Reloading pressures

[majordisorder]

Another newbie question, I'm thinking about other ways to boost the .45 ACP to shoot out to 100m+ in a non/less loopy manner.

I've found the pressure limit for .45 ACP is 21,000psi and for .243 (which is what my new rifle is based on) is 50,000psi+.

What does this mean to me? My action will (should) handle 50,000+, can I load the .45 ACP upto say 50,000 (if that's possible) ? Or is the case itself a limiting factor?

[Sandgroper]

From my (limited) understanding the rifle and the case are limiting factors.

Take two of my rifles as examples

My 9mm Largo Spanish Destroyer can accept 9x23mm Winchester ammunition, but there is no way the rifle could accept those sort of pressures - it wasn't designed for it. Using 9x23mm Win ammunition the rifle would fail before the case would.

My Ishapore which I will convert to a 45 of some description is proofed to 7.62NATO pressures. If I tried to crank up a normal 45ACP case to those pressures, from what I understand the case will fail before the rifle will.

What I don't know is how a case failure would take place, how it would fail or anything like that.

I understand what you are trying to achieve because have thought of it as well but in the end there will be only so much you can achieve from a 45 ACP size case. Another limiting factor regarding range and trajectory is bullet shape and 45 pistol bullets just don't have what it takes.

For my own 45 project I'm either going to go for 45 Super cases and loads or take this to the next level and make a 458 SOCOM bolt gun.

[EagerNoSkill]

Some thing to consider

Convert 308 to 45 to handle pressure

http://forums.handloads.com/archive/for ... p?TID=7070

[saddler]

Why not look at the 45 Colt cartridge instead?
Much better ballistics than the ACP round

[Sandgroper]

Why not look at the 45 Colt cartridge instead?
Much better ballistics than the ACP round

For me these are the reasons for not going the 45 Colt route.
1) The availability of various magazines for the 45 ACP,
2) The ACP conversion works,
3) The 45 ACP offers three recognised pressure levels - ACP, ACP+P and Super,
4) IMO the 45 Colt offers no real advantage over the ACP with 'normal' loads
5) When you consider the OAL of the 45 Colt, I rather go for the 45 Win Magnum instead - a purpose built high pressure round/case.

From http://www.chuckhawks.com/high-pressure45.htm

The strength of .45 Long Colt cases

The following is a direct quote from the Sierra Reloading Manual.

"Although it has internal capacity comparable to that of the .44 Magnum, the thickness and strength of the .45 Colt cartridge case is much less than that of the .44 Magnum, imposing a limiting factor upon the older cartridge which cannot be avoided."

And this is a quote from the Speer Reloading Manual.

"Some handloaders have assembled .45 Colt loads that exceed the pressures of the .44 Magnum! The .45 Colt case is not as strong as the .44 Magnum case and you must not attempt to load it as high, regardless of the gun model."

The following quote is again from the section of the Speer Reloading Manual devoted to high pressure .45 Colt loads for the Blackhawk and Contender.

"We recommend that these loads be used in new or once-fired cases known to be of recent manufacture."

As is also mentioned in the Chuckhawks article if you want a 45 Magnum, then go for the 454 Casull. Why risk case failure when upping the loads/pressure when you don't have to?

From http://www.realguns.com/archives/020.htm

From left to right - .45 ACP, .45 ACP +P, .45 Super®. The difference is actually quite significant in the web area, as marked by the yellow vertical line. The Winchester measured .175", the Starline +P .182" and the Super .198". .023" over standard is a lot of brass and makes it easy to see what the Super brass is critical to proper function and safety.

Just my thoughts on the subject.

[ovenpaa]

The idea of trimming down a rifle cartridge is quite appealing and once the brass has been trimmed and formed to parallel you in theory would be able to shoot something quite meaty in an action designed for the pressure, getting the reamer is not an issue (At the moment!)

Hmm, I am off to chop down a couple of .308 cases and see what they look like

[ovenpaa]

A bit of fun spurred on by a certain forum member who was throwing text messages at me this afternoon...

I turned a mandrel sized at .453 as I so not have any .45ACP dies and dropped it into a Sinclair Mandrel die, this is not a straight forward job as they are only designed to go up to around .340" however it is doable. Then chop some RWS brass off to length, I use a collet chuck and parting tool and they take just a few seconds to chuck up, part off, de-burr and remove.

The cases sized with the new mandrel using Imperial Sizing Wax (Accept no substitutes!) Finally seat the bullets with very little finesse and this is the end result.

L-R is an original .45ACP case, a .308 RWS trimmed to size and then two 'longer' builds because I could, the stretching of the case is the work of the mandrel not the bullet and gives an idea of how far it would need blowing out in the fire form stage. I would be inclined to build a dedicated sizing die using a PTG blank (Cheaper than building my own) The expanding can be done in one hit.

HTH..

[saddler]

Hmm, I am off to chop down a couple of .308 cases and see what they look like

I was about to say that chances are they will look like 44 AutoMag brass

[Sandgroper]

A rough comparison between some of the various loads with a couple of extras for comparison.

From a 50m zero. drop at 100m. Bullet Sierra 230 gr. FMJ Match

45 ACP 850fps ME 369ftlb
13.87 inches

45 ACP+P 950fps, ME 461ftlb
11.02 inches

45 Super 1100fps, ME 618ftlb
8.27 inches

460 Rowland 1275fps, ME 830ftlb
6.76 inches

45 Win Magnum 1400fps, ME 1001ftlb
5.6 inches

450 Bushmaster 2200fps with 250gn FTX bullet, ME 2696ftlb
1.15 inches

Looking at the different loads I think ME over range was the biggest factor that influenced the creation of the different loads up to 460 Rowland and 45 Win Magnum. This is primarily due to the use of handguns for self defence and hunting in the USA. The 450 BUshmaster is designed for the AR-15 platform.

All in all, I don't think going beyond 45 Super levels is really worth the effort, not when you consider the effort in obtaining and then trimming 460 Rowland brass.

[majordisorder]

All in all, I don't think going beyond 45 Super levels is really worth the effort, not when you consider the effort in obtaining and then trimming 460 Rowland brass.

And I've just gone and bought some .460 today

Those fps figures you got, were they for rifle length barrels or pistol? Since everything I've seen says add 250fps+ for the longer barrel. Infact BBTI has just got some data for the Rowland too http://ballisticsbytheinch.com/460rowland.html