Why don't you have the 270 gibbs it was the most popular of them all wan't it? Ya mine shoots a 130 tsx barnes at 3375 over 65 gr of reloder 22 and cci200 primer out of a tc encore pro hunter. This load works in my gun but recommend orking up to that load. So how does the 25 gibbs shoot and what load. Do you have any of the reamers for those cartridges?gun)
With the 264 and 7mm with high bc bullets I just had no need for the 270. The 25 is a screamer and bridges the gap between the 25-06 and 257 wby. It is actually closer to the wby. Chris over at Pac-Nor barrels has reamers to do all the gibbs. I sold everything I had when I moved from my shop and 1000 yard range. I started doing the JRS design which is off the longer 280 rem case instead of the '06 case. Powder capacity and performance is basically the same as the gibbs but the neck is longer. The short necks on the gibbs were the primary reason that line never really took off like it should have. I agree, the performance is there. All of mine are the equivalent of there short mag caliber equivalents and knocking on the door of the full length mags.
Is the jrs kind of like jdj cals? I really like the 270 gibbs that is my main elk rifle. I also have the 25 ackly imp that is actually formed out of 280 brass. I guess it is called a 25-280. It shoots a 110 accubond at 3440 fps. I couldn't find any reamers available at the time for the 25 gibbs. What do you shoot out of the 7mm, 30, and 338 gibbs. Right now i'm working on a 243 ackly imp!!! looks like it is going to be a shooter.gun)
I use 35 whelen brass for the 30 and 338 gibbs because it is easy to form a shoulder for headspace when I neck them down and use 30-06 for the 7mm. The 225 nosler accubond shoots very well in the 338 gibbs and is very near the 338 winmag. The 150 grain e-tips with a .469 bc do very well in the 30 gibbs. I run those in the 3300's. I shoot a variety of bullets in the 7mm jrs and gibbs. the 162 hornady amax does a good job at long range. The 120 Barnes tsx shoots extremely flat and accurate and wil kill anything out to 500 or so yards. It is great for a flat shooting point and shoot deer rifle out to that range.