Lee Enfield Front Sight Question

[Ganderite]

Shot some rifles for the first time yesterday. The EAL and Jungle carbine need elevation adjustments.

I have the actual sights in different heights. Is there a rule of thumb of how much adjustment there is in each sight?

 

[tiriaq]

There should be a number stamped on the sight. Compare this to the sights in the rifles, and you should be able to calculate the sight you need.

 

[Ganderite]

I know one needs higher one and the other a lower one. Rather than trial and error, I was hoping if there is an estimate, of say, 4" per increment, so I can get it close on the first try.

If I had any math skills, I wouldn't have to ask.

If I had any machine shop skills, I would grind off the post, drill and tap, and install a SKS post.

 

[Ganderite]

Found it! I love Google.

"Each change of foresight to the next size, up or down, will change the MPI, up or down, 2 inches at 100 yards."


All Lee Enfield's utilized a dovetailed, blade type, front sight. (Note: SMLE and No4 front sights will not interchange because of different dovetail dimensions) There were nine different front sights available and were marked on top of their base with their sizes. They were: .090, .075, .060, .045, .030, .015, .0, -.015 and -.030
Remember there are nine sizes of foresight available, each being .015 of an inch different in height. Note: this height difference was achieved by altering the front sight’s base not its blade height, so each sight has the same blade dimensions. The sights will have its height stamped onto the top of its base. Each change of foresight to the next size, up or down, will change the MPI, up or down, 1/2 inch at 25 yards and 2 inches at 100 yards.
So, before accurate zeroing can be accomplished, the shooter must make several decisions:

1) What type of ammunition will normally be used when firing the rifle,
2) What sight (Battle or Flip-up Micrometer) will be used. Noting that the battle sight was calibrated for 300 yards, so if zeroed for 100 yards the micrometer scale will be rendered most useless. Just to elaborate, the rifle was designed to be zeroed using the micrometer sight, set at 200 yards. The front blade sight was then exchanged until the correct blade height was found that gave the proper elevation.
3) What range to zero from, 25 or 100 yards.

Note: The adjustment details provided below are based on using the military MkVII Ball round (174-gr FMJ bullet, muzzle velocity of 2440 fps). Commercial ammunition should provide similar results, but because of the infinite combinations with regards to handloads. It would be impossible to say for certain, how specific changes would react.

SIGHT ADJUSTMENT CORRECTIONS (Rifle, No1 & No4, all marks)

Elevation

Zeroing begins with elevation, the correct height of front sight blade must be found prior to adjusting for windage. To correct up or down the front sight may have to be replaced with a different height. It makes no sense to get your windage on, only to have to replace the front sight to correct for elevation.

Zeroing at 25 yards, using the micrometer sight set for 200 yards, the Mean Point of Impact (MPI) should be 3/4 of an inch (plus or minus 1/2 inch) above the Point Of Aim (POA).

Zeroing at 100 yards the MPI should be 3 inches above the POA.

 

[bigedp51]

Found it! I love Google.

"Each change of foresight to the next size, up or down, will change the MPI, up or down, 2 inches at 100 yards."

Actually your 2 inch Google estimate is a little high by 0.13 of an inch (give or take a RCH)

The British manual I have states each change of foresight blade will change the MPI, up or down, 1.87 inches at 100 yards.

And the complete sighting manual is in your sticky above that I donated to Badgers website
In Milsurps Lee Enfield On-line Knowledge Libraries (Index of Articles)

REME Precis No. SA-Rifles-3 (Zeroing of No.1, No.3, No.4, No.5 Rifles)

http://www.milsurps.com/showthread.php?t=3312

So why are you Googling something when its at your fingertips in your sticky at the top of the page!

One more mistake like that and I will turn you over to the Enfield inquisition team and have you stretched exactly 1.87 inches.

 

[Ganderite]

Not so fast. Your table is for the #4. Longer sight radius than an EAL or #5.

The shorter radius will increase the change per sight height change. Probably by about 0.13"....

Thanks for you contribution of solid info. I did not see the right sticky.