Throat size and cb for .44

[dkonrai]

Noob here. Been reading alot about cb.
My 629 throat is .429. So do I need a 429 or 430 mould?
Powder is 231, 296, blue dot.
Thinking 240 grain or so.
I will powder coat.

So thoughts? Will the 430 chamber?

O, and Dillon 550, either rcbs roll crimp or Redding taper crimp?


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[mdi]

An S&W 629 throats should be larger than .429". Mine run a hair under .431". I size the bullets for the throat diameter, .431", and its a good fit for the .429" groove diameter of the barrel. Most of my 44 molds, with my alloy drop bullets around .431"-.432".

For a new caster, I'd suggest a "Keith" SWC running between 240-250 grains, roll crimped, and start with plain lube, alox, 45-45-10, panlube, etc.. Easier learning curve just learning two simple methods; casting and lubing (which have been done for many, many years).

[dkonrai]

Got it. I checked with a cheap hf digital. It checks out when I use the 1.00 and 2.00 checks so I'm sure its pretty close.
Guess i really need to shove a sinker down the throat and see.
How does one mearure the chamber? Stupid question, but, my hammer doesnt fit in the frame .
What crimp dies are you using so not tobsquish the cb?

An S&W 629 throats should be larger than .429". Mine run a hair under .431". I size the bullets for the throat diameter, .431", and its a good fit for the .429" groove diameter of the barrel. Most of my 44 molds, with my alloy drop bullets around .431"-.432".

For a new caster, I'd suggest a "Keith" SWC running between 240-250 grains, roll crimped, and start with plain lube, alox, 45-45-10, panlube, etc.. Easier learning curve just learning two simple methods; casting and lubing (which have been done for many, many years).

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[mdi]

For my 44 cast bullet reloading I use two crimp dies depending on the bullet and load. One is a Redding Profile crimp (much like a regular roll crimp) and for some cast and jacketed I use a Lee collet crimp. I used a plain Lee and RCBS roll crimp dies for many years and got very good results (bullets with a cannalure or crimp groove get a roll crimp and smooth sided bullets get a taper crimp.).

Measuring a small ID with a caliper doesn't give accurate measurements due to the shape of the jaws (the flat portion of the jaw edges doesn't exactly fit the curvature of the throat ID.). I use plug/pin gauges and often slug the cylinder just like I slug barrels. I just remove the cylinder and drive a slug through, from the chamber side, while resting the cylinder on a padded surface. Don't try it while the cylinder is in the frame because of possible "tweeking" of the crane...

I'm sure others will add their thoughts, but this is how I've done 3, 44 Magnum revolvers, one 357 Magnum and 3, 38 Specials...

[dkonrai]

For my 44 cast bullet reloading I use two crimp dies depending on the bullet and load. One is a Redding Profile crimp (much like a regular roll crimp) and for some cast and jacketed I use a Lee collet crimp. I used a plain Lee and RCBS roll crimp dies for many years and got very good results (bullets with a cannalure or crimp groove get a roll crimp and smooth sided bullets get a taper crimp.).

Measuring a small ID with a caliper doesn't give accurate measurements due to the shape of the jaws (the flat portion of the jaw edges doesn't exactly fit the curvature of the throat ID.). I use plug/pin gauges and often slug the cylinder just like I slug barrels. I just remove the cylinder and drive a slug through, from the chamber side, while resting the cylinder on a padded surface. Don't try it while the cylinder is in the frame because of possible "tweeking" of the crane...

I'm sure others will add their thoughts, but this is how I've done 3, 44 Magnum revolvers, one 357 Magnum and 3, 38 Specials...

That makes alot of sense. The mic not meeting surfaces square, err round.
Thanks for the tips. I have 2 redding profile crimp dies. I think the rcbs I just got is a roll crimp.


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[fredj338]

IMO, almost impossible to get an accurate cylindrical measurement with calipers, regardless of cost. You need an inside micrometer or pin gauges. Having said that, you want the throats to match the bore dia + 0.001". So unless your bore is 0.428", doubtful, you want the throats larger, like 0.431" to match a 0.431" bullet. If the throats are smaller, they are sizing the bullet down before it hits the bore. The result is often leading early in the bbl & accuracy will suffer a bit.

[murf205]

Got it. I checked with a cheap hf digital. It checks out when I use the 1.00 and 2.00 checks so I'm sure its pretty close.
Guess i really need to shove a sinker down the throat and see.
How does one mearure the chamber? Stupid question, but, my hammer doesnt fit in the frame .
What crimp dies are you using so not tobsquish the cb?

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Go to Meyer Gage Company web page and look at the single pin section. You can buy them for reasonable $ and you wont need a full set. For a 44 I bought .427, .428, .429, .430, .431, and .432. Clean the cylinder throats and apply a VERY light coat of oil and you will know for sure what your throats measure. I wouldn't be without mine. shoot the gun first but I had the same .429 measurements on my cylinders and opened them up to .431 and they shoot cast boolits a lot better with NO lead in the barrel anywhere. Remember-shoot first and ream later. Welcome to the brotherhood. This place is a wonderful spot to fuel the addiction!

[waco]

I agree with mdi. Size to the throats and call it good. Roll crimp is your friend with revolvers.

[Mal Paso]

Tight throats are common on 629s. Mine were closer to .428". That is still larger than a .429" groove when you include the metal displaced by the lands. The throats were designed for jacketed bullets and were within S&W Specs. It should shoot ok with tight throats but 431" is a better throat size for shooting cast, with boolits to match. It cleaned up the leading on the trailing edge of the rifling and increased velocity for me.

Get some pin gauges or drive an oiled soft lead slug through the chambers and use a micrometer. mscdirect.com has a full set of .251-.500" pin gauges for $100 if you use this number HS86463023.

It's OK, just not ideal, to shoot bullets larger than the throats and harder or water dropped boolits will spring back slightly after passing a tight throat.

I would suggest a .432" mold and a Lee or NOE Sizer if cost is an issue.

[DougGuy]

Unless you have a comparator and a 110 degree V block, miking a slug with 5 lands and grooves is pretty difficult to get an accurate reading.

OP you'd be best served with .4315" ~ .4318" throats and size to .431" for them. In a perfect world, cast boolits work better when they are .001" to .002" larger than groove diameter, rather than sized to groove diameter, and throats should be .0005" to .001" greater than boolit diameter to insure they are not down sizing boolits as you fire the gun.

[dkonrai]

Unless you have a comparator and a 110 degree V block, miking a slug with 5 lands and grooves is pretty difficult to get an accurate reading.

OP you'd be best served with .4315" ~ .4318" throats and size to .431" for them. In a perfect world, cast boolits work better when they are .001" to .002" larger than groove diameter, rather than sized to groove diameter, and throats should be .0005" to .001" greater than boolit diameter to insure they are not down sizing boolits as you fire the gun.

Wow
So much great info!!!!
So I can use the pin set to check the chamber? That would be fantastic. Well worth the 100.00 then.
And I guess there is the cost to ream and polish the cylinder bores?
I also have a couple of 357 as well. 586 and 686 which might be in the same boat.
If bores are opened? Does it effect j rounds?
Sorry for all the questions

Dino

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[DougGuy]

It actually helps any round you shoot to form a better seal in the bore if it has to be swaged down a bit when it hits the rifling. J words have a soft lead core inside the gilding metal jacket so they will obturate or bump up to fill cylinder throats when they are fired. They will exit the front of the cylinder at throat diameter unless you are shooting fairly weak target loads, any magnum loads will bump them up.

You really don't need a whole set of gage pins, and you can order singles from Meyer, this is how I got started with mine, but you need the half thousandth increments not just thousandths. For a 44, you would likely need .428" .4285" .429" .4295" etc up to maybe .4325" or so.

I am traveling right now, but you are welcome to send a PM and get the details about cylinder services I offer, lots of happy shooters here after their cylinders come back from being "dimensionally corrected."

[Bodean98]

Hindsight being 20/20, I would skip the pin gauges and simply send the cylinder to DougGuy. It will return to you with six round, properly sized, and polished chamber throats in pretty short order and the cost will be less than the gauges! Re install your cylinder and find the load your pistol likes and shoot happily. You might shoot some before groups to see just how much of an improvement is achieved. I would be willing to bet you will not be disappointed.

[dogdoc]

Simply size bullets to .429 and shoot. If it shoots well you are good to go. No need to open up and it will shoot jacketed great. All of my newer smiths have 429 throats

[dkonrai]

Simply size bullets to .429 and shoot. If it shoots well you are good to go. No need to open up and it will shoot jacketed great. All of my newer smiths have 429 throats

10-4 have a mould coming from one of our wonderful members here. Mp .429 Keith black.

I am saving some $$ for the cylinder work. Definately need my 586 and 686 opened up a bit.

Dino

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