Sizing Question: 0.429" vs 0.430"

[Jumping Frog]

For my semiautos, I've sized by boolits to 0.001" over bore size, such as 0.452" for my .45 ACP.

However, I slugged all 6 cylinder mouths of my S&W 629, and they all slug out to 0.429".

Do you recommend I size the boolits to be the same size as the cylinder mouth, or 0.001" over that. In other words: 0.429" vs 0.430".

I am buying a new sizing die for my new lubesizer and am trying to decide which size to buy.

[MakeMineA10mm]

If your boolets have a driving band that extends into the leade area of the cylinder's chamber mouths, you'll have to size accordingly (.429"), but if your boolets do not project into the leade, I'd get the .430".

[bobthenailer]

Id would go with .430 dia sizer

[Larry Gibson]

If your boolets have a driving band that extends into the leade area of the cylinder's chamber mouths, you'll have to size accordingly (.429"), but if your boolets do not project into the leade, I'd get the .430".

+1.

I have to size the 429640HPs at .429 so they will chamber in the .429 throats of my Anaconda. I size most every other .44 cast bullet at .430 for use in my five .44 revolvers. I blissfully sized .44 cast (mostly 429421's) at .429 for many. many years with excellent accuracy in every .44 revolver I shot them in (Hawes, S&Ws, Colts and Rugers). Never knew I could get "better" accuracy with larger sized cast until all the hullaballou was printed in magazines and then forums............got moulds that dropped larger bullets (the Lyman mould would drop at .432 with a harder alloy or one with a correct amount of tin in it) and sized at . 429, .430, and .432...........Never noticed after testing that the increased sizing ever really improved accuracy except if the throats were .004 - .005 over the groove diameter. My thoughts are that the bore sizing down an over sized cast bullet is just as detrimental to accuracy as using the under sized (for the cylinder throat) cast bullet.

However, considering te .429 size of your S&Ws throats, I'd bet you won't notice any actual difference between .429 sized bullet and .430 sized bullets except the .430 may give chambering problems as MakeMineA10mm suggests.

Larry Gibson

[youngda9]

If you buy a .429 you can easily turn it into a .430 with a dowel rod and some sandpaper if the need arises.

[Maven]

If you buy a .429 you can easily turn it into a .430 with a dowel rod and some sandpaper if the need arises.

Correct! Here's a detailed tutorial: http://www.castpics.net/subsite2/HowTo/How%20to%20Hone%20a%20Size%20Die.pdf

[mdi]

If my 629 had .429" throats, the first thing I would do is slug the barrel. If it too was .429", I would ream the cylinder throats to .431" and size bullets to .431". My older (mfg. '84) 629 has .431" throats and .4295" (or so) groove diameter. I shoot .431" bullets cast for this gun (Lyman 429421) or .432" bullets cast for my Puma (Ranch Dog RNFP @ .432"). Both shoot well...

[Larry Gibson]

My Anaconda has .429 throats and a .429 groove diamter barrel. It is the most accurate revolver I have ever had or shot. I size .430 with 200 - 250 gr cast just for convenience and .429 with the 429640HP for chambering ease. The RCBS 44-250-K, the Lyman's 429244 at .430 and the 429640HPs are all more accurate than I can shoot any more. Just my experience and I would not even consider reaming the Anaconda's throats oversize.

Larry Gibson

[bones37]

If my 629 had .429" throats, the first thing I would do is slug the barrel. If it too was .429", I would ream the cylinder throats to .431" and size bullets to .431". My older (mfg. '84) 629 has .431" throats and .4295" (or so) groove diameter. I shoot .431" bullets cast for this gun (Lyman 429421) or .432" bullets cast for my Puma (Ranch Dog RNFP @ .432"). Both shoot well...

This is what I plan to do with my 629 to simplify things, since I have a two other 44s, one a Ruger, the other a Marlin that require larger(432") boolits.

[fredj338]

I would slug the bore & then open the cyl throats if necessary. Smaller cyl throats almsot enver shoot well w/ cast bullets in any caliber.

[Jumping Frog]

Well, I sized some to .430 using my Lee sizer and cannot get them to push through the chamber without really driving through like I was slugging them all over again.

I am going to get the .429 for now, but I do believe the longer term strategy is to find a good revolver smith and open the cylinder chambers up a touch.

When I slugged the barrel, it slugs out at 0.4296", and having a barrel slightly larger than the cylinder is not optimal.

BTW, these are both LSWC-style moulds I am casting. One is a Ray Thompson design Lyman 429215 gas checked, the other is the NOE version of a 429421 Keith. Thus there is a driving band sticking out of the case.

Here are some of the Ray Thompson design Lyman 429215 gas checked, from back when I was still tumble lubing with LLA. Looking forward to sizing them with my Star.

http://i247.photobucket.com/albums/gg126/Jumping_Frog/DSCF2823-1.jpg

[Larry Gibson]

Shoot those loads first as the revolver may not be "broke" and may not need "fixing". A "problem" based on internet examples (including my own) may not be a real problem at all. Let your revolver tell you if it needs "fixing".

Larry Gibson

[Mal Paso]

I have reamed 3 Revolver Cylinders where the Throats were smaller than the Groove with great results. 2 629s and 1 Colt Anaconda that has a .430 groove. I prefer the slight tooling marks left by a reamer to trying to polish by hand. I opened them to .431 which works well with .429 and .430 grooves. .431 Boolits also work well in the Ruger with .432 Throats. The greatest increase in accuracy was with 44 Specials.

The Anaconda is my best gun too although it had problems from the factory such that whoever owned it for the first 12 years had not put 50 rounds through it. Now the forward band of Miha's #503 is just in the cylinder throats and those Boolits go exactly where pointed.

[mdi]

Shoot those loads first as the revolver may not be "broke" and may not need "fixing". A "problem" based on internet examples (including my own) may not be a real problem at all. Let your revolver tell you if it needs "fixing".

Larry Gibson
Amen! My example is what I might do if all else fails...