Triggers and primer ignition?

I have been referred to the Forum by members of the Shiloh Rifles Forum.
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I just bought an S&W 640-1 revolver. While it is precisely what I wanted, I have interrelated problems. I intend to shoot only factory ammunition. I have narrowed my choices to two - Federal 38 Special 129-grain Hydra-Shok, or Remington 125-grain JHP GS because I cannot tolerate the noise or recoil of 357 Magnum ammunition in such a small revolver.

Now to the problems. I have a progressive illness that affects much of my body that makes arthritis seem like fun. When I tried snapping the trigger, the finger pain was close to unbearable - but an emergency trumps pain. I have obtained grips that are shorter centerline of trigger to back strap. This will allow me to use more finger and less finger tip. I must obtain a trigger job that will reduce trigger action's poundage and, if possible???, have the trigger action stack near the finish and ease at the beginning.

1. Between the two factory cartridges, which one accepts the lighter firing pin impact while providing reliable ignition?

2. What gunsmiths can do the job(s)? If any is in western Montana, please identify the smith.

Naphtali said:

I have been referred to the Forum by members of the Shiloh Rifles Forum.
***
I just bought an S&W 640-1 revolver. While it is precisely what I wanted, I have interrelated problems. I intend to shoot only factory ammunition. I have narrowed my choices to two - Federal 38 Special 129-grain Hydra-Shok, or Remington 125-grain JHP GS because I cannot tolerate the noise or recoil of 357 Magnum ammunition in such a small revolver.

Now to the problems. I have a progressive illness that affects much of my body that makes arthritis seem like fun. When I tried snapping the trigger, the finger pain was close to unbearable - but an emergency trumps pain. I have obtained grips that are shorter centerline of trigger to back strap. This will allow me to use more finger and less finger tip. I must obtain a trigger job that will reduce trigger action's poundage and, if possible???, have the trigger action stack near the finish and ease at the beginning.

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Welcome to the Forum

You do not tell us why you have acquired a firearm. I will presume that you want this for personal defense against animal and human assailants.

Based on your description of your hand/finger abilities at the present time and your statement that the condition is progressive, therefore we can presume that your ability to safely and effectively deploy a handgun for personal defense will decline as this condition progresses.

I have to question your choice for personal defense. You have picked a firearm design that is forced to have heavier a trigger because of simple physics. A larger framed revolver has less issues. Other firearm choices may be more suitable to your condition.

Naphtali said:

1. Between the two factory cartridges, which one accepts the lighter firing pin impact while providing reliable ignition?

2. What gunsmiths can do the job(s)? If any is in western Montana, please identify the smith.

Click to expand...

As to question one, the answer is not relevant. The components used today are not the same as the components used yesterday and may not be the same components used tommorrow. Any comparison between the particular ammunition offerings are only relevant to the batches tested.

However, generally speaking, Federal primers are believed to ignite with the least force.

As to question number two, I would never recommend a gunsmith for such a job based on the knowledge we have of you. I doubt, if explained as above, a gunsmith would take this job. You are asking for a trigger that is just above the failure level to ignite the lightest primer available.

That job sounds loaded with liability.

In a target or competition firearm, a cartridge that fails to ignite will not add jeopardy to one's life.

When it comes to a defensive firearm, a reputable gunsmith will want to produce work that will have enough force to reliably ignite any ammunition you, a friend, relative or the next owner might stuff in the cylinder.

Firearms, ammunition, dust, dirt, lubrication, rust, declining finger strength, etc. are variables that are simply too random to tune a defensive firearm toward the easiest firing ammunition available at the moment.

When you pull the trigger on a double action revolver you are causing the revolver to do several things: rotate the cylinder into position, move the hammer back and load the hammer spring with enough force to ignite the primer and at the same time load up a spring that will quickly return the trigger spring and cylinder rotating mechanism back to the home position. The guns action can be smoothed up reducing the movements friction and different springs can be installed that lighten the trigger pull by lowering the forces needed to load the springs involved. Smoothing things up causes no problems in reliability and actually increases it because in the case of the hammer less friction via frame rubs and hammer stud friction slows the hammer causing it to depart less force to the primer. Installing a lighter hammer spring causes less force to the hammer and less reliable ignition. With a self defense gun you need to keep a greater margin of power to the spring because reliability is paramount. The same thing applies to the trigger return spring. These can be reliable with less force but not large amounts and retain reliability. Plus, S&W revolvers design causes them to NOT stack during trigger pull

So, while your guns action forces can be improved upon a lot of improvement is going to cause dependability issues. The friction issues depend on how well fitted your revolver was initially. Some are better than others and almost all smooth out to some degree. Most can also remain reliable with SMALL decreases in the spring tensions. But, unless something abnormal causes it to have a terrible action to begin with you probably won't see more than around 25% reduction in double action trigger pull and retain reliable ignition. Probably around 10# at the least. At 10# I would want to fire at least of the ammo I was planning to use for self defense with no failures before I would trust it to save my life.

I am a revolver guy, but in your case you might be better off with a good single action auto with a good safety set up. Something similar to the 1911 in a smaller lighter frame size and a caliber like 9mm. You might have problems racking the slide to load the initial round, but you can do that or have it done for you at anytime and then all there is is disengaging the safety mechanisms and overcoming say a 4-5# trigger until the gun is empty as it will self cock and use its own recoil to reload the chamber and spring tensions.

Sorry about your condition.

While the 640 is an excellent revolver, it is one of the poorest choices you could make with the limitations you describe. The J-Frame, because of the size and weight of its' internal parts, does not lend itself to light trigger pulls. I would not suggest any small automatic, because of the difficulty/pain you may experience in trying to operate the slide. What I would suggest is a double-action revolver with exposed hammer that can be thumb cocked, so you do not have to contend with the heavy double-action trigger of the 640.

The cold, hard, fact of the matter is that it is impossible to lower the double-action trigger pull of any J-frame to the point you will be able to operate it and have any degree of reliability with any ammunition!

Welcome to the forum! For the reasons mentioned above, I hate to say it, but you'd be better off with a Glock. Simple, light trigger on every shot.

If your condition makes it difficult to rack the slide on a semi auto, and the gun is for home defense, then a pump shotgun is an even better option.

While I choose (and usually recommend) a Revolver for civilian personal CCW in your particular case I would agree with the above poster who suggested an Auto-loading pistol.

S&W J Frame Revolvers used for personal protection should be 100% reliable and for that will tend to "feel" a bit heavy on the trigger pull. The reason I say "feels heavy" is that I find J Frames to actually feel heavier than the exact same weight trigger on let's say a K Frame. I believe this is in part due to the smaller frame, smaller trigger surface and a less perfect grip. Because the small hammer of the J has less mass, it needs a harder hit to reliably set of a primer. K Frame revolvers (with heavier hammers) lend themselves to a lighter trigger and smoother action than J's do - again keeping in mind reliability.

You can play around with changing the rebound spring (Wolff Spring) to let's say a 13 pound weight and remove any burrs that might be on the internal parts, but I would NOT recommend lightening the coil mainspring at all for a SD gun. Even though progressively lighter Rebound Springs will continue to ease up on the pull weight, lighter than 13 lbs. will usually retard the trigger from properly returning in a correct fashion and decrease reliability of setting off primers. Lighter might be OK for Target Only guns, but IMHO I would not go lighter on a SD gun.

If that does not help you out shooting the J Frame, then I'd look at a good quality Auto Loading Pistol.

While I personally tweak my Target Only designated firearms, I am quite conservative with SD guns. I would NEVER carry a SD gun that will not 100% reliably fire CCI primers even if I used other brands of ammo for actual CCW. I figure if CCI is 100% reliable then everything is good to go.

As ALK8944 states, the gun you purchased IS AMONG the worst choices for someone with your condition. Even a run of the mill M36 or M60 (also J Frames) usually has an easier (or lighter feel) trigger pull than the one you bought. You should try some of them too!

While I am not a Glock or Sig owner, they are both fine quality and reliable guns - although a bit larger to say the least. You could look into them as well as other J Frame models. You could also look at something like a vintage (pre I/L) 2" RB M10 K Frame which would be reliable with a lighter trigger pull than on a J Frame. See how one of those fits your needs. K's with their heavier hammers and larger grip frames are more "tweak-able" - again with 100% reliability in mind!

Previous posters have stated things pretty well. However a simplified explanation may help in your understanding what is going on. Suppose you have to change a tire. To loosen the lug nuts on your wheel would you choose a "compact" 6 inch ratchet or a "larger" 2 foot breaker bar? The same principle is at work in a revolver. Very small "compact" revolvers have shorter internal Leverages than a larger "medium or large" frame revolver. Since both use basically the same ammunition it can be expected that the smaller revolvers will feature triggers that require more force than the trigger on a larger revolver.

Note, the above is a bit of an over simplification but in the case of the S&W J frame revolver lineup it still holds true. A couple of years back a member posted his results of experimenting with tuning the trigger weight on his J frame revolvers. What he determined was that it's not possible to get reliable double action ignition with a trigger tuned to less than 10.5 lbs on something like a model 640. In contrast to that with something like an L frame model 686 tuning the DA trigger to a weight as low as 7.5 lbs can result in perfectly reliable ignition.

Now, about ammunition. Colt SAA makes an excellent point in that the components used for ammunition can change. Currently one driving aspect of Change is concern over lead exposure caused the the Lead Stipenate used in primers. Current lead free primers have gained a reputation for being harder to ignite than older formulations containing Lead Stipenate. Since there may come a day when lead free primers are mandated by Law you can see one area where components may change.

I can also tell you that direct experience with Remington UMC ammunition in 45 ACP in a model 625 I had tuned to an 8 lbs. DA trigger resulted in my tuning all of my revolvers to a 9 lbs. DA trigger weight. Because for me the increase wasn't noticeable and I like Remington brass for reloading, so from time to time I'll shoot up a 250 pack of UMC just for the brass. Point is, I've round that Remington currently has the "hardest" primers with a close second being the CCI 550 Magnum primers. For easy to ignite primers Federal, Winchester, and CCI standard pressure primers have proven to be basically equal with all being 100% reliable in that 625 with the trigger tuned to the lighter 8 lbs. weight.

So, if you want the best ammunition for your specific needs I would advise you but the Federal and purchase enough for your expected life time to avoid the potential coming change to lead free primers. Note, people are currently still using ammunition produced for WWII and finding it mostly reliable so it's easy to conclude that ammunition properly stored can last for many decades.

I would also suggest that you sell your 640 and shop for a 3 inch 686, 2 1/2 or 3 inch model 66, or 2 1/2 inch model 19. These revolvers can be carried easily in a good IWB holster and can be easily tuned to a lighter DA trigger. BTW, all are 357 Magnums and the reason for the suggestion is due to a distinct lack of K frame snub nosed revolvers. If you want to go 38 special only look for a 2 inch model 10 and I'll warn you they are rare.

BTW, I recently picked up a 1971 vintage 19-3 that was nearly unfired and found it was factory manufactured with a DA trigger pull of 8 1/2 lbs. I also found it was manufactured with a "short" hammer nose that caused misfire issues in double action but an "extended" hammer nose purchased from Brownell's has cured that issue. In fact it cured that misfire issue enough that I just may experiment with shimming the strain screw to see just how light I can go with the trigger on the model 19 and still get reliable ignition with CCI magnum primed ammunition. I can also tell you that in a Galco IWB holster that model 19 is a very comfortable carrying revolver.

BTW, the hammer nose was made by Power Custom and the instructions provided were absolutely EXCELLENT. I'll also note that hammer nose which is stated to be for with post 1989 hammers was a perfect drop in fit in my 1970 vintage hammer. The length is also extended enough that I may break out my diamond files and reduce the length a bit. Because right now it will shoot the rim off a snap cap in about 500 strikes and Azoom Snap Caps aren't cheap.

DA revolvers should never be used with the tip of the finger squeezing the trigger. That is of course a rifleman's technique and it translate well to semi's that are single action. For the revolver you should have the trigger positioned at the first joint back from the tip and it should stay there. That gives a much smoother DA pull. Having said that, think about a Colt defender carried "cocked and locked". It will give you the lightest and smoothest trigger anyone needs and be the easiest pull with your degenerating condition.

I must obtain a trigger job that will reduce trigger action's poundage and, if possible???, have the trigger action stack near the finish and ease at the beginning.

Click to expand...

I have some students with severe arthritis, and some, like you, bought the wrong gun and then demanded that it work the way they want. Others took good advice and got a gun they could manage.

Perhaps you could get your gun down to 9# trigger pull and be reliable with commercial ammo. On the other hand, you could buy the 4 1/4" barrel M&P 9 Pro, and have a 4 1/2# trigger. Your choice.

Unfortunately, I sometimes see students show up with a neat small gun that they can't shoot accurately, hurts their hand, and they doggedly insist it is their perfect gun, carrying it more as a talisman than a weapon they can use effectively.

Best of luck to you.

All that being said.
I've got a degenerative peripheral motor nerve condition and have been told by my neurologist that I have profound weakness in my right hand and moderate weakness in my left hand.
My condition doesn't directly cause pain but the weakness can sometimes make doing simple things rather uncomfortable.
However, my daily carry gun's a S&W 442.
To make it usable for me, I took it apart, replaced the rebound spring with an 11 pound Wolff spring and the main spring with a Wolff 8 pound spring and smoothed the guts a bit with an extra fine Arkansas oil stone.
I put a Pachmayr Compact grip on it and now it shoots with complete reliability.


I shot this.


From about this far away. I'm the fellow on the left.

Many thanks for the cogent replies. There were several "AHA!" moments reading replies.

1. Reduce grip circumference that my index finger has more purchase. And this is one goal for which I'm searching for results. I have the OEM Uncle Mike's extended grip as I type. While it's not what I would use by choice, there's nothing wrong with it - were my hand larger. Its filling in beneath trigger guard is desirable. Back strap cushion-cover is not needed. And front strap thickness beneath trigger guard filler is also subject to reduction. Thickness side-to-side could be significantly reduced for me. For any grip [set] for this revolver, I have no idea how much mass can be removed before the grip is likely to fall apart. Many years ago I fitted a set of "N" Frame Magna grips to my hand. They were a joy to use until I bumped them against an unknown object. Left grip panel didn't crack; it broke where my middle finger would grasp it.

2. Since the initial movement of the trigger is my pain problem, any way or combination of ways to get the trigger moving tends toward the solution. I mentioned stacking trigger action to ease starting with increased resistance near final pull. Isn't this how several small but powerful semiautomatics slides function - that is, progressive springs or springs nested?

3. Work on changing my grip to facilitate #s 1 and 2.

4. Since there is strong consensus that Federal primers are likely to be of at least minor assistance and 129-grain Hydra-Shok ammunition has shown itself to be at least adequate for my intended purpose, that's that.

5. If nothing results in a solution, swap for 2.5-inch barrel M-66 and repeat #s 1 and 2 as needed.

I just replaced my grip set with an S&W logo [Uncle Mike's??] boot grip. I never would have believed it if I hadn't tried them.

No trigger-associated hand pain.

Complete control of trigger and trigger action.

Unbelievable!
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And then, of course, my minor foul-up. I removed the grips to clean the revolver. . . . As most have anticipated, the grip screw went to the floor, probably somewhere under my stove. I just wasted the last 45 minutes searching my kitchen and beneath my stove for the screw.

Anyone who has the grip screw, please let me know the price shipped you want.