Seating depth question

ACLakey · Jul 6, 2011

I worked up some OCW loads for my 223AI and 75gr Amax bullets. I found my charge weight at 26.2 of RL15 and my seating depth at 2.455 which is .005 off the lands gave me 3050fps(just where I wanted to be).

My problem is the mag box on this rifle is at 2.410 which is .045 from my optimal depth and I don't want to turn this into a single shot rifle. I have had two different gun smiths try to make a mag box for a 22-250 work with no luck. After eight months of tinkering and waiting for parts I installed a factory mag box and the rifle feeds great. What are the odds of me finding a seating depth around 2.400 that will produce similar results?

I should have had this rifle throated for the mag box, when I put a new tube on I will do that. I am going to do a OCW with RL15, Varget, H4895 and IMR8208 XBR just for kicks....hopefully I can find a good combo that will feed in this rifle. Any thoughts or suggestions?

DrMike · Jul 6, 2011

Looks like a super load. The problem of mag depth is common. It is entirely possible that you will find a second node for the bullet at a significant distance from the lands. I have had rifles that gave me great accuracy at 0.25 inches from the lands. I would test some to fit the mag and seat them deeper just as you've done to this point, but with a view to fitting the magazine.

SJB358 · Jul 7, 2011

I agree, I would bet you will find another node further back. All my rifles are factory guns and most are seated to mag length of less. I haven't had too many issues finding a load that shoots well. Getting to lands is pretty tough with alot of bullets in factory rifles. Scotty

ACLakey · Jul 7, 2011

Thanks for the info, that is what I was thinking(hoping) but thought I would post for conversational purposes.

I just sent my scope off for some warranty work so it will be a few weeks until I can get to the range. I will report on the results.

Guest · Jul 7, 2011

I tend to agree with the idea that you'll find another node at a shorter COL. I don't have any rifles that shoot their best right at the lands. In my rifles I always start at magazine length and move back from there. Maximum COL for me is the longest length that will feed reliably. Any longer, and I no longer have a hunting rifle, so I don't work with those lengths. I've not had much trouble getting good groups from my rifles, though most of mine won't shoot as good as your last two loads did. A couple will, and they both do so at below mag length.

ACLakey · Jul 22, 2011

Finally got my scope back and was able to get to the range. All loads were set to COL of 2.405 which was a 0.055 jump to the lands and 0.010 from the max mag length. The round feed well now!

I pulled quite a few shots today, too much coffee I guess but just about 1 out of every group did not feel great but I have good enough results to play with.

The RL15 loads did not shoot quite as well as they did seated out farther.

Varget shot well, the fliers were me today.

I am going to be sticking with Varget and fine tuning a few things. Interestingly enough I ran the OCW loads in the winter below zero temps and came up with the same result with Varget.

Shot at -2F

I wish I would have had the chrono that day.

The RL15 loads showed pressure signs where I had good results in the cold.