Gas Check .357 Bullet

[red rick]

I have a SP101 3 " that I am going to work up to the bullet or book max. with 4227 and a 160 gr. WFN bullet .

Do you think I need a gas check bullet ?

The throats measure .3577 and the bore .3575 . What size bullet would you use and would you use the same size gas check bullets as plain lead bullets ?

 

[rcmodel]

You need .358" bullets.
They need to be a tight press fit in the chamber throats.
Regardless of what the bore size is.

And gas checks only come in one size for .357 bullets.

They flatten and expand when they are crimped in place by the sizer die and fired.
Be that .356", or .360".

All else being equal, with proper size, alloy hardness, and lube, gas checks are not needed in .357.

It was developed in 1934, and made it's reputation over the next 40 years with plain base 158 grain LSWC bullets.

If it worked then, it will work now.

rc

 

[243winxb]

At 22BHN , no gas check needed. .358" is good. Make sure the COL will fit your cylinder when crimping in the groove.

 

[red rick]

Thanks for the help . Non gas check will save me a little money . I was thinking that I might need .359 bullets .

 

[rcmodel]

I doubt .359" bullets will press fit through your .3577" chamber throats.

And may not even chamber in your cylinder.

BTW: How did you get so precise on the throat & bore measurements?

.0001" difference is pretty fine frog hair to measure precisely with your typical measuring tools.

ec

 

[red rick]

I slugged three out of the five cylinders with a .358 bullet and the used a Starrett micro meter to measure them . All three measured the same so I stopped there .

Is there a better way or reasonably priced tool you would use ? Not trying to be a SA , I looked for a cylinder measuring gauge , but could not find anything .

The bore was measured by Dardas .

 

[rcmodel]

Don't matter.
Don't over-think it!

Bullets only come in .001" size steps.
Cast bullet sizing dies only do to.

So stressing out over the difference between .357" and .3577, or .3578" is too much of nothing to stress out over!

Because there is nothing you can do about it anyway.
Except buy or cast & size the next .001" larger size bullet.
Which would be a .358" bullet.


BTW: The 'only' way to accurately measure a chamber throat that closely is with a precision ground set of steel plug gages.

http://www.starrett.com/metrology/p...xed-Gage-Standards/111501-Pin-Gages/S4005-500

Way overkill for what we want & need to do here.

rc

 

[red rick]

Not stressing at all . Just seems like everyone is concerned over .0001 " with lead bullets .With my micrometer it measures .0001 at the same time it measures .001 . That was just the measurement I got measuring each slug in 2 places and then re-measuring them . I am glad to hear that I don't need to be so precise with the measurements .

 

[red rick]

How do you measure your chamber throats ?

 

[rcmodel]

I push sized bullets through all of them until I find the size that is a tight push fit.
In most of them.

If it falls through, it is too small.
If it won't go through without beating on it, it is too big.

Seriously, that's how I have done it my whole life!

On the other hand.
How do you suppose the factory's do it to make .22 lead bullets fit every .22 ever made?
Or every lead .38 special fit every revolver ever made?

They make them out of soft lead.
So one size fits all when they slug up to fit when fired!

rc

 

[red rick]

I had to beat those .358's through .

 

[red rick]

I didn't measure the bullet I used before I slugged the throats . They were packaged as .358 . I just measured another one from the box and it measured .3598 .

 

[rcmodel]

There ya go then!

.360's have to beat into submission?

.358"'s should be just right!

Again, don't over-think it until you pop some caps with them.

rc

 

[Jesse Heywood]

Load and shoot them. With 4227 you should be able to find an accurate load. Be prepared for a lot of muzzle flash and noise. Very accurate powder. In bigger bores I find compressed charges are best, but start low and work up.

 

[Walkalong]

Just seems like everyone is concerned over .0001 " with lead bullets

Not sure where you were seeing that. As posted, .001 is close enough.

If you size the bullet to just push through the throats, and the bore is smaller than the throat, and you do not get leading when you shoot a reasonable BHN bullet for the pressure/velocity, you are good to go, no matter what the throats and bore measure.

 

[GP100man]

As posted earlier , if they don`t fall thru or bind up upon chambering a loaded round load & shoot em !

GP

 

[MEHavey]

throats measure .3577 and the bore .3575.

That's a perfect throat/bore match. Count your lucky stars.

Cast/Shoot .358 (assuming the ogive will fit the throat) and let that throat "custom" size
it that last 3/10,000ths.

You don't need "superhard" with good throat/bore fit like that. In fact it will hinder you.
Wheel weight will do fine out to moderate 357 velocities, and Lyman #2 (15BHN) for
anything reasonable beyond that.

 

[PapaG]

Lyman 358156 sized to chamber throat diameter and hornady gas check with any sensible charge of appropriate powder and you are good to go.

 

[red rick]

Thanks for all the help and replies . I just started reloading and do not know anyone local to ask for help & advice . I am glad I can come here for help and knowledge .

 

[red rick]

I sent Dardas my throat slugs that I measured at .3577" and they measured them at .3578". They recommended min. size bullet .359" .

I also sent in my throat slugs for my .44 Redhawk . The bore measured .4295" and the throat at .4310" . They recommended min. size bullet .431" .

 

[243winxb]

Dardas website

Cast bullets must be .001" larger than groove diameter.

This is the barrel, not throat. .359" is to big IMO. I size to barrel groove diameter for handguns & .001" for rifle. Or .309"- .3575" -.451" & .452" - .430" The normal standards for hard cast.

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[Walkalong]

.358 should be fine.