GP100 In Local IDPA Match

[JonInWA]

Yesterday I shot the GP100 in an IDPA match, an 8 stage affair where I expended some 100 rounds. The GP100 pereformed magnificently, wth absolutely zero hiccups or malfunctions. Reloads were performed with Safariland Comp III speedloaders, and the revolver was carried in a Galco Switchback holster; cartridges were Federal American Eagle 158 gr semi-jacketed soft points.

Several takeouts from the match:

First, it rained pretty much all through the match, which I thought provided a good working challenge. The VZ 320 G10 grips in Black Cherry worked well, and my revised grip better suited for revolver use (especially with full-house .357 magnum cartridges) worked nicely; no blister raised this time. I did apply a moleskin bandage as recommended earlier at the base web of my string hand thumb, but it probably was unnecessary. I will admit that the recoil still stung a bit, though, but it was eminently manageable.

I liked the ergonomics of the VZ G10 grips; they really situate the revolver in hand nicely. I was a bit concerned later in the match, when both the grips and my hand were slick with rainwater, but the grips acquitted themselves well under actual firing. However, beautiful and ergonomic as the VZ 320s are, I've decided that the VZ G10 Twister grips (in my case, black with silver hardware) are probably a bit better in heavy weather, as their troughs and slightly rougher finish will likely be a bit less slick, so their the ones that I've currently installed on the GP100. The Black Cherry G10s will likely be my "barbecue gun" grip set for the GP100.

The work Ruger performed on the revolver seems to have completely resolved the experieced issues. The mainstring is a bit heavy, though, so I plan on experimenting and giving a re-look to the ISMI chrome silicon spring set for the GP100, and then subsequently see how the Wolff spring sets (11# and 12# mainspring, 10# trigger return spring) work. In actual use, the OEM spring set worked fine; their relativeness heaviness (14# mainspring, 12# trigger return spring) was unnoticible in actual use during the match.

In one head shot only standards stage, I decided to shoot single-action only-which turned out to be a mistake, as the advantage of the short triggerpull was mitigated by the increased manipulation movements-I would have been better to simply have shot everything double action, but the relative heavy mainspring was a bit of a deterrant to me. The lighter spring sets might well have made the DA alternative more palateable (but greater skill and focus on my part would have doubtlessly been apprecatedt too...)

At the end of the sodden day, I had a great time, and believe that I'm well on my way towards developing and refining my revolver skill-sets with the GP100.

Best, Jon

[03RN]

[JonInWA]

Update: After the last match shot in continuous rain where I shot with the VZ 320 G10 Black Cherry grips, where the gun shot flawlessly, I decided to do several things:

1. I re-installed the VZ G10 Twister grips, as their slightly more pronounced ridges in the G10 laminate and the trough cuts I thought might provide more gripping surfaces, especially in incliment weather;



2. I removed the Ruger hammer spring and trigger rebound/triggerguard latch spring and replaced with a brand new set of ISMI chrome silicon springs.

I then met up with a friend to a local square range, and proceeded to test using Fiocchi 145 gr SJHP .357, Federal 158 gr SJSP, and some 160 gr SJSP .357 handloads with CCI primers.

I did not expend a huge amount of ammunition; only about some 50 rounds, but I did come to some conclusions:

1. The ISMI springs, as did the previous set, provide a very nice, smooth, non-stagey triggerpull.

2. The ISMI triggger rebound spring provides a crisp reset.

3. I experienced 3 primer light strikes insufficient to denote the primers, with very shallow primer indentations in all 3 cases; one with the factory 148 gr Fiocchi and 2 with the handloads with CCI primers.




4. Examining all fired cases primer indents, there is evidence that the ISMI hammer spring provides varying levels of energy to the hammer, as there was a mix of depth in the primer indentations in multiple cartridges, above and beyond the 3 with very shallow indenting that did not ignite.




5. The non-firing cartridges were successfuly fired when re-attempted in either the GP100 or in my accompanying Ruger Blackhawk.

6. There were no issues experienced in single action firing, in either the GP100 or the Blackhawk with any cartridges.

Marc Cosat, the owner of ISMI is a great guy, and we've had some indepth conversations. His chrome silicon springs have performed magnificently and flawlessly in my Beretta 92D for years. Unfortunately, this is not the case with the two seperate sets of ISMI GP100 springs; and while my experiences and testing is neither scientifically conducted or encompassing of statistically significant numbers of cartridges, I personally at this point consider the ISMI GP100 hammer spring to be suitable only for range use with soft primered cartridges-and that's after appropriate vetting in your specific revolver. I do not believe that the ISMI GP100 hammer spring consistantly provides sufficient force on a consistant, reliable basis to the hammer of my GP100. The trigger rebound spring, however, seems to work just fine.

For my upcoming match this Saturday, I have replaced the hammer spring with a Wolff 12# spring, and the trigger rebound/triggerguard latch spring with a Wolff 10# spring. Dryfire triggerpulls feel quite nice and smooth.

The VZ Twister grips provide excellent ergonomics, but G10 is a hard, unyielding medium. While I encountered no blistering at the base of my string hand thumb in my last two firing sessions due to my revised hand positioning grip, firing full-house .357 magnims does sting and is moderately uncomfortable, although I was operationally unhindered. At the match I plan on proactively applying moleskin bandaging at the base of my string hand thumb to mitigate against the discomfort and pain.

Conversely, shooting the same ammunition in my 4.6" stainless New Model Blackhawk is a joy, due to the combination of heavier weight (46 ounces versus 40 ounces-although my GP100 with the heavier VZ G10 grips is probably between 40 and 45 ounces), grip architecture (mine has the timeless traditional plowhandle grips, in rosewood laminate), and frame design/ergonomics. It's simply a blast firing the Blackhawk, which is exceptionally accurate as well. The GP100 with full house .357 isn't crippling or debilitating, but it is somewhat painful and a bit annoying.

While full-house .357 cartridges such as Winchester 145 gr Silvertips and 158 gr Federal Hydrashoks will be used for carry, I plan on experimenting with some lighter velocity handloaded 158 gr cartridges, probably around 1000-1100 fps for a more enjoyable match experience.

In short, with 11# and 12# Wolff hammer springs in the past I have had no issues with reliable ignition, covering a wide spectrum of commercial .357 magnum cartridges, and while I had previously been running the Wolff hammer springs with an 8# trigger/triggerguard latch rebound spring, I've decided to slightly up that to their 10# spring; Ruger OEM spring weights are reputed to be 14# for the hammer spring, and 12# for the trigger rebound spring. I'm thinking that the 12# hammer spring weight is an ideal compromise for triggerpull weight and primer impact strength and ignition-for thorough ignition.

If this spring combination is successful in the match, I'll also run an amount of 145 gr Silvertip, 158 gr Hydrashok and 148 gr Fiocchi hollowpoint carry ammunition to verify adequate function.

If there are any issues experienced with the Wolff springset whatsoever, I'll likely (and prudently) revert to the OEM (heavier) Ruger spring set-ups. Hey, I'm doing all this for science!

Best, Jon

[gato naranja]

In short, with 11# and 12# Wolff hammer springs in the past I have had no issues with reliable ignition, covering a wide spectrum of commercial .357 magnum cartridges, and while I had previously been running the Wolff hammer springs with an 8# trigger/triggerguard latch rebound spring, I've decided to slightly up that to their 10# spring; Ruger OEM spring weights are reputed to be 14# for the hammer spring, and 12# for the trigger rebound spring. I'm thinking that the 12# hammer spring weight is an ideal compromise for triggerpull weight and primer impact strength and ignition-for thorough ignition.

I am currently running Wolff 12# hammer and 8# trigger springs in my GP-100. IIRC, 11# hammer springs were as low as I could reliably go in a GP100, but I can't seem to find new springs in that particular weight any more, thus the 12-pounder. The #8 trigger return spring is probably a bit light/slow, but the 10# is heavier than I like and nobody I know of makes a "Goldilocks" 9# spring.

Your comments comparing the Blackhawk to the GP-100 are similar to my thoughts. The Blackhawk in .357 is so much more pleasant to use that - for me - it isn't even close. I don't HATE firing double-action, but I don't do it for fun and recreation. If I had more trips around the sun ahead of me, I would be tempted to spend the money and get a blued 4-5/8" .357/9mm convertible Blackhawk (with a stainless grip frame fitted to it "just because") and enjoy the experience.

[JonInWA]

I shot a local ASI match last Saturday, with the Wolff 12# mainspring and Wolff 10# trigger rebound/triggerguard latch spring. Again, another typical Pacific Northwest December match, with rain throughout the entire match, until the very last stage. Again, full-house .357 magnum cartridges used throughout.

Initial out takes:

-The VZ Twister G10 grips work superbly, both ergonomically and in terms of grip security. No slippage with rain-moistened hands and grip surfaces. The raised G10 striations and the inset grooves really do effectively anchor the GP100 in hand, while not inhibiting adjustments and index. I plan on remaining with this grip as my primary GP100 grip-but be advised, even with a revolver-appropriate hand positioning on the grips, the .357 magnums will still sting the web of the string hand when firing (I used moleskin patches to help absorb the recoil force on that portion of my striong hand, which worked pretty well).

-With the Wolff springs, the GP100 effortlessly fired Federal 158 gr SJSP, Fiocchi 148 gr SJHP, Magtech 158 gr Cowboy flat point lead, and Federal 158 gr HydraShok JHP. Things were going swimmingly, until...

-I tried the Winchester 145 gr JHP Silvertips, my preferred defensive carry load. Out of the cylinderfull, I had 2 light-strike non firing cartridges. Crap.

The rest of the match was fired uneventfully, using the Federal 158 gr SJFP and Magtech flatpoint 158 gr Cowboy cartridges. After drying off, cleaning and lubing the GP, I removed and reboxed all of the Winchester Silvertips, and was resigned to:

1. Carrying the Federal HydraShoks as my carry/duty/defensive cartridge, whch frankly is not a bad choice or a bad way to go. It's a well vetted cartridge, and mine are all recent production, or

2. Replacing the Wolff 12# mainspring with the OEM Ruger 14# one.

Additionally, while perfectly functional, I wasn't all that totally pleased with the Wolff 10# trigger rebound/triggerguard latch spring; as I found myself short-stroking the trigger, partially due to the softer trigger return characteristics with it, at least to my tastes and perceptions.

I discussed the situation with a friend and instructor, who's been following (involuntarily and probably reluctantly) my ongoing GP100 saga. He suggested that while the HydraShoks were fine, it might be advisable to have a mainspring that I could trust to fire any and all commercial .357 magnum cartridges, as the additional triggerpull weight with the heavier Ruger 14# mainspring wasn't all that onerous.

What he said made sense, so this morning I did the following: The mainspring was replaced with the Ruger OEM 14# one, and the trigger rebound/triggerguard latch spring was replaced with the ISMI chrome silicon unit, as I liked the strength and feel of it, and really wanted to give it a fair shake. I'll discuss with ISMI owner Marc Cosat the comparative weighting and characteristics of it compared to the OEM Ruger and reduced power 10# Wolff springs.

I liked the feel of the trigger with the Wolff 12# mainspring-but it simply wasn't 100% dependable in my GP100 with one cartridge. Unfortuately, that specific cartridge is my preference for defensive use, and overall I like the idea of having certainty of primer detonation in anything I have to chamber. I'll run with the Ruger/ISMI combination, and if I have any trigger return issues, I'll also revert to the OEM Ruger trigger rebound/triggerguard latch spring.

The saga continues...

Best, Jon

[revchuck38]

How clean were the chambers when you shot the Silvertips? If you hadn't brushed out the chambers after a few stages and used the cowboy loads (uncoated lead, right?) prior to the Silvertips, there might've been enough crud in the chambers to keep the rounds from seating completely.

FWIW, in the several years I shot SSR in IDPA, I brushed out the chambers after every stage for this reason.

[gato naranja]

I liked the feel of the trigger with the Wolff 12# mainspring-but it simply wasn't 100% dependable in my GP100 with one cartridge. Unfortuately, that specific cartridge is my preference for defensive use, and overall I like the idea of having certainty of primer detonation in anything I have to chamber. I'll run with the Ruger/ISMI combination, and if I have any trigger return issues, I'll also revert to the OEM Ruger trigger rebound/triggerguard latch spring.

Well, hell...

Now you have me thinking I just might have to up the spring weights in my pet GP-100, because it has not had near the variety of ammo through it that it would have had back in the old days. As with the utility shotgun, one of my primary goals with a revolver is to have reliability with a wide variety of ammunition regardless of the craptacularness of said ammunition.

I don't mind changing out springs in a GP-100, I just don't look forward to tracking them down in my clutter of "stuff&things." Might as well buy some new ones and save myself some grief.

[JonInWA]

How clean were the chambers when you shot the Silvertips? If you hadn't brushed out the chambers after a few stages and used the cowboy loads (uncoated lead, right?) prior to the Silvertips, there might've been enough crud in the chambers to keep the rounds from seating completely.

FWIW, in the several years I shot SSR in IDPA, I brushed out the chambers after every stage for this reason.

What you're suggesting is certainly possible. It was at the match mid-point that I tested the HydraShok, Fiocchi and Winchester Silvertips. However, I always check for cartridge full insertion after using a reload via speedloader, and thumb press any non-fully chambered cartridges before closing the cylinder. I recall having to do so several times throughout the match, but I don't recall if I had to, or needed to do so with the Silvertips. And I had zero light-strike issues with ANY of the other cartridges I used before of after the Silvertips, and I went through the match without brushing out the chambers (which is a great idea, and after Caleb's recommendations earlier, I got, and had on hand both a .40 and .38 caliber Boresnakes and now include them as part of my range bag load-out).

So while it's possible accumulated chamber GSR precluded the Silvertips from fully seating (or at least the two cartridges that didn't detonate), I doubt it; there were no issues with cylinder rotation. And while I've very successfully used the GP100 with Wolff 11# and 12# hammersprings before, the fact thet there were 2 light strikes in one cylinderfull indicate to me that I simply need a heavier hammerspring for guaranteed "all cartridge" success. Adding 2 more pounds to the triggerpull weight isn't all that big of a deal. And yeah, I could just avoid the Silvertips, but I'd still have nagging doubts if any duty cartridges have thicker or heavier primers. In the next week or so, at my next firing opportunity, I'll run some Silvertips through to verify that I'm good to go with the Ruger 14# spring; if not, I'll be having conversations with both Olen Winchester and Ruger.

Since the gun just came back from Ruger after a very thorough going through, I doubt that the issue is with the GP10 per se-it's likely either with insufficient mainspring power or with the ammunition/primer.

Best, Jon

[JonInWA]

Results from shooting an IDPA match on Saturday. First, I fired a cylinder comprised of 2 Winchester Silvertip JHP, 2 Federal Hydrashok JHP, and 2 Fiocchi SJHP; I immediately had one primer failure to detonate with one of the Winchester Silvertips, all others were fine. The GP100 is equipped with an OEM brand new Ruger mainspring, and a brand new ISMI trigger revound/triggerguard latch spring. Based on repeated issues with the Silvdertips encountered with a 12# ISMI mainspring, a 12# Wolff mainspring, and a 14# Ruger mainspring, I have raised the issue with Olin Winchester, and, until satisfactorily resolved I have removed the Silvertips from duty/EDC/defensive carry in the GP100. there are clearly some ongoing primer issues going on. Federal 158 gr HydraShoks will be used for all defensive/duty uses (which isn't a bad way to go, but the Silvertips really have a steller reputation. But at this point, I can't justify using them, or in good faith recommending them. We'll see what Olin Winchester says.

Am experienced and skilled reloader and personal friend of mine provided me with 100 rounds of relaoded ammunition that he had personally crafted to my specifications-SJHP 158 gr bullets, with a muzzle velocity of 1000 fps. CCi 550 primers, 12.45 IMR 4227 powder, Norma and Aquila cases used. While the accuracy and recoil impulse was superb, some problems immediately developed; after one cylinderful was fired, reloads required thumbpressing into the chambers to seat, and even that was not sufficient, and difficulties in closing the cylinder and if closed, cylinder rotation problems were experienced. Several light srtikes were experienced as well.

The closing and binding issues were resolved by brushing the ejection star (both front and back) and the rear of the cylinder itself. I also boresnaked out each chamber, but that was probably unnecessary; vigerous brushing of the ejection star, ejection axle supporting the ejection star, and the rear cylinder face satisfactorily resolved the issue(s)-both with the handloaded cartridges, and subsequently with Magtech 158 gr flat-nosed lead Cowboy cartridges.

I'm thinking that a combination of GSR accumulation at the back of the cyllinder and on the face of the ejector star are causing the issues; I'm also ensuring that the ejection rod axle, ejection star, cylinder ejector guide pins and cylinder back are dry and without any oil or cleanser residue that would serve as an attractant for GSR.

After the match, both fired cases and unfired cartridges (and control factory cartridges) were carefully measures in all dimensions, as were the cylinder charge holes; all were within allowable specifications, reinforcing our suspiscions that the issues were caused by GSR residue and accumulation. I'm not concerned with factory ammunition, as the cylinder closing, binding and heavy triggerpull issues were only experienced with the reloaded cartridges.

For now, both my load and unload protocols with these cartridges will be with ejector star/rear cylinder toothbrushing bith prior to loading and subsequent to scenario firing. as part of the "unload and show clear" process. My reloader may also swiotch to another propellant powder.

Thoughts, critiques and recommendations welcome. Oh, and in the last stage of the day, we had heavy, driving rain. Operationally it presented no issues; I continue to be impressed with the VZ black G10 Twister grips

Best, Jon

[Lester Polfus]

Results from shooting an IDPA match on Saturday. First, I fired a cylinder comprised of 2 Winchester Silvertip JHP, 2 Federal Hydrashok JHP, and 2 Fiocchi SJHP; I immediately had one primer failure to detonate with one of the Winchester Silvertips, all others were fine. The GP100 is equipped with an OEM brand new Ruger mainspring, and a brand new ISMI trigger revound/triggerguard latch spring. Based on repeated issues with the Silvdertips encountered with a 12# ISMI mainspring, a 12# Wolff mainspring, and a 14# Ruger mainspring, I have raised the issue with Olin Winchester, and, until satisfactorily resolved I have removed the Silvertips from duty/EDC/defensive carry in the GP100. there are clearly some ongoing primer issues going on. Federal 158 gr HydraShoks will be used for all defensive/duty uses (which isn't a bad way to go, but the Silvertips really have a steller reputation. But at this point, I can't justify using them, or in good faith recommending them. We'll see what Olin Winchester says.

Am experienced and skilled reloader and personal friend of mine provided me with 100 rounds of relaoded ammunition that he had personally crafted to my specifications-SJHP 158 gr bullets, with a muzzle velocity of 1000 fps. CCi 550 primers, 12.45 IMR 4227 powder, Norma and Aquila cases used. While the accuracy and recoil impulse was superb, some problems immediately developed; after one cylinderful was fired, reloads required thumbpressing into the chambers to seat, and even that was not sufficient, and difficulties in closing the cylinder and if closed, cylinder rotation problems were experienced. Several light srtikes were experienced as well.

The closing and binding issues were resolved by brushing the ejection star (both front and back) and the rear of the cylinder itself. I also boresnaked out each chamber, but that was probably unnecessary; vigerous brushing of the ejection star, ejection axle supporting the ejection star, and the rear cylinder face satisfactorily resolved the issue(s)-both with the handloaded cartridges, and subsequently with Magtech 158 gr flat-nosed lead Cowboy cartridges.

I'm thinking that a combination of GSR accumulation at the back of the cyllinder and on the face of the ejector star are causing the issues; I'm also ensuring that the ejection rod axle, ejection star, cylinder ejector guide pins and cylinder back are dry and without any oil or cleanser residue that would serve as an attractant for GSR.

After the match, both fired cases and unfired cartridges (and control factory cartridges) were carefully measures in all dimensions, as were the cylinder charge holes; all were within allowable specifications, reinforcing our suspiscions that the issues were caused by GSR residue and accumulation. I'm not concerned with factory ammunition, as the cylinder closing, binding and heavy triggerpull issues were only experienced with the reloaded cartridges.

For now, both my load and unload protocols with these cartridges will be with ejector star/rear cylinder toothbrushing bith prior to loading and subsequent to scenario firing. as part of the "unload and show clear" process. My reloader may also swiotch to another propellant powder.

Thoughts, critiques and recommendations welcome. Oh, and in the last stage of the day, we had heavy, driving rain. Operationally it presented no issues; I continue to be impressed with the VZ black G10 Twister grips

Best, Jon

I have purchased Winchester revolver ammunition 3 times in the last 8 years:

In 2013 during the Sandy Hook ammo panic, I scored a couple boxes of Winchester .38 special ammo. I think it was White Box 130 grain MC? if there was such a thing. I had multiple failures to fire out of the box out of an otherwise reliable J-frame. I also had rounds that were noticeably hard to seat in the cylinder because the brass visibly got bigger toward the base. It was like there was a ring of metal above the rim that was larger than the outside diameter of the rest of the cartridge, if that makes sense.

In 2018 I bought two boxes of 50 Winchester 145 Grain, .357 Magnum Silvertips in Nickle cases. I fired about half a box and had problems with a stiff trigger pull because rims were dragging the cylinder shield. I chalked it up to a dirty gun, so took it home and cleaned it. Next range session I fired about another 30 rounds and had intermittent issues, same problem. It finally dawned on me "Hey! Maybe it's the ammo. About 1 round in 5 had a burrs just ahead of the rim that kept the rounds from seating fully. Winchester customer service sent me a UPS shipping label, but refused to send a call tag. They said if they found a problem, they would give me a pro-rated refund for the rounds I hadn't shot. The only place I can actually ship the ammo is a UPS hub that is a 50-mile drive, so I said "f-it" and just shelved the matter.

Because I'm stupid, earlier this year I bought 3 20-round boxes of 145 grain Silvertips because they were on sale at Midway USA at pre-Rona prices, telling myself "It'll be different this time." I chamber checked every single brass-cased round. They all chambered fine but your tales of ignition issues do not give me a warm fuzzy

That's my round-about way of saying your gun may be fine, and the ammo may be the problem.