I've been thinking of my next conquest and the model 66 has caught my attention. I think it might be a K-frame? If it is, how well can it hold up to a steady dose of .357 loads? I specifically saw a pair of 66-3's that don't look like they've been fired much at all. I just don't know if a K-frame 66 is as durable as a L-frame 686.

Thanks,
Dave

Most of the issues with the k-frame magnum was with lighter (125) gn bullets at higher velocities. Ive used the 158 gn (factory pressured loads) for years and my K's are still going strong. You will get years of service from your 66 if you decide to buy. Good luck in your quest.

Obviously it isn't, since the L addressed the K weak points.
However, the 66 will handle .357 loads, particularly if you aren't loading them up to escape velocity and shooting them by the bushel.

__________________
Science plus Art

Thanks. I baby my 868 anyway. I shoot mostly .38s with only 3 or 4 cylinders of .357s per trip to the range.

The 66 is not as durable with 125 grain Magnum screamers. It is more at home with a full-time diet of any 38 Special and Magnums with weights of 145 grains or higher.

To be fair about it, I am always somewhat skeptical of anyone who says they will fire a "steady diet" of Magnum ammo. If you can afford that, then just buy several Model 66s and shoot them with 125 grain Magnum ammo until the barrel shank cracks, then throw them away and start on the next one. After all, if you have no trouble paying for that much Magnum ammo, then the revolvers should be no trouble to purchase.

On the other hand, I know of a few Model 19s and 66s with 20,000 or more 158 grain Magnum rounds with no ill effects over a 30 year period. The K frame life will be greatly extended with use of Magnum ammo with bullet weights over 145 grains.

I agree with the above comments, I stick with 158 grn factory loads in my 66s and have never had a problem.

For K-frame and steel-frame J mags, I like the CCI Blazer .357 Mag 158gr JHP. Not as hot as other loads, but not a powderpuff either. Easy to control in double-taps, if that is your game.

I picked up a Model 66 (no dash) a few weeks ago. My intention is to shoot only 38 sp. at the range, but I keep it loaded with 357 mag. JHP - 158 gr. That would mess a bad guy up pretty well!

Please excuse the elementary question but, higher grain magnum loads are less powerful than lower grain loads? Why would higher grain loads be better/safer for a model 66?

Also how does grain count affect recoil? I know very little about grain count and velocity. Somebody school me please!

Dave

PS. I will also post this question in the Ammo forum.

I guess we have been lucky with our K Frame. My dad's 66-1 was bought new by him and has had tens of thousands of primarily Federal Red/White box 125gr JHPs through it. There's also been some 158s as well as SuperVel and Silvertips when they were all the rage. The gun has been carried as an off-duty/ backup by my dad (and then me) since the 1970s, and the only problems experienced were a timing issue, and a sheared the barrel pin. Great gun. Oh, there's some flame cutting as well (go figure!). After reading all the horror stories of 125gr bullets, I consider ourselves lucky we got such a durable K frame.

Personally, I don't think it's particularly valuable to beat up a K frame with hot loads on a routine basis but I will freely admit that it's awfully hard to actually ruin a S&W revolver with normal usage. The few blown up ones that I have seen, my first Model 19 among them, have all met their fate from what I am pretty sure was incorrectly handloaded ammunition. In any event, I don't do it, I don't see the point. If I want to routinely shoot .357 Magnum loads I'd just use my Model 27. But that's just me; YMMV.

OTOH, because I really believe this, I routinely warn against using full house magnum loads in defensive guns. Yes, they'll mess up a bad guy. But they'll also mess up the neighbor, the guy across the street, the baby in the next room, etc. For defensive purposes high quality .38 Special or +P ammo will suffice to mess up bad guys without the penetration of magnum loads. Same thing in re .44s, but that's a different thread....

***GRJ***

Grain refers to the weight of the bullet, not the gunpowder.

Ah ok. So that's why higher grain magnum loads have lower velocities than lower grain loads. (light bulb just went on in head) Knowing this, why are lower grain magnum loads bad for a K-frame? A lot of posters above said they wouldn't shoot low grain magnum loads out of their 66. I would assume a lighter bullet would put less stress on a gun. Or is it the higher velocity of low grain loads that's bad?

It has to do with the length of the bullet. The lighter the weight, the shorter the bullet (projectile). The shorter 125 grain bullet does not seal the barrel/cylinder gap quite as long (we are talking milliseconds here, but it apparently makes a huge difference), which allows the corresponding hot gasses and flames to escape from the barrel/cylinder gap just a very tiny amount of time earlier, thereby doing more damage.

This problem was known in the 1970s, and it is what caused development of the L frame, which has more steel in the critical area at the 6 o'clock position of the barrel shank.

This is not a problem with 38 Specials of any weight or velocity, whether standard or +P.

When the FBI was using the K frame Magnum revolvers (3 inch Model 13s), their standard load was the 158 grain 38 Special +P Lead Hollow Point. When their revolvers were used with Magnum ammo, they used 145 grain Silvertips, which limited the problem.

The higher velocity, lighter weight bullets work harden the forcing cone, or so I have been told, faster than the heavier bullets as they hit the forcing cone harder. That and the gas cutting affect of the shorter bullets. I once worked on a 66 that had the entrance of the forcing cone rounded from a lot of rounds through it. I thought it was amazing that it was not cracked!

Keep in mind that the K frame .357 Magnum, the model 19, was developed back in the age when almost all officers practiced with .38 wadcutter target loads, then carried full .357 Magnums for duty use. Imagine the officer that had never fired magnums, touching one of those off during a life and death situation. It was reported back then that some officers thought they had blown up their guns after firing a magnum! Back then, officers had much stronger protection from liability issues, than now. Court cases demanded officers be trained in situations they would encounter, which led to officers being trained with the ammo they carry on duty. That led to the guns being subjected to many more rounds of full magnum ammunition than they were designed to handle, leading to malfunctions and the development of the 586 and 686. That is history in a nutshell as I recall it.

Oh, yes, back when the 19 was designed, virtually all.357 ammunition consisted of 158 lead bullets.

If you examine K, L, and N frame barrel forcing cones, you will see a significant difference in thickness at the bottom where the yoke enters the frame.

__________________
Richard Gillespie
FBINA 102

My 3" 66-3 shoots Winchester 110 gr. 357 mag the best. It is much "milder" than the full house 125 gr. loads at 200 fps slower and 15 gr. lighter. What is the verdict on this load's effect on the K frame?

Somewhere way back when I read S&W either advised not to shoot 110gr 357s' out of their K frames or they would void their warranty if you did. How true this was I seriously don't know. Simple fact I do know about these lower grain bullets is they are shorter which leaves a small void when they exit the cylinder to the cone. The end result is the hot gas from the powder and primer tends to act like a cutting torch on the forcing cone and top strap as well. Repeatedly shooting 110 or 125 gr rounds over a period of time can cause the forcing cone and or top strap to eventually crack. As for me I believe in better safe than sorry since I shoot a K,L and N frames myself I prefer to use the 158gr bullet hands down. Not trying to be a smart a-- here but I shoot 357s' out of my 357s' If I wanted to shoot 38s' I think I would get a 38. Sorry but I have never understood why someone would get a 357 to shoot 38s' out of it.Nice to know you have that option I guess

How did the barrel pin get sheared by shooting the gun?

How the pin was sheared is unknown. Maybe a metallurgy problem compounded by the shock of all the magnum ammo! All I know is after a session at the range one day in the late 1990's, I noticed the barrel was canted. I drove the pin out and found it was fractured.
I did ask my dad as to why the 66 had a primary diet of Federal 125gr JHPs. He told me that it was what Department issued, and he had an almost limitless supply of it. He carried it in his 28-2, so the 66 got the same because it was his off-duty gun. He wanted to always train with the ammo he was going to fight with. He didn't want any surprises. He knew exactly how that round would behave in every situation. He was a Force Recon Marine and survived three tours in Vietnam, so who am I to question his methods? It's funny, before I joined the forum, I had no idea about the K Frame/125gr connection. When I pick up my 66-4 F Comp this week, I'll try some 158s in it first.