Good cylinder for Colt SAA

[desmobob]

I was just looking at the "Favorite Revolver Cartridge" poll and noticed how popular the .45 Colt is. Several years ago, I bought a SAA in .45 Colt from the Colt Custom Shop; not for collecting, but for shooting.

It didn't shoot worth a darn. Years later, it was bugging me and I looked into it. It turns out the cylinder throats are oversized. I could drop a .452 cast bullet clean through, so I bought a bunch in .454 only to find they also fell through!

I remember reading that this was a known issue. I'm wondering if there is a popular maker who offers an aftermarket cylinder for the Colt that has the correct dimensions and has a good reputation.

 

[ontarget]

Maybe try Colt.
They might take care of it.
Even if you have to pay for a new cylinder it might be worth the cost.

 

[CraigC]

This is unfortunately a very, very common malady. Especially with SAA's and replicas. Whereas Rugers can go either way. Virtually all of them will have oversized chambers. The solution is relatively easy though not necessarily relatively cheap. The solution is to procure a factory cylinder is a smaller chambering such as .357Mag, .32-20 or, heaven forbid, .44Special. Have a gunsmith fit it and rechamber it to tight, minimum specs with proper throats for cast bullets. They 'should' be able to do this without refinishing the cylinder.

 

[Tall]

I just finished reading an article in Handloader magazine #109 where they compared various revolvers to see if throat size had anything to do with accuracy. The most accurate revolver (Colt New Frontier in 45 Colt) had the largest throats. The myth was completely busted. Likely you simply are using the wrong load in your Colt.

 

[Driftwood Johnson]

Very common, particularly with 2nd Gen Colts. I don't have the numbers handy, but I think the chamber throats on my 2nd Gens run around .455 or so. It never really bothered me, they are both capable of acceptable accuracy.

 

[Tall]

Accuracy results, freehand at 25 yards:

 

[desmobob]

I just finished reading an article in Handloader magazine #109 where they compared various revolvers to see if throat size had anything to do with accuracy. The most accurate revolver (Colt New Frontier in 45 Colt) had the largest throats. The myth was completely busted. Likely you simply are using the wrong load in your Colt.

Very common, particularly with 2nd Gen Colts. I don't have the numbers handy, but I think the chamber throats on my 2nd Gens run around .455 or so. It never really bothered me, they are both capable of acceptable accuracy.

Accuracy results, freehand at 25 yards:

View attachment 1145498

That is very encouraging news, Tall and Driftwood. Maybe I was expecting too much and gave up on load development too early. At this point, I don't think I have a record of what loads I tried, other than probably the data in the box with the last load I put together. I'll start over and keep careful notes. That should keep me busy for a while.

Thanks again,
Bob

 

[StrawHat]

A lot of the perceived problems come from the fact you may be expecting competition grade accuracy from a gun that is not capable of delivering such levels. It is a 45 long Colt, not a target revolver. I still have a S&W Model 25-5. I have no idea what the chamber throats measure. I do know, for a fact, it is certainly capable of harvesting deer. That is accurate enough for me.


Kevin

 

[Tall]

The Remington 255 grain RN gave outstanding performance in a factory loading.

 

[CraigC]

The myth was completely busted.

100% wishful thinking. Firstly, those are offhand groups. I shouldn't even have to point out how relevant that is. Second, it completely ignores all other myriad factors affecting revolver accuracy. Along with the fact that tons of people have proven that throats absolutely do affect accuracy.....and leading. If throat dimensions didn't matter, we wouldn't need linebored, minimum spec chambers for the absolute best accuracy.

 

[desmobob]

The Remington 255 grain RN gave outstanding performance in a factory loading.

Do you mean the 250gr.? Not in my Colt. At least not the several boxes of the old green and yellow Remington 250gr. RN (or 225gr.) factory loads that were the source of my .45 Colt brass...

 

[Jackrabbit1957]

From what research I've done the throats should be 2 to 3 thousands of an inch over bore size. Much over is not that big of an issue until you get way over, may have something to do with gas leakage at the barrel/ cylinder gap. It becomes a problem when the throat is too small and squishes the bullet as it leaves the chamber. This can also cause pressure spikes and felt recoil. I just reamed the throats in my 44/40 1875 Uberti to .435. The throats were various diameters from .429 to .431. Accuracy was questionable at best. I need to go shoot the thing and see if things improved.

 

[Alaskamike]

View attachment 1145497


I just finished reading an article in Handloader magazine #109 where they compared various revolvers to see if throat size had anything to do with accuracy. The most accurate revolver (Colt New Frontier in 45 Colt) had the largest throats. The myth was completely busted. Likely you simply are using the wrong load in your Colt.

I think you've overlooked a critical thing that table shows. The ONLY revolver in the table that has chamber mouths larger than bore diameter is the New Frontier. All the others show chamber mouths equal to, or tighter than bore diameter. This means that bullets won't even be gripping the rifling at all. I don't see where the table shows groove diameter of the revolvers, and that would be interesting to see.

Any revolver that has chamber mouths tighter than bore diameter is going to have poor accuracy, and will also be a leading nightmare.

 

[.38 Special]

If the OP does decide to replace the cylinder, there are several options. Peacemaker Specialists normally has a good stock of originals, across all generations. As mentioned, for proper dimensions, it is usual to start with undersized chambers and recut them.

It also is possible to come across cylinders on eBay, often for less than the price from places like Peacemaker Specialists - and often for much more!

Finally, if extreme accuracy is the goal, the gun can be sent off to someone like Hamilton Bowen who will fit a new cylinder "blank" and line bore it, to perfect dimensions, while installed in the frame. This ensures that the chamber mouths align with the bore and nearly ensures better accuracy than the shooter can prove.

There is, of course, a significant price tag for any of it...

 

[Tall]

I think you've overlooked a critical thing that table shows. The ONLY revolver in the table that has chamber mouths larger than bore diameter is the New Frontier. All the others show chamber mouths equal to, or tighter than bore diameter. This means that bullets won't even be gripping the rifling at all. I don't see where the table shows groove diameter of the revolvers, and that would be interesting to see.

Any revolver that has chamber mouths tighter than bore diameter is going to have poor accuracy, and will also be a leading nightmare.

Actually the table shows the Ruger also has chambers that are larger than the bore size.

 

[Alaskamike]

From what research I've done the throats should be 2 to 3 thousands of an inch over bore size. Much over is not that big of an issue until you get way over, may have something to do with gas leakage at the barrel/ cylinder gap. It becomes a problem when the throat is too small and squishes the bullet as it leaves the chamber. This can also cause pressure spikes and felt recoil. I just reamed the throats in my 44/40 1875 Uberti to .435. The throats were various diameters from .429 to .431. Accuracy was questionable at best. I need to go shoot the thing and see if things improved.

Generally you want chamber mouths to be a couple thousandths larger than groove diameter, not bore diameter.

 

[Alaskamike]

Actually the table shows the Ruger also has chambers that are larger than the bore size.

Ah, good catch. Not sure how I missed that.

 

[Dave T]

Based on my 38 years experience the Colt 45 SAA was built and intended as a duty weapon, not a match gun or even a casual target gun. It just had to be accurate enough and more importantly reliable enough to do its job. Think of the WWII GI 1911s that rattled and had hard trigger pulls. Yet the 1911 and the SAA both killed or stopped a lot of enemies and bad guys.

My experience with 1st Gen Colts was all with full black powder loads back in the 1980s & 1990s. I found that contrary to most advice back then, soft (1-20 tin-lead alloy) .454" cast bullets up-set and filled the throats, then swagged themselves down to groove diameter. This with no pressure spikes or leading. I've been shooting soft lead bullets, no harder that 1-16 tin-lead and softer is better, in all the 45 Colts I've owned ever since.

YMMV,
Dave

 

[Driftwood Johnson]

While the relationship of chamber throat diameter to rifling groove diameter is important, chamber throats should also be about .001 larger than bullet diameter. It takes all three to make an accurate revolver.

The old test I used to do was to hold the cylinder pointing down at the ground and drop bullets of different diameters into the chambers. If the bullet fell through the chamber throat, it was too small. If the bullet required a lot of pressure to force it through the chamber throats, it was too large. If the bullet could be gently pushed through the chamber throat with the end of a pencil, it was the correct diameter for that chamber throat.