Tight cast boolits in my .44 question

[Larry in MT]

Greetings. I had a S&W 629-3 for many years. My bear load was/is a 285 grain hard cast w/gas check loaded with a near max load of H110. It was very accurate and didn't recoil badly at all.

The -3 got stolen and I replaced it with a -4, with the same 5" barrel and full barrel lug. The -4 has tighter cylinder charging holes (at the barrel end). In fact, it was difficult to seat the hard casts in the cylinder fully. However, once in place, they were just as accurate as they had been in the -3...

Because I was concerned that possibly a not fully seated cartridge would cushion a primer strike and because it took a rap on the extractor rod to dislodge unfired cartridges in a partially fired cylinder, I took emery cloth and carefully "sanded" the side of the hard casts (near the meplat). Now they seat fully with no pressure.

Am I apt to cause a problem or create a safety concern shooting these tight hard casts in this revolver? Extraction of the fired cases shows no pressure signs.

[John Boy]

You might want to start by measuring:
*Case OD of reload
* Throat ID of cylinder
measure the difference of the diameters
Then fireform several rounds - measure the OD of the fired cases to determine if you have to have the throats reamed

[Larry in MT]

No answer to my question?

[reddog81]

There shouldn't be any problems. Lead swages down realatively easily. More of a nuisance than anything else. A good tight fit probably helps accuracy.

People shoot bullets .001 to .002 over throat size all the time.

[dhom]

I was shooting a 45 Colt BH in a silhouette match and had the same problem. I had to push the bullets in hard to get the cylinder to rotate. Needless to say it got on my nerves and took away my concentration on the match. The next batch I reloaded I tried to seat bullets a little deeper, this worked somewhat but the problem still existed. Long story short the cylinder throats measured .451. Sent it to Dougguy and had it reamed correctly. Problem solved!!!

[DougGuy]

There shouldn't be any problems. Lead swages down realatively easily. More of a nuisance than anything else. A good tight fit probably helps accuracy.

People shoot bullets .001 to .002 over throat size all the time.

Well, one thing for certain, that oversize boolit will exit the front of the cylinder at throat diameter so all this is doing is creating excessive pressure. You cannot push a .432" boolit through a .430" throat and have it come out any larger than .430" physically cannot be done unless you give a bit of wiggle room for springback in the alloy.

Larry in MT, it is very common for a cylinder to need the throats "dimensionally corrected" for shooting cast boolits as we tend to size them a bit larger than groove diameter, but you would want to deliver the boolit to the barrel at advertised diameter, not what the cylinder throats squeeze it down to be.

In a perfect world, the boolit would be .001" to .002" over groove diameter, and the cylinder throats would be .0005" to .001" over boolit diameter. This arrangement works very well for cast boolits in any caliber revolver. Having the cylinder throats reamed and honed is the proper way to address the problem, and having throats all even in diameter and round is always a good improvement over factory throats as they can be rather all over the place in size and roundness. S&W size are more consistent than Ruger because of the tooling each mfgr uses to make cylinders, but they can be slightly out of rounds and you would never know it. Send a PM for details, I do a lot of cylinders for this very reason.

[Larry in MT]

I appreciate your responses.