625 JM Accuracy Woes

[MissouriCrowinMass]

I recently bought a 625 JM in .45ACP and a Combat Masterpiece K277____. The attached photo shows the groups at 50-feet shooting slow and braced. This is good for me. (I love the Combat Masterpiece!)

The problem: After shooting that group the 625 JM was all over the place in an unpredictable pattern? I was shooting one of my favorite .45 ACP reloads, a 230 gr. Rainier bullet over 4.2 grs. of Bullseye. That's a good load in my .45 ACP semi's. The 625 JM would literally shoot two shots 1" from the "X" and then put one 8" off target. The more I shot - the worse it got. It by far shoots much worse than my other Smiths, a Model 28-2 4 and a Model 686 4. I had a problem the first ime out with the 625....the extractor rod loosened up and the cylinder jammed up. From reading this great Forum.....I knew what it was. I have it tight, now. I checked the rear sight screw.....it's secure. The cylinder/barrel gap on this revolver is uneven. One side is .007" and the other is
.011? The action & trigger are fine. The bore looks pristine.

If I were to send it to S&W.....what exactly should I ask for and what should I expect to pay? I'm wondering if the muzzle is funky? Any tips?

Thanks, MC

PS - I'm not letting the Combat Masterpiece out of my sight. What a great revolver.

 

[scooter123]

I'd suggest you try a different front sight before you decide it's the gun. Those hivis sights are good for combat accuracy but not ideal for precision shooting. It's quite possible that you're not repeating your sight alignment well enough to get the accuracy you're expecting.

 

[Bullseye Smith]

It may be it don't like those colt loads, just kidding - I think the gun will shoot - you just need to find what it likes. Try some factory ball to clean her out(and see what they do??) then take it and try some differnet loads on her.

 

[MissouriCrowinMass]

Thanks for the tips, guys. I replaced the Glo-Site with the factory Gold-dot. You are correct - the long base of the Glo-Sight moves a bit to the L & R. The S&W locking design isn't rock solid.

I tried 200 grain LSWC's today under 5.0 grains of Win 231. The results were better. Look at Sheet 2 - the 6 Rainier's that I shot were WAY "Eastbound & Up". The 625 does not like my plated Rainiers. (What is a Colt Load? Light?)

These Groups approximate how I shoot freehand. Not really pleased with them. But who know's...maybe it's me?

Some metal Moon Rings came with the revolver. I think a couple are bent as the cyclinder hangs up a bit......any tips on type & make to buy? The 625 is a nice handling fun revolver. I did take Jerry's wood grips off - didn't like 'em.

Thanks,

MC

 

[one eye joe]

Those Hi-viz sights are useless for precision shooting, as Scooter123 pointed out. I suggest that you try the RIMZ moonclips. They are polymer, easy on the hands, no need for tools, very durable, do not bend, hold the ammo VERY securely. Denny is a GREAT guy and he sells a wonderful product.........

 

[pctech]

Check and see how the barrel crown looks. I've seen some 625JM's recently that look like they were done by monkeys with Dremel tools.

Maybe S&W is having Century International Arms make some of their barrels to keep up with production. ;-)

 

[Bullseye Smith]

Thanks for the tips, guys. I replaced the Glo-Site with the factory Gold-dot. You are correct - the long base of the Glo-Sight moves a bit to the L & R. The S&W locking design isn't rock solid.

I tried 200 grain LSWC's today under 5.0 grains of Win 231. (What is a Colt Load? Light?) I did take Jerry's wood grips off - didn't like 'em.

Thanks,

MC

The colt load - I was kidding that you used rounds that were loaded for your 1911 colt . For the stock - very few like them - feels like a ax handle.

 

[MissouriCrowinMass]

I checked the crown with a magnifying glass. It appeared like part of the edge "overlapped" a couple of grooves at the end of the barrel. I saw Larry Potterfield from Midway, USA do a crown job on an old rifle with a brass wood screw on YouTube. So I carefully tried it with some polishing compound. I didn't have a wood screw bigger than .45 so I used a brass plumb bob that I had. It just made that inner edge concentric. (I did it by hand - no drill.)

I shot 3 different reloads today. The results were a significant improvement. I believe - the crown is definitely a big factor with accuracy. Look at the Rainier's - I could barely keep them on the paper before.

I fired a Hornady 200 gr. LSWC into a sand bank and recovered it. I shoot pins alot and see all kind of bullets sticking out of pins or lying on the ground behind the table. This one has almost no marks from the barrels lands? It got swaged down from .452 to about .445 but you can't see any channels from the lands? Is that normal on revolvers vs. semi's or is the barrel shot out? I can't believe it because the revolver looks brand new (I did buy it used.) And the bore is like a mirror.

Thanks,

MC

 

[ellioga]

Same problem with my 625JM

MC, I had the exact same problem with my new 625JM. It shot about 3 rounds into the bullseye, then throw the other 3 several inches out. I tried several bullet/powder combos and finally got the best groups from 200 grain Berrys plated SWC and 5.1 grains WW231. I also seated the bullets long to make up for the wilson rings that I was using out to 1.310" OAL. This gave me about 1.5" groups at 25 yards. I think that I will also look at the crown on the barrell, now that you mentioned it. I also noticed the very shallow markings on the bullets. .452 bullets have to be driven through the cylinder with a dowel, so the throats are pretty tight. I have not slugged the barrell yet to check it out. I have not had this many issues with a new Smith since the Banga Punta days.

 

[scooter123]

I checked the crown with a magnifying glass. It appeared like part of the edge "overlapped" a couple of grooves at the end of the barrel. I saw Larry Potterfield from Midway, USA do a crown job on an old rifle with a brass wood screw on YouTube. So I carefully tried it with some polishing compound. I didn't have a wood screw bigger than .45 so I used a brass plumb bob that I had. It just made that inner edge concentric. (I did it by hand - no drill.)

I shot 3 different reloads today. The results were a significant improvement. I believe - the crown is definitely a big factor with accuracy. Look at the Rainier's - I could barely keep them on the paper before.

I fired a Hornady 200 gr. LSWC into a sand bank and recovered it. I shoot pins alot and see all kind of bullets sticking out of pins or lying on the ground behind the table. This one has almost no marks from the barrels lands? It got swaged down from .452 to about .445 but you can't see any channels from the lands? Is that normal on revolvers vs. semi's or is the barrel shot out? I can't believe it because the revolver looks brand new (I did buy it used.) And the bore is like a mirror.

Thanks,

MC

Take a close look at the rifling in your barrel, if the lands and grooves look like they are radiused, you have a barrel that was produced via the EDM process. It's sort of blend of Glock's octaganal rifling and traditional cut rifling. I have this style barrel on my 620 and that gun will shoot a 3/4 inch group at 35 yards, so it does work well.

However, I also did NOT have a good experience when I tried some Blaser LRN in the 620, the leading was so bad it was tearing patches when I patched the barrel. Took me a full 3 hours to clean the barrel and my 620 is only going to be fed jacketed ammo in the future.

IMO, with the EDM barrels, lubrication with lead bullets is absolutely CRITICAL and it may be best to just not use non jacketed bullets. If vou've been patching your barrel and haven't noticed any leading issues, then it's obvious that you didn't cut any corners like Speer did with that Blaser. However, if you haven't been patching your barrel, I would suggest you do so, you may find some of your accuracy issues are due to leading.

Another factor that may effect accuracy is incomplete ignition. There have been steady reports of the 625 having problems with misfires. My suspicion is that part of hte cause may be a result of the casing interaction with the metal moon clips, they may be allowing some brands of casings to sit a little too deeply in the chambers. I would suggest that you try a bench rest session with careful attention being paid to get the sight alignment as perfect as possible. If you see distinct vertical stringing, you may want to look into installing the Cylinder and Slide extended length firing pin and see if that helps reduce the vertical stringing. You may also want to try the Rimz polymer moon clips, they may hold the cartridges just a tick higher in the cylinder.

 

[MrEarl]

If the chamber throats are tight, that could be a factor in accuracy. They should measure at bullet diameter, according to Hamilton Bowen. If yours are less than .450, you might consider having them opened up. I had Bowen do a .45 Colt (SA) cylinder, the cost was $75.

 

[philinms]

+1 on MrEarl

Mine didn't like any cast bullets until I had the chamber throats opened to .4525. Much better after that but it still prefers jacketed.

 

[foxnews]

I have a 2 month old 625JM and it is doing almost the original poster indicates. Saturday was the second time I had it to the range. The first time was about 3 weeks ago and I only fired about 25 quick shots to test it out.

On Saturday, I put 60 rounds of UMC, 230gr, FMJ though it. Granted that is about the cheapest US made ammo you can find, but I generally get good results from it in all my guns.

I also put 20 rounds of Federal 230GR JHP Personal Defense rounds through it.

With the UMC, I'd get about 4 rounds right center of the bull, great accuracy with groups acceptable to me. Then, with one or two of the rounds, I would get fliers about 4 inches high almost every time. (Just above the black of the target) Just outside the bull. This was consistent on all 10 loads of 6 rounds in the cylinder. No matter how much I concentrated, there was always at least one flyer. It seemed to be more common with one cylinder chamber more than the other, but it happened in different chambers at different times.

I was sitting when shooting. Using 2 handed rest over sandbags.

The 20 rounds of Federal grouped well also, but still had two fliers out of the 20 that went high. Maybe 3" high.

I wonder if there is an issue with the current manufacture of 625JMs.

It never shot 8" from point of aim, so I can't complain too bad. Maybe with a little more shooting it will settle down, but it is definitely noticeable as to the fliers. None of my other S&W revolvers of any age have this noticeable accuracy issue.

 

[scott625b]

Are you shooting single or double action? This could make a difference. Just from looking at the targets, the spread seems to be the same, IMO, the longer barrel should have a smaller group. Both guns will be different in how they handle. More practice may be required.

 

[YamaLink]

My first range trip with the new 625 JM had two issues.

1) I was a brand new revolver shooter so my trigger control was, uh, lacking.
2) I had a reload the gun did not love. Shooting all over the place no matter what distance or how slow I went.

Put a slower 230gr plated rn in with about .4 grain less WST. Made one click to elevation and one to windage. Perfection!!!

I expect it to get even better when I load some 200 grain moly. I love my 625. I had another but my brother could not come to grip with a big N frame revolver so I am in the process of selling it to a forum member.

When idpa season starts a f/o front sight is coming on. The Hogue monoblock rubber grips are also user friendly at least for my hands. My accuracy and FUN level is so much better with the 625 than my M&P9L set up for gaming. The only firearm I confidently do better than the 625 is a very nice 1911, but that is not an apples to apples comparison obviously.

 

[superdave2]

I just bought a used 625JM as well. Hardly shot by the looks of it. I'm less than impressed. Gun shoots way high right. You know doesn't it just piss you off that you buy this revolver thinking this is a real high quality gun and there are issues with the muzzle crown. Thats just crap. I'll look at mine under the magnifying glass. I have to shoot mine some more before I decide if its a keeper or not.

 

[badge#7]

Update?

I'm a new member, posting to an old thread. Just wondering if anybody returned their 625JM to Smith to correct the problems and if so, were they satisfied? I've got one that i bought a couple of years back and have not shot it much. Got to looking at it today and noticed the uneven crown and what looks like dents to the muzzle face (bought it new, never dropped). The edges of the dents are radiused, indicating to me it was dented at the factory before final polish. Bummer.

 

[Dale53]

I have a 625-8 JM Special and two friends have them. I have shot all three and they are our most favored revolvers. All of them shoot well under an inch at 25 yards off a rest with our own cast bullets (Mihec version of the H&G #68). Mine also shoots the original H&G #130 as well as the 250 gr Keith (NOE version of the 454424) just about as well.

I am sorry to hear that others are not happy with their JM Special. The only thing I have done to mine is to replace the springs with a spring set from Jerry Miculek (Bang, Inc) and have set the double action at 9.0 lbs and the single action at 3.0 lbs (my preference).

I did replace the grips with Pachmayr grips and use a Red Dot sight.



This was shot, standing, at 25 yards with the Mihec #68 (200 gr SWC) ahead of 4.0 grs of Titegroup.

FWIW
Dale53