.358 Hard Cast Bullets

[red rick]

I bought some 160 gr. , .358 diameter hard cast , GC bullets to load for my SP101 3" revolver . I loaded a few and found they would not go into the cylinder all the way . I then tried them in my GP 100 with the same results .

I had the cylinder measured and it measured .3578 and the barrel .3575 .

Should I , or would you get the cylinder reamed or just shoot jacketed bullets ?

 

[kerreckt]

You can resize the bullets, just as you would do, if you had cast them yourself.

 

[Sunray]

No way I'd machine a revolver for an odd weight bullet. Or size the bullets.
Who measured the cylinders and how? Doesn't sound right to me. Regular factory ammo fit? The SAAMI spec diameter of the .375 Mag/.38 Special case is bigger than .3578".

 

[rcmodel]

Any chance you have .38 Special carbon rings in the chambers??

Or over-crimping and leaving a bulge in the case??

Color a round with a black marker and chamber it and see what is tight where.

rc

 

[red rick]

I don't think that it was over crimped because I could not push a new bullet through the cylinder . Factory .357 ammo drops right in . I will try the black marker .

It's rubbing the marker off at the halfway point of the bullet , but not all the way around the bullet , just on a small section .

 

[ArchAngelCD]

I don't think that it was over crimped because I could not push a new bullet through the cylinder . Factory .357 ammo drops right in . I will try the black marker .

It's rubbing the marker off at the halfway point of the bullet , but not all the way around the bullet , just on a small section .

When you say bullet are you talking about the actual bullet or the round?

 

[PapaG]

Did you measure the bullets....they might be larger than .358

 

[chris in va]

Sounds like they are a bit oversize for your cylinder. Have you measured them with a caliper yet? You could get a Lee sizing die to 'fix the glitch'. Probably out of round too.

As the all-knowing RC mentined you may have a ring in the cylinder from 38's like my SP 101 had.

 

[red rick]

I know this is not good for lead bullets , but I ran them through my Lee factory crimp die and now they load .

I don't think that I have a carbon ring because factory .357's drop right in the cylinder .

I measured 2 of the new bullets and they measured .3587 & .3586 .

 

[mdi]

Any time there is a "fit" problem, measure! How far is "won't go in all the way"? .575",? 743"? Measure the round to find out where the cartridge is too big and that will prolly tell you when it becomes too big.

BYW over crimping will often squish the case down, distorting the case walls, and producing bulges.

 

[red rick]

They sure didn't look over crimped to me , but they might have been .

When I load again I will see if they will chamber before I crimp them .

Do y'all think that a .3587 bullet should chamber in a .3578 cylinder ?

 

[ArchAngelCD]

Do y'all think that a .3587 bullet should chamber in a .3578 cylinder ?

You are talking about >1/1000", yes I think it should easily chamber.

 

[41 Mag]

There is sometimes spring back when a bullet is sized especially with some of the harder alloys. This combined with you possibly having a slightly tight chamber could result in having an issue with your fit.

However I have two GP-100's that I run cast through. I size everything to .358" which usually ends up being slightly over if I let them sit a while before loading. I have not had any issues with any of them except when I loaded some DEWC's out a little too far and they hit the front of the cylinder chamber.

It only takes a slight amount of bulge on the neck to get a snug fit however and I have done that quite a few times myself in the past with both jacketed and cast loads. Nowadays however I use segregated brass, and I trim to length so I have everything on the same playing field.

 

[RPegram]

I had a similar issue when I started loading for my GP-100. I've only used 158gr lswc from MBC. My problem turned out to be three brands of brass: PRVI, GFL and WW Super. Once I removed all these types brass, everything now drops right into the cylinder.

 

[Jesse Heywood]

Have you tried pushing a bare bullet through the throat of the cylinder? It should be a snug fit and might take some pressure to push one through. If the bullet won't push through it's too big and needs to be sized. If that's the problem call the seller or buy a Lee sizerr die.

 

[red rick]

Yeah I tried pushing the bullet through the cylinder and cannot push it through .

I only bought a 100 of these bullets to try & the company ( Montana Bullet Works ) closed up right after my purchase . So I can't return them .

I played with them some today and I found if I seated the bullet at the top of the crimping groove they would load . I found the same with some Missiouri .358 SWC I had .