Home Forums Hunting & Shooting Custom Rifles & Wildcats 300 Ackley Improved Info

Good morning!
Yesterday during my great journey to the local metropolis, I came across a nice Pre 64 Model 70 in very nice condition that had been rechambered to 300 Ackley Improved (the barrel has not been restamped and still reads 300 H&H) for $750. They had a case taped to the price tag and its headstamp reads 300 H&H but it definitely was "improved" with sharp shoulders, etc. My question is this, can this gun be rechambered to a 300 Wby or can you use any other brass than 300 H&H to fireform cases. It is otherwise such a nice specimen, I hate to just buy it to strip it down for parts. I understand that 300 H&H ammo is getting very hard to come by.

Just bringing this to the top of the list. Certainly someone has a little bit of knowledge about the 300 Ackley Improved. I've "Googled" it but found conflicting information... some say you can fireform cases with 300 Wby while others say that you can't but have to use 300 H&H which could be tough in the future. Thanks for any pertinant information!

Don't know anything about the dimensions on the 300 AI, but if it can be formed from a 300 H&H it can be formed from a 375 H&H. I've reformed 375 down to 300 H&H quite easily.

Lundtroller: I think you want to take some critcial measurements (length to shoulder and diameter at shoulder) of the case because there can be alot of variations in so called "improved cases." For example, Hart makes a 30 Hart which has a 40 degree shoulder based on either the .300 Win Mag or Weatherby. You should check to see if gun comes with a set of dies. If the dies are standard off the shelf dies, the manufacturer should have the dimensions. Once you have the dimensions, you can look at re-chambering.

Run a chamber cast in it.If you don't like what you see cut off a thread or two and run the Roy reamer in it.For that price I would be all over it reguardless.

+1.

Page 440 of Ackley's hanbook states:

"The Ackley .300 Improved is the same as the .300 Weatherby
except for minor details. The Weatherby has what is known as a venturi
shoulder (curved corners) while the Ackley has sharp corners and a 40 degree angle.

The capacity is badly exagerated for the .30 bore and faults are more
numerous than good points.

Case life is better than for the standard .300 H&H.

Loading data is same as for the .300 Weatherby."

IF the person who did the rechambering followed Ackley
dimensions, you should be able to size .300 Weatherby
cases in Ackley dies and come out with suitable cases.


I would either fireform a few H&H cases or do a CERROSAFE
chamber cast to see how the chamber was re-cut.

Bob

No dies with the rifle, I checked. I don't know if the rifle was a trade in or part of an estate. The case taped to the tag was formed from a 300 H&H and was described as a "300 Ackley Imp." and it looks like what was described in Ackley's book. Ackley's book unfortunately does not list any dimensions for the round. I don't really need the gun, but have a hard time passing on nice pre-64 M70's, especially those with magnum actions for reasonably good prices!

Wouldn't the action alone be worth the price of admission? If not, damn close.

If the rifle is in good condition, at worst you could rebarrel it for less than $400. Those mag length actions are a bit more uncommon - the action length is the same as the 30-06 but the rear bridge is milled back and the ejector is modified.

A 300 H&H would be a dandy addition to my safe!

Key word in your aoriginal post was "I came accross a NICE m70".

That says it all for me.

Each one seems to have it's own character, and is worth the price for that alone.

Action alone is worth some bucks.

If I had it, I would shoot it.
If it fit me well and shot well i would keep it.

You might get a .300 Weatherby sizing die off ebay, and use it as a neck sizer
for initial load deveopment.

Believe that Elmer Keith and others used 300 H&H in Weatherby rifles for a lighter load. The belt should hold the case in position for fireforming.

Keep us posted on your progress.

Bob

There are quite a few different reamer designs out there. Mine was Chambered by Baity's Custom in Nc. The reamer was designed by Alvin Johnson. It has a .334" Neck (tight neck). I use Norma .300 Wby cases to form the cases. A loaded Norma .300 Wby cartridge measures .335". The Ackley is a .300 Wby blown out slightly w/ a 40�shoulder. As long as the chamber is not a tight neck you should be able to fire Factory .300 WBY rounds though it with out any problem. But of course when you eject the case it will be an Ackley. A unloaded Wby will chamber in mine. I load it w/ 14 gr. of Unique, fill to the neck/shoulder junction w/ COW top it w/ 1/4 sheet of toilet paper rolled into a cylinder, pack it down w/ a drill bit, spay it w/ one shot and fire. Comes out 90% formed. Then I turn the necks to a loaded round of .332" and I am good to go. 31.5" Broughton 5C 1 in 11" 210 gr. Berger VLD @ 3,050 fps. First group @ 1000 yrd measured 5 shots 5.124". Norma .300 Wby H20 capacity is approx. 98 gr., my .300 Ackley is 103 gr.
I attached a couple of pick. Maybe you can zoom in an see the loaded rounds.