264 IMP. Information

[Lees Tactical]

I bought a custom rifle a short time ago only markings for caliber are 264 imp., Best guess is it's an older build maybe FN single shot action with set triggers(around 4 oz) , was able to shoot 264 win mag ammo with no problems, 26" bull barrel, very nice groups, the brass comes out fire formed to look like the 25-264 brass... But thats 25 cal and the 264 is 6.5mm.... is there a 264 imp that matches that ? Im needing to reload, do I try to find 25-264 dies? Any help ? BTW Thanks for having me

 

[nkyshooter]

I don't know of a SAAMI or CIP recognized 264 Win Mag Improved - however - the "Improved" designation is a loosely accepted standard way to communicate the walls have been slightly blown out to less taper and the shoulder angle has been increased from original to 40 degrees (although some are 35 or 30 degrees). These "improved" cartridges - by their loosely accepted meaning - by definition will fire the parent/native cartridge resulting in fireformed brass.

P.O. Ackley is the first I am aware of to do this and it results in both advantages and disadvantages over the original parent cartridge.

From your description, it "sounds like" you have a 264 winmag ackley ...

You've answered 1 question already - does it safely fire standard 264 winmag - and it would seem it does since you were still intact to post

My experience with ackley improved cartridges is based on short action 308 based cases ... most notably the 260 Ackley ... (260 Rem Ackley Improved 40deg shoulder). My fireformed cases result in approx 6-7% more volume for powder and approx 150 feet per second additional muzzle velocity. The new dimensions also serve to reduce case stretch during subsequent firings as well as (arguably) increasing barrel life by retaining more of the "flame" from the powder burn inside the case during fireing. The down side/trade off is that is does not feed AS smoothly as a standard 260 Rem ... but if I need to feed THAT smoothly, I can still feed it standard 260 .

If you reload, you can likely increase your muzzle velocity over standard 264 winmag ... but you must work up with caution and be very attentive to pressure signs and don't push the limits.

 

[Lees Tactical]

Thanks, I've been looking everywhere for info on the 264 ackley inproved, the only thing I can find is for the 25-264 improved, My Barrel is 6.5mm, not 25 cal ? Did ackley make a 264 improved? Im guessing im having to buy custom dies.....?

 

[johnnyk]

Hey, WELCOME aboard! Glad to have you.
I did a quick search but couldn't find anything either. IIRC, Hornady will make you a die if you send them three of the fired cases from that chamber. I think they're in the $200 range. Some will consider that too expensive (my wife!) but I would try to justify it by telling her; "It will allow me to be able to shoot and reload for this fine, semi-custom rifle. Otherwise, I'll have to buy brass, shoot it and throw it away"!

https://www.hornady.com/reloading/dies/custom-dies#!/

Good luck with your project. Would love to hear how it's going and see that jewel in action. I bet those 156gn Bergers, ahead of Retumbo or RL26, would put the smack down on those Texas whitetails from a long ways off! Makes me want one! So many cartridges, so little time!

 

[nkyshooter]

I am able to reload my 260 ackley using Lee Ultimate 4 die set for 260 Remington ... as long as I don't need to full length ... for that, I then use a Redding body die for 40degree improved ...

I bet you could do this for 264 as well if you can find the dies.