I suspect you've misinterpreted "Drift" in the table. This is not gyroscopic drift (a still-air constant) but wind drift, the effect of the fact that the bullet is moving through a fluid (air) which may itself be in motion relative to the stationary rifle and target.

The posted tables are calculated to show the displacement of POI from still-air zero (already adjusted for gyroscopic drift) as the result of a 10mph 90-degree crosswind - an arbitrary but useful fiction from which one can extrapolate the actual "windage" required in a wind of different speed and angle. Such information is critical in long-range competition where a gentle breeze can move one's otherwise-perfect shot over to an adjacent target at 1000 yards.

Image below is Hatcher's concise explanation of gyroscopic drift. For a more thorough discussion, see (You need to Login to view media files and links)) and/or (You need to Login to view media files and links)

This is all quite fascinating!  So here's an interesting thought:  Since the Long Range Match consists of two firings (first the Critchfield Match, and immediately after, the Viale Commemorative Match), what if I fire the 1903A3 in the Critchfield and the Krag in the Viale Commemorative?  I may not win... but I'll bet I'll be talked about! 

In all seriousness, shooting the Krag really sounds like an interesting proposition.  Since I have 200 of the Hornady 178 grain ELD-Match bullets, what would the chances be if I shot those out of the Krag?  What would my load, pressures and ballistics look like?  I may just do that instead.  It might actually simplify things for me.  I have 100 new Graf cases, and I'll order 100 more (if I'm going to shoot at near max pressure, I'd want new brass). 

According to the Hodgdon site, a 180 grain bullet loaded with 46.0 grains (compressed) of IMR-4350 should achieve 2,445 FPS at 38,700 CUP.  This is listed as their max load.  Loaded with 49.0 grains (compressed) of 4831 should give 2,425 FPS at 35,900 CUP (also listed as max).  Since I have 2 pounds of the H4831SC, I might like to used that powder for this.

Your thoughts?

psteinmayer wrote on Mar 23^rd, 2019 at 2:45pm:

You'd be amazed how old that data is. Here's a copy of the same stuff from a 2003 downloaded IMR booklet (PDF of 2 pages attached) which is the same as that found in a printed version so old it has "DuPont" on the cover -

.30-40 KRAG
WIN. CASE; WIN. 8 1/2-120 PR
REM. 180 GR. SPCL
.308" DIA.; 25.5" BBL.; 3.00" C.O.L.
Powder - Gr. - Vel - CUP
SR 4759 24.0 1940 39100
IMR 4227 23.0 1900 37800
IMR 4198 29.5 2150 39800
IMR 3031 38.0 2375 39300
IMR 4064 41.0 2435 39000
IMR 4895 35.5 2270 38800
IMR 4320 35.5 2210 38100
IMR 4350 46.0C 2445 38700
IMR 4831 49.0C 2425 35900
C=Compressed

An odd feature of this data is that the "maximum" for some compressed loads is not because of pressure, but rather it's all they could stuff in the case and still seat the bullet.

Anyhow, the 178's don't have a high enough BC to reach 1000 comfortably supersonic when launched at reasonable Krag velocity. Close, but on the edge of the nasty transonic region That's why I'd want those pricey Berger 185's if I had to fire that course with my Krag.

I think you're wise to stick with the 03A3 simply because it groups better. Nostalgia is fun - but not as much as a string of 10's and X's at over half a mile!

Parashooter wrote on Mar 21^st, 2019 at 11:10pm:


Ok, I've shortened the spare blade by 0.16.  The standard blade height on my 03A3 is 1.496, and the height with the reduced blade is 1.351.  I'll sight it in using the 600 yard setting at 100 yards using Para's calculations.  Hopefully, I'll be close and won't need to file it down too much more!

Howdy Vic...

Naw, I got sidetracked temporarily.  I'll hit the range in a couple weeks when family things settle down a bit.  I did create a target with a 39 inch spread between two bulls.  Holy Schmoly…  that's one hell of a spread between POA and POI!  Hope they let me hang that target (state owned range).

Better than loading your own?

Well all... finally made it to the range today.  I loaded up Lake City 72 cases with 60.0 grains of H4831SC and 178 gr A-Max bullets.  I had a target with two 4 inch bullseyes at 39 inches apart.  It was a little difficult sighting because the wind was blowing the lower bull around a little... but with my reduced sight blade and the rear elevation set to 600, the results were close enough to convince me I'm on the right track, and at 1000 yards, I'll be squarely in the ball park!  The bang was quite sharp, and the kick was pretty hard, but no signs of excess pressure either.  I'll load up the actual match ammo with 178 gr ELD-Match bullets!

Thanks so much to everyone for their help and advice!