Need load info for a .45 AR with 160 grain bullet

[Nightowl]

Years ago my friend gave me 500 Hunter Supply 160 grain .45 Colt bullets. I have 500 new .45 Auto Rim cases that I have had on the back shelf for about 15 years. The virus thing has kept me reloading and I am about out of projects. Thought I would combine these two components, but the loading manuals do not go down to a 160 grain bullet. After checking the manuals, I am thinking that a 4 grain load of Bullseye should work.
I have Bullseye, Unique, and Trail Boss on hand.

Any suggestions from .45 AR loaders?
Thanks in advance.

 

[rockquarry]

You might get a copy of the Lyman Cast Bullet handbook. Good bit of data using a variety of powders for 160 and 170 grain cast bullets for .45 ACP. Auto Rim data is interchangeable.

 

[HKSmith]

The latest Lyman cast bullet manual lists a 160 grain bullet with 5.8 grains of Bullseye as the starting load for .45 ACP. Velocity is 980 ft/sec and pressure is 13,800 CUP. The maximum load is 6.4 grains Bullseye at 1048 ft/sec and 16,500 CUP. I've loaded lots of .45 AR with 200 grain bullets and 5.0 grains of Bullseye with excellent results. That would be a good starting point with your 160 grain bullets.

 

[PPCSHOOTER]

4.0GR OF TRAIL BOSS IS WHAT A FRIEND OF MINE LOADS WITH THE 160GR LEAD BULLET. IN 45ACP FOR HIS 625 REVOLVER. JP

 

[Nightowl]

Thanks for that info. I have looked at the Cast Bullet Handbook and the two other manuals I have for AR but was not sure about using ACP loads.
Looks like 6 grains of BE or 4 grains of Trail Boss! Thanks

 

[HKSmith]

When the .45 Autorim cartridge was developed in 1920 for all the WW I surplus revolvers out there, it was loaded to the same pressure as other big bore revolver cartridges, like .44 Special and .45 Colt rather than the higher pressure of the .45 ACP cartridge. I don't know if this was done because of concern about non-heat treated cylinders or some other obscure reasons, but these old revolvers have been used with full-strength .45 ACP loads since 1917 without any problems. However, the SAAMI specifications remain 3000 CUP lower for .45 AR than .45 ACP to this day. Some reloading manuals follow these specs and some don't. Since the two cartridges have the same internal dimensions, pressures for a given load will be the same for both cartridges.