Will silhouette loads tear up my GP100?

[000Buck]

I just bought a 4" GP100 a few weeks ago and would like to try out some of Alliants published silhouette loadings. I am going to work up to their 158@1600fps load with Bluedot. It rates this load at 42,900 pressure.

Is the GP100 up to this, or is a large frame revolver better for these high pressure loads?

 

[HSMITH]

I shot some VERY heavy loads through my GP with no apparent ill effects. Keep a close eye on pressures and work up in small increments. I did have to switch to small rifle primers to keep the cratering down, pistol primers were cratering and I was fearful of a primer piercing. New brass and only a couple or maybe three loads before tossing it is a good idea too, you are asking a LOT of 357 brass at pressures like the ones you aspire to hit.

If your GP is like most you need to polish the charge holes before starting, they seem to run from 'rough' to 'bored with a rock' rough. You will get false sticky extraction at quite low pressures if you don't.

 

[JohnKSa]

NOTHING will tear up your GP100.

If, somehow, you manage to ruin your GP100, please post pics here--you'll be the first.

 

[MJRW]

The poster clearly must be proposing that he actually shoot at his GP-100 with those loads fired out of a completely different weapon if it is tear up his GP-100. The idea of something being "too potent" for the GP-100 is like a woman that can resist my charms. In other words, nearly impossible.

 

[James Bondrock]

158 grains @ 1600 fps? I think it unlikely you will achieve this velocity from a four-inch revolver. That data is almost certainly from a closed-breech pistol with at least a ten-inch barrel. But if you must shoot these loads from a medium-large (or light heavyweight) frame revolver, I can think of none stronger than the GP100.

 

[mtnbkr]

Is the GP100 up to this

If the GP100 isn't up to this, few guns would be.

FWIW, I doubt any book load for the 357mag will have a noticeable effect on the GP100 unless you shoot many, many thousands of rounds.

Chris

 

[Ben Shepherd]

Your GP should handle those loads fine. I've actually went past them(VERY carefully) in mine. You may want to consider using 2400 instead of blue dot though, if you're sticking strictly to alliant powders.

If you're gonna push this hard, I reccomend trimming all your cases to egual length, and seat and crimp as a separate operation.

Also please use winchester or starline brass. Remington will work(once, maybe twice) if that's all you have though.

One last thing: Use a chrono if you have it to "map" your progress.

 

[Majic]

Sounds like you are being a little optimistic with just a 4 inch tube. Silhoulette shooters use at a miminal a 8 inch barrel and you don't know if this load was developed in a revolver or a closed breech single shot handgun.
I would start with the revolver data and slowly work up while chronoing loads and watching the pressure indicators.

 

[000Buck]

I dont expect to get 1600fps out of my 4" barrel, but I would like to work up to the silhouette load to see what kind of velocity I can get out of it using my chronograph. I am doing this just for entertainment, not for silhouette shooting. I have a feeling I might just be making a bigger and bigger fireball once I get up to the max load, not any more fps.

I just wanted some opinions on whether or not the load would be damaging to the gun, evidently it shouldnt be. I only have experience loading for a 629 and G20, never up to that pressure(42k)

Thanks for all the replies and advice.

 

[HSMITH]

What Majic and Ben are saying , if I may be so bold as to speak for them here, is keep a CLOSE eye on the chrono. When your charge increases you get a velocity increase, for the sake of simplicity let's say you get 20 additional FPS for every .2 grains increase from a mid-level load and it is more or less consistent all the way up near the top load. You load up .2 grains more and you only get 10 FPS, kinda strange but no pressure signs that are scary, so you load up .2 more on top of the last load that only showed a 10 fps gain and get another abnormal gain or very little gain. This is your key that you better stop and stop now. When a normal gain is not seen it is telling you the reaction of the powder to the situation in the case at firing is not normal and that you cannot assume the reaction of any changes to the load will be normal. It could be that nothing will happen with another increase or it might be that you will be having your hand sewn back on, you just don't know until you try it. Some powders will actually start lowering velocities with further increases and some will blow your gun up. The key is to know when to stop and 'mapping' your loads with the chrony is the only scientific and somewhat valid way of working loads up without pressure testing equipment.

Granted this is a very simplistic flyby from high altitude but I hope it helps.

 

[stans]

I am absolutely certain that such heavy loads will accelerate wear on the gun. Now the question is, has anyone actually worn out a GP-100? I can think of a couple of revovlers that might be stronger than the GP-100. The two that immediately spring to my mind are the Freedom Arms single action and the rare Ruger Redhawk.

 

[Roger Williams]

NOTHING will tear up your GP100.

If, somehow, you manage to ruin your GP100, please post pics here--you'll be the first.

Roger that. I don't think anything you cook up that is found as a published load will hurt a GP100.

 

[mtnbkr]

Corbon uses one for load development.

Chris

 

[halvey]

I don't think you can destroy a GP100.

 

[Ben Shepherd]

I have one(GP100) and while they are REALLY strong, but they are not a redhawk or freedom arms. I have some loads for my hawks that would most likely be disasterous in a GP, but luckily they are long enough they won't chamber in a GP.

The non-rambling version: Yes, your GP100 is strong, but it's not indestructable, so be careful.

 

[gogetumnow]

Let's not forget the New Model Blackhawk in 357. A slight strength edge might still go to a Redhawk in 357 but not by much. Both the Redhawk in 357 and the New Model Blackhawk in 357 are built on 44 Magnum frames. In addition to that you have a 44 magnum cylnder with 357 mag holes. The equates to a LOT of metal surrounding the cartridge. I would almost think that you'd have case failure before you have anything on these guns let go, not that a case failure is good in any way.

The GP is still hell-for-stout though. I think your wrist will be hurting long before you loosen these guns up.

 

[Magnum88C]

I am confident that no factory or published load for the .357 Magnum will hurt the GP-100, even after you've fired thousands of them. I have, and my GP is still going just fine. Other than the Redhawk, I doubt there is a double action .357 that is as strong as the GP.

 

[Nightcrawler]

The GP100 is the strongest revolver in its size class. The only ones that are tougher are the ones that are larger (.44 Mag frames) like the Freedom Arms .353 Casull, the Ruger Blackhawk, the Ruger Redhawk, and the large framed Dan Wesson.