sizing for revolver

[357shooter]

Your long range results with the BFR are just amazing!

I'm coming to the same conclusion that the .357 is mayb a little quirky compared to larger calibers.

[mdi]

I've found with my revolvers if the bullet is much over cylinder throat diameter I'll get leading (or mebbe lead "spray) on the cylinder face, frame, and around thr forcing cone...

[Moonman]

mdi,

Check the Barrel/Cylinder Gap, it may be EXCESSIVE.

Cylinder Gaps that are TOO MUCH and Bevel Base Bullets lead even more.

[bones37]

I've found with my revolvers if the bullet is much over cylinder throat diameter I'll get leading (or mebbe lead "spray) on the cylinder face, frame, and around thr forcing cone...

I am having this same problem with a 629-6. I am getting lead smearing in the chamber beyond the end of the case(using 44 special) and up into the throat(s) Also, there is this " spray" on the cylinder face, frame and forcing cone as you described.

[44man]

mdi,

Check the Barrel/Cylinder Gap, it may be EXCESSIVE.

Cylinder Gaps that are TOO MUCH and Bevel Base Bullets lead even more.

Gap is something I never paid much attention to. Boolit jump to the cone and rifling doesn't seem to be important either.
In the .357 I am thinking tension can vary too much on boolits just from the diameter of the brass. Then there might be too much primer pressure so I would try standard primers too, even with H110 and 296.
I have to load some .357's for my mailman so I will measure seating pressure. I will have to borrow his gun to test primers.

[MtGun44]

My THEORY on why some guns need "over throat diameter" is possibly an out of
round throat or boolit so that without oversize there is still a bad fit.

Not proven, just a theory. FACT is that some of my revolvers shoot better with .001
or .002 oversized - most do not need .002, but many seem to like .001 over.

Bill

[Char-Gar]

There is no reason on earth to go over throat size. The boolit just gets sized down anyway. A perfect thumb push through throats is all you need. Even a hard boolit will upset enough to seal the throat if it is close. Seal in the bore is always more important.
Stop skid in the bore and the seal will be right.

I would agree with this, IF a fellow is working with one revolver. There are times when I am loading ammo that will be used in sixguns that have cylinder throats that vary. In that case, I size for the largest throat size and shoot the ammo in the others as well.

Example... I have many 38/357 sixguns with throats that run from .357 to .359. I will size the bullets .359 and use that ammo in all of them.

I freely admit that this is for the sake of expediency and will probably not deliver the very best accuracy in each revolver, but the accuracy will be plenty good enough for 99.9% of what we shoot at.

This is the one "reason on earth", I can think of to go over throat size. Some of us, just have to darn many sixguns to fiddle around loading tailor made ammo for each individual sixgun. Other than this exception, 44man is dead nuts on.

[44man]

I would agree with this, IF a fellow is working with one revolver. There are times when I am loading ammo that will be used in sixguns that have cylinder throats that vary. In that case, I size for the largest throat size and shoot the ammo in the others as well.

Example... I have many 38/357 sixguns with throats that run from .357 to .359. I will size the bullets .359 and use that ammo in all of them.

I freely admit that this is for the sake of expediency and will probably not deliver the very best accuracy in each revolver, but the accuracy will be plenty good enough for 99.9% of what we shoot at.

This is the one "reason on earth", I can think of to go over throat size. Some of us, just have to darn many sixguns to fiddle around loading tailor made ammo for each individual sixgun. Other than this exception, 44man is dead nuts on.

That is correct, right way to go.
I would lap all to .359".
What you say might be the reason some of the .357's are picky. I only measured all throats on a few guns.
Lapping can round out an oblong throat too.
The big problem we had with one .357 was it had all .357" throats but the bore was out of round with the largest groove at .3599".
Lapping is easy and really works. I found it can work better then a reamer.

[357shooter]

My THEORY on why some guns need "over throat diameter" is possibly an out of
round throat or boolit so that without oversize there is still a bad fit.

Not proven, just a theory. FACT is that some of my revolvers shoot better with .001
or .002 oversized - most do not need .002, but many seem to like .001 over.

Bill

+1. Glad I'm not the only one, there may only be two of us though.

[Char-Gar]

That is correct, right way to go.
I would lap all to .359".
What you say might be the reason some of the .357's are picky. I only measured all throats on a few guns.
Lapping can round out an oblong throat too.
The big problem we had with one .357 was it had all .357" throats but the bore was out of round with the largest groove at .3599".
Lapping is easy and really works. I found it can work better then a reamer.

Most of my 38/357 sixguns are of the vintage/collectable stage of their lives and I don't feel inclined to modify them in any way, just to get a smidge better accuracy.

I am something of a 38 Special nut with over 20 vintge Smiths and Colts. I also have a number of Smith and Colt 44s that I regard the same way. I still enjoy shooting them and each takes thier turn seeing the light of day, being removed from the safe. I have a generic load I shoot in these sixguns. Works for me.

With the Rugers, I will size to exact throat size mentioned.

[Char-Gar]

+1. Glad I'm not the only one, there may only be two of us though.

I have not be able to prove or establish in any sixgun that oversized (for the throats) improve accuracy. I am however convinced, by shooting, that oversized bullets either do not degrade accuracy or only by a small and insigniciant (to me) amount. Others who into ultimate accuracy may not find that amount insignificant.

So much of the stuff we talk about here is subjective and personal that it is hard, or impossible, to lay down the law and say..this is the way it is! We are taking about personal experience and not hard and fast proof by lab protocols.

[Mal Paso]

I am having this same problem with a 629-6. I am getting lead smearing in the chamber beyond the end of the case(using 44 special) and up into the throat(s) Also, there is this " spray" on the cylinder face, frame and forcing cone as you described.

Both of the 629s I've measured had Cylinder Throats smaller than the Barrel Groove.

[44man]

I have not be able to prove or establish in any sixgun that oversized (for the throats) improve accuracy. I am however convinced, by shooting, that oversized bullets either do not degrade accuracy or only by a small and insigniciant (to me) amount. Others who into ultimate accuracy may not find that amount insignificant.

So much of the stuff we talk about here is subjective and personal that it is hard, or impossible, to lay down the law and say..this is the way it is! We are taking about personal experience and not hard and fast proof by lab protocols.

That is how I feel. Most times it does not hurt accuracy to go larger then throat but it has never improved it for me. This will depend on the boolit too. The Lee TL can have the GG's and lube removed before the bore is reached.
Then a boolit that enters the throat can not be chambered.
I feel a boolit just barely under throat by .0005" or a little less is fine. Yet I can shoot boolits well under throat. Alignment I guess.

[1bluehorse]

Most everything I've learned about shooting cast lead bullets has come from here and places referred to from here. It's been quite a journey. (one I'm sure isn't near over) What I have come to believe from all the information and what shooting I have done is the the bullet should be sized to the cylinder throat. (as long as it (throat) is slightly larger than barrel groove size.) ie; for 45 colt, .4525 cyl, .451ish groove dia. MtGun 44 makes a very good point to consider, but I trust the sizing die in my lubrasizer to size a 453ish bullet to .452(ish) at least as well as the cylinder throats on my revolvers. I have measured all the Ruger 45 colts I have had (many, with 4 left) and they all were undersized in the cyls. and groove on all were .451/.4515. All had varying amounts of thread choke and some had tight spots in the barrels. I reamed all cyls to .4525 and firelappped each of them to where a .442 pin gauge will slide completly down the barrel, ( a .443 won't start from the muzzle) I think this is about as good as I can do with them. I would take these same steps with any caliber (in fact have done so with my wifes .357s) ( I have not the equipment or knowledge for line boring nor does my shooting ability warrant it) This is a long winded way of saying I agree with 44MAN and Char-Gar, and this is quite possibly way more info than anyone wanted to read....but I enjoyed sharing it with you all....

[Char-Gar]

I have run into zero Colts and only one Smith and Wesson that had cylinder throats larger than barrel groove diameter. That one Smith was an early 6" blue 29 with the underlug barrel. The throats were OK at .430, but the barrel groove was a whopping .432. I sold that gun down river ASAP.

I am not big into Ruger SA sixguns, but have owned 6 or 8. The NM Blackhawks were too tight in the cylinder thoats. I had them reamed. Recently I bought one of the new Lipsey's 45 Flatop sixgun on the smaller frame. This is the best Ruger that has passed through my hands. The cylinder throats are a uniform .452 and the barrel is .451 and is so smooth there is zero leading from any load I have put through it.

I first read of the relationship of cast bullet, cylinder throats and barrel groove in a Guns Digest piece written by Elmer Kieth entitled Sixgun Miscellany, published in the mid 1950s. So this issue has been around quite some time. The advent of the jacketed bullet in the sixgun put the art and science of cast bullets in the sixgun on the back burner for a generation or two. I am glad to see it coming back to the forefront again.

[9.3X62AL]

So much of the stuff we talk about here is subjective and personal that it is hard, or impossible, to lay down the law and say..this is the way it is! We are taking about personal experience and not hard and fast proof by lab protocols.

THIS! ^^^

There's a least a metric ton of great info in this thread. My only addition would be that we all should assure that those boolits we so carefully size to fit or slightly exceed our cylinder throats AREN'T being reduced while seating via use of undersized expander spuds in our die sets. MOST die sets these days "assume" the use of jacketed bullets, and most of their expander spuds/balls/stems are TOO %^$# SMALL. Perhaps the folks using the boolits @ .002"+ throat diameter are unknowingly accomodating & adjusting to such tooling quirks.

[MtGun44]

Good point, Al.

Bill

[Char-Gar]

RE: Al's excellent point

I am a believer in soft cast bullets in sixguns.
I am a believer in soft bullet lube in cast bullets in sixguns

Therefore; I expand case necks to not not under .001 smaller than bullet size.

[Piedmont]

A couple of points that don't seem to occur to some of you are that if you have loose chambers an oversized bullet will center better and give a straight launch into the throat. Also, an oversize bullet will change the resistance and therefor how the powder burns. That can change accuracy.

[357shooter]

I agree that Al made a good point. That's why I checked and verified that my over throat size bullets aren't being swaged down by the brass. They aren't.

They are still more accurate in my 357's.

I don't shoot bigger calibers and don't suggest this is true of them, or that handloading for all calibers is the same.