Ruger 45 Colt Cylinder Reaming

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Nathan

New member
I like many other have a Ruger 45 Colt with .450 - .451 cylinder throats. I have not slugged the bore yet, but I plan to this week. It is a pretty accuratee gun to 25 yards, but I would really like to see it be good to 75 yards with a decent rest when hunting. I am struggling with that.

So this made me question the throat diameter.

Has anyone received the official "why" from Ruger why they reaam these to ~.450" instead of .4525 like so many gunsmiths offer?

Is there a negative to the .4525" size?

If you had it done, who did it for you?
 
Did the slug the cylinder throats, measure with a caliper, or use another method? In other words, make sure you actually slug the throats as well as the bore. We really can't comment until we see where the differences are. With any luck, the bore will be smaller than the throats, then you can probably just use bullets sized appropriately. Of course, if the barrel comes out to be bigger than the throats, you'll need to ream them.
 
So this made me question the throat diameter.

Has anyone received the official "why" from Ruger why they reaam these to ~.450" instead of .4525 like so many gunsmiths offer?

Is there a negative to the .4525" size?

If you had it done, who did it for you?
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I haven't received the 'official word from Ruger' on this but I can only conclude they're still doing this because they are hardheaded or obstinate. I am told that the New Vaqueros are generally better now, but of course that doesn't help those of us with the older guns. There are no negatives to having uniform .4525" throats in a 45 revolver. I can personally recommend http://www.cylindersmith.com for this work.
 
Thanks. I haven't slugged the bor or cylinders yet. Just measured with calipers.

What is good 25 or 50 yard accuracy with 300 gr loads at ~1200 fps? Right now, I think I'm under 3" at 25 yards... I need to reconfirm today. I'd like to be 8" or better at 50 yards.

It sounds like switching to jacketed is another solution?
 
What is good 25 or 50 yard accuracy with 300 gr loads at ~1200 fps? Right now, I think I'm under 3" at 25 yards... I need to reconfirm today. I'd like to be 8" or better at 50 yards.
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3 inches at 25 yards is equal to 6 inches at 50 yards. It sounds like you are better than your goal so what's the problem?
 
Nathan, my better Ruger revolvers in 45 Colt or 44 Mag have been capable of 4", 100 yard groups, once around the cylinder. Lots of 2", 50 yard groups but that was sandbagged shooting when my eyes and reflexes were young. I can't always (or even often) shoot them that well anymore, but it's awfully nice to know the gun is capable whether I am or not.

This is more typical of my shooting from field positions, these days.

Edited to add: And no, this one hasn't been reamed yet but it's going to get the treatment. I expect it'll shoot as well as any Ruger 45Colt I've ever had, afterward.
 
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No real reason to slug the bore in my opinion. Ruger .45 Colt barrels seem to be very uniform... Slugging the bore is useful if you are looking for a constriction though. Then slugging will show that up as you will feel it get tighter as you tap the slug down the bore. If you have a constriction, firelapping may be in order. As for the throats not being .4525, <shrug>. Some say ok for jacketed bullets. If you are going to shoot mostly (as I do) lead, then you need to open those throats up to .4525. My accuracy gains in two of my Rugers was to cut the group size in half. The other two, it helped, but not as dramatic. Never will 'hurt' accuracy. Must point out that the last two I did, the throats were .451, so not that far out.... Anyway there is no downside to opening the throats up that I can think of. Some say that you may get a bit lower velocity when shooting jacketed, but ... so what.... My guns have only seen a very limited number of jacketed bullets anyway. My latest two .45 flattop convertibles have never seen a jacketed bullet.....

I did the reaming myself. Since I knew I was going to do several, the tool paid for itself. I've done a few for others too.

Others have sent their cylinders to cylindersmith. He does a fine job.

http://www.cylindersmith.com/
 
I bought the kit from brownells and did it myself. If you plan on owning more than one Ruger in .45 Colt it's worth investing in.

The process is very easy to do.
 
Thanks. I haven't slugged the bor or cylinders yet. Just measured with calipers.
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Given that Ruger has a modern manufacturing facility, I would believe that they have a calibration lab. It is very likely that your caliper is more out of adjustment than what Ruger used to measure their chamber throats.

Whose gages are correct is a dead end argument, what really matters is does your pistol shoot well?

If it does, don't mess with it. I have had greater inaccuracy with large chamber mouths than smaller.

I am of the opinion that the more you shoot your revolver, the larger the cylinder mouths will grow through erosion.
 
Ruger has a long history of producing 45 Colts with undersize throats. A good explanation of the detriments of this condition and the advantages of reaming, including before and after target photos, can be found here.
 
It is very likely that your caliper is more out of adjustment than what Ruger used to measure their chamber throats.
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I use minus plug guages for my measurements... Oh, and another quick test is try to push a .452 lead bullet through the throats. Should easily pass with finger pressure. If it appears you need a hammer to get 'em started then they need reamed. After reaming, mine all pass a .452 bullet with finger pressure.

I have had greater inaccuracy with large chamber mouths than smaller.
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This is very true IF the lead bullet doesn't fit the throat. Then can cause blowby and/or bullet entering the forcing cone not quite straight which will cause accuracy problems. That is why old Rugers which 'normally' have larger than normal throats shoot better with .454 size bullets rather than .452. The problem with too small thoats is the bullet is sized 'down' and then sent into the barrel. Because the bullet doesn't have a tight seal, you get blowby and again accuracy suffers and you usually get leading. In summary you want the bullet to fit the throat (and be soft enough to 'bump up' (obturate) and seal ) and then be big enough when it reaches the barrel to seal it as well.... So if throats are .452 and barrel is .451, you are good to go with a .452 bullet....
 
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OK, I think I said this before, but I'll say it again. This gun is a Ruger Bisley Blackhawk in 45 Colt bought new in 2002 - 2005. It has always shot pretty well, just never super.

My only comparison is a Ruger Super Blackhawk in 44mag. It had a 10.5" barrel and 4x scope. As a ~18yr old kid, I killed a big (for me) deer with it at ~125 yards. I had been shooting it at 100 yards and getting 6 - 8" groups if I remember correct with a good rest.

So, I get a few years older and buy this 5.5" Bisley. I like it and can usually keep 6 on the paper plate 12" at 50 yards. At 75 and 100, I might as well have been shooting a cap and ball! I could rarely make hits at 75 yards and 100 yards was just way too far!

So, I'm trying to get this thing on target with 255 - 300gr bullets. In a 45 Colt, my opinion is cast is ideal for hunting. A JHP is more just wishful thinking and possibly killing penetrations.

So, on to the measurements. I measured the barrel at .4507" I did this by slugging 2 slugs down it and measuring it in 3 locations around the diameter and taking a rough average. Measurements were .4506 - .4508.

Then I slugged the cylinder throats. I only used 1 slug. It was tight in all 6 throats. It gave me .4507" after running it through all of them. Surely 1 was bigger, but the smallest let .4507" pass.

So, while tight, I would say it is acceptable for .452" slugs to pass this way. Ideally, the throats would be .4515 - .4525"

So, am I good?
 
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