Can anyone here ream a 16-4 cylinder to .327?? Can it be done without needing to reblue the cylinder? Larry
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Ream cyl to .327
- Thread starter Jebus35745
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I think member Big Cholla may be doing this, but it might be he is doing 32S&W to 32 H&R which is basically the same thing. Just different start and finish points.
I have not done this particular conversion. But, it would be one of the simplest chamber conversions possible, you can do it yourself fairly easy with just a padded vise and a tap holder, some light cutting oil and solvent. You can rent a reamer from 327 Federal finish reamer - 4D Reamer Rentals
Plus a no go gauge, for $39 plus shipping. You could use a new empty 327 mag case to check depth,, but the no go gauge is only a $4 extra charge.
If your careful the outside and face of the cylinder blue will not be effected. The 0.125 the chamber is cut deeper will be bare steel and the blue in original chamber area maybe scuffed up depending on how tight your original chambers are and the exact tolerance of the reamer, plus possibly being rubbed a little by the cuttings. This can be taken care of by quality cold blue.
Remove cylinder from gun and yoke. In this case because extractor is already correct size remove it too. Place cylinder in padded vise, rear of cylinder facing up, a couple piece of leather will work well. place some rags under cylinder to catch the cuttings and oil etc. Coat reamer and chamber with light oil. A spray type works, I use a bottle of rapid tap myself, but any good light oil will work fine. Place reamer in chamber and with a bit of downward pressure turn it clock wise a few turns, (don't turn it back ward after cutting as trapped cuttings may score a bit), remove reamer, clean well, spray and mop chamber. oil reamer and chamber and repeat. Start trying the no go gauge after cleaning the chamber and keep working until it goes. Repeat on all chambers. After the first chamber you should have a good idea as to when your going to be close enough actually need to start checking with gauge.
You can get a inexpensive tap handle from most hardware stores if you don't have one.
I have not done this particular conversion. But, it would be one of the simplest chamber conversions possible, you can do it yourself fairly easy with just a padded vise and a tap holder, some light cutting oil and solvent. You can rent a reamer from 327 Federal finish reamer - 4D Reamer Rentals
Plus a no go gauge, for $39 plus shipping. You could use a new empty 327 mag case to check depth,, but the no go gauge is only a $4 extra charge.
If your careful the outside and face of the cylinder blue will not be effected. The 0.125 the chamber is cut deeper will be bare steel and the blue in original chamber area maybe scuffed up depending on how tight your original chambers are and the exact tolerance of the reamer, plus possibly being rubbed a little by the cuttings. This can be taken care of by quality cold blue.
Remove cylinder from gun and yoke. In this case because extractor is already correct size remove it too. Place cylinder in padded vise, rear of cylinder facing up, a couple piece of leather will work well. place some rags under cylinder to catch the cuttings and oil etc. Coat reamer and chamber with light oil. A spray type works, I use a bottle of rapid tap myself, but any good light oil will work fine. Place reamer in chamber and with a bit of downward pressure turn it clock wise a few turns, (don't turn it back ward after cutting as trapped cuttings may score a bit), remove reamer, clean well, spray and mop chamber. oil reamer and chamber and repeat. Start trying the no go gauge after cleaning the chamber and keep working until it goes. Repeat on all chambers. After the first chamber you should have a good idea as to when your going to be close enough actually need to start checking with gauge.
You can get a inexpensive tap handle from most hardware stores if you don't have one.
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cgt4570
SWCA Member
I agree. This is diy if you have average or above mechanical skills. If you can't change your own oil, etc., Then take it somewhere or mail just the cylinder to a reputable Smith.
I agree with steelslayer.
I've done many 32 Long to 32 H&R, and 32 H&R to 327 FM. Simplest conversions to do.
You won't need the go-no-go gauge; just stop when the rim recess cutter on the reamer is flush with the cyl face.
Don't worry, it's a very easy job. You can rent the reamer on-line; just google. Or buy at:
Chamber Reamers, Headspace Gauges, and Firearm Accessories Since 1957 - Pacific Tool and Gauge
Makes a 327 reamer: Chamber Reamers, Headspace Gauges, and Firearm Accessories Since 1957 - Pacific Tool and Gauge
$119
Request the pilot tip of the reamer to be your ~chamber throat size.
Clamp the cyl in a padded vise with the rear face pointing up. Apply cutting (or just plain gun) oil and the reamer will go all the way into the chambers as you twist it slowly by hand with slight removal of the bluing inside the chamber until the free spinning pilot bushing enters the chamber throat. The sharp reamer will be snug. The pilot in the throats of the chambers will align the reamer straight in the chamber.
When the reamer is inserted, the front end of the reamer cutting flutes will bottom on the existing H&R Mag case mouth shoulder in the chambers and the 327 reamer will stick out of the chamber when it bottoms on the case mouth 'shoulder' of the chamber, the amount you need to ream. You don't want to recess the chambers because, of course the headspace for the rim will be altered. So you just ream until the top of the reamer cutter is flush with the chamber mouth which extends the chamber shoulder ~ .140", only a bit more than 1/8", and you’re only shaving off .013” from each side of the chamber. This is literally the easiest reaming job that there is.
To ream apply constant medium pressure and turn the reamer clockwise until the shoulder is extended, and it only takes a couple minutes or so per hole. Do that six times and you’re done.
The secret is to turn the reamer very slowly and keep even pressure on the reamer while it's turning. Don't push too hard or it'll try to cut too big a chunk and you can get 'chatter'; you want to avoid 'chatter' to have a nice smooth cutting action. USE PLENTY of oil as you turn the reamer and remove the reamer occasionally to clean metal chips out of the cutting flutes with an old toothbrush.
Most small drill presses won't go slow enough and will create chatter. So if you have a drill press, you can chuck up the reamer in the drill press for alignment only, then use the chuck key to hand turn with one hand and hold pressure on the drill press feed handle with the other hand.
Or you can use a T handle like used for turning a threading tap. Don't use a crescent wrench or ratchet handle, it's possible to apply sideways pressure which will oblong the chamber holes.
Check each chamber when done to be sure a loaded round will go in all the way to the rim, clean chamber, and use touch up blue if you want, and that’s it. I prefer Brownell's Oxpho blue or Nu-Blue. Heat the cyl with a hairdryer for best results and use 3 or 4 coats.
I've done many 32 Long to 32 H&R, and 32 H&R to 327 FM. Simplest conversions to do.
You won't need the go-no-go gauge; just stop when the rim recess cutter on the reamer is flush with the cyl face.
Don't worry, it's a very easy job. You can rent the reamer on-line; just google. Or buy at:
Chamber Reamers, Headspace Gauges, and Firearm Accessories Since 1957 - Pacific Tool and Gauge
Makes a 327 reamer: Chamber Reamers, Headspace Gauges, and Firearm Accessories Since 1957 - Pacific Tool and Gauge
$119
Request the pilot tip of the reamer to be your ~chamber throat size.
Clamp the cyl in a padded vise with the rear face pointing up. Apply cutting (or just plain gun) oil and the reamer will go all the way into the chambers as you twist it slowly by hand with slight removal of the bluing inside the chamber until the free spinning pilot bushing enters the chamber throat. The sharp reamer will be snug. The pilot in the throats of the chambers will align the reamer straight in the chamber.
When the reamer is inserted, the front end of the reamer cutting flutes will bottom on the existing H&R Mag case mouth shoulder in the chambers and the 327 reamer will stick out of the chamber when it bottoms on the case mouth 'shoulder' of the chamber, the amount you need to ream. You don't want to recess the chambers because, of course the headspace for the rim will be altered. So you just ream until the top of the reamer cutter is flush with the chamber mouth which extends the chamber shoulder ~ .140", only a bit more than 1/8", and you’re only shaving off .013” from each side of the chamber. This is literally the easiest reaming job that there is.
To ream apply constant medium pressure and turn the reamer clockwise until the shoulder is extended, and it only takes a couple minutes or so per hole. Do that six times and you’re done.
The secret is to turn the reamer very slowly and keep even pressure on the reamer while it's turning. Don't push too hard or it'll try to cut too big a chunk and you can get 'chatter'; you want to avoid 'chatter' to have a nice smooth cutting action. USE PLENTY of oil as you turn the reamer and remove the reamer occasionally to clean metal chips out of the cutting flutes with an old toothbrush.
Most small drill presses won't go slow enough and will create chatter. So if you have a drill press, you can chuck up the reamer in the drill press for alignment only, then use the chuck key to hand turn with one hand and hold pressure on the drill press feed handle with the other hand.
Or you can use a T handle like used for turning a threading tap. Don't use a crescent wrench or ratchet handle, it's possible to apply sideways pressure which will oblong the chamber holes.
Check each chamber when done to be sure a loaded round will go in all the way to the rim, clean chamber, and use touch up blue if you want, and that’s it. I prefer Brownell's Oxpho blue or Nu-Blue. Heat the cyl with a hairdryer for best results and use 3 or 4 coats.
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I forgot to mention: once reamed to 327, on request I've followed up with a 2nd reaming to 32-20. This allows use of all four cartridges in the same cyl.
rog8732
US Veteran
Great tutorial by steelslayer and Hondo44, which is not to say I have ever converted a cylinder.
I like the idea of the drill press for keeping every thing plumb, but I always remove the drive belts. Two reasons. The spindle turns easier plus when "Mr Forgetfulness" makes his appearance there is no harm in hitting the on switch.
I like the idea of the drill press for keeping every thing plumb, but I always remove the drive belts. Two reasons. The spindle turns easier plus when "Mr Forgetfulness" makes his appearance there is no harm in hitting the on switch.
I personally use my milling machine to ream cylinders, but I have replaced the motor with a 3 phase motor and installed a Variable feed drive to control the motor speed. I can make it turn very slowly. Works on lathes, drill presses and band saws. Motors and drives have gottten reasonable and once done no more belt changing to control rpm
"I've done many 32 Long to 32 H&R, and 32 H&R to 327 FM. Simplest conversions to do."
Since the .327 FM has a significantly higher pressure than the rest of the chambering's, what concerns regarding this conversion is applicable (besides cylinder length).
Since the .327 FM has a significantly higher pressure than the rest of the chambering's, what concerns regarding this conversion is applicable (besides cylinder length).
While I wouldn't hesitate to do it to my K frame 16-4 because of its cylinder size and the wall thickness of it, plus its modern steel and heat treat, I would never do it to either of my early I frame 32 longs. My newer J frame 32 long would require some thought. Would the cylinder be long enough? Seeing as how S&W made J frame 327 mags, the cylinder would be strong enough if long enough.
No concerns in the K frame cyl. Plenty of wall thickness and much more than the 357 in the same size cyl. This is a common re-chambering amongst the pro smiths as well.
I frame 32 cyls are too short but the frame is not for the 32 H&R. The J frame cyl in an I frame will work.
J frame 32 cyls are fine for the 32 H&R and even for the 327 Fed Mag. But I wouldn't trust the cyl strength.
The factory 327s only used the new "J MAG" frame which is not only longer but specially strengthened.
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Just to clarify - you wouldn't trust the J frame cylinder strength for the 327, or for 32 H&R as well? I've got a spare cylinder for my Model 31-1 I was considering reaming up to .32 H&R only.
Sorry about not making that clear:
You're correct, the 32 H&R is fine, I've been shooting a couple I did for years.
But not the 327!
You're correct, the 32 H&R is fine, I've been shooting a couple I did for years.
But not the 327!
*Whew* thanks - I was hoping that was the case.
S&WIowegan
US Veteran
I bought a reamer from Dave Manson years ago when Federal began making 327 Fed Mag ammo. My revolversmith and I reamed a 6" Model 16-4 and Ruger Blackhawk. Easy job and does not ruin the guns' exterior appearance.
OP
Just an update, Andy Horvath has the 4” 16-4. He could probably do it in his sleep. Only 75.00 to do it. He built 2 custom revolvers for me in .32 long. Used .22 cylinders converted to .32 and the chambers were pretty tight. Both guns shoot great. Renting the reamer was abt the same as him doing it. He’s abt 6 months behind but my gun would be 2 weeks. Gonna try to have some ammo loaded before it’s done. Thanks for all the advice, Larry
I have wondered if some of the J Frame (recent manufacture) such as the 431PD or 432PD would handle the 327. The chambers appear sufficient in length, but I would be concerned about the alloy frame and the strength of the cylinder. The guns are built for the 32 H&R, but I'm concerned the 327 may be too much for them.
Anyone any thoughts on this?
Anyone any thoughts on this?
Cal44
Member
Not a gunsmith, but here are my thoughts.
Most likely the 32 H&R Magnum cylinder would take the pressure. Assuming it's long enough to fit. It's stainless steel, and other stainless J frame cylinders have been used for 357 Magnum, and even a few 327 Magnum models.
I suppose it's possible that magnum cylinders are made from higher strength steel, so there is still a question.
The frame would be the problem.
All the magnum AirLites are made with Scandium added to the Aluminum alloy for strength.
And the Aluminum Airweights are prone to cracks even with 38 Special loads.
So my thoughts are that you would be taking a significant risk of cracking the frame of a 431PD if you shot the high pressure 327 Federal round -- even if the round would fit in the cylinder.
Those were my concerns also, that and the recoil from that light a revolver would be a lot to handle in that small a package.
Smith produced a 327 in the J mag frame Models 632-1 & -2 (Centennial).
These are stainless frames including cylinder versions of the 632 alloy frame with SS cyl.
The 632 is only a 32 H&R. So yeah, the alloy frame was the show stopper for the 327.
These are stainless frames including cylinder versions of the 632 alloy frame with SS cyl.
The 632 is only a 32 H&R. So yeah, the alloy frame was the show stopper for the 327.
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