Rebarreling and Home-Shop Machining

Accurize the Factory Barrel

If you have tried to sell a factory barrel, you will realize that they have no value. So this experiment is just to see what can be done with one.

Poor results with 165 grain Nosler Accubond

I shot an incremental load test with Nosler 165 grain Ballistic Tips, Varget powder, Federal cases and found my maximum load with this bullet was 45.7 grains of Varget. No clusters were apparent. Not good. I did some load experiments from 45.4 - 45.6 grains of varget and from 6 to 18 thousandths bullet jump (in a 3 x 3 Factorial design). The best load was 1 and 7/16 inch. The resulsts of these test are shown in the bubble chart in photo 3. The bigger the bubble the bigger the group. The jump can be read of the left axis. The powder charge can be read off the bottom axis. The barrel seemed to prefer 12 thousandths bullet jump with this bullet but the barrel seemed to be pretty whippy and produced poor groups.

What happened is that I removed 7/16 inch from the big end of the barrel for my rechambering. The front of the chamber is now in the first tapered section of the barrel from the breech end. The steel is thinner here so there is more barrel flex and there is more case stretch than originaly.

Better results with 150 grain

I removed 4 inches from the barrel to improve its rigidity and I changed to a 150 grain bullet. This barrel length is identical to Remington’s light tactical rifle at 18 inches. The incremental load test is found in photo 2. This is from 45.6 to 46.2 grains of Varget increasing each case by .1 grains to make 7 rounds. This bullet is showing more promise that the 165's. I'll post some groups if I have some luck with it. 46.2 grains showed no pressure signs but is likely to be near the maximum load. I have some very straight cases now that have been run through the rifle. When resized they are at about .0005 inch (5 ten thousandth) runout or less. This may or may not help with this barrel, but it sure does with a heavy barrel.

Best Results with Nosler 150 grain Ballistic Tip

The Incremental load target in photo 2 indicated that I should try loads at 46.2 grain and maybe a little higher which I did not test. I loaded a few loads with different overall lengths at 46.2 grains and 46.3 grains. The 4.6.3 grain target in at the right in photo 1 showed good promise. The two groups are two different loads one slightly longer. I’ll reshoot the best load and see if it is just a random good group. The left hand target were the last two shots from a box of of Winchester Supreme 150 grain Ballistic Silver tips. This showed promise as well. Note that I have put the hell for stout Farrell scope base back on the rifle and that the stock has a home built bedding block which is described in topics below.

The factorial design and Incremental Load method as well as the preparation of straight cases are show in detail in Precision Rebarreling.

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