GP100 question

A

Andy1

New member
Could someone explain to me how the GP100 can be sold in .357 with an 8-shot cylinder (Super GP100) but only a 7-shot cylinder in .327 Federal.

Shouldn't it hold 9 shots?
Shouldn't hold at least 8 shots in .327 Federal?
Shouldn't it hold a 6-shot cylinder of .41 magnum?

I'm in the market for a .327 magnum. I'm split between the GP100 and the Single Seven.
 
TruthTellers said:
I would get the Single Seven. I don't see the point of a GP100 in .327 when you can get it in .357 also in 7 shots.
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I wouldn’t get a 7 shot GP100 in 357 at all. The fact that there are ammo choices that cause it bind is enough to deter me. The 327 should have an advantage here with the smaller case rim not binding.

JohnKSa gave the answer though. The 8-shot Super GP100 isn’t built using a standard GP100 cylinder or frame, hence the extra round.
 
Cylinder diameter plays a part. OOPS, I was comparing to a Single 7, had one.
 
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I don't know about that... I would say the Super GP100 is a modified Redhawk.
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It does look more like a Redhawk, because they dropped the frame extension that gives the Super Redhawk its unique look.

But it's actually the Super Redhawk, not the single-spring Redhawk design.

https://ruger.com/products/superGP100/models.html

Utilizes the superior action of the Super Redhawk® to allow for a two-spring lock work arrangement providing a more even double-action cycle and better ignition.​
 
The 327 Federal Magnum operates 10,000PSI greater than a 357 Magnum.
Check SAAMI for operating and proof pressures.

Putting 8 rounds in a GP100 cylinder would turn it into a hand grenade.
 
"...between the GP100 and the Single Seven..." You want a single action or a double action. The Seven is only available through Lipsey's too. And they may or may not have any. Plus there are a couple models that are no longer made.
"...One wonders..." Ruger has been operated by MBA's who know nothing about firearms for eons.
"...would turn it into a hand grenade..." Nope. The difference between 7 and 8 is how much machining is required and the diameter of the cylinder. Has nothing to do with the strength that Ruger revolvers are famous for.
The SuperGP100 "Utilizes the superior action of the Super Redhawk" according to Ruger. The Super GP is a bit bigger than the GP too. 7 ounces difference in weight.
 
I thought it was the other way around, the Super Redhawk use's the
lock work from the GP 100. I've seen the seven shot GP 100 and the web
thickness between chambers is very thin.
The super gp100 may be much different.
 
Putting 8 rounds in a GP100 cylinder would turn it into a hand grenade.
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Considering that it is physically impossible to cut eight .327 Federal chambers that can all be loaded at the same time in a GP100 cylinder, I'd have to agree that it's a dumb idea. - Not necessarily a hand grenade, just a dumb idea.
But we're primarily talking about the Super GP100 here, whereupon that statement is pure BS.

If you'd like to see what modern metallurgy can handle, go do some digging on the Ruger revolvers chambered for .480 Ruger. A large (nearly .50 caliber), 48,000 psi cartridge, which in the 6-shot variant of the Super Redhawk, has some of the thinnest cylinder walls to be found in any production revolver.
Scares the hell out of a lot of people. Yet, the only ones that blow up are the ones being shot by people doing the same stupid crap that blows up any other revolver: Overcharges, duplex powders, wrong powder, double charges, bore obstructions, or just idiocy and thinking that if 48k psi is good, then 68k psi is better!
 
jaguarxk120 said:
The 327 Federal Magnum operates 10,000PSI greater than a 357 Magnum.
Check SAAMI for operating and proof pressures.

Putting 8 rounds in a GP100 cylinder would turn it into a hand grenade.
Click to expand...
Unless there was a lower pressure .327 load around 35k PSI. A .327... Special if you will.
 
Guys, the price is about the same , GP100 vs 686, I'd buy the S&W every time, every time.
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Since the introduction of the IL and their current quality control problems I'm not buying any new S&Ws. Ruger is a viable alternative.

Dave
 
The Super GP-100 cylinder is larger than a GP-100. It is the Redhawk's size cylinder and fits in a Redhawk frame. The reason Ruger chose to align it with the GP-100 moniker and not the Redhawk is that it features independent main and trigger reset springs like a GP-100. The Redhawk's mainspring does not allow for the independent tuning of the trigger reset. So if the mainspring is lightened to lower the trigger pull weight, the trigger reset will be too slow for competitive speed shooting.

The GP-100 cylinder is slightly smaller in diameter than the L-frame -- about 9 thou. To my knowledge, neither was specified with an intention of chambering 7 cartridges. S&W was simply fortunate to have had that little bit extra to avoid problems.

Certainly, neither was specified for the .327. Remember they were specified to fit their respective frames in the late 1970's (S&W) and early 1980's (Ruger). While .32 caliber cartridges existed, they were not popular and certainly weren't thought of for use in these large revolvers. The .327 Magnum did however present a meaningful proposition, but not until 2007.

According to my calculations, there is enough diameter in the GP-100 cylinder to accommodate 8 chambers for .327 with the same cylinder wall thickness resulting from 7 chambers of .357. Here is the reason it doesn't work:

As you decrease the diameter of the chambers, you would ideally push the chamber centers out to a larger diameter circle. Extreme example: You wouldn't want your .22 LR chambers on the same center as .44 Magnum chambers. You'd want the .22 chamber centers farther toward the outside diameter of the cylinder so you could fit lots more of them in the cylinder. The problem is the center of the chamber must be aligned with the center of the bore and the firing pin. The bore and firing pin's centers are a function of the frame and cannot be changed just by drilling the chambers where you want them.

Because chambers for .327 must have the same center as chambers for .357 in a given frame, the advantage of their smaller diameter in allowing more chambers is diminished. Only with a unique frame that raised the center of the bore farther toward the outside of the cylinder diameter can the .327's advantage be fully utilized. Even if the bore was drilled off-center in the barrel blank, without a totally unique frame, the firing pin would still be aligned on the smaller diameter circle.
 
The Super GP100 is essentially a GP100 lower on a Redhawk upper and the Redhawk cylinder is certainly bigger than the regular GP100 cylinder which is why it can hold eight. It's kinda cool because with any luck, they'll release the Super GP100 in .41, .44 and .45 Colt at some point (in not so costly versions).

Side note, I recently picked up (and soon thereafter got rid of) a 7 shot GP100, it stuck all 357 Mag like crazy, had to tap the ejector rod with a rubber mallet to get them free. I bought a six shot instead and it's great.
 
I hope I'm not going off topic, but perhaps this fits in because we're discussing options for revolvers with more than 6 shots.

Before I would fiddle around with a 7 shot .357 magnum, which had loading and ejection problems because of the too small chamber spacing, I would just buy a smith & Wesson 986. It is built on the L frame, has 7 shots of 9x19mm, and loads and ejects quickly with moon clips. It comes with either a 5 inch or 2.5 inch barrel. If you want 8 shots of 9mm, then there's the 929, but it is built on the larger N frame and has a 6.5 inch barrel. 9 mm ammunition is cheap, has less recoil, and for night use, has less muzzle flash than a .357 mag.

Another member has a thread on a new, 7 shot, charter arms "professional", chambered for .32 H&R. That looks intriguing.
 
I'm telling ya, Ruger just admitted the S&W L Frame has always been larger (ie bigger) by introducing the Ruger 1771 with a known issue that the 7 round cylinder that doesn't fit all factory cases

The Ruger 1771 has binding issues with 7 shots. The 686 Plus does not and fits all cases fine.

Yes. The 8 shot is not on the GP100 frame. It also costs the price of a S&W R8.

Which would you think is better?
 
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