Long Range Chances

[psteinmayer]

Yes, the Springfield and Vintage are combined events, but I shoot both (Vintage will be shot Saturday afternoon after the Garand match, and Springfield will be shot Sunday morning).

Now I wish I had a separate 03A3 for the Long Range match.... things would be a lot less complicated! Anyway, I really do appreciate all of the advice, and I hope I'm not sounding curt or crass. I'm just trying to take all of this in. With all of the experience I've gained in loading and shooting over the last 30 odd years, this LR shooting is a totally new deal for me, and I'm eager to learn, but definitely willing to listen to advice too.

It sounds like I'd better get a separate front sight blade that I can modify. My 200 yard accuracy is dead on for the 200 yard setting, and I really don't want to screw with that, so I would take a different blade and tools to swap it out after shooting the Springfield match. Any idea of how short to cut the blade as a starting point to get close? I'll take a file to the firing line too!

[Parashooter]

. . . Any idea of how short to cut the blade as a starting point to get close? . . .
Center hold: +6.5 MOA x .008" = .051" shorter (presuming issue blade prints center at 200 yard setting and range)
6:00 hold: +2.1 MOA for 22" radius of aiming black x .008" = .017": Total .068" shorter
Frame hold: +3.4 MOA for half of 6' frame height x .008 = .027": Total .078" shorter.

Below is trajectory data with 1000 yard zero. "PATH" column shows where we expect group center at various ranges. Handy if you have to sight in at shorter range.

Top image is "standard" atmosphere. Bottom is corrected for altitude at Viale range and a medium-hot summer day. Note how much difference this makes in drop, path, and drift. Working with 1000-yard stuff can get complicated!

[Kerz]

Paul
You might consider a USMC type reproduction sight from Bill Bentz. These are significantly wider than standard sights (plus as-issued legal should you want one for Springfield games). He does make them in various heights. Send him an email and advise your intended plans. I'm sure he can help out.
dcm450shtr@comcast.net
Vic

[TexTenn59]

Have you tried the old M1 Rifle sighting target? I've used them to get in the ball park. Set target at 50 yds and use a 6 O'clock on the black circle at the bottom. For scopes, you sight with horizontal cross hair like a 6 O'clock hold.

I bought mine from National Target Company (ST-1) at: https://www.nationaltarget.com/product_info.php/-p-116?osCsid=9fbdc9273f5ed89235634632384af423


I could mail you a couple if you would like.

[psteinmayer]

I emailed Bill Vic... thanks very much.

Tex... That would be amazing. Please let me know what I would owe you.

[Parashooter]

If you have to sight in at 50 yards, the ST-1 target should work well since it's designed for M72 Match ammo, with a MV ~2650fps and BC near .500 - the same as we've been suggesting for your LR handloads. See this article for some M72 handload information - https://www.ssusa.org/articles/2018/2/1/tips-on-how-to-duplicate-1950s-era-30-06-m72-match-load/

Looking at the ruler on the target, we can see the 1000-yard line is ~19.3" above center bull, corresponding to ~38.6" at 100 yards (drop being negligible from 50 to 100 yards).

If you can sight in at 100 yards and want the same effect, just mark your target some 38.6" above center bull and adjust sights to group there. To simulate a 6:00 hold on the LR target at 1000, use a 4.4" aiming black.

[Kerz]

Hey Paul
Let us know what Bentz recommends for a 1000 yd sight.
Vic

[psteinmayer]

Well... Mr. Bentz offered to sell me a sight, but did not recommend a height. He just told me to let him know what height I need the sight to be. I haven't got a clue! I guess I need to know what height I need to be able to use the 600 yard setting on the rear sight for 1000 yards. That way, I can go up or down to fine tune things! Does anyone know?

Sorry if I sound like I'm in over my head, and haven't got a clue. The truth is... I'm in over my head, and I haven't got a clue!!! I really want to get this right the first time, and learn! I'm just asking for help...

Addendum: I just noticed Para's recommendations on blade heights. Pardon my ignorance, but I'm not quite sure which height I need, so if someone can please explain to help me understand. Thanks.

[Parashooter]

. . .I just noticed Para's recommendations on blade heights. Pardon my ignorance, but I'm not quite sure which height I need, so if someone can please explain to help me understand.. .

OK, first thing would be to determine where to measure. You could measure from the top of the blade to the top of the base, from the top of the blade to the top of the barrel, or even from the top of the blade to the bottom surface of the band that holds the base on the barrel. If you want to remove the blade, you can measure it from top to bottom or from top to pin hole.

Once you've chosen where to measure, apply that choice to your existing front sight and measure it as precisely as you can. Then make, buy, or alter a new blade that will be shorter than the existing one when measured in the same way. How much shorter depends on your load and your hold.

If you'll be using the same hold ("6:00" for example) at 1000 yards as you do at 200 and your 03A3 puts your long-range handloads in the center at 200 with the existing blade, you'll want your new blade to be about .050 shorter than your existing blade. Leave the blade a bit tall and bring a file to the range for final adjustment.

You can check the new blade at 100 yards by setting the elevation to 800 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.

[Parashooter]

. . . I need to know what height I need to be able to use the 600 yard setting on the rear sight for 1000 yards. That way, I can go up or down to fine tune things! . .

Sounds like a good idea, giving you some leeway if you need to come up a bit and don't have time to start filing on your blade. To calculate this, we need to look at Bob S's table of MOA values for the A3 sight at https://www.tapatalk.com/groups/collectorguns35625/table-of-elevations-for-03a3-rear-sight-t3769.html

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.