I have a PC .44 mag hunter that is driving me crazy. I have tried several brands of factory ammo, several different powders with handloads, bullet types etc...this thing will not group under 2.5" at 25 yards at all and usually runs 3". Forget 50 yards...its abysmal. Im shooting from a dead solid rest with a Weaver 2.5-8 pistol scope. cylinder throat dia is .431 and slugging the bore gives me ameasurment of .431 for bore dia also...that seems a bit loose to me but maybe im wrong?

Any suggestions would be appreciated, thanks.

And the size slugs are you running? .431 is no good for a bore measurement...should be .429 I would think. A .429 bullet is definitely rattling down a .431 bore....

Welcome to the Forum

How did the revolver shoot before mounting the scope on it?

Do other shooters experience similar group sizes?

Your slugged bore measures .431? What did the Factory say about that when you called them to discuss the accuracy issue?

Im actually getting better groups than anyone else thats shot it. it was owned by a friend who brought it to me because he couldnt get it to group. Im the one everyone brings problem guns to and this is the first one ive not been able to get to group well. I have made it a pet project but its about to confound me.

So far I have not called S&W, but when i slugged the cylinder throats and bore and they both came up .431 I started thinking its time to call them. And i triple checked that bore measurement to be sure. The cast bullets Ive tried were .431 and things improved from buckshot groups to around 2.5" groups.

It seems that all factory ammo shoots basically the same...2.5" at 25 yards. I shot a load of 23 gr. H110/CCI Mag primers/240 gr Hornady XTP this morning that finally got under 2" with 12 shots going into a 1.625 group at 25 yards...but for this level of revolver it should be doing that at 50 yards easily from a dead solid rest and scope, if not better.

23 gr of H110 is an absolutely full house strength load in my book, almost like a rifle. I normally start with some easy bullseye or W231 loads and see how the gun does, what bullets it likes and take it from there. It's a long barrel gun and with grizzly loads I am not sure. The barrel may start recoiling before the bullet is out. Plus I never heard of new production guns with such large throat. Normally they are all 429. Plus slugging the barrel and getting a seriously professional measurement is also not easy. I'd use a Sierra JSP or something like that in 210 grain in 4295 diameter. Those shoot like lasers in all of my modern model 29s with 8gr HS-6 and take it from there. I had tried some 430 hard cast lead bullets too but got an atrocious pattern with some loads. If that won't work, call SW.

My PC 44 mag-competitor has 428 cylinder bores-the smallest of all of my44's

The XTPs are known to be a hair bigger than the rest of the jacketed offerings. Perhaps that is where the accuracy is coming from.

Zero bullets makes a .431 240gr JSP that is good for loose rifle bores and the large throats of older smiths. My 29-3 and 29-4 has large throats while my 29-6s and 629-4 are tight. I shoot different cast and jacketed bullets in both of them depending.


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Also consider getting a NOE expander die if you're shooting large for diameter cast bullets. You need to expand the necks a little more than just a flare or you run the risk of squeezing down your properly sized bullet in a tight case. If you want more info on this I can elaborate. I have to shoot .433 bullets in my Rossi 92 and the cases need properly sized for this to work.

My load is on the target: PC 44 mag Hunter

A .431 chamber bore should be fine. My two Smiths shoot fine with .432 chamber bores ... a .4316 bullet pushes thru with a pencil, a .4325 will not start. I don't know the bore diameters of any of my .44's and don't care. They don't shoot .428-9 copper plated bullets well, but shoot .4292 Noslers, .4302 Hornadys fine, and love .4312 Zeros.

"Tight" throats are no advantage and quite possibly a disadvantage. All that's need is a bullet that exits the chamber still slightly bigger than the
groove diameter. Check to see that your "bore slug" is at least a slip fit in your chambers.

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Carry.."hope" isn't a strategy

Im not so much concerned with the throats as much as I am with the bore diameter, Im going to order some cast .432 Keith bullets from Beartooth Bullets and see how those do, the .431 Keiths were giving me some prety bad lead fouling that had to be scrubbed out. So far the H110 powder and Hornady XTP JHP's are doing well, i worked up to 23.5 gr. of H110 and it now sends 6 of the XTPs into a ragged 1.250 cluster at 25 yards. Its getting there slowly...

50 yards with same load was a disaster...3" groups.

What kind of accuracy are you looking for? You may be asking too much from that revolver.

Recut the forcing cone and muzzle crown with PILOTED cutting tools. Done properly, the barrel will then be as accurate as it's ever going to be. Nearly all the revolvers I've ever had had either or both ends out of spec, mostly off center. Seen a lot of forcing cones too rough, too small, off center, out of round, etc. Muzzle crowns are usually just off center by varying degrees. Do this first, or you are just wasting ammo.
My 8-3/8 629 will shoot 5-6 inch groups at 200 meters, 2" or less at 50. Yours should do as well or better.

Doesn't your revolver have (5) groove rifling? It's hard to get an accurate reading with them without a special tool.

Did you use a pin gage to determine the throat size?

If so, Toolguy's suggestion might be the answer to your problems. Check those two items for flaws.

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Waiting for the break of day

My PC 629 Magnum Hunter is scary accurate, with just about any ammo fed to her. So much so it's not worth it to shoot it at anything under 40 yards. Bore/throat dimensions you mention should be a moot point with jacketed ammo. I'd check the crown and then the scope/mounts.