300 Ackley Magnum

[baltz526]

This is a Quick Overview for anyone who happens to Put 300 Ackley Magnum in an internet search engine and finds this. Check this link for my learning process. viewtopic.php?f=9&t=29167 To give a quick recap: The 300 Ackley magnum is in effect a 300 Weatherby Magnum Improved. The Improved aspects are the Shoulder is not Weatherby radiuses and My rifle has a Standard throat typical of most .30 rifles. The cases can be made by fire forming 300HH brass Or by just using factory 300 weatherby brass. You can "NOT" shoot factory 300 Weatherby ammo due to extreme pressure. Even though it fits and head spaces just fine. When looking at reloading for the 300 Ackley based on the 300HH case. I would suggest just buying new 300 Weatherby brass. Load data for the 300 weatherby can be used as a starting point But you must look at it like this, The Starting loads will be your MAX loads due to the standard throat free bore of the Ackley. The Ackley seems to be more efficient, You get good velocity with less powder than a typical Weatherby. If you adjust the standard Lyman 300 Weatherby sizing die to neck size brass, Without touching the shoulder. It works just fine. Same for the Lyman Bullet seating die and the Lee crimp die for 300 weatherby. Check your rifles barrel twist. Mine turned out to be a high quality 6 groove 1-12" twist. It prefers short bullets. Good accuracy has shown with 150gr-165gr-168gr Ballistic tips, 180gr protected point Partition and 180gr accubonds are the longest I got usable accuracy with. IMR7828, H1000 are the two powders I have tested with good results. Velocity's are good 150gr at 3400-3500fps, 165-168gr at 3200-3300fps, 180gr 3150-3200fps. Which are right at the top of the 300 weatherby range, with less powder burned. Good luck!

 

[JD338]

Impressive round for sure.It would like for a great long range elk hammer.

JD338

 

[SJB358]

I think your spot on. I believe it is hard to beat that case for a truly awesome 300. The RUMs use quite a lot more powder and punch the shooter a little harder. I've enjoyed my sons 300 WBY. Awesome performer with 200's.

Are you hunting elk with it this year?

 

[baltz526]

I will have it on the Elk hunt, I pack my timber rifle up high and in the thicker areas. The 300 Ackley will be used if the Elk are out in the Juniper/sage. I will also use it for Bear and Cougar in the open country/Canyons when time allows. One point I need to clear up. I have seen a Picture of a case that was represented as a 300 Ackley Magnum, Here it is. This is not the 300 Ackley I have. Mine is almost an exact match to the 300 Weatherby Improved. It has the long neck of the Weatherby, Not the short neck in the Picture marked Ackley.

 

[baltz526]

With Retumbo powder and the Nosler 180gr Protected point Partition. 88gr gave 3325fps and acceptable hunting groups. There is room for up to 91gr in RP brass with the PP Partition OAL 3.590" without excessive powder compression. Lee crimp die used. 88gr is near Max in my rifle. Next update will be after I find Federal Magnum rifle primers.

 

[SJB358]

3325 is hauling the mail buddy. That would be a crusher!

 

[NWBlacktail]

Next update will be after I find Federal Magnum rifle primers.

Fishermans in Portland had a several bricks of Fed Mag Rifle primers, they've had them for a few months now. A bit of a haul from Bend, but in case you are ever in town…

215M must be discontinued, because I haven't seen those for years now. :roll:

 

[baltz526]

As a minor up date. At Elk camp I Shot a few rounds to make sure it was sighted in for 6000' plus elevation. The Vortex 6-18x40 $220 model scope is not up to the task for recoil on this magnum. It is dead. So Back to Vortex it go's. If they replace it, I will put it on a 223 or 243. Moral to the story, Buy better scopes. Thought I could cheat for a year or two.

 

[Kodiak]

In the past I have tried Vortex rifle scopes on two different rifles. The .300 Win Mag ate up the first scope in less then 25 shots and it took the .338 about 10 shots. They were both returned to Vortex in exchange for a spotting-scope.