Long Range Chances

[Parashooter]

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).
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!

[madsenshooter]

All this talk of wind drift and such has me thinking back to the late 80s. M-14s and M1As ruled, guys had built Garands trying to compete with them. From 600yds on a windy day the mouse guns were hitting targets next door to the one they were shooting at! 600 is the longest range I've shot from at Perry. I did pretty good back then, I had a Devine M1A that I'd built up very much like my Garand. I didn't know the collector value of the Devine, sold it when going to college in the 90s. I don't think I'll be sticking around for your long range attempt Paul, but I'll be anxious to see how it goes for you.

[psteinmayer]

Adding up the MOA values for all the graduations from 200 to 600, we get a total of 16.5 MOA. Looking at the ballistics for a BC ~.500 bullet at ~2650 fps, we find we'll need to come up about 36.5 MOA from 200 to 1000. Since the 600-yard setting gets us only to 16.5 MOA, we get the remaining 20 MOA with a shorter front sight. One MOA change requires a .008" change of the sight, so .008" x 20 = .16". You'll need a blade about that much shorter than your existing one. That will look pretty short compared to the issue blade.

Now you can check the new blade at 100 yards by setting the elevation to 600 and looking for a group ~39" above center bull - or ~74 at 200 (presuming a MV near 2650 fps and BC near .500.). If using a 6:00 hold at 100, use a 4.4" aiming black to emulate the size of the 44" LR target black at 1000 yards. At 200, use 8.8" bull.

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!

[Kerz]

Hey Paul
Any update?
Vic

[psteinmayer]

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).

[carbon outlaw]

Ok 1000 yard match .. you want a good bullet with a good load that is going to go out to 1000 yards and be accurate enough to hit the target ... here one thing you can do go to J&G sales and order some 30-06 Danish 148 gr 1960 AMA manufacture ammo ... 20 round box 15.99 ...

[Whig]

Better than loading your own?

[Parashooter]

Looks like M2 Ball to me. Not exactly 1000-yard medicine.

[psteinmayer]

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!

[Parashooter]

Keep in mind that at 1000 yards, the LR target's 10" X-ring is about 1 MOA, the 10-ring 2 MOA, and the 9-ring 3 MOA. You'll have to center 20 shots inside that 3 MOA to earn a decent score. If practicing at 100 yards, the MR-31 target will give a fair approximation of scoring on the LR at 1000. Practice at 100 in some wind with a good .22 to refine the wind-doping skills essential at long-range.