Ruger .45 acp Cylinder -problem Solved

[bocash3]

Model: Ruger Stainless Flat Top .45/.45 Convertible Lipsey model 5.5 inch:


A few weeks ago, I had trouble with stuffing .45 acp into the auxiliary Ruger convertible cylinder while at the cabin.

Most were stopping at about 90% "in" and had to be pushed in with a lot of thumb force........ and some of them stopped so far out that the thumb attempt was useless.

Well, I addressed that today and am convinced that Ruger .45 acp cylinders are exceptionally tight and chamber holes actually tapered near the ends. (At least this one is).

First, I was using Lyman T/C dies I purchased around 1970 and have no idea how many thousands of rounds have gone through them.

So............I decided to replace the nearly 50-year-old Seating/Crimping die with a new RCBS of like character............ordered from Fleabay two weeks ago.

Today, I ran an assortment of 60 brass fired several times and kept a micrometer on the table as I "tuned" that new seating die.

I also took time to fine tune the sizing and belling dies while at it.


SUCCESS!! Here is the scoop:::::::::::::::::::

Factory specs call for the shell diameter at the mouth/crimp after seating to be: Point 473"

I pulled several loaded rounds out of a few boxes loaded earlier, all with the same 200 gr. SWC.

I was getting a diameter of anywhere from .472 to .474" from shells loaded earlier.

I pulled the .45 acp cylinder out of the revolver and placed it on the bench. I would attempt to place previously loaded shells into it. Those that were .474 would go in about 3/4ths of the way and stop - - without thumb pressure. Those that were .473 would go in almost 7/8ths of the way. Those that were between .472 and .473 had to be stuffed "home" with pressure from a thumb.

OK..............so I kept messing with the seating/crimping die until each Newly Crimped shell was right on .471 diameter at the case mouth. THESE would fall out of the chambers of that cylinder when I turned it upside-down. ALL of the others above had to be punched out with a dowel.


Switch gears: I have never had in my memory a .45 acp shell to jamb or NOT go into battery in any 1911 I have had and probably had around 15 over the years and still own 6. This tells me that all of my reloads coming from those Lyman dies are fine for the 1911, even if they are a 1,000th over at the end.......maybe even 2/1,000 over.................

I might could have tuned that Lyman seating die further but lost confidence in it. Besides, it has earned its keep over 49 years.

Now I have around 1200-1500 rounds of loaded .45 acp ammo that may be too fat on the ends to use in this Flat Top Ruger.........but are still fine for the 1911's.

I loaded the 60 brass from start to finish and the end diameters where right at Point 471 - - - 2/1000ths less than factory specs. I am now convinced that this cylinder is not only tighter than specs but also has tapered interior walls.

THEN................. I pulled out 4 boxes of previously loaded 200 swc ammo and ran every one of them through the new RCBS seating die and stopped to measure quite a few of them to make certain they were squeezed down to Point 471.

So now I have 5 boxes I know will feed into the Flat Top and I stuck a bright yellow sticker on each of the 5 boxes that read: "RUGER OK"

I hope someone on the forum will benefit from this experience.

Y'all take care, Bo in western NC

PS: By the way, having several 3-screw Rugers, I am not crazy about the "new" models, but.............. this NM Flat Top is crazy accurate with the .45 acp cylinder. Seems so-so with the .45 Colt but scary with the acp. Go figure!!

[C-dubb]

I have the same gun and dealt with the same problem. Took me quite a while to figure out that it was the crimp. Funny thing was, the jacketed bullets never caused any problems I guess the harder bullet took the taper crimp differently.
PS. my flat top is a 4 5/8 barrel and out shoots all of my long barrel Rugers. I love it.

[Moonie]

Most of the ruger cylinders have undersized throats, Dougguy has the equipment to hone them out to the perfect size and is very reasonable price wise. He has done many for the guys here, and he is a fellow North Carolinian.

[DougGuy]

It isn't the crimp at all. Lots of Ruger cylinders have undersized throats. Almost NONE are .452" which is what minumum should be, for a .451" barrel. Take a known .451" boolit or j-word bullet and try to shove it into the cylinder throats from the front. If it doesn't go, that right there tells you the throat is smaller than the boolit/bullet. If you have pin gages, those are the best tools to measure with but you need Zminus, and you need them in half thousandths to be accurate.

Long story short, you can jump through any hoops you want to at the press with various dies to get them to plunk, BUT, the throats are going to size them down regardless, and they will exit the front of the cylinder at throat diameter.

The proper fix is as mentioned, to resize the throats to .4525" and size boolits to .452" this way you will be delivering an actual .452" to the barrel instead of forcing it through a multi-port sizing die when they are fired.

Then, standard dies will work, I use Lee and a Lee taper crimp to finish with, works a charm in my 1911s and if I had a SA in 45 ACP they would work in it without issue.

[Dale53]

As usual, DougGuy has "hit the nail on the head". I have a Ruger SS Bisley (large frame) .45 ACP/.45 Colt convertible. It had cylinder throats of .449-.450". I did an article on the revolver for "The Fouling Shot" (magazine of the Cast Bullet Association) detailing my experiences with it. Long story short, after I reamed the cylinders (and those of a couple of buddies) to .4525", the revolver ended up being a DREAM piece. It is NOW very satisfying. I mostly use the .45 ACP cylinder but it shoots under an inch at 25 yards off a rest with a variety of loads (wild to mild) with either cylinder.

The reports I have read on the Flattop convertible, stated that the cylinder throats are correct. However, apparently, not all of them. At any rate, DougGuy has detailed how to check them. That should solve the problem.

FWIW
Dale53

[Bob Busetti]

A Lee taper crimp die for 45 ACP cured all my problems. Never had a problem since. Of course shooters at the range are surprised as I run cylinder after cylinder of 45 ACP with no problems.