does anyone have load data or a favourite load that they would like to use in one of these rifles as I cannot find anything on a net about it

welcome to AR

It's generally called a 458 Ackley -
in my experience, (and if i remember correctly) one can shoot 458 lott in that chamber, but not the other way around, as the ackley is slightly longer.

here's a longer discussion on the matter
http://forums.accuratereloadin...1044/xsl/print_topic

I would NOT use Ackley's load data in his books, rather start with moderate 458 lott loads and work up. Parker's loads are known to be a bit hot

it's gunna kick, watch out for the scope (if you have one), and remember, you decide where the bullet goes!

His improved 458 is just a standard case slightly blown out.

Is this the one?

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Just use standard 458 data; that is the dumbest wildcat I ever heard of.
It couldn't possibly offer any benefit. Maybe one percent.

Thanks mate 300 grain pill at 3000 feet per second must be some sort of improvement

1 - 500 gr at 3000fps is IMPOSSIBLE with a HH based case -- which is why i told you not to use parker's reloading data - He didn't have a "real" chronograph, and his vel estimates are "optimistic" ..
2 - if you believe you can go way higher than a 458 winmang, you have a 458 Ackley - not a 458 winmag ackley improved
3 - realistic load vels are 2% over a 458 lott
4- my 458 AccRel case has greater volume than the lott/watts/ackely, and 500gr at 2600 is PAST max pressure for an African hunting round
5 - no, you can't get 3000 fps with a 400gr .458 bullet in the case - this case is Drastically smaller than a 460 weather -
6- there's maybe 500 people that have shot the watts, ackley, and lott cases, and MAYBE 100 that can add in the various 404/RUM 114gr ish cases .. and nearly all of them are here on AR, and I've hunted with them
6 - a 300 gr .458 bullet is a varmit load - i wouldn't even shoot Texas whitetails with that

That is awesome; do you have the 2.4 inch case?

I didn't say 500 grain I said 300

458 ackley improved lott

What threw me, and maybe others, off, is that Joe said you had a 2.4 inch improved 458. The full length 375 case is different; A lot different.
Yes, a 300 at 3000 is doable in that.

Thank you for understanding I'm just trying to get some more load data I've anything anyone has tried different wait for bullet grain sizes different powders eccetera

if it where mine, as i said I would start with 458 lott loads and work up. the case is, iirc, 0.05" longer, and only a couple grains of h2o capacity larger - the working rule of thumb is that you take the PERCENT increase in capacity, and expect to get a QUARTER of that percent in increased velocity, at the same pressure.

Ok thank you

If it were mine, Id start all over, there are just much better 45 caliber options out there.

My first thought was if you blow out the shoulder of a .458 or 458 Lott, you might get two more grains of powder in the case as its as close to a straight case and you can get is it not? Just curious?

It is a Lott that has been Ackley improved

quote:

Originally posted by 338madhunter:
It is a Lott that has been Ackley improved

No - the 458 Ackley was designed and shooting about a decade before the Lott -

So is my gun all so known as an Ackley 450 magnum or is it a 458 ackley improved

If I wanted to by a book I would it's not what I am looking for thank you