I've had a 686 no dash several years, it's my favorite revolver and I've NEVER had anything close to a locked cylinder, even with max loads.

I made some .357 158 SWC with a max load (weighed) of 2400 using standard Winchester primers as recommended in the books I have. It has always worked fine.

Yesterday at the range, BOOM, BOOM, locked. The hammer wasn't stuck in the firing pin hole, so when I got it home I was able to tap the cylinder open. I checked the two cartridges that were shot and did they ever look different. (see photo)

One primer looks normal. The other is as flat as a flitter. I've been reluctant to send the gun for the 'M' modification because it's dang nigh perfect and I didn't want it messed with. So I called and got a shipping label today, but I wanted to ask what you guys thought of this and if you have any idea what would have caused it instead of the dreaded "686 cylinder lock up"

Attached Images

DSCN0052[1].jpg (62.9 KB, 1020 views)

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"He was kinda funny lookin'"

Id say too much gunpowder
I have a 686 pro 5" While the cylinder seems fine, the bore is really tight... Like .354, I also tend to get 100 fps higher than published data. I back off accordingly and dont exceed max published velocity unless there is real good reason.
Like Lyman using a 4" barrel and my gun is 5, so with slower powders I would expect morew velocity

Looks like maybe a borderline load on the edge of being too hot. I would back off a grain or more. A good statistical analysis would need a sample of more than 2, but you don't want to blow up a nice gun in the process of getting those samples.

Perhaps...
Don't mix* cases with Max-loads ?

The primer in the Starline-case looks normal,
the primer in the Winchester-case...hmmm.

*Different cases may have different case-volumes,
different crimps etc

P.44

This may not have anything to do with it but, I have found Winchester brass (at least in .357) to have extraordinarily tight primer pockets. I almost have to flatten them just to seat them. In fact I don't even reload Winchester brass anymore. For that and other reasons.

You say this load has worked fine for you in the past in your L frame. Why would this one round suddenly be different? It may have been a slight overload, but revolver primers don't usually show pressure signs like primers in rifles do.

If I had to guess, it could have been the primer was not fully seated, it fired, and the cartridge moved back against the breach face, flattening the primer? That may have been enough to cause the primer to flow slightly into the firing pin hole, causing the hard cylinder opening.

As with your gun, I have a no dash L frame that has had thousands of factory & reloaded rounds thru it without any issues.

Larry

You've gotten several good and logical
explanations--mixed brass, slightly high
primer smashed on recoil, too close to
the danger line in loads or a slightly
mis-loaded round.

When you get the gun back,I suggest
you back off on your loads; max loads
are never a good idea because of the
variables in gun dimensions, brass and
even the outdoors temperatures not to
mention slight reloading errors.

With the distinct differences between the WW brass and the Starline, my first suspect would be the brass. How many times have this brass been reloaded with magnum loads? I have been shooting magnum loads in WW brass for years and what I see in your photo is not uncommon with what I see after extracting WW that has been reloaded with max loads numerous times from my K,L or N frame revolvers.
I have had primers “flow back” into the hammer nose bushing, forming a nipple on the primer cup tying up the gun. This usually is a result of max loads, loose primer pockets. But pan caked primers are not unusual in WW brass with full throttle loads in my experience.
My recommendation would be to load the same load in new brass of the same headstamp and see if you have any difficulties.
I have always adhered to loading manual data for my reloads, and I have shot thousands of full throttle loads in my 357’s, but Varied types of brass will react differently with the same load.

The StarLine brass has a normal looking primer. The Winchester brass has a FLAT! primer. The gun was locked up because that load was way over pressure.

I highly doubt the use of mixed cases caused that much variation. Either a heavier bullet somehow slipped in or more powder somehow got into that case.

I've reloaded thousands of 38 special & 357 magnum and I usually stay in the middle or upper 1/3 of the load range. In other words, if the starting load is 9.2 grains and max is 14.9. I'll load up around 12-12.5 or so. There's really no need to load up to the max unless you're going to use them for a specific purpose. If you're just plinking, then stick to the middle ranges. What i do is set my primed cases in a loading block, then run it under my powder drop one case at a time. You have to allow for some variance in the powder charges. Now like I said, I've reloaded thousands of revolver rounds and it's not unusual to have a perfectly fine case crack lengthwise down the case after firing. I've seen new commercial rounds do that.
I think your revolver is fine. What happened was one of two things. One, you had a case split, which would cause a sticking cylinder or hard extraction of the empties or possibly a unfired round that had a bullet creep forward out of the case from heavy recoil, locking the cylinder. That has happened to me a couple times as well as primers backing out too.

I regularly shoot a 4" 686-6 and it's a ridiculously strong design built to fire magnum loads for life.

Max loads are not a good idea. Anything shot with a few grains less powder will never know the difference... but the gun will.

Depending on where you got your load data, you may very well be over the safe operating limits, or at least SAAMI specs.

The older loads used a rather hit and miss (no pun intended) method of measuring chamber pressure. That's why if you look up old loads in new books, you'll often find powder amounts smaller, sometimes considerably. Also, shooting at maximum, you should always dial back when starting on a new batch of powder and/or primers.

I absolutely agree with what has been said about using mixed brass with max loads as well.

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So many S&W's, so few funds!!

I sent my 586 no dash in for the recall work a few weeks ago. Got it back in my hands 4 weeks to the day from when I sent it in. Works great.

I've seen more than a few old classics shot loose with long term use of hot loads. If I want to shoot near max loads, I use a new /warrantied gun with no collectors/ sentimental value.
I'd vote to give the old girl a brake from that kind of punishment.

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Dave

Back it off a bit. Powerful loads will mushroom the primer back out and stick tight. If the primer is absolutely flat, you're are pushing it too much. If they mushroom and stick, well your playing with the wrong load. Always test loads in small amounts and you'll find one that is just right.

All of these factors are very likely.

Like I said, I weighed each load on a digital scale. Maybe the scale sticks when trickling powder. I'll have to watch that.

My info comes from Lyman 49 and Speer 14.

Yes, I obviously used mixed brass. SOMETHING was obviously a little different about this load. I may shoot some more of this batch to get an idea if the load is too hot. I'll back off the load, but I want to see if this is the limit. I believe that I'm a long way off from damaging the gun with slightly too hot loads.

PS: I did go up in increments. I shot six a full grain light and six more one half grain light.

I shoot a great many 'warm' loads, but I also like to shoot some 'hot' loads for visceral effect and some max loads, like these.

My eyes aren't too good, but I thought that I saw what appeared to be a small spike in the middle of the hole in the flat primer that wasn't there when I took the picture. It may have been extruded primer from around the firing pin/hole.

My 686 might be a 1980 gun, but it has been shot very little. It was almost mint when I bought it and I've probably only shot several hundred rounds through it with most of them being .38 special loads. I'm not an explosion freak. I do a lot of experimentation and shoot a lot of sub minimal loads as much as hot ones.

Thanks for your comments and help. I'm going to drop the load some simply because a weak link in the components/gun can let this happen. I'm not so enamored of hot loads that I want to lock up guns at the range. But I also want to find out what went wrong with this load. All 686s didn't have the 'lock up' problem and I thought mine was one of them. Maybe 'borderline'.

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"He was kinda funny lookin'"

The flat primer means too much pressure . The primer on the right is normal.
2400 powder is not known for that mysterious "detonation" effect that most reloaders claim blow their guns up.
Since you were in charge of the ammo making , go back and review your procedures and try and determine what happened and why this occured.
It's OK to be anal and OCD when measuring powder and loading ammo....keeping it safe is critical in this hobby. Sticking scale might be answer. I reverted back to powder scoops just so I could see the amount of powder going in the case , hard to be fooled by a scoop.

Glad you and gun were not damaged. Be careful out there.
Gary

I had a no dash-but it had the "M" and was smooth as a slide trombone.

Interesting discussion. I have a 686 no dash without the M. I have had once batch of Monarch 158 gr where a couple of the rounds had flattened primers that prevented the cylinder from rotating. I had to really beat on the cylinder to free things up. I assumed that what I needed was the M modification. Monarch claims a velocity of over 1400 fps for these which seems pretty fast for 158 gr. So I wonder if it was not the firing pin bushing that was the problem but just that a few of cartridges were over pressure.

if the starline case was fire first you might of had bullet set back (maybe a weak crimp) in the ww case causing higher pressures. i have both a 585 and 686 that i've have been very happy with

On older guns with a hammer nose (firing pin on the hammer), the hammer nose bushing will usually develop a burr around the hole after long use. This burr can sometimes tie things up as the rounds scrape across it when the cylinder turns or a fired primer may form over it. The fix is to stone or file the burr down flat. The burr may return a time or 2, but will stop forming after the 2nd or 3rd time.

Monarch is good stuff but they load 'em kinda hot. I had the exact same problems with 158gr 38 special JHP's in my model 10. 1 out of 10-12 rounds would jam the cylinder. it was the primers backing out.

Just wanted to add. Hornady American gunner 125gr XTP in 357 magnum is a wicked load also but I never had any issues with Hornady. But hold on to your hat when shooting it.

I sent mine back, no more problems. Send it back...

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NRA Benefactor

I HAVE TO AGREE WITH Toolguy. I DOUBT THAT THIS IS RELATED TO THE RECALL ISSUE.....

I WOULD PULL THE REMAINING BULLETS IN THIS BATCH. I WOULD CLEAN YOUR PRESS, THEN REDUCE YOUR POWDER A TAD. CHECK WITH A SCALE, TO VERIFY THE LOAD THAT YOUR PRESS IS ACTUALLY THROWING, THEN REASSEMBLE YOUR AMMO.......


NOW TRY IT, AGAIN. KEEP US ADVISED OF THE OUTCOME......

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'Nam 1968-69.DAV,VFW,NRA Inst.

Monarch was the ammo that caused me to send mine to S&W. Got it back, shot some Monarch just fine.

First thing, with maximum loads, I would not use brass from different manufacturers or even different lots from the same manufacturer. Different brass most often means different internal volume and that will affect pressure. Different manufacturers may also use different brass alloys. Remington has a reputation for using a very soft brass, while other brands use harder brass. Different manufacturers also have different thicknesses at the case mouth, so between hardness and thickness at the case mouth, you will have different levels of crimp and case neck tension on the bullet.

The long and short of it is, it is inadvisable to use mixed brass with maximum loads.

I just got back the 686 today with the 'M' modification. I'm going to finish up that batch to see if there's any more trouble. Then I'm going to back off a little on those hot ones.

Turn around was fast. I sent it in not even two weeks ago.

Also I've got a Lee balance scale to check my loads on if my digital is sticking, that should tell.

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"He was kinda funny lookin'"

I’ve had my fair share of flattened primers in magnum revolvers (357 & 44) over the years.

I used 2400 with my first manual, Speer no 11.

I also enjoyed the hot loads but always stayed 1 or 0.5 grains below max. But I think it’s clear now that the old Speer manuals were optimistic in their upper range.

Mind you I’ve also had flattened primers on quality commercial ammo.

I never worried too much about it, the guns still run fine. Well except the 66-2 with a cracked forcing cone, but that’s more on design weakness. Runs great but only use .38 Sp in it now. For the hot stuff I’ve got a 586-1 M and a Manurhin MR 73.

[QUOTE=ken158;140006330]Max loads are not a good idea. Anything shot with a few grains less powder will never know the difference... but the gun will.[/QUOTE

I TOTALLY AGREE, WITH ken158. THERE IS NO NOTICEABLE ADVANTAGE, TO SHOOTING MAXIMUM LOADS, IN ANY FIREARM.....

JUST BECAUSE A VEHICLE IS CAPABLE OF A SPEED OF 130MPH--SHOULD YOU BE DRIVING IT AT THAT SPEED, CONSTANTLY ? ? ? REGARDLESS OF THE LEGAL ISSUES---WHY BEAT YOUR CAR UP ? ? ?

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'Nam 1968-69.DAV,VFW,NRA Inst.

Monarch loads 'em kinda on the hot side IMO. With Monarch 158gr JHP 38 specials I've had on average of 1-2 out of 12-18 rounds primer jam the cylinder on both my 686 & model 10.

Monarch 158gr JHP in 357 magnum will jar your crowns loose or pop a filling.... Their brass is good for reloading but euro spec'd ammo tends to be on the hot side.

I have to agree that the W-W round had more pressure & I doubt it was because of not having the "M" mod. too.

Previously I checked the volume of some of the different brand cases I use. My notes show that a:

Starline, 357 Mag case holds 26.7grs. of water

and a

W-W (nickel), 357 Mag case holds 25.8grs. of water.

That's about 3.5% less, on these selected cases. (~3900 psi increase.)

I think that W-W flattened primer represents a higher difference than shown on the Starline's primer. Either an overcharge or too deeply seated bullet would be my guesses.

.

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Waiting for the break of day

Most of the shots fired through my 686 are target .38 special to about 25% below max load with 2400. At the end of a range session I like to let off some fireballs. I made about a dozen of the full max loads looking to shoot two cylinders full. Usually all goes well, but this time I had a problem. I've had the 686 since 2012 and haven't had a hint of trouble no matter what I shot. Maybe tolerances stacked up and pressure got over the line.

I got my gun back with the 'M' stamp today. I'm going to the range Saturday and I'm going to try out the rest of those loads, about 10 shots. I can see flattening, piercing or otherwise distorting with a hot load but is it normal for a gun to lock up with a slight overload?

Afterthought: I may pull some and weigh the powder, too.

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"He was kinda funny lookin'"