Belted Magnum AI

[degreen]

Has anyone heard of doing an Ackley Improved belted magnum? I have searched the internet, and can't seem to find anything on this. The reason why I ask is because I have a 30-338 Win Mag, and would like to get it up closer to the 300 Win Mag. I don't want to have to modify my mag well.

 

[Garycrow]

Why don't you have it reamed to a 300 win mag instead?

 

[degreen]

Why don't you have it reamed to a 300 win mag instead?

Like I said in my original post. I don't want to mess with the magazine well. Plus I am looking at seating the bullets out as far as I can.

 

[Garycrow]

You shouldn't have to mess with the magazine, the cases are very similar. It would help if you said what action you have.

 

[degreen]

I am using an 03 Springfield action.

 

[Edd]

A 30-338 doesn't have much case taper and it has a 25° neck. I don't think your gain from improving it would be worth the effort.

Look at a 30 Nosler. You could easily reach 300 Win Mag velocity with it and it is only about 1/16" longer than your 30-338.

 

[Deleted member 46119]

What Edd said.

A 30-Nosler would do what you want and a little more at lower pressures.



As far as I know there is no 30 cal improved version of the 264/7mmRM/338 length belted case.

There is a 240 Incinerator which has a wider shoulder and 35° angle.

Applying the dimensions of the 240 Incinerator to the 30-338 WM yields a 3 grain increase in capacity. There is only ~4.3 grains difference between a 30-338 and a 300WM.

Applying full Ackley style 40° shoulder gets another .2 capacity so very close.

At that point you have the same capacity depending on brass brand/lot and a longer neck than the 300WM (~.290 vs ~.263) which can be a good thing.

so

IIWM: go 30 Nosler and load conservative or I can send you the dimensions and you can have a reamer made, dies made, fire form brass and all that.

If you go 30 Nosler, I know a guy with the reamer..... Me.

With all that, unless you set the barrel back a little, you won't know how far off the lands you will be until the rechambering is done. Mag length and optimal length may not work out.

All the best.

 

[Jerry M]

What type of gain are you looking for? 30-338 is a great cartridge, if you reload. IMHO I think a new action would be prudent for any case based on the ultra mag case.

 

[J E Custom]

Has anyone heard of doing an Ackley Improved belted magnum? I have searched the internet, and can't seem to find anything on this. The reason why I ask is because I have a 30-338 Win Mag, and would like to get it up closer to the 300 Win Mag. I don't want to have to modify my mag well.

The main advantage to AI a/any cartridge is better brass life and a more efficient powder burn.
Also Once you fire form the brass if you don't full size the brass, It becomes a shouldered case and no longer needs the belt to head space.

The gain in capacity is minimal but with the improved efficiency, the gain can be significant.

I once had a 30/338 and it was a great cartridge for long range and converting it to an AI could only improve it. Plus you probably already have lots of brass that could be fire formed. And there would be no reason to alter your action or load length.

Just my opinion

J E CUSTOM

 

[FEENIX]

The main advantage to AI a/any cartridge is better brass life and a more efficient powder burn.
Also Once you fire form the brass if you don't full size the brass, It becomes a shouldered case and no longer needs the belt to head space.

The gain in capacity is minimal but with the improved efficiency, the gain can be significant.

I once had a 30/338 and it was a great cartridge for long range and converting it to an AI could only improve it. Plus you probably already have lots of brass that could be fire formed. And there would be no reason to alter your action or load length.

Just my opinion

J E CUSTOM

+1! You might also consider a longer barrel and faster twist (should the bullet you are going to use requires it).

 

[degreen]

This rifle has a new barrel (don't remember the manufacturer) with a 1:10 twist. It is 26 inches long. I was told by the smith that did the work for me that 180 grain bullets are what he shoots in his. When I checked for seating depth it looks like I could throat the chamber a little more so I can seat the bullets out further. This is why I'm asking about doing the AI. I thought that while the barrel was off that would be the time to do it.