military sight question

[Beekeeper]

I have been shooting a lot of my old military rifles( all with cast) and have found that 400 yards on the sight is not good for 400 yards.
On one I had to use 800 to get to 400.
I presume this is due to not loading to milspec using cast.
Does the fact that there is no jacket also figure in to the mix?
Is there some where that you can get info on sight settings with cast or is it up to each individual weapon?


Jim

[felix]

Jim, weapons and ammo for them are manufactured according to a military spec. In the civilian market, the guns and ammo made for them are somewhat arbitrary. So, if you are using your gun as a weapon, then obtain the military ammo made for it and you very well could be delightfully surprised. Otherwise, you are on your own, and that is the sportsman's way. ... felix

[koehn,jim]

I agree with felix above, I also shoot military with cast and find it takes some adjustment my no 5 carbine needs the sights set at 500 yards for the 200 yard range and my m1 likes the 300 yard setting for 100 but once set it holds zero. You are after all moving the bullet slower so gravity affects it more, and in some cases a bullet that weighs more.

[Uncle Grinch]

In shooting cast or most commercial loads, I've often had to replace the front sight with a taller one in order to hit the paper at 100 yards. Numrich sells tall Mauser sights, but you can get by with JB Weld and shape an extention on top of your existing sight.

[Larry Gibson]

For the zero at the various ranges on milsurp sights the ammunition needs to be similar in velocity and bullet BC to the original milsurp load the sights are regulated for. Most cast bullets lack the BC and the velocity.

Larry Gibson

[WineMan]

I have tried to use a ballistics program to show the drops of a cast bullet at 1500 fps and then match the MOA drops to the military sight for the issued Ball rounds. I always find that I am using a longer range than the calculation would suggest. I am not sure what is going on but if a cast bullet drops 10 MOA I would have though that a sight setting of 400 yards would be right on but in practice a sight setting of 600+ yards is required for POI to equal POA. I am sure there is a logical reason but I have not been able to figure it out.

Wineman

[bruce drake]

I use the ballistic charts for the milsurp rounds and then match them with the velocity reading I get from my cast boolits. If the FMJ bullet is going at 1800fps at 400 yrds, I'll know to use that sight setting for my 100 yard sights since most of my cast loads have that velocity reading. It puts the boolit on target and then I can tweak it into the bullseye from there.

Bruce

[WineMan]

Bruce,

That is a neat idea. Is the 1,800 fps the velocity at 100 or at the muzzle? I am shooting a 314299 at 1,500 fps MV. The drop at 200 yards is 18 MOA and for a M2 Ball the range of an 18 MOA drop is 575 yards. In practice to hit rams at 200 yards the rear sight of a 1903A3 (with a "C" front) is set at 800 which would be a 30 MOA drop for M2 Ball. If I match the velocity at 200 yards of the cast load (1,150 fps) to a M2 Ball ballistics chart, the sight would have to be set at 950 yards which a closer match to the actual setting. Getting on the paper or vicinity of the steel is what I was looking for.

Wineman

[Dutchman]

I have been shooting a lot of my old military rifles( all with cast) and have found that 400 yards on the sight is not good for 400 yards.
On one I had to use 800 to get to 400.
I presume this is due to not loading to milspec using cast.
Does the fact that there is no jacket also figure in to the mix?
Is there some where that you can get info on sight settings with cast or is it up to each individual weapon?


Jim

Not all military rifles zero at the same range. The 1903 Springfield has a 395 yard battle setting when the ladder is down. If lifted the peep can be set to 100 yards. Many Mausers use a 300 meter battle setting with the ladder or elevator at the lowest setting. The m/38 Swedish Mauser zeros at 100 meters while the m/96 zeros at 300 meters though the m/96 can be zeroed at 100 meters using a taller front sight blade.

Many of my Mausers require 400 meter setting to zero at 50 yards using a 6 o'clock hold on a black 50 yard pistol target. So in essence it's shooting about 4" high at 50 yards but I'm hitting the X ring using a 6 o'clock hold. In .30 caliber rifles I'll be shooting a 200 gr cast bullet at 1,400 to 1,500 fps typically.

A copper jacket has no effect on ballistics. Interior ballistics, that is prior to exiting the barrel, is all about the weight of the projectile and the speed. Exterior ballistics is about weight, speed, nose shape, angle of departure (trajectory). Every rifle is different. You need to work with each rifle and each particular load and know where that rifle shoots at what range. I zero everything at 50 yards and then use Kentucky windage for everything else.

Using Kentucky "windage" (and elevation) means you have to know the flight characteristics of each bullet you shoot and the amount of bullet drop at various ranges. That can be a bit much if you shoot a lot of different rifles and bullets.

One of my older Hornady handloading manuals has a really good and complete section in the back of trajectory tables for just about everything from zero to many hundreds of yards at various speeds. It's worth having that kind of data. It's purely mathematics.

Dutch

[WineMan]

Dutch,

That is a good place to start. I do not have any dope on ranges over 200 for jacketed and the sight is on 250 for a center on the SR at 200. More work to be done for sure.

Thanks

Wineman

[FAsmus]

BeeKeeper;

There is a thread up on "C/B Loads in Military Rifles" called; "Still a few hits in the old M1903" ~ or something like that. There is, in turn, a photograph of a sight elevation card in this thread showing elevations required, using the issue sight, for distances on out to 834 yards.

Just a thought ~ go take a look. I believe the data was collected using 22 grains 4198 and a 311284 or some such combination.

Good evening,
Forrest

[Bob S]

As a point of reference, my usual mild 2400 loads (311291; 15 or 16 grains in US cal .30 or 7.5 x 55) will zero at 100 yards with the military sight at about the 800 yard/meter setting. Springfields, 03A3's, M1917, Mausers, Schmidt-Rubins; "800" usually gets me in the black on the standard HP target (MR-31) or the 100 yard smallbore, prone w/sling.

BTW, battle sight zero for the M1903 (ladder down) is 547 yards with either M1906 or M2 cartridges and the standard front sight. With USMC front sight, 250 yards.

Resp'y,
Bob S.

[Dutchman]

Memory is a terrible thing to loose:).

http://images54.fotki.com/v461/photos/2/28344/1676633/1903Springfield1911Manual-vi.jpg

1940 Bluejacket's Manual, US Navy.

http://images116.fotki.com/v700/photos/2/28344/1676633/1940_Bluejack_Manual-vi.jpg

[Three44s]

My best advice is start close and work out!

Just give it the real world heave ho!! I have never been able to pre- predict a bullet impact worth beans ....... the real deal always trumps the paper tiger.

I do like Bruce Drake's usage of the ballistic charts ..... that makes a lot of sense and would make a good yardstick for a starting point.


Three 44s

(Whooo Hoooo ...... there's my 1000th post!!)

[FAsmus]

Three44s;

~ Is your handle coming from anything like the 444 Marlin?

I have two of these in single shot for long range shooting with 500 grain bullets ~ but that is another story.

I wanted to share/point out that one of the most rewarding things that can be done in the long range shooting game is to park the car, get out your gear, settle into the cross-sticks, consider the conditions, set the sight where you think it'll do the most good ~ and get a hit with the first shot out of a cold barrel.

This is trick that my M1903 will do with the chosen load of 4759. Also, it will repeat elevation numbers pretty much dead-nuts ~ with density altitude conditions being kept in mind.

Good evening,
Forrest