Issues with a new(to me) S&W 686

[tazman]

I recently picked up an almost new 686 4". It is a new enough model to have the lock on the side. The trigger on this one is smooth and works well so apparently the extra parts didn't bother this one. I had been looking for an older pre-lock version, but those are not available around here. This was the only used 686 I have seen in 3 months of looking.
I started shooting with loads that worked well in my other revolvers and had rather poor results. I kept trying different loads until I started shooting some 358311 boolits I had recently cast.
These worked really well.
I checked the cylinder throats when I got home and found they would, just barely pass a 357 jacketed bullet. A .358 boolit would not pass through any of the throats.
The 358311 boolits dropped from the mold at .357 so that is probably the reason they worked so well. I haven't slugged the barrel yet, but I had no leading with over 200 rounds through the barrel so I am not too concerned about it.
Today I took more of the 358311 boolit loads and some Hornady XTP loads with me to the range. These all shot extremely well for me. Roughly a 1.5 inch group at 10 yards.
The other loads still shot poorly in it.
As a test, I brought my Target Masterpiece along as well. It performed it's usual outstanding results with all loads so it wasn't just me having a bad day the first time.
I guess this one is a bit picky.
Should I have the throats reamed out to .358 or should I leave well enough alone and just shoot the loads it likes?

[snowwolfe]

Depends on what you want. Generally revolvers that are set up well usually will shot a variety of loads well.

[Piedmont]

Try some of those 358311s out of magnum cases. Maybe the jump is causing your inaccuracy with that bullet. I wouldn't ream until I had done lots of testing. It probably won't be necessary.

[leftiye]

Don't ream until you slug the bore. It's about the boolits being able to get through the chamber mouths and remaining about .001" larger than groove size.

[Petrol & Powder]

I agree with leftiye, I wouldn't ream the throats until I knew the barrel diameter.

[376Steyr]

Any problem with it spitting lead back at you? Especially when using SWCs? If the cylinder is misaligned with the barrel throat, a round nose might shoot better than a SWC. You mention that it has a smooth action, so maybe somebody did an action job on it and messed up the timing?

[tazman]

Any problem with it spitting lead back at you? Especially when using SWCs? If the cylinder is misaligned with the barrel throat, a round nose might shoot better than a SWC. You mention that it has a smooth action, so maybe somebody did an action job on it and messed up the timing?

The lockup is tight. Doesn't have any slack front to back or sideways. Cylinder gap is hardly visible.
I put nearly 200 rounds through it with no noticeable spitting of any kind. No leading in the barrel either. There are a couple of things that I need to check yet(slugging the barrel being 1). I will get back when I get them done.

[Forrest r]

It's not so much the cylinder diameter/hole size that counts. It's what the cylinder size is compared to where the bullets starts that makes a huge difference. I've always loaded the bullets long in 38spl cases when shooting them in 357's. I shoot/load bullets seated like these in all my 38spl cases and use them in all my 357's and 38spl firearms. The h&g #50's are 357 specific and do extremely well in every 357 I own (4 of them). The 640's fit in all my 38spl's and 357's and shoots lights out in everything I've tried them in.

http://i162.photobucket.com/albums/t242/forrestr-photo/8e26ef61-5d72-4232-9996-108bde84fb55_zpsymwzcftj.jpg (http://s162.photobucket.com/user/forrestr-photo/media/8e26ef61-5d72-4232-9996-108bde84fb55_zpsymwzcftj.jpg.html)

Those 640 bullets seated long produce groups like these in my target grade revolvers and open up to quarter sized groups in standard revolvers. Doesn't matter if the revolver is a 38spl or a 357, same thing with my contender bbl's I have both a 38spl bbl and a 357 bbl. The h&g #50 loads are 357 specific and being a p+ load have a pretty good hit along with being accurate.

http://i162.photobucket.com/albums/t242/forrestr-photo/keepers_zpsrmfa629l.jpg (http://s162.photobucket.com/user/forrestr-photo/media/keepers_zpsrmfa629l.jpg.html)

The other thing I've noticed over the decades is that 38spl ammo that is loaded for 357's tend to be more accurate if their loaded to max 38spl or p+ levels. Of the 2 loads pictured above, the 640 bullet is seated long/crimped in the bottom crimp groove and was loaded with 3.3gr of bulleye (.2gr under max) and 3.5gr of international clays/max load. The h&g#50 was seated long (middle lube groove) and loaded with 3.8gr of bullseye/max p+ load for a 357 only load/ammo.

As far as shoulders on swc's go, the 358311 has a shoulder also. For some reason your 686 likes the diameter of the front drive band on that that 358311 and where it sits/starts. Or your load likes the longer bullet base/bottom drive band. I'd start with retesting the cylinders but this time I'd drop different bullets in them and measure where they stop at/distance from the nose of the bullet to the end of the cylinder. Then put a loaded 38spl/same bullet in the same cylinder and measure the difference. Now you know where to measure the cylinder diameter where that particular bullets starts out at. Just because your cylinders measure .357 at their tightest spot doesn't mean that the cylinder diameter where the bullet starts out at. You might find that it's .360 or .361 where the 38spl's bullets shoulder is starting out at in the cylinders.

Just something to think about.

[tazman]

I hadn't envisioned that. Now I have another thing to check.
Thanks for bringing that possibility to my attention.

[RedHawk357Mag]

Mister R, thanks sharing that information.

Sent from my XT1254 using Tapatalk

[Dan Cash]

When I ordered a mould for my S&W 57, LBT had me do some very careful measurement of the chambers (not cylinder) to determine where the chamber throat began and what the dimension was at that point. The resulting bullet is profiled to seat in the case to the crimp groove and the forward major dimension of the bullet just touoches the chamber throat. That gun with that bullet really shoots.

[tazman]

When I ordered a mould for my S&W 57, LBT had me do some very careful measurement of the chambers (not cylinder) to determine where the chamber throat began and what the dimension was at that point. The resulting bullet is profiled to seat in the case to the crimp groove and the forward major dimension of the bullet just touoches the chamber throat. That gun with that bullet really shoots.

I did something similar with my NOE hollow base wadcutter mold and my S&W target masterpiece. The cylinder throats are exactly .358. I sized my boolits to .358 and crimped them in the middle lube groove. This put the front driving band of the bullet into the throat slightly. I needed to push slightly to get them to chamber as they were a light press fit. They shoot really well that way but are a pain to load in the cylinders. They shoot very nearly as well without doing that with a lot less effort.

[tazman]

UPDATE-- After a couple of range sessions where I was trying out some jacketed loads, suddenly the gun started shooting everything well. Other than the possibility of wearing some burrs off the rifling, I have no idea what changed. It now shoots everything that it wouldn't shoot well before into small groups just like it did with the XTP loads.
I have never had a revolver do that to me before.