s&w 14-1 throat/bore size

[brotherdarrell]

About 6 months ago I ended up with this revolver after one of those four way trades that covered about 2 months and involved some strange things being swapped back and forth. The gun itself is in pretty good condition though it is missing some blueing due to holster wear. Trigger is wonderful and I think I have finally found some grips that fit my hand.

Planning on taking it out tomorrow and seeing exactly what I can do with it accuracy ways, so last night I started with the cylinder throats to determine what size for the boolits. I first tried a .359 slug, too large. Ran it down to .358, too large. Hmm. Dug around and found a .356 die and ran the boolit through, perfect fit in the cylinder throats. My first thought was 'Here I go again with cylinder throats way too small for the bore'.

Next I decided to slug the bore, just to make sure. Ran a pure lead that was .358 through and when it fell out I found.... 5 lands and grooves, kind of hard to measure. So, I drank another cup of coffee and burned a few more brain cells and decided all I really needed to know at this time is how the slug fit the throats. I placed the slug over a throat, let go and......it fell through without slowing down, on all six cylinders.

It would appear that I have a .38 spl. that has throats @ .356"(9mm) and bore that is under .356". Can anyone say 9mm spl. ?

I see no reason to fight it, size @ .356" to match the throats and shoot my s&w 14-1 9mm spl. the way it wants to be shot.

What say you gurus? Any flaw in the plan?

brotherdarrell

[HeavyMetal]

I'd check my as cast diameter,if it was .357 I think my first batch of load would be shot as cast.

I would then decide, after target exam, on my next move if any.

[Char-Gar]

I see lots of problem with your plan. The first thing that comes to mind as you have no idea what size are your cylinder throats. Your method is fraught with errors and miscalculations.

Size your bullets .358 and never look back.

[brotherdarrell]

Actually I have to disagree. I 'know' .359 is too large because I tried that. I 'know' .358 is too large because I tried that also. I 'know' .356 is a very snug fit in the cylinder, because......I tried that also. I also 'know' that the slug that was used to measure the barrel is smaller than .356 because it is not as tight a fit as the .356 boolit that was a snug fit on the throats. I thought that was clear from my orignal post, I guess not.

What I don't know(or did'nt) was that this gun was as tight chambered as it was, and may be that this is normal. I did have one person state that 38 spl. was based on .356 bullet, but can find nothing that backs that up. After stating all this if my method is still fraught with errors and miscalculations I would seriously like to know. My understanding and experience with a 44 mag and 45 colt is to match boolit size to throats, which is what I am doing. The throats are @.356, the barrel slugs @<.356, so size .356. Thanks for responses.

brotherdarrell

[sagamore-one]

My K 38 Masterpiece (pre model 14) has very similar measurements. It will shoot .358 o-k, but really thrives on.357 boolits.

[brotherdarrell]

My K 38 Masterpiece (pre model 14) has very similar measurements. It will shoot .358 o-k, but really thrives on.357 boolits.

Good to know. I love the opportunity to discover what a new gun wants and how it wants it, in this case the small throats kinda threw me.

brotherdarrell

[Shooternz]

My M14-3 is the same throat diameter is .357" bore near as I can measure is .356"
it won't shoot .358 " worth a damn, I tried all the soft swaged WC bullets I could find the only one that shoots ok is the Hornady, with cast bullets the best result was with the RCBS 148 gr WC sized .357",
Yet my 586 the barrel is .357" and throat is .358" and it out shoots the M14 any day all day with just about any load I put through it, only problem is the 586 is to heavy
for bullseye type shooting with one hand,
I can shoot the M14 all day one handed with WC loads.
Robert.

[sffar]

Could it be when you sized the slug to .356 it's actually measuring more like .357?
Sam

[brotherdarrell]

Could it be when you sized the slug to .356 it's actually measuring more like .357?
Sam

Boolit is a Lee 358-150-1r cast of straight SOWW, drops from the mold @ .360. After pushed through a Lee push-thru mics @ .355 - .356. I was thinking (hoping) that there was some spring-back after sizing down but does'nt look like it.

I don't particularly care what size the boolits end up being, but I am glad that the bore appears to be smaller than the throats.

I have only shot this pistol one time, and that was with .358 boolits. My initial impression was that my old gp-100 shot circles around it, and that was not what I was expecting. Tomorrow or the next day I will take out both .356 & .358 to try out. The Dillon is set up for 3.3 gr B.E. Should be a good charge.

brotherdarrell

[uscra112]

At the level of precision needed to measure revolver throats, lead is a very poor tool. Better get some proper pin gages from www.gageshop.com and try again. Grade Z pins cost only $2.50 each. A range that will cover your problem will be $20.00, and you'll have 'em for next time.

[brotherdarrell]

At the level of precision needed to measure revolver throats, lead is a very poor tool. Better get some proper pin gages from www.gageshop.com and try again. Grade Z pins cost only $2.50 each. A range that will cover your problem will be $20.00, and you'll have 'em for next time.

I agree completely, and the anal part of me wants to do just that, but the 'good nuf' side says to load with different sizes and find out what the gun wants. Believe me, I never need much of an excuse to buy another measuring device. I am actually trying very hard to find ways not to spend money:!: If I ever come face to face with a set of pin gauges I imagine they will follow me home.

brotherdarrell

[sffar]

The micrometer doesn't lie, and soft lead accounts for the size alright. Maybe the throats taper some? A couple of my guns seem that way when I measure them with hole gauges.
I just sprung for a set(s) of pin gauges from Grizzly. Didn't want to spend the money either, but I like 'em! Very handy!
Sam

[Char-Gar]

I have in my records the cylinder throat and barrel groove diameters of over 100 Smith and Wesson and Colt revolvers on 38 Special. I have slugged the barrels and measured the throats of each cylinder with precision Starrett instruments.

With the exception of one Model 36 Smith that went .356 in the throats, all Smith and Wessons ran .357 to .358. In the throats. Most closer to .357 than .357.This includes a dozen or more K38/Model 14s that cover the production life of that model.

sizing lead bullets and seeing if they fit in the throats will not produce accurate results. it takes a machinest hole gauge or pin gauge to be spot on.

A good cast bullet of .358 size will chamber and fire in these Smiths and give good results. soft swaged bullets unless fired at no more than 750 fps will not do well at all.

Of course the usual stuff about the proper alloy, good lube and correct charge do the right powder all apply.

[brotherdarrell]

'sizing lead bullets and seeing if they fit in the throats will not produce accurate results. it takes a machinest hole gauge or pin gauge to be spot on."


My contention is that the actual size of the boolit is completely irrelevant; it is either the right size or not,... it either fits or it does'nt,.... it is either too small, too big or the right size. As stated before, I don't care what size it is as long as it is accurate.

As far as the cylinder throats go a boolit sized in my .356 sizer fits, the same boolit of the same alloy cast at the same time but run through my .358 sizer does not fit, it is too large. Now what they measure is not important for my purposes.

Now don't get me wrong, there is a part of me that loves to go the the fourth decimal point, but I don't find it necessary for this application. I will load ammo from both dies and see which shoots the best.

As far as alloy goes I am planning on 3.0 grains of Bullseye. The books show between 750 & 800 fps. If this is more than the SOWW will handle it is easy enough to add some Sn or COWW to harden it up a little. What say yee?

And thanks for all the ideas. I love data and information almost as much as I love measuring devices.

brotherdarrell

[Char-Gar]

Darrell. you come here and say ..this is what I have done, do you see any flaws? someone says, yes there are flaws. But yor response seem to be..who cares, I like what I did. Why are you asking for input if you don't want it?

Do what ever you want and best of luck.

[fecmech]

Fellows--When checking for throat size does one order "minus" gauges in .0005 increments and then see what fits and what does not?? If. a .357 goes and a .3575 does not, do we call that throat a .357 throat?

[9.3X62AL]

My pin gage set is a minus-.0002" set. If my revo throat accepts a .357" gage but not a .358" gage, I assume .357" and usually start out with .358" boolits. I'm not convined that +.0001 to +.001" oversize makes a whole heap of difference, but undersize sure as h--l can. If I were in the OP's shoes, I would start with castings sized at .357", assuming that the alloy in my sizer truly produces that end result. Just keep in mind that EVERY element of the dimensional equation can introduce error, to include alloy--tooling--and measuring gear. Take no dimension for granted, and all will be well.

I haven't mic-ed out as many S&W revos and Char-Gar has, but my results are practically identical to his stated findings.

[Char-Gar]

Fed mech...in your example we would know the throat is larger than .3570 and smaller than .3575. While this is not exact, it is plenty close enough for cast bullet shooting.

I use a Starrett machinest ball hole gage. the gage is read with a Starrett micrometer that reads to .0001. It takes some practice to develop a feel with the tools, but I can measure a round hole to .0002 for certain, perhaps to .0001, bit I would not bet more than five bucks on that.

Folks who try and measure holes with lead are at best getting an aproximate number, which may be good enough, but they should not feel they truly know the diameter of the hole.

Having a bullet a little larger than the throat will do no harm to the accuracy for 99.9 percent of our shooting. Having a bullet a little bit smaller that the throat most often will do no harm unless the alloy is to hard to slug up at the pressure of the load. Back about 1965 , I cast some 38 wad cutters from linotype, sized then .357, loaded them over 2.7/BE and fired them in a K-38 that had .3575 throats. The result was the worse leaded barrel I have ever seen.

Colt revolvers tend to run .359 in the cylinder throats and .354 - .355 in the barrel grooves. Decades ago I adopted .358 as the sizing diameter for 38 Special target and mid-range loads for both the Colt and Smith and Wesson revolvers. I use an alloy not harder than air cooled ww and I get sterling accuracy in throat that run .357 to .359 and barrels with grooves of .354 - .357.

I managed to win quite a few matches with the loads in both the Smith K38 and the Colt Officers Model Match. It works for me, for many years.

[brotherdarrell]

Darrell. you come here and say ..this is what I have done, do you see any flaws? someone says, yes there are flaws. But yor response seem to be..who cares, I like what I did. Why are you asking for input I'd you don't want it?

Do what ever you want and best of luck.

Not at all, I am by no means dismissing what has been offered in the way of advise. The use of pin gauges to measure the cylinder throats is by most means the most accurate way to measure. I am simply saying that for the purposes of fitting the bullet to the throat actually using a bullet is more than sufficient, they are after all what needs to fit. I have two sizes of dies, one seems to fit better than the other. Any boolit i shoot through this pistol will most likely pass through one die or the other. I simply dont see the 'flaws' that were set forth as being 'flaws'. I apologize for not agreeing with these 'flaws'.

brotherdarrell

[Char-Gar]

Darrell.. The flaw is your way of trying to determine bullet fit is little more than guesswork or tea leaf reading. If you get lucky and get the pistol to do well it will be nothing more than luck.

Yes,yes..I know...you don't agree!

[Frank]

Did you save the muzzle slug? Do a muzzle slug, then do a slug all the way through. Use any aluminum can, cut a strip and wrap it around the bullet. Now measure both. You are probably right. You probably have a .355 muzzle and a .356 throat. If you have a .0005 constriction you can shoot it out with a lap kit in 20 rounds.

[brotherdarrell]

Did you save the muzzle slug? Do a muzzle slug, then do a slug all the way through. Use any aluminum can, cut a strip and wrap it around the bullet. Now measure both. You are probably right. You probably have a .355 muzzle and a .356 throat. If you have a .0005 constriction you can shoot it out with a lap kit in 20 rounds.

Frank,

I have two slugs, and when slugging I can't 'feel' much in the way of a constriction at the any point in the barrel. As for the size of the slug I don't have an accurate way to measure it except to say that it passes through 4 throats much easier than a boolit sized to .356 which leads me to believe it is smaller.

Char gar,

Again, thank you for your contribution. I appreciate your time and effort. Just because I don't agree completely does'nt mean I don't appreciate your contributions.

brotherdarrell

[Char-Gar]

If you have a good micrometer you CAN measure the barrel slug on a 5 groove Smith and Wesson. I know most folks say you can't do it without some special stuff, but that is not correct.

You rotate the slug between the jaws of the micrometer while opening the mic. You will find two high spots on the very edges of the grooves which will give you and accurate reading of the barrel groove diameter.

You must be slow, careful and gentle with the slug, because if you "horse" it through the jaws of the mic the soft slug will deform and there goes any reliable reading.

If you don't want to do this, just assume the barrel groove diameter is .357 and I will give you a 99.99 % guarantee on that plus or minus .0002.

I will also give you the same guarantee that your cylinder throats run .3570 - .3575. While Smith and Wesson specs have swung some on their 44s and 45s, their 38 Spl./357 Mag. post-war specs have been remarkably uniform. There will be a rare odd ball, but chances are you don't have it.

Darrell, you don't know me from Adam, but I do know what I am talking about on this thread. I have been shooting and fiddling with Smith and Wesson sixguns since before you were born (probably) and what I know comes from many years of experience and not reading magazines or internet posts. This does not mean I am smarter than you or better than you. It just means I have made all of the mistakes before you have and have learned not to keep making the same mistakes over and over again.

I have discovered the wrong way to do things and the right way to do things and you are going about this in a way that wont give you the information you want. I understand the desire to do something "quick and dirty" and try and find shortcuts. I am not free of those tendencies myself. But life has taught me that that is an impulse I need to resist, if I want good predictable results on just about anything.

When I find myself in this kind of situation, I remember what Will Rogers said..."Some folks learn by watching, some by listening and some by reading. All the rest have to pee on the electric fence."

I am sure you are a nice fellow and I once lived in Deming NM. I know folks in that part of the world tend to be independent spirits and want to do things their way. So, I will just wish you well and take leave of this thread while I am still in a good mood. I hope to meet you down the trail and wish you all the best as you travel on through life.