GP100 Plan B

[Lefty SRH]

Need some insight, suggestions, opinions....etc. A friend of mine wanted me to come up with a HOT HEAVY .357 magnum load for his 6" GP100 in .357. I told him I have just the boolit and load and My GP100 really shoots it well.

I sit down to day and start loading for his GP. I get the 1st 6 rounds done and try a chamber check them, 2 of the 6 don't go all the way. GREAT, whats this....
I checked the throats because I using a Cast Performance 187gr FNGC (I don't have a heavy .357 mold yet) and the some of the .358 diameter is north of the crimp groove and is bumping the leading edge of the throat. And thats the problem! His throats are slightly undersized, .357".

I chose this boolit for him because he's going into bear country later this year and wants some handgun protection. All they plan on hunting with is a traditional bow.

I need a plan "B" for this gun. I doubt he will want to have the cylinder honed out to .358". Is there a heavy J-word bullet on the market that still penetrates DEEP like a hard cast?

Suggestions?

 

[gwhokie]

try cleaning the chambers. if he has been shooting 38's, it's possible the carbon ring in the cylinders will prevent a 357 from seating properly.

 

[Lefty SRH]

Gun is brand new, never fired.

 

[lfpiii]

Can you load factory ammo in the cylinder? If not send the gun back to Ruger for repair. If you do any major work Ruger might not be will to repair problems down the road.

 

[WESHOOT2]

The Remington 180g conventional JHP can be launched at high velocity from the GP100.
Use new sized cases.
Use the Redding Profile Crimp Die.
Use 3N37 or AA9 or W296 or N110 or N350 or H110.
Use the appropriate primer for the powder chosen.

 

[Jimbo357mag]

I like the 180gr XTP but if you want more penetration there are several FMJ flat points used for silhouette. There is also a 180gr CP LWFNGC. Is that bullet different than the 187gr?

http://www.midwayusa.com/product/1988218433/cast-performance-bullets-38-caliber-358-diameter-180-grain-lead-wide-flat-nose-gas-check

http://www.midwayusa.com/product/411386/cast-performance-bullets-38-caliber-358-diameter-187-grain-lead-wide-flat-nose-gas-check-box-of-100

 

[GP100man]

Clean the throats/cyl/chamber ,measure the boolit ,some alloys grow a bit as they age . slug the throats.

If they are larger than ya need a Lee push thru sizer is your next best bet.

If ya buddy is gonna shoot lead exclusively it may be worth the time/effort to send the cyl. to CAS & have it reamed . or at least all the throats the same size!

If I were to go for max penetration I`d go with a FMJ no heavier than 160gr. , I feel anything heavier in the 357 ya have to sacrafice speed for weight & 160 gives the most penetratin with shock.

This is just my 2cents worth .

 

[Sal1950]

Lefty SRH,
Did you have the throats on your GP reamed? All my Ruger 357s have throats sized at 357 and have the same problem you ran into with 358 sized bullets if they protrude far enough to try and enter the throat. I have to pull out a special trick or two to load most LSWC without problem.

Missouri Bullet casts a 180g RNFP in 18BHN that should avoid this issue, but I don't know if you could get them fast enough for your friends trip.
http://www.missouribullet.com/details.php?prodId=119&category=5&secondary=10&keywords=
Sal

 

[s4s4u]

If I were to go for max penetration I`d go with a FMJ no heavier than 160gr. , I feel anything heavier in the 357 ya have to sacrafice speed for weight & 160 gives the most penetratin with shock.

I like the 160 CL-SIL that Hornady used to make as it has just a small portion of lead open at the flat tip, which makes for a nice mushroom when hit from my 357 Max T/C. I will be trying it in my 360DW when it is done, but I expect it would give about as much penetration in the 357 Mag as any other slug, and is "legal" as a soft point or expanding bullet in states where that is a requirement. I agree that there becomes a point of diminishing returns when equating velocity and mass and diameter and trying to push a 220 grain slug out of a GeeP would seem to be a waste of potential. If you wish to push a bigger slug step up in bore size, JMNSHO.

 

[meshugunner]

As someone new to bullet casting indulge me in a bone headed question.

Being as .357 is the specced dia for .357 mag, why don't you size the .358 cast bullets down to that dia. ?

 

[Lefty SRH]

I think he should send it back to Ruger or have the throats opened to .358". The problem I am expecting is if the throats stay .357" and using something that does chamber is barrel leading. The bullet being .358 will still have to pass thru a smaller throat essentially sizing it down possibly NOT making a good seal in the bore. The other thing I don't like is the added pressure of a larger bullet passing thru a smaller throat.
Thanks for the suggestions.

 

[Lefty SRH]

Lefty SRH,
Did you have the throats on your GP reamed? All my Ruger 357s have throats sized at 357 and have the same problem you ran into with 358 sized bullets if they protrude far enough to try and enter the throat. I have to pull out a special trick or two to load most LSWC without problem.

Missouri Bullet casts a 180g RNFP in 18BHN that should avoid this issue, but I don't know if you could get them fast enough for your friends trip.
http://www.missouribullet.com/details.php?prodId=119&category=5&secondary=10&keywords=
Sal

I like that bullet Sal, thanks for the link. My 4" GP100 came with .358 thorats when I bought it new. I'll just have to see what he wants to do.

 

[DGW1949]

As someone new to bullet casting indulge me in a bone headed question.

Being as .357 is the specced dia for .357 mag, why don't you size the .358 cast bullets down to that dia. ?

What he said. And more 'specialy considering that were're talking about a special-purpose gas-checked bullet that aint going to actualy be used all that much.

Far as sizing the bullet to the throats/bore goes, have you measured the actual diameter of the bullets in question?....I ask that because in my experience, commercialy-cast bullets are seldom the size/weigth that the box say's they are.

When fooling with guns, always work on the cheapest part first...just sayin'.

DGW

 

[Jimbo357mag]

How about your run of the mill 158gr JSP bullet. Good velocity, good penetration and some expansion? That should be about as good as any. :shock: :shock:

 

[eveled]

One is a beat up blued gun the other a 97% stainless gun with the rarer 6" barrel. Ed