Precision And Base Pins

Although shooter technique is often the cause of boolits that don't go to the same spot, I'm wondering if a tight base pin could prevent a cylinder from moving ever so much to align each cartridge chamber with the forcing cone. Obviously I need to grip the same way each shot, etc. But, my question is ... is it worth purchasing a standard Ruger base pin to see if this is contributing to shots that go askew? I have only a high quality aftermarket base pin.

Possible, but I doubt it. What do you have happening?

Group size consistently large. Flyers. Three different shooters. Cylinders bored properly by Bowen, so I don't expect that issue. Base pin is incredibly difficult to get in and out, with cylinder present.

What kind of ammo have you tried? What bullet weights?

Many different brands and weights

Simple way to check: Remove the base pin from the gun, insert through the cylinder and try spinning the cylinder. If it won't spin freely, its too tight.

But that may not be the cause of your groups enlarging.

Mark one chamber and fire a group from only that chamber, do that with all six chambers. Maybe one chamber is off and throwing your bullets off.

Bob Wright

4MUL8R said:

Group size consistently large. Flyers. Three different shooters. Cylinders bored properly by Bowen, so I don't expect that issue. Base pin is incredibly difficult to get in and out, with cylinder present.

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If your cylinders(?) are line bored, as your statement suggests, the throats and chambers of those cylinders would have been line bored using the base pin and locking bolt provided with the gun. Replacing any part of the equation will throw things askew.

I think the cylinder was bored separately to ensure throat consistency. Previous owner did that. I like test procedure one bore at a time.

A $10 factory base pin is a modest expense to test your theory. I have often heard that a little play in the cylinder lock up was a good thing in a Ruger handgun.

4MUL8R said:

Although shooter technique is often the cause of boolits that don't go to the same spot, I'm wondering if a tight base pin could prevent a cylinder from moving ever so much to align each cartridge chamber with the forcing cone. Obviously I need to grip the same way each shot, etc. But, my question is ... is it worth purchasing a standard Ruger base pin to see if this is contributing to shots that go askew? I have only a high quality aftermarket base pin.

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4MUL8R.... your theory has merit and is widely shared. The bullet acts as an alignment tool and may improve chamber-to-bore alignment at the moment of passage. However, the good work of the bullet means nothing in the presence of a lousy forcing cone. Further, the good work of the bullet to align chamber with bore may distort the bullet, in the process destroying the bullet's balance to fly straight.

Let us for the moment remove shooter and ammunition from the equation. We are talking REVOLVER ACCURACY, a deep enough subject by itself. And presume the ammunition is capable of 4-inch groups at 100 yards----ammunition loaded by top marksman and markswomen from the hairy days of silhouette had better hover in the 2-inch zone from one football field away. Non-factory parts were not permitted in Production (closed breech) and Revolver category competition.

To answer you question directly, Yes, by all means fetch a factory base pin. Find out for yourself whether one base pin shoots tighter than the other. Shoot CREEDMOOR, or the steadiest, most relaxed bag position with the longest eye relief possible, and which dry-fire results in no sight movement at hammer fall.

50 yards is a reasonable minimum distance for trying to separate the accuracy potential of one base pin from another. Use a target which doesn't distract your eye from the sight picture. To continue your question, details and/or photgraphs of revolver.
David Bradshaw

Obviously I need to grip the same way each shot, etc.

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Are you shooting off-hand, or rested? If rested, how so? I found long ago that resting the barrel and/or base of the grip on a hard surface can cause erratic grouping. I prefer resting my forearms/wrists on a bag and just holding the gun in the two hands. Or hold the gun with both hands, wrists between the knees while sitting down. You can squeeze with your knees to reduce the wobble and shoot some pretty tight groups.

How tight of groups are you shooting? How tightly do you need to be able to shoot?

A Ruger factory basepin is cheap, just buy one and try it. If you can honestly shoot well enough to be able to tell the difference in base pins in your groups, I tip my hat to ya. I can kill deer at 200yrds with a revolver, working on 250 now, and I can't say I can tell the difference between two one of my customs which cost more than 5-8 times more than their factory competition, just based on basepins. I use a slightly expanded case with a Match (size) range rod before I purchase any revolver to check cylinder alignment. If it it slides in without contact, I buy it, and it'll shoot straight.