I wouldnt bore that barrel out. Heres a little info on it.
The 308 x 1.5 inch was developed by Frank C. Barnes in March of 1961. It is based on the 308 Winchester case shortened from the original 2.01 inches to a length of 1.5 inches. The only other difference is in the shoulder diameter which is .003 inch larger than the original cartridge. Two rifles were made up for the developmental work. One a Swedish Model 96 short military bolt action (1 in 12 inch twist) by Les Corbet, and the other on a Remington rolling block single shot action (1 in 10 inch twist) by P.O. Ackley. Both rifles proved to be extremely accurate although the 1 in 12 inch twist appears to be the one that has become more or less standard for this cartridge. The 308 x 1.5 inch is similar to the 7.62 x 39mm Russian (M43) military round, but is larger in base diameter and has a greater powder capacity. Consequently, it can be loaded to produce higher velocity with any given bullet weight. At the time the cartridge was introduced, several gun designers, working on assault rifle designs they hoped to sell to the government, chambered their weapons to handle the 308 x 1.5 inch. However, nothing came of these efforts, and the cartridge has never been seriously considered as a military round. A number of individual experimenters have worked with variations of the original 308 x 1.5 inch Barnes case configuration by lengthening it to 1.6 inch, 1.7 inch, etc., and it has been necked down to 22, 6mm, and 7mm caliber and necked up to 375. The case capacity of the 308 x 1.5 inch is close to that of the 223 Remington, and if necked down to 22 caliber, it delivers approximately the same ballistics. The original case forming dies were made by RCBS and these can still be ordered as a regular stock item.
