S&W 686 accuracy

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S&W 686 accuracy

Post by Pat Nemes on Sun May 11, 2014 7:56 pm

I have an S&W 686 with the 6 " barrel. I've been trying to find a 50 yd load that will shoot less than 4 inches at 50 yd. The loads are using cast bullets 158 grain SWC with 4.5 grains unique and with 4.5 grains bullseye. Cases are R-P brass with CCI magnum primers.

The best grouping I've been able to to do so far is 9 inches and that's off the sandbags. It's not just 1 flyer it's the whole string of 5 rounds that are all over the target. Any suggestions? Am I expecting to much from the gun?

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Re: S&W 686 accuracy

Post by Rob Kovach on Sun May 11, 2014 8:34 pm

I feel your pain Pat, I went through the same struggle with my Model 14.  Try some factory ammo, especially the Remington LRN ammo, then try to create a load that can match the best factory ammo.

148gr HBWC ammo is much easier to make an accurate load.  Try that bullet instead.

Check out this thread: My first batches of handloads could barely hold the backer much less hit the black!
http://www.bullseyeforum.net/t2221-distinguished-revolver-loads-that-don-t-suck

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Re: S&W 686 accuracy

Post by Rob Kovach on Sun May 11, 2014 9:11 pm

Oh, and those SWC bullets that you have are anything like mine, they will work just fine at 25, but for some reason, mine turn worse than a major league knuckle ball between the 25 and the 50.

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S&W 686 accuracy

Post by Pat Nemes on Mon May 12, 2014 7:26 am

Thanks for the input Rob. I'll need to get the factory Remington ammo as a baseline to measure against. I think my next step will be to weigh and measure a few dozen of my cast bullets, measure the cases for length and inside diameter and go from there. I do notice that when I bell the case mouths some cases extract harder than others from the dies indicating to me the ID on some is smaller than the others even though they are all the same R-P headstamp.

I like a challenge. I only hope I'm not fighting windmills here should I have a revolver that isn't up to snuff.

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Re: S&W 686 accuracy

Post by Virgil Kane on Mon May 12, 2014 8:04 am

Two questions.

Why are you using magnum primers with these powders? Just curious not flaming you.

Have you checked the forcing cone on your 686?

 I ask about the forcing cone because I have 3 "K" frame S&W and the forcing cones on all 3 are non-existent when measured with a Brownell's forcing cone gauge. Not even minimum with my guns and have checked a few others and found the same thing ! I know the 686 is an "L" frame but I wonder if these forcing cones are cut to minimum also. As a side note all my "N" frames the forcing cones are cut properly and have shot lead fine from the first day I got them. When I re-cut the forcing cones and polished them all three of my revolvers cut the usual groups in half when using lead bullets.  To say I was amazed to find out how much a forcing cone effected accuracy would be an understatement. Definitely  worth checking if you haven't done so already.

Virgil

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Re: S&W 686 accuracy

Post by james r chapman on Mon May 12, 2014 8:43 am

I agree with Rob, get a box of decent factory ammo. if you want a pure accuracy baseline, use any of the 148 hbwc loads.

I've not been able to get any swc to shoot as well as a swaged round nose bullet.

I know my 6" mod 66 will hold 1" @ 25 yds with 148 gr hbwc and 3.0 gr ww 231

jim


Last edited by james r chapman on Mon May 12, 2014 8:46 am; edited 2 times in total (Reason for editing : added yards)

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Re: S&W 686 accuracy

Post by Steve B on Mon May 12, 2014 10:05 am

Are you using 38 Special or 357 Magnum brass?  4.5 gr. Bullseye is awful hot for a 38 Special load.

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S&W 686 accuracy

Post by Pat Nemes on Mon May 12, 2014 10:58 am

You all make good points. I am using .357 mag cases. I'll try some standard pistol primers also. I was using the mag primers thinking that with the smaller powder charge in the larger mag cases I would get more uniform ignition.

The forcing cone will be another place I'll look. What are the specs for that? I can't believe that this gun can't shoot tighter than 9" at 50 yds.

Thanks for the inputs.

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Re: S&W 686 accuracy

Post by james r chapman on Mon May 12, 2014 11:52 am

I know it will with .38 spec ammo...

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Re: S&W 686 accuracy

Post by Steve B on Mon May 12, 2014 6:07 pm

I would try softening that load.

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Re: S&W 686 accuracy

Post by varmint243 on Mon May 12, 2014 9:55 pm

A 6" 686 will do anything you need in terms of accuracy at 50 yards.
I cast my own bullets and believe that a square true flat base is key to good accuracy.
I put all my bullets in the little plastic trays base up so I can inspect each one.
.358 - .359  diameter, soft lube
The bulk bevel base semi-wadcutters are horrible stay away from those.
HBWC did shoot very well in my gun before I started casting.
3 - 3.5 grains of your favorite fast powder is all you need.
If you think about it the crown and bullet base are the last thing to make physical contact.
You want both the crown and the bullet base to be as good as they can be.

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S&W 686 accuracy

Post by Pat Nemes on Thu May 15, 2014 10:07 am

I went to the range yesterday and set up at the 50yd line. I had made up 3 separate loads for the 686.

Load #1  R-P cases trimmed square at the mouth, CCI 500 primers, cast SWC bullet weighed to a range of 159 +/- .3 grains, 4.8 grains unique

Load #2 R-P cases trimmed square at the mouth, CCI 500 primers, Hornady 158 gr JHP seated to the cannelure, 4.8 grains unique

Load #3 R-P cases untrimmed, CCI 550 primers, Hornady 158 gr JHP, seated to the cannelure, 13.5 gr 2400

Set up on sandbags

Load #1 10 shots grouped 7 1/2 in. 

Load #2 10 shots grouped 4 1/2 in.

Load #3 5 shots grouped  3 1/2 in.

From the previous loads with unique of 4.3 and 4.5 grains  I had used previously it appears that as the loads became heavier the groups tightened up. The 13.5 gr 2400 load I had used years ago in mettalic silouette shooting worked well then and does well now.

My next step is to order a small quantity of 158 gr RN cast bullets. The comments made previously in this string are that the RN bullets shoot better. This is supported by the fact that the Hornady JHP are round nosed. I really want to find a cast bullet load that will be accurate out to 100 yds. The Hornady JHP are just to expensive and hard to get to shoot on a regular basis.

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Re: S&W 686 accuracy

Post by Rob9mmshooter on Wed May 28, 2014 8:35 am

I shoot a 686 with a 6" barrel in the DR matches and I found in mine that I needed to size the bullets a little smaller to shoot accurately out of the standard size cylinder that is supplied with the gun.  The chamber mouths on the cylinder on my gun are all exactly the same at something between .356" and .357".  If I tried to shoot .357" or even worse .358" size lead the accuracy was awful.  Since I cast my own I just sized them down to .3565" and now it shoots well at 50 yds 2.5"-3.0".  You can either go to the smaller bullet or buy a extra cylinder to open up the cylinder throats to accommodate the commercially available cast .357".  If you send me some contact information I would send you some bullets to reload to try before doing anything that starts to cost a lot of money.  I use 3.5 Bullseye for these loads.  r831hanson@icloud.com.

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Re: S&W 686 accuracy

Post by Jerry Keefer on Wed May 28, 2014 10:44 am

Getting a revolver to shoot x ring at 50 yards is nearly as labor intensive as building an x ring 1911.
One poster mentioned the forcing cone.. This is a large portion of the process. The factory cones are archaic and all over the place dimension wise.  I have yet to find one that is concentric with the bore center line. This goes for the crown also..Often an overlooked or under considered area. These areas should be single point cut in a lathe, barrel removed and held in a spider to allow alignment of axis'. .. Piloted reamers will not do the job.   The barrels are 18 X 1 twist. Not ideal for accuracy work, but not impossible to work with. The 14 X 1 twist of the Colt made it popular for many years. There was once an old saying among revolver smiths." The accuracy rotates around the cylinder "..meaning the the cylinder must be adjusted and set up to allow the projectile to enter the barrel as close to the bore center line as possible, every time.
Forcing cones begin to upset the bullet while making the transition from cylinder to barrel.. Not an ideal situation for accuracy. The Taylor Throat is by far superior to the forcing cone, and immediately improves accuracy. The chamber throat diameter should be adjusted to compliment the bore diameter. The cylinder is supported largely by a gas ring at the front. This can be changed to a bronze bushing if rules allow, or a custom made steel ring to comply with DR rules. Custom gas rings allow precise fitting, of the cylinder and allows closer end shake, and barrel gap tolerances.  All of which aid accuracy.
The powder choices mentioned have never proved useful in my experience.. 231 and WST were superior to most others and an excellent starting point...Use 38 length brass cases ( no nickel)  and forget the Magnum primers.. 
Jerry

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Re: S&W 686 accuracy

Post by Jack H on Wed May 28, 2014 11:36 am

Jerry
I got to tell again about a Colt OMM 38 I had in the 70s.  I never benched it or anything.  Just knew it was darn good.  I bought it brand new , special order from local shop. (Eugene Surplus Sales, now gone for urban renewal Sad

I found 10 factory rounds in my box at the range on day in the early to middle 70s.  I decided to shoot them off the last thing before I closed the range for the day.  I was alone, the sun was low and shone well on my front sight.  I set up for a 50 yard slowfire but not at the usual pistol benches.  I used one of the rifle benches for the box and scope. 

For some reason I set my mind on the sight and trigger more than usual.  And the scope being in an unusual position, I did not scope, for eight of the ten rounds.  I used a trigger style that is today frowned upon.  I applied and held pressure according to what I saw in the sight.  In my 20s I did have the eyes and physical ability to do so.  Long holds, very precise alignment, and that "surprise break" was all I had in mind.  I also made extra effort to sense the grip on the front and back straps to be perfectly in line.  I shot those eight loading five and five.  For some reason, I'll never know why, my thought strayed to the target, and I broke position and looked in the scope at a hollow X ring.  All eight shots inside the X.  

I cannot explain how or why I got into that state of mind.  BUt I lost it for shots 9 & 10.  (They were an 8 and a 9).  I kick myself for not saving that target.  I have been trying to reproduce the mind set for 40 some years.  I can not reverse engineer the technique at my age. 

Any way back to revolver accuracy.  Those 60s and 70s Colts were perfect in my opinion right out of the box.  The trigger was absolutely the best I ever experienced.

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Re: S&W 686 accuracy

Post by Jerry Keefer on Wed May 28, 2014 12:16 pm

When I began law enforcement/competition in 1980 Colt revolvers, mostly Pythons, dominated the distinguished class. That changed later, with the S&W Underlug Model 14 and the L Frame. Not because these models shot any better than the Colt, it was a $ factor, ergonomics, trigger geometry, availability, etc.  
I am not a slow twist fan.. It is better to err on the fast side, in my opinion. The best shooting HBWC revolvers of my time were 10 and 12 twist barrels.
The very best 1911 barrel test I have ever had was from a 14 twist barrel.. I want to try a 12 twist, as soon as I get time to make one..SmileSmile
Interesting stuff..
Jerry

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Re: S&W 686 accuracy

Post by 9146gt on Thu May 29, 2014 11:52 am

I have a Python with action work by Reeves Jungkind that I used for PPC distingushed Revolver. When shooting  25 yards and further many 158 LSWC (Star) would tumble. He said that was a common problem and the cure was to use hard cast projectiles.

Tom Johansen

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Re: S&W 686 accuracy

Post by james r chapman on Thu May 29, 2014 12:10 pm

and Jerry Moran used to bust 200m rams with regularity with his pythons.

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Re: S&W 686 accuracy

Post by 9146gt on Thu May 29, 2014 4:11 pm

Tried to get Jerry to work on one of my guns when I was in Michigan in the early 90's but it did not work out. I remember being told that there were not many stock internal parts left when Jerry was done Smile 

Tom

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Re: S&W 686 accuracy

Post by james r chapman on Thu May 29, 2014 4:23 pm

Probably right! one of the very few that could tweak that trigger to be better than the old S&W's. This was shooting with him back around '79 when he was getting IHMSA started in Michigan . a shame he no longer smiths.

jim

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S&W 686 Accuracy

Post by Pat Nemes on Fri May 30, 2014 9:11 am

Well I bought 100  of the 160 Gr RN cast from Acme Bullet Company and proceeded to load up several test batches.

 All groups fired at 50 Yds off sandbags.  R-P cases, CCI 500 primers and the 160 gr Acme cast bullet taper crimped to .375".  OAL 1.613"

Each group represents 10 shots. 

Load #1   4.8 gr Unique           5.0 in with 1 flyer
Load #2   6.5 Gr Longshot       4.0 in. with 2 flyers
Load #3   4.5 Gr Bullseye         3.0 in. with 1 flyer 
Load #4   4.8 Gr HP-38            3.5 in. with 2 flyers

With all loads groups tightened appreciably using the 160 Gr RN cast bullet. I am shooting with iron sites and old eyes so I do attribute the flyers to my own sighting error.  However I do see where the groups are consistently tighter than before.

The Bullseye and HP-38 loads look to be the best so far. My next step is to move back to the 100yd line to see what happens.

This is why reloading can be so addictive.

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S&W 686 accuracy

Post by Pat Nemes on Tue Jun 10, 2014 8:10 am

Went back to 100 Yds after getting reasonable groups at the 50 Yd line with the HP-38 and 160 Gr RN cast bullet. At the 100 yd line the groups opened up to over 8 inches off the sandbags. I now have to look at my benchrest tesing technique. I feel that this is contributing to the spread. I'm using the factory iron sights with my old eyes. I do use the merit clip on diopter to sharpen the black bullseye in the target.

Anyone out there with ideas on how to best test a handgun off of sandbags?

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Re: S&W 686 accuracy

Post by LenV on Tue Jun 10, 2014 9:11 am

Pat

    I also have the old eye problem.I have found that when I want to test a load in my wheel guns the best thing I can do when testing off of sand bags is mount a scope on the pistol.The 686 comes drilled and tapped so it is easy to do and takes my eyes out of the equation.

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Re: S&W 686 accuracy

Post by james r chapman on Tue Jun 10, 2014 9:41 am

yeah,mount a 16 power scope on it....

othewise, a mechanical rest if your testing silhouette loads...

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Re: S&W 686 accuracy

Post by LenV on Tue Jun 10, 2014 4:56 pm

I was thinking 2x or maybe 4x but hey 16x would work.I would put my leupold mk8 2x on one I was shooting so the recoil didn't hit me in the eye. The loads your working with wouldn't actually be a problem. The nice thing about Smith sights is you can remove and replace without ever changing zero.Just remove the front screw and slide it back.

Len

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Re: S&W 686 accuracy

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