Beretta 81 mod to 32NAA cal & groups

xtriggerman · July 24, 2020, 11:48 PM

Hello folks, I bought this Beretta model 81BB recently exclusively to convert to 32NAA. My goal is to match its grouping abilities to a 32NAA casing loaded with Lehigh 55g all copper defense bullets. For now, this is what the used M81 can do at 30 feet shooting off a wooded 4X4 block as a frame rest. Prior to the rechambering, the average speed of some pretty old PMC 71g FMJ loads were 962 fps out of the 10 round string. The PPU averaged 914 fps.
To do a conversion on a Beretta Model 81, it simply requires renting the reamer from 4D rentals for a total cost of $47 bucks, adding a model 84 380 magazine and some ammo. No other mods are needed since Beretta uses the same bolt face in their 81/84 model slides. The thick gripped Beretta is a most comfortable gun to shoot. In 32ACP its a real kitten. Stepped up to the new chambering and you know immediately, this aint your grandfathers ACP! The 80g Defensive HP's stepped out at an average of 1067fps in the pictured 10 shot string. I'm looking forward to see what kind of velocities I can generate with the 55g Lehigh copper pills. They should have some serious splash out of the Beretta's 4 3/4" barrel. Then I couldn't help giving the Guardian a go at the 30 foot target with the PMC's. There is some evidence of slight key holeing out of the Guardians shallow rifling but hitting the paper regularly at that range with those sights is still acceptable in my view. ;D

gonzogeezer · July 25, 2020, 06:14 AM

My Guardian NAA is an uncomfortable handful. Having a proper grip and some more mass sounds like a real improvement.

- gonzo, SoCenPA. "Before all else, be armed." --Niccolo Machiavelli

JERRYS. · July 25, 2020, 08:13 AM

interesting project, but why not just use the sooped up .32acp ammo like BB et al.?

HighValleyRanch · July 25, 2020, 08:39 AM

Neat mod. I've always liked how those looked. Is the 81 the same size as the .380 84,85?

xtriggerman · July 25, 2020, 10:40 AM

No way a 32ACP casing can match the capacity of the necked down 380 casing used in the 32NAA. Also,
"If" you can get a die set, 380 brass sizes easy by just pressing it up into the 32NAA resizer die. Hornady will make you a set of dies for $210 bucks But I'm working on a solution to that. Dillon makes a carbide sizer for the 380 that is free bored up from the carbide inset bushing. I think I might be able to cut down my 32acp sizer and friction fit it down into the Dillon die to the proper depth and weld it in place. That would fix the sizer problem just as a neat project and still save a few bucks. The 81 is identical to an 84 except for the bore size. Also, the extractor may have a slightly longer claw on the 81 but at this point in my testing, it appears to be running the slightly wider 380 cartridge rim OK. If there are any feed issues in the future, shortening it a tad is not a biggy.

gonzogeezer · July 25, 2020, 11:18 AM

I have read about a Kahr P380 being modified to shoot 9x18 Police. I wonder if the Beretta 84 could support the same modification. The Police round would be a step up from the .32 NAA. And I imagine regular 9x19 cases can be trimmed to use.

I own examples of three of the four production pistols produced in 9x18 Police but don’t reload so I keep my eye out for production ammo...not real common.

- gonzo, SoCenPA. "Before all else, be armed." --Niccolo Machiavelli

Metric · July 25, 2020, 05:57 PM

Neat project, keep us informed! Also, that's a beautiful 81BB.

silvermane_1 · July 27, 2020, 12:19 AM

Quote:

Originally Posted by xtriggerman

Hello folks, I bought this Beretta model 81BB recently exclusively to convert to 32NAA. My goal is to match its grouping abilities to a 32NAA casing loaded with Lehigh 55g all copper defense bullets. For now, this is what the used M81 can do at 30 feet shooting off a wooded 4X4 block as a frame rest. Prior to the rechambering, the average speed of some pretty old PMC 71g FMJ loads were 962 fps out of the 10 round string. The PPU averaged 914 fps.
To do a conversion on a Beretta Model 81, it simply requires renting the reamer from 4D rentals for a total cost of $47 bucks, adding a model 84 380 magazine and some ammo. No other mods are needed since Beretta uses the same bolt face in their 81/84 model slides. The thick gripped Beretta is a most comfortable gun to shoot. In 32ACP its a real kitten. Stepped up to the new chambering and you know immediately, this aint your grandfathers ACP! The 80g Defensive HP's stepped out at an average of 1067fps in the pictured 10 shot string. I'm looking forward to see what kind of velocities I can generate with the 55g Lehigh copper pills. They should have some serious splash out of the Beretta's 4 3/4" barrel. Then I couldn't help giving the Guardian a go at the 30 foot target with the PMC's. There is some evidence of slight key holeing out of the Guardians shallow rifling but hitting the paper regularly at that range with those sights is still acceptable in my view. ;D

Nice there xtriggerman, I bet you you're getting a decent amount of extra velocity in the 81 verses the Guardian length barrel that 32NAA usually is chambored in.

tallball · July 27, 2020, 09:10 AM

Very cool project!

xtriggerman · July 27, 2020, 11:19 AM

Thanks for the comments guys. If anyone is considering having a conversion barrel made up for their 84's or Browning BDA's for that matter, model 81 barrels are pretty much hens teeth. The very only option aside from buying an 81 is something I'v been thinking about. Numrich has Taurus model PT 57 barrels. That is a 32ACP barrel exactly like the 81 except its scaled up by about 20 percent. Iv been thinking about buying one and lathe turn and mill the smaller barrel dimensions out of it. Its a bit longer so it could be threaded and most of all, unlike the slightly loose Beretta barrel fit to frame, I could cut it to a press in friction fit to my frame, eliminating the wandering target hits all together.

The other issue I'm trying to uncover is PTG makes the chamber reamer. The odd thing is on their web sight they list 2 different reamers. A standard 32NAA finisher and a 32NAA SAAMI spec reamer. I called them to see what the difference is and the woman said one "may not" be US made. Thats BS all PTG reamers are in house, so I emailed them the question. Nothing yet. The standard reamer is a bit oversized IMO with fired case expansion of .009 and a few cracked necks on the hornady fired casings. I'm hoping the SAAMI spec reamer is a bit tighter around the cartridge. That way, I could make a real "Target" barrel out of a PT57 barrel. IDK, what folks would pay for one but its a play project that might have some stumpy legs on it if there is any kind of supply on 57 barrels.

July 24, 2020, 11:48 PM	#1
xtriggerman Member Join Date: January 4, 2012 Posts: 44	Beretta 81 mod to 32NAA cal & groups Hello folks, I bought this Beretta model 81BB recently exclusively to convert to 32NAA. My goal is to match its grouping abilities to a 32NAA casing loaded with Lehigh 55g all copper defense bullets. For now, this is what the used M81 can do at 30 feet shooting off a wooded 4X4 block as a frame rest. Prior to the rechambering, the average speed of some pretty old PMC 71g FMJ loads were 962 fps out of the 10 round string. The PPU averaged 914 fps. To do a conversion on a Beretta Model 81, it simply requires renting the reamer from 4D rentals for a total cost of $47 bucks, adding a model 84 380 magazine and some ammo. No other mods are needed since Beretta uses the same bolt face in their 81/84 model slides. The thick gripped Beretta is a most comfortable gun to shoot. In 32ACP its a real kitten. Stepped up to the new chambering and you know immediately, this aint your grandfathers ACP! The 80g Defensive HP's stepped out at an average of 1067fps in the pictured 10 shot string. I'm looking forward to see what kind of velocities I can generate with the 55g Lehigh copper pills. They should have some serious splash out of the Beretta's 4 3/4" barrel. Then I couldn't help giving the Guardian a go at the 30 foot target with the PMC's. There is some evidence of slight key holeing out of the Guardians shallow rifling but hitting the paper regularly at that range with those sights is still acceptable in my view. ;D

July 25, 2020, 08:39 AM	#4
HighValleyRanch Senior Member Join Date: July 15, 2005 Posts: 4,066	Neat mod. I've always liked how those looked. Is the 81 the same size as the .380 84,85? __________________ From the sweet grass to the slaughter house; From birth until death; We travel between these two eternities........from 'Broken Trail"

July 25, 2020, 11:18 AM	#6
gonzogeezer Member Join Date: March 18, 2014 Posts: 74	Beretta 81 mod to 32NAA cal & groups I have read about a Kahr P380 being modified to shoot 9x18 Police. I wonder if the Beretta 84 could support the same modification. The Police round would be a step up from the .32 NAA. And I imagine regular 9x19 cases can be trimmed to use. I own examples of three of the four production pistols produced in 9x18 Police but don’t reload so I keep my eye out for production ammo...not real common. - gonzo, SoCenPA. "Before all else, be armed." --Niccolo Machiavelli

July 25, 2020, 06:14 AM	#2
gonzogeezer Member Join Date: March 18, 2014 Posts: 74	My Guardian NAA is an uncomfortable handful. Having a proper grip and some more mass sounds like a real improvement. - gonzo, SoCenPA. "Before all else, be armed." --Niccolo Machiavelli

July 25, 2020, 08:13 AM	#3
JERRYS. Senior Member Join Date: September 23, 2013 Location: Alabama Posts: 2,969	interesting project, but why not just use the sooped up .32acp ammo like BB et al.?

July 25, 2020, 10:40 AM	#5
xtriggerman Member Join Date: January 4, 2012 Posts: 44	No way a 32ACP casing can match the capacity of the necked down 380 casing used in the 32NAA. Also, "If" you can get a die set, 380 brass sizes easy by just pressing it up into the 32NAA resizer die. Hornady will make you a set of dies for $210 bucks But I'm working on a solution to that. Dillon makes a carbide sizer for the 380 that is free bored up from the carbide inset bushing. I think I might be able to cut down my 32acp sizer and friction fit it down into the Dillon die to the proper depth and weld it in place. That would fix the sizer problem just as a neat project and still save a few bucks. The 81 is identical to an 84 except for the bore size. Also, the extractor may have a slightly longer claw on the 81 but at this point in my testing, it appears to be running the slightly wider 380 cartridge rim OK. If there are any feed issues in the future, shortening it a tad is not a biggy.

July 25, 2020, 05:57 PM	#7
Metric Senior Member Join Date: December 4, 2016 Posts: 353	Neat project, keep us informed! Also, that's a beautiful 81BB.

July 27, 2020, 09:10 AM	#9
tallball Senior Member Join Date: October 17, 2014 Posts: 2,444	Very cool project!

July 27, 2020, 11:19 AM	#10
xtriggerman Member Join Date: January 4, 2012 Posts: 44	Thanks for the comments guys. If anyone is considering having a conversion barrel made up for their 84's or Browning BDA's for that matter, model 81 barrels are pretty much hens teeth. The very only option aside from buying an 81 is something I'v been thinking about. Numrich has Taurus model PT 57 barrels. That is a 32ACP barrel exactly like the 81 except its scaled up by about 20 percent. Iv been thinking about buying one and lathe turn and mill the smaller barrel dimensions out of it. Its a bit longer so it could be threaded and most of all, unlike the slightly loose Beretta barrel fit to frame, I could cut it to a press in friction fit to my frame, eliminating the wandering target hits all together. The other issue I'm trying to uncover is PTG makes the chamber reamer. The odd thing is on their web sight they list 2 different reamers. A standard 32NAA finisher and a 32NAA SAAMI spec reamer. I called them to see what the difference is and the woman said one "may not" be US made. Thats BS all PTG reamers are in house, so I emailed them the question. Nothing yet. The standard reamer is a bit oversized IMO with fired case expansion of .009 and a few cracked necks on the hornady fired casings. I'm hoping the SAAMI spec reamer is a bit tighter around the cartridge. That way, I could make a real "Target" barrel out of a PT57 barrel. IDK, what folks would pay for one but its a play project that might have some stumpy legs on it if there is any kind of supply on 57 barrels.