Bore diameter on 625?

DeanD

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Is the bore on a 625-5 .452? Don't have mine available to measure but want to buy some hard cast 255 gr. SWC bullets. Should I get .452 or .453" bullets? Dardas bullet company gives a choice.
 
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I've never tried .453" bullets in a 625, but assume they would probably work fine, though .452" bullets are generally considered best diameter for .45 ACP and Auto Rim, semi-auto and revolver. A hard bullet may not shoot as well as a soft one, but it would be worth trying as there are always exceptions.

If you're experimentally inclined, order a hundred of each diameter and try several loads. I found recoil to be an objectionable factor with a bullet like you describe if heavier loads are used. Good luck-
 
What is confusing to me, and the reason I asked, is that nearly all the hard-cast .45 Colt bullets are .452" which I believe is the same as the .45 Colt bore size, but generally speaking it is recommended that lead bullets be .001" over bore diameter. Dardas is the only bullet manufacturer who offers a choice of .452" or .453"

.45 ACP and .45 Auto Rim have a bore of .451" so .452" bullets are fine there.
 
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I found .454" bullets generally better in .45 Colt than .452", but many shoot .452" with satisfaction. However, I have a couple of .45 Colt 25-5s with oversize chamber throats. They'll shoot accurately, but only with .456" bullets.
 
Cast bullets are most likely to be accurate in a revolver if their diameter is matched to the cylinder throat diameter, not the groove diameter. With one exception S&W centerfire revolver barrels have five grooves so it is difficult to measure a slug driven through them. For those two reason very few of us measure our S&W revolvers' groove diameters.

The exception is .45 ACP barrels made before S&W changed from broach cutting rifling to using electricity to erode metal away to create grooves. The change was about 1997. For the first 90 years that S&W made .45 ACP revolvers they used army specification 6 groove rifling.
 
...generally speaking it is recommended that lead bullets be .001" over bore diameter.

As mentioned, you need to size your bullets for the throats as that's the first thing they goes thru. And generally .001" over throat size is recommended. Ideally your groove should be .001" smaller than your throats, but you get what you got.

My 325TR & 625PC groove are right at .452", the same as the throats.

Either size will likely be fine, unless your throats are way off, but sometimes just trying different sizes is what's needed to see what works best for your pistol.

.
 
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We need to clarify something , it's the " groove " diameter , not the bore diameter of the barrel that's important . The bore diameter is the smaller of the 2 measurements . Measuring even the newer smiths is not a big problem . Yes , the 5 groove rifling does " slightly " effect the measurement reading but it is still important enough to obtain .
The first measurement is the barrel as that is the last thing that the bullet must fit to . The accuracy is from the barrel , not the cylinder .
After verifying the groove diameter and add at least .0001 thousandths to that meaurement this is the size cast bullet you want . THEN--- fit the cylinder throats to that size bullet , not the other way around . It should push through the cylinder with firm finger pressure , not using a hammer and a stick . In my 25-5 , I shoot .454 cast bullets with great accuracy . The cylinder throats were already oversize which did not create a problem . Oversize is better than undersize as it won't " down size " your cast bullet .
Veral Smith @ LBT Molds sells a soft back small booklet for about $15 explaining all this in great detail called , " Jacketed Performance with Cast Bullets " . You can email him as well . I have bought his book and corresponded with him numerous times over the years and learned much . His molds are top notch and he is a wealth of information on shooting cast bullets in rifles , revolvers and semi auto's . I hope this helps clarify some of your questions . Good Luck , Cowboy4evr
 
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Jim Stroh of Alpha Precision, Inc. has the correct answer

Jim Stroh from Alpha Precision, Inc. provides the best advice. I've not met one respectable gunsmith (e.g. Linebaugh, Bowen, Gallagher, etc.) that disagrees with Stroh's advice. Here is the opening paragraph from his treatise: Revolver Accuracy by Alpha Precision, Inc .

"As with other firearms, accuracy of the revolver is dependent upon several factors. First, the bullet must be the correct diameter with relation to the cylinder chamber throats, and the interior barrel dimensions (the groove diameter is most often referenced, but bore diameter is important as well). When cast bullets are used, the bullet should be .0005 to .0010"larger than the barrel groove diameter. Ideally, the cylinder throat will be .0005 to.0010" larger than the bullet. To illustrate, Douglas .44 handgun barrels typically have a groove diameter of .429". The cast bullet should be .4295 to .4300". The cylinder throats should then be .4300 to .4305". Jacket bullets are more tolerant and can be groove diameter + .0010. Cylinder throats .0010" larger than bullet diameter."

I've followed this advice with every custom revolver I've ever had built. The results were always superb. This assumes that all other issues with regards to cylinder barrel alignment have been addressed.

Keith
 
Is the bore on a 625-5 .452? Don't have mine available to measure but want to buy some hard cast 255 gr. SWC bullets. Should I get .452 or .453" bullets? Dardas bullet company gives a choice.

Dardas offers lead slugs to tap through your barrel and send in to him to have measured by him professionally for the right diameter. That would be the very best answer to your question:)
Karl
 
I load the 200gr .452" LSWC for my 5" 625-2 45acp/45AR and unpinned 4" 25-5 45 Colt from the company linked below.

The cylinder throats on both these revolvers is a tight .452"

I also buy 240gr .430" for my S&W 44spl and a few different 38cal .358"

The bullets are VG quality and cheaper than other hard cast bullets

My last order was 2000 bullets and shipping was $14.00

Welcome to Summers Enterprises, LLC, makers of fine hard cast lead bullets.
 
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I stand corrected by cowboy4evr, yes it is the groove diameter of the barrel I need to know not the bore. As I said I don't have it available to slug or measure but I have found out it is .451" so .452" is the right size cast bullet.
 
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