normal speed for this length barrel or on the slow side for this case.

 

[just_jon]

With a 40 grain Nosler BT, QL shows 27 grains at 3,469 fps and 53,214 foot pounds of pressure. Max pressure is listed as 55,000.

 

[couesaddict]

Thank you.

 

[couesaddict]

If I'm interpreting quickload correctly, the additional 100fps I'm getting over it's prediction would indicate that the load in the rifle is creating more pressure than the prediction and it is indeed tapped out? Confirms what I saw in my pressure test anyhow.