I just want to start off by extending a sincere "Thank You" to everyone who has generously taken the time to educate me throughout the past year. You guys have been patient with me. This is my very first Long Range Gun I had built by a very reputable gunsmith in Phoenix. It is a 280 AI tight-necked chamber (.311). It is built on a Alpine/Timberline action (Thanks for the advice with this Kirby, I do think this is the best action for the bucks) with a NF 5.5 X 22 X 50 scope and set in a McMillan Lazzeroni Thumb Sporter stock. I sent the stock off to Shawn Carlock to have painted and am VERY happy with the way it looks! Thanks Shawn! The barrel is a Krieger 25.5" 5.5 contoured & fluted barrel.
I went down to my local outdoor gun range in Phoenix over the weekend and braved the 110 Deg heat. I never imagined a gun could shoot this well and I have just started in my load development phase! I neck turned most of my brass to a .0125 thickness and then weight sorted my Nosler 280 AI brass. After reading on the forums here that it usually takes a gun 20 - 40 rounds to break in the barrel and start grouping, I decided to use the brass that were extremely heavier or lighter than the rest. In other words, this is with brass that varied as much as 2.0 G in weight. Here is my target and I'll explain the hits.
Because I just can't go running out onto the range whenever I want, I decided to use this big target initially because I wanted to sight in my AR-15 also. All I did was dial the NF down 20 mils (1 complete turn) and was off to the races. I decided to use H-4831 as well as RE-22. I loaded up 6 shots with 56 g of H-4831 to go along with my 168 G Berger VLD seated .010 off the lands, figuring it would take me this long to get this thing zero'd so I could start my ladder test. I also decide to use CCI Magnum 250 LR primers since I still have a bunch to shoot. The first 3 shots are shown at the bottom right and made one big hole. Next, I made a scope adjustment for zero and fired two more shots which are covered up by tape. I did this so that I could start my ladder test. I cleaned the barrel after every 4 shots.
Then I started my ladder test with H-4831:
1. 54 G 2686 fps
2. 54.5 G 2725 fps
3. 55G 2747 fps
4. 55.5 G 2742 fps
5. 56 G 2744 fps
6. 56.5 G 2825 fps
7. 57 G 2766 fps
8. 57.5 G 2799 fps
I can't explain shot #6. I'm not sure this was an accurate reading. Also, I had to tape over the far right shot because the guy 2 lanes down "accidentally" put a round into my ladder test! Then I shot a 4 shot group of 56.5 G H-4831 and got the following:
2 hours was all I could take in the heat. I'm not sure how much this affected my tests, but I did have a hard time getting the barrel to cool down. I'm blown away by the accuracy of this gun. I was hoping to get a little more velocity out of this thing, but I knew that H-4831 is not the fastest powder. I ran out of time and didn't even get to try the RE-22 powder. This is the first time I've ever had a LR gun, but it appears to me that I got lucky and 56.5 is a good load for this gun. I'd appreciate any feedback trying to interpret this ladder test, but I think the next time I go to the range, I'm going to try a 4 shot group at 55, 55.5, 56 & 56.5. As always, I would appreciate any feedback. Should I try some loads with more powder? 57.7 is the max load listed on the Hodgdon website. FYI, even at 57 G I wasn't showing any signs of high pressure.