Throat-Choke Is No Joke

By Jeff “Tank” Hoover

I love Ruger revolvers, especially those chambered in .45 Colt. Built tough and able to withstand pressures most other guns can’t, doesn’t mean they’re without issue. We’re talking about the dastardly Ruger throat-choke! This dreaded disease strangles any semblance of accuracy from these sensational sixguns.

In laymen’s terms, the exit hole in the cylinder is just too small. I’ve had some as tight as 0.449″ while most are 0.450″. When throats are undersized, the bullet is squeezed down, causing a loose fit as it travels down the barrel. Loose fitting bullets will not engage the rifling, causing the bullet to skid, leading to poor accuracy and a leaded bore when shooting cast bullets. It’s easy to fix! Hell, even I can do it!

Pudding-proof opening-up cylinder throats works. Shot with the same box of reloads at a benched 25 yards.
Targets on the left were shot with 0.450″ throats, on the right, after honing throats to 0.452″.

Geometry?

For perfect shooting geometry, the cylinder throat should be, minimally, the same size as the bore of the barrel, preferably 0.001″ oversize. Think of a funnel as the bullet passes from the cylinder throat, to the forcing cone and into the barrel. As the bullet is gently sized-down, a perfect seal is maintained during its travels, preventing gas blow by. So what do we do to help this process? We take a bit of metal off your cylinder throats!

Removing metal is surely easier than adding it. I know from personal experience. But, I’ve done at least a couple dozen using the following method and not one cylinder was rendered scrap! Even better, all showed a vast improvement in accuracy. Don’t be squeamish or faint of heart, just dive in.

Here’s all you need to open-up your cylinder throats. Tank’s already done one,
as you can see the metal dust on the face of the cylinder. The Hornady FTX 0.452″
bullet was used as a makeshift pin gauge.

The flap goes into the throat and peeks out a tad. Hold things firmly and spin the drill.
Go easy and check often. It’s easier to take metal off than put it back on!

You don’t need to be a pinhead to use pin gauges. They do come in handy if you like to tinker
with your toys! Here’s the “old” at 0.450″ and the new at 0.452″. Perfecto.

How to

Round up an electric hand drill, a 3/8″ steel rod about 6″ long, some 120 grit emery cloth, some 320 wet or dry paper, scissors and a 0.452″ bullet (or pin gauge set). Use a hacksaw and split the 3/8″ rod about 1.5″ down at the end to hold the paper. For the .45 Colt cut your sandpaper about 7″ long and the emery cloth about 2.5″ long.

Stick a strip in the slit you cut in the rod, and wrap it tightly around the rod. It doesn’t matter which way you wrap, just as long as your paper/cloth spins the same way as your drill so the paper tightens. All we’ve done is made a polishing-bob. Holding the cylinder in your weak hand, push the “bob” through the chamber side of the cylinder. It will be a close fit but as you run the drill, the paper will tighten. You need a snug fit for this to work. Remember, you’re just polishing the throats, not the chambers. Don’t let the bottom of the paper/cloth exit the cylinder. If it does, stop the drill, remove the paper and start over.

The emery cloth will cut quicker than the paper. I find about two cycles of emery cloth is enough to polish out the cylinder enough to pass your 0.452″ bullet. Once you can push the bullet through with finger pressure, go over it with your 320 grit sandpaper for final polishing. Check for fit after every cycle.

For years, I used sized cast bullets as my pin gauge, but recently bought a pin gauge kit. Rechecking my previous work with the pin-gauges, I found I was dead-on at 0.452″. If you buy a pin-gauge kit, make sure it’s a negative (-) kit, which runs slightly small. All my “fixed” guns shoot great now!

Don’t let throat-choke choke the accuracy from your gun! It’s easy to fix and you’ll feel fully satisfied fixing it yourself!

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2 thoughts on “Throat-Choke Is No Joke

  1. Joe Rolles

    Many thanks! Tried digital calipers, then telescoping gauge with micrometer, but found pin gauges on ebay for $4.41 each (combine shipping $7.70). Three pins were worth the ease and accuracy. The throats were 0.450 or 0.451, now all are 0.452″. My groups shrunk by 0.55″ from 2.3″.
    You get a big “Atta Boy” from this reader.

    1. Tank

      Glad it worked out for you Joe! Amazing how something so simple can help so much. Thanks for letting us know your results.

      Tank

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