.338 ultra neck down to .30?

[ugsly]

Has anyone ever taken a .338 ultra and necked it down to .30 cal and chambered a rifle to shoot 150-165gr bullets to achive vel around 3750 or 3800 or so? I know it may sound little sketchy but any input on this would be greatly appericated.

Thank you guys

 

[M700]

I believe the .300 Rem Ultra Mag actually has a tad bit more powder capacity than the .338 Rem Ultra Mag. The case is slightly longer.

That's why Idaho gunsmith & long-range shooter Shawn Carlock builds his .338 Edge rifles to take the .300 RUM necked up to .338 diameter. His "Edge" gets more velocity than Remington's own .338 Ultra.

I've seen some surprising,to me) velocity from the standard .300 RUM, including factory loaded 200 grainers that pushed just past 3200 fps from a 26" factory barrel...

 

[ugsly]

Thank you M700.I can get 3600 outa a 150 in my 300 ultra sendaro with 26" barrel, but its alittle hot.

 

[M700]

Yowsa!

 

[Wild_Bill]

Hi M700 if you are running into pressures with the full length 300 ultra mag case shortening it 90 thou will not help you gain more velocity. My advice is to forget the light projevtiles and load up some 220gr projectiles and you will cut your wind drift a significant amount at the longer ranges and also your barrel will last longer. Use Retumbo and you are good to go. If you want more go you can go to a 30-378Wby or 30-338 Lapua improved but they are bigger than i would use in your action. Forget about the low BC high velocity caper it is looking at things back the front. The heavy projectile may have more drop at the longer distances but they have a lot less wind drift. It is easier to guage ranges especialy with fixed ranges or a good range finder but it is harder to accurately judge the exact wind drift.

Cheers Bill
Australia

 

[JamesinAsheville]

ugsly, I built a 300ulta mag ackley for a guy and he was using 150gr bullets to fireform the brass and barrel breakin and he was getting at tad over 4000 fps. His final load was 165's at 3650. He could push them faster but the groups opened up. It was a 29" barrel not nothing I'd want to carry much though.

 

[Tim_in_TN]

Ugsley, I have that very reamer. I had 2 made when the 338 RUM was introduced. The fit is so much more accomodating in a L/A Remington. I built the 7mm/338 RUM first, and have not seen a need for the 30 caliber yet as the 7/338 is everything I could ask. The 140 grain Nosler Accubond to just under a 3700 will get the job done on an antelope way out there. Trust me.........