Sporter barrel as accurate as heavier barrel?

[dmr400]

This is an area I feel I have quite a bit of experience since I build and shoot both BR rifles and hunting rifles at 1000 yards for group. The sporter barrels will shoot very close to as well as the heavy barrels when perfectly in tune. Your load will change with temp and humidity and the heavier barrels have less amplitude in the vibration pattern. So as they both go out of tune the heavier barrels do it less dramatically than the sporters. Many confuse this with a wider load window, they both go out of tune the same amount its just thinner barrels will produce larger groups than heavier barrels at the same amount of tune error. The nodes will be just as far apart in the two contours, so tune widths are equal. At 1k an out of tune sporter can shoot real big in a hurry. I really wish more guys would shoot paper at those ranges. Moral of the story, go with the heaviest barrel you can stand to carry, or plan to stay on top of the tune really well.

Alex,

How wide of a powder charge do you think the tune is in a midsized cartridge, say a 284 or 280AI? Are we talking .2 grains, .5 grains, more, less? Thanks!

 

[wasskeet]

A McWhorter sporter (probably#4) 26" in 7 WSM was as accurate as anything I have owned for the first 3 shots - ragged hole from cold, fouled barrel. If I did my part, high .2's to .3's - initial shot included - I can't imagine wanting better for hunting.

 

[Alex Wheeler]

Alex,

How wide of a powder charge do you think the tune is in a midsized cartridge, say a 284 or 280AI? Are we talking .2 grains, .5 grains, more, less? Thanks!

At distance you can expect about 1/2% for peak accuracy. So 60 grains of powder, about .3gn window. Now barrel quality and tune plays a big role. If you have found the right powder and primer combo the barrel likes that will help. And really good barrels can help a lot. Also distance, at 100 you will see nice wide windows, take it to 1k and they will be tiny. You have a 600yd max cartridge in my opinion (so long as its accurate) so if you tune at 100, it should hold up for your needs.