I am about to have a Rem 700 rebarreled to 22-243 Middlestead or 22-250 Ackey Imp. and would like your opinion on Pac-Nor prefit barrel? Or should I go safe and have a Shilen instead?

Anyone know how the chamber dimensions are on these prefit Pac-Nor barrels? Should it be a problem using Ch4D diset?

Last, 22-243 Middlestead or 22-250 Ackley Imp.??

Pac-Nor barrels are superb, though I don't know how they are dimensioned on the pre-fits. I would certainly go with the Ackley chambering, though, as making Middlestead cases is supposed to be a real chore. Velocity is fine, but either cartridge is going to be kinda harsh on the barrel. I guess that is the price you pay for the performance.Best of luck in your choice and your endeavors.

I have a 22-243 Middlestead, and brass is just necked down 243 and fireformed. No hassle at all. It's a pretty quick cartridge, about the same as the Cheetahs, a little quicker then the 22-250 AI. Yes, they are a little hard on barrels. - dan

I've got a 22-6mm, 1:7 twist pac-nor and a 22-250 AI with a 1:9 twist for shooting 80 grBerger VLD's. Personally, I'd prefer buying an unchambered barrel and do the machine work myself. Lot's of folks have been very pleased with their pre-fit barrels. You can have them long chambered or short chambered depending on your preference. I pretty much use Pac-nor barrels for everything now.-Rob

Tomjac:

I may be biased living in Oregon where PacNor Barrels are made, but I think they are as good as you can get from any of the other big named shops. I have 4 guns rebarreled with PacNor Barrels. All are very very accurate shooters.

A gunsmith here in my hometown builds a lot of 22/243s. However as a handloader, I go for efficiency and know the less powder I burn to achieve the velocity I want, the less throat erosion you will get, or not as fast.

I have not gone with the Ackley Improved 22/250.
All I can tell you is using 40 grain bullets in a regular 22/250, with RL 7 ( which is made in Sweden, but I don't know what it is called over there, or if it is even distributed) I can chronograph consistently 4450fps with Sierra or Nosler bullets. 5 inches elevation at 100 yds puts it dead on at 500 yds. How much more flat shooting do you need if range and velocity is your goal?

The Ackley Improved gives no improvement on that as far as seen by those I know who shoot it.

Oh the receipe I use is 34.5 grains and a Federal 210 primer. That is out of a 24 inch barrel. I am having another rifle rebarreled to 22/250 ( a 30/06 Browning), but this time I am going with a 28inch heavy sporter PacNor barrel on it. This should up the velocity a little on it.

I use it for prairie dog shooting for shots over 250 yds. when I set up, I shoot a 223 downloaded to 2600 fps for the shots under that.
Using Blue Dot shotgun powder in it, with 45 or 50 grain bullets it takes care of most of the high volume shooting. This load also takes quite a while for the barrel to heat up, and it cools down quickly. I can also get almost 600 rounds out of a pound of powder!

I have barrels by kreiger,schneider and pac-nor and all seem equally accurate.My two 300ultramags both have pac-nors and they both average 1/2" or better for 3 shot groups.Neither however was prefit.My own gun builder now uses more pac-nors than any other barrel.