I pin gauged a new S&W M29 cylinder and all throats are .428"

[NuJudge]

I've never seen a .44 Magnum with throats that small. Anybody else seen one that small?

[Murphy]

I have.

A friend was gifted with a brand new Model 629 several years back. I couldn't get a .429 diameter boolit to push through the cylinder throats.

It isn't totally uncommon for S&W 29/629's to have undersized throats. The theory at the factory is like this: If it passes the accuracy test with "J" word bullets? It's good to go. I don't currently have anyone (should I need them) that does this work.

Anyway, I'm sure someone will be along shortly with a good recommendation who to send your cylinder to to have the throats reamed.

Murphy

[Petrol & Powder]

What does the barrel measure?

[Heavy lead]

Both my 629's and one previously owned one had .428's. Never slugged the barrels on them, they shoot fine with .430's.
Strange thing is my Ruger .44's (several) all have .430's to .431's however my .41 collection is just the opposite, the two Ruger's (both blackhawk variants) have .409 throats while the Smiths (3-657's) have .410-.411's.
Go figure.

[MtGun44]

Murphy is dead on. Factory checks with J-bullets and if OK, it is good to go. J-bullets work
fairly well when just a hair undersized, unlike boolits.

HOWEVER - you would be wise to shoot it a good bit with various different boolits and J-bullets
and see how it does before you ream it. Some individual pistols didn't get the word and shoot
well when they "shouldn't".

Bill

[376Steyr]

Not a Magnum, but I have a new, unfired 696 cylinder in .44 Special with .427 throats, waiting to be built into an L frame .44. Maybe I'll do some before-and-after testing one of these days.

[Tatume]

S&W went to the 0.428" cylinder throats specifically to provide excellent accuracy with jacketed bullets, which is what the majority will shoot in them. Brian Pearce has written on this subject several times, following conversations he had with factory representatives. There was a long-running thread in this forum centered on a claim that the throats are "defective" and S&W should ream them under warranty service. As expected, this strategy went precisely nowhere.

As MtGun44 suggested, you should shoot the gun before having it modified. It may be surprisingly accurate with cast bullets.

Take care, Tom

[Alablam]

The fellow at Realguns.com tested a Ruger .45 Colt Bisley with under sized throats. He used a primer only to stick a 0.452" bullet in the bore and it measured 0.451" which was bore diameter. The throats were 0.450". I would first shoot the gun with different hardness cast bullets and see what worked best (Betting on soft!). If it needs fixing, then find a smith.
http://www.realguns.com/archives/indexa.htm

[bones37]

You are correct, Sir. That is exactly what the S&W rep told me on the phone when I called them concerning my 629-6...but that is Not why I called them. I had other issues with the cylinder not related to throat size.

S&W went to the 0.428" cylinder throats specifically to provide excellent accuracy with jacketed bullets, which is what the majority will shoot in them. Brian Pearce has written on this subject several times, following conversations he had with factory representatives. There was a long-running thread in this forum centered on a claim that the throats are "defective" and S&W should ream them under warranty service. As expected, this strategy went precisely nowhere.

As MtGun44 suggested, you should shoot the gun before having it modified. It may be surprisingly accurate with cast bullets.

Take care, Tom

[kweidner]

I fear not reaming throats. Split dowel, 400 grit, go slow check with pin gauges often. Matched more than a few. Turned a SBH into one of the most accurate revolvers I have ever fired with this method. My DW 741 is the same way. Had my Smith build a custom fast twist bbl for it and he even commented on how nice the throats were. I learned it here. This forum is awesome. If your weary take it to a smith only after you check it. In my SBH I could make great groups firing out of the same throat prior to matching. Largest one was .431 now they all are. Full cylinder will stack em now. here is group testing out of my .41 after matching throats and new bbl.

[Art in Colorado]

I have had several 629's over a 20 year period and they all had small cylinder throats. Thats just the way S&W makes them.Art

[9.3X62AL]

In the situation described above--.428" throats and unknown groove diameter in the barrel--I would determine barrel groove dia. spec. If it was .428"-.429", I would give it a thorough test drive with .429"-.430" castings before turning wrenches on a device that might not be "broken". If accuracy was sub-standard, or leading of the bore resulted, I would consider honing the throats......but only after pretty extensive test drives, and I have a lot of 44 caliber bullet designs to test with, both plain-based and gas-checked. Jacketed bullets aren't a consideration in this caliber, in a rifle or a handgun. Just won't happen due to cost.

[NuJudge]

I measured my groove diameter and got .431".