Have a brand new Blackhawk convertible, shoots long colt reloads like a champ, super accurate, love it. Different story on the acp, sent it to smith like a lot on here and he did an outstanding job but I still have a problem. I use a Wilson gage to check shells, they go in slick as heck, just like new shells, oal is 125.8 consistent but they will not go fully in my cylinder and hang up. When I do shoot 6 rds they are all over the target(well twice as big a group as the long colt). Ideas?
.45 acp dilema
- Thread starter ftlupton
- Start date
schloss
Single-Sixer
What exactly is hanging up? Bullet or brass? Is the accuracy problem the same with new cartridges as with reloads?
WIL TERRY
Buckeye
125.8 what ??
over all length(oal), the brass doesn't seat as fully as new but yet goes in the Wilson gage just fine. I'm going to have a friend of mine who shoots a lot of .45 in steel matches load me up 10 rds and see if it's my dies or the cylinder. any more thoughts let me know and thanks.
cellar701
Buckeye
I assume you mean oal is 1.258 inches rather than 125.8?? What is the cartridge case length? the acp cartridge head spaces on the "neck" or end of the cartridge case so if it is a head space issue, the case length may be an issue.
DeletedMember275
Hunter
- Joined
- Apr 17, 2002
- Messages
- 2,759
Taper crimp or roll crimp?
Iron Mike Golf
Blackhawk
- Joined
- Feb 15, 2010
- Messages
- 945
The issue is with headspacing one the case mouth in a revolver cylinder. It can be aggravated by a tight throat.
Look at the chamber drawing for 45 Colt: http://www.saami.org/PubResources/CC_Drawings/Pistol/45 Colt.pdf
You'll see a tapered transistion from chamber to throat (some folks refer to that as a "ball seat"). You can't have that with a cartridge that headspaces on the case mouth. You need a ledge for the case mouth to rest against. It seems that you you go from .474 at the case mouth right to whatever the throat diameter is (.450? .451?)
You might end up having to seat 45 ACP bullets deeper to get them to chamber in the revolver as compared to a semi-auto pistol, meaning preventing the full diameter of the bullet getting forward of the case mouth.
I'd want to know precise diameters of the chamber at the forward end (where the case mouth rests) and the throat. Might need reamed. You ought to be able to have .4525 diameter throats and have enough ledge for safe headspacing. You won't have that taper from chamber to throat like the 45 Colt, but with .4525 throats, you should be able to seat 45 ACP bullets to normal OALs and have them chamber fine.
As to accuracy, I'd also slug the bore. Hopefully, your groove diameter is .450-.451 and not .453-.454. If it's at the lower end, which I'd expect it to be, then you should be able to work things out fine.
Look at the chamber drawing for 45 Colt: http://www.saami.org/PubResources/CC_Drawings/Pistol/45 Colt.pdf
You'll see a tapered transistion from chamber to throat (some folks refer to that as a "ball seat"). You can't have that with a cartridge that headspaces on the case mouth. You need a ledge for the case mouth to rest against. It seems that you you go from .474 at the case mouth right to whatever the throat diameter is (.450? .451?)
You might end up having to seat 45 ACP bullets deeper to get them to chamber in the revolver as compared to a semi-auto pistol, meaning preventing the full diameter of the bullet getting forward of the case mouth.
I'd want to know precise diameters of the chamber at the forward end (where the case mouth rests) and the throat. Might need reamed. You ought to be able to have .4525 diameter throats and have enough ledge for safe headspacing. You won't have that taper from chamber to throat like the 45 Colt, but with .4525 throats, you should be able to seat 45 ACP bullets to normal OALs and have them chamber fine.
As to accuracy, I'd also slug the bore. Hopefully, your groove diameter is .450-.451 and not .453-.454. If it's at the lower end, which I'd expect it to be, then you should be able to work things out fine.
tacklebury
Single-Sixer
Run them through a Lee FCD. I had a lot of issues with the tight chambers on my BH Convertible until I started using the FCD. Never an issue now and more consistent in my findings also. ;) $9.95 pretty cheap out for a fix too.
Dale53
Blackhawk
ftlupton;
My SS Ruger .45 Colt/.45 ACP convertible would not even allow me to seat factory ammo until I reamed both cylinders. Now they both shoot like match guns.
Since you have already had the cylinders reamed, I agree with "tacklebury" that the Lee FCD should solve your problem. I use the Lee FCD and have NO problems chambering my rounds.
Keep in mind, that you can adjust the amount of taper crimp. I taper crimp until the mouth of the case is .470" (use the knife edges on your dial calipers to check this right at the case mouth O.D.).
Good luck!
Dale53
My SS Ruger .45 Colt/.45 ACP convertible would not even allow me to seat factory ammo until I reamed both cylinders. Now they both shoot like match guns.
Since you have already had the cylinders reamed, I agree with "tacklebury" that the Lee FCD should solve your problem. I use the Lee FCD and have NO problems chambering my rounds.
Keep in mind, that you can adjust the amount of taper crimp. I taper crimp until the mouth of the case is .470" (use the knife edges on your dial calipers to check this right at the case mouth O.D.).
Good luck!
Dale53
TomC321
Single-Sixer
It sounds as if the .45 Colt cylinder was checked/modified as necessary to have the proper chamber throats, but it sounds like the .45 ACP cylinder is too tight. I have had to ream all my .45 Colt cylinders and most of my .45 ACP cylinders. When properly sized, they all shoot well.
Erich
Single-Sixer
FWIW, I had difficulty with .452" .45 ACP handloads in a New Vaquero .45 ACP I bought a few months back. Measuring the cylinder mouths showed .450" (Ruger might be sharpening their reamers a few too many times).
I took greater care seating my bullets (I always use a Lee FCD, BTW) and have been able to enjoy some remarkably accurate handloads from the gun, but there are some bullets (a 255-gr LSWC, for instance) that just will not work for it.
I took greater care seating my bullets (I always use a Lee FCD, BTW) and have been able to enjoy some remarkably accurate handloads from the gun, but there are some bullets (a 255-gr LSWC, for instance) that just will not work for it.
TomC321
Single-Sixer
Erich said:
Ream the cylinder and try again.
tacklebury
Single-Sixer
Great to Hear Ftlupton. Hope you have as good of accuracy as I get with mine. ;)
Erich
Single-Sixer
That's what a friend says, but it's working wonderfully for me now but for those bullets. Which work fine in other guns I have, so I can use it there. I think the best plan for me is to just use lead that fits my gun instead of actually 'smithing it. :)
TomC321
Single-Sixer
Erich said:
The .45 ACP is much more tolerant of oversize throats than undersize throats. I have a S&W 25-2 with .456” throats that shoots great with just about anything. I have several .45 NMBHs with .45 ACP cylinders. One is .451”. It shoots so well with MILBALL that I don’t dare do anything to it. A couple I reamed to .452” and one came at .455”. All seem to shoot equally well. Go figure.
2 dogs
Buckeye
1. Use your cylinder as your case gauge.
2. Try some new brass. If you are using Range pick ups or some such it may be swollen at the base from being fired in a oversize auto chamber.
2. Try some new brass. If you are using Range pick ups or some such it may be swollen at the base from being fired in a oversize auto chamber.
Seams to be many people with 45 ACP cylinders having the same ammo fit problem. Six months ago I bought a 5.5" NBH. .45 Colt shoots good, no problem. The .45 ACP, endless problems with reloads using .452 lead (reformed via swaging). Tried seating depth, all forms crimping including the Lee factory crimp die. Next I was convinced the factory finished reamed the cylinder too tight. I borrowed a near new chamber finish reamer and re reamed the six chambers. That exersize told me there was nothing wrong with the chambers. A throat job was done shortly after the gun purchase (to .4525"). By this point I was running out of hair to pull out. Going over some of the chamber spec's of the various .45's particularly the .45 Colt. Struck me the if a gun smith were to re ream the chambers to the .45 ACP chamber stop with a .45 Colt finish reamer that would solve the problem or if I did it myself. Do I have solid brass b....s?? Could wreck the whole cylinder!!! Weeks of thought went by, NO info on the net. The .45 Colt reamer would enlarge the chambers .003 to about .006". Well I bought the .45 colt reamer and went to it. 90 minuters later it was done except for some finishing work.
Time for testing. Loaded a bunch of .452 lead wad cutters with the bullets seated out somewhat. OVL at 1.218". 185, 200 and 218gr swaged wad cutters and SWC's were loaded up and run through (not shot) the newly reamed cylinder. I expected all sorts of problems. There were NONE. Chambered rounds were factory crimped via Lee. Each chambered round chambered snug, no wiggle, yet each ejected without problem. I have not fired any for grouping but I did for function (6) no issues. I took a deep breath. So far I am very happy, may my happiness continue through grouping!! More info to come.
Time for testing. Loaded a bunch of .452 lead wad cutters with the bullets seated out somewhat. OVL at 1.218". 185, 200 and 218gr swaged wad cutters and SWC's were loaded up and run through (not shot) the newly reamed cylinder. I expected all sorts of problems. There were NONE. Chambered rounds were factory crimped via Lee. Each chambered round chambered snug, no wiggle, yet each ejected without problem. I have not fired any for grouping but I did for function (6) no issues. I took a deep breath. So far I am very happy, may my happiness continue through grouping!! More info to come.
Chapter II : Grouping. Where the rubber hits the road.
The 5.5" NBH set up with the newly reamed .45 ACP cylinder. Several three shot groups were fired with two different bullet weights 183 and 203 made with button nose wad cutter design swaged. The powders were Titegroup, Power Pistol, W231, AA-5 and Clays. W231 has never shot well in this gun but after this work accuracy improved 20%. with Titegroup and Power Pistol the improvement was dramatic, especially with the 203Gr, about 40% better. AA-5 shot about 30% better. Clays at 4.5gr improved the most. halving its group size to 1.25" at 50' from a 3" typical size.
I was shooting at 7:00 AM this morning here in Florida, hot and humid. All these loads would benifit with some fine tuning. Next project fine tune and shoot at 25 yards. More to come. I am very happy so far.
The 5.5" NBH set up with the newly reamed .45 ACP cylinder. Several three shot groups were fired with two different bullet weights 183 and 203 made with button nose wad cutter design swaged. The powders were Titegroup, Power Pistol, W231, AA-5 and Clays. W231 has never shot well in this gun but after this work accuracy improved 20%. with Titegroup and Power Pistol the improvement was dramatic, especially with the 203Gr, about 40% better. AA-5 shot about 30% better. Clays at 4.5gr improved the most. halving its group size to 1.25" at 50' from a 3" typical size.
I was shooting at 7:00 AM this morning here in Florida, hot and humid. All these loads would benifit with some fine tuning. Next project fine tune and shoot at 25 yards. More to come. I am very happy so far.
