Has any one measured the bore
On a model 544? Have a new
Unfired one in safe I bought
Brass and dies to load for it
But did not buy any bullets.
I have heard that they have
model 29 barrels on them and
Don't shoot very well with 44-40
Ammo (.4225) does any one
Know if this is true?

Mine had a .429" barrel and .428" throats. It shot wonderfully with Nosler 200 grain JHPs at .4295", less so with Hornady at .430". It will do anything a 357 magnum will do with a bigger, heavier bullet - I never should have sold mine. Great revolver!

Some reloading and chronograph data....

Marlin 1894S, 20" MG barrel; S&W 544, 5" barrel:

44-40 200 grain Nosler JHP, Starline cases, CCI 300 caps, and

-18.0 grains 2400 (it shoots very well in the 1894S)
Rifle - 1389 fps, ev 1351-1453
Revolver - 1139 fps, ev 1128-1158

- 8.5 grains Unique, a great revolver load
Rifle - 1095 fps, ev 1050-1145
Revolver - 897 fps, ev 841-971

-16.0 grains AA#9
Rifle - 1183 fps, ev 1120-1301
Revolver - 833 fps, ev 807-857.

I finished up my search for the upper end of Longshot 44-40 data; at 12.0 grains, extreme spreads grew quickly. There was still no primer flattening nor unusual case expansion, but if I want a magnum, I'll buy one.

The 'sweet spot' for consistent velocities with this caliber/powder/bullet combination lies between 10.5 and 11.5 grains, with the very lowest extreme spread (ES) at 11.0 grains, which provides 976 fps mean velocity in the Smith and 1344 fps in the Marlin. I think I'll edge upward at 0.1 grain increments to find the best accuracy between 10.5 and 11.5 grains.

The weather was 70 degrees with about 10-15 mph winds. The data is also for 5-shot groups.

Charge Weight     S&W Mean Velocity   Extreme Spread     Marlin Mean Vel   Extreme Spread

11.0 grains               976 fps                     63 fps                   1344 fps            48 fps
11.5 grains             1,018 fps                    72 fps                   1414 fps           121 fps
12.0 grains             1101 fps                   298 fps                   1499 fps           290 fps

I've found 'the' load. It's 11.2 grains of Longshot behind the 200 grain Nosler. It gives me 1005 fps mean velocity with the Smith, 1421 fps with the Marlin; ES is 68 fps revolver, 81 fps rifle, and the groups reflect the consistency. I tried 10.8 to 11.8 grains in .2 grain increments; 11.2 was the 2nd best for ES, but far and away the most accurate. Groups were round, symmetric with no stringing; at 25 yards I chewed the center out of my homemade targets with 20 rounds from the Smith after sight adjustment, and the nearly same at 75 yards with the Marlin, which also required sight adjustment (no fun with the Williams 5D, by the way). Second best was 11.4 grains with slightly larger groups and an extra 23 fps revolver and 34 fps rifle, but I'll stick with best groups and caution on pressures.

The Unique and 2400 data are in several manuals, but I relied on Lyman 49th and Hornady for those. Didn't find Longshot data for 44-40, as there is really no source for Longshot data & the 44-40 that I've found. That's a shame - it really works well.

Velocity and extreme spread data is from my chronographing the loads.

From all I have gathered , the groove diameter of the barrels is .429 and the cylinder throats are .428 . I have often thought of buying one . I reload 44-40 for my 1894 Marlin rifle . I find it exceptionally accurate and not that hard to reload . Just take your time , be patient . Regards Paul

Thanks for the input.
Will buy a can of long shot
And some 200 gr bullets.
Have the new brass ,
Now if it cools off a bit
So I can keep sweat
Out of my eyes I will
load some.