Martini-Henry rebarreled in .303 Brit.

[M1fuzz]

I have a load question. Can one use the data for a .303 British and cast loads in a Lee Enfield safely in a Martini-Henry rebarreled in .303 Brit by someone’s military?

I want to try my classic 314299 bullet. The classic load of Red Dot and/or Unique? My personal favorite,IMR4227? 2400? 5744?

Thanks in advance.

[swamp]

I have a Martini carbine that was re barreled by Enfield to 303 Brit. I use Milsurp and my loads and have not had any problems.

[john.k]

The Martini Enfield 303s were just 45 s rebarreled to 303 ,and the firing pin,block and extractor altered slightly ........the guns were designed to fire service ammo,and still do............as with all Martinis ,if you load high enough to crater the primer,the block may be jammed by the primer metal.

[M1fuzz]

Excellent info guys/gals. It is appreciated.

[Wilderness]

M1F: Your rifle is referred to as a Martini Enfield, as distinct from the original Martini Henry. There is a also a Martini Metford (conversion with Metford rilflng).

If you look at the sides of the action you will see two cartouches (?) - one for the original .577/450 rifle and the one on the other side for the conversion, the latter with of course a later date.

Apart from the obvious barrel and extractor replacements, you should find that the firing pin diameter has been reduced. Original bolts were converted by dovetailing a piece laterally across the bolt face and drilling a new hole. There are also reportedly some replacement bolts made for .303 with the smaller firing pin hole.

When you come to shoot the Martini you will find that bullets lighter than the original 215 gn will shoot quite high. With 150 gn jacketed bullets mine came back to zero at about 350 yds. I would suggest either you find some 215 gn bullets (source? Woodleigh perhaps) or use the heaviest cast bullet available, like #311299.

It is perhaps interesting that the Martini (P14 likewise) shoots high with lighter bullets and extra velocity, while the SMLE is the opposite - lower velocity shots go high. Target shooters called the SMLE behaviour "compensation" and derived accuracy benefits from it at long range. MK VI ammo (215 gns at about 2000 fps) shot high, relative to Mk VII (174 gns at 2440 fps), all the way to 900 yds. When the 7.62 came in, shooters found the SMLE No 4 conversion to 7.62 also delivered "compensation". Compensation is definitely a function of velocity variation, but I can't say if bullet weight itself contributes other then via velocity.

[M1fuzz]

You are correct Wilderness. Also, good info on the ballistics and the sights.

[gunnie]

I can't see any issues with you diving in with your usual loading. Others here with more knowledge than me will certainly help.
Now bear in mind this is from my perspective, so in Australia.
Personally, I have an 1896 Martini Enfield 303 that I run my cast loads in. Im using a 220gn projectile cast from one of CBE's moulds. Its a long bore riding style projectile that I cast using wheel weights, powder coat and gas check, then size to .316". I load these over a mild load of an Aussie powder (AR2206H) and have found that they shoot very, very well out to 100M. I'm considering upping the load slightly to pushing velocity to see how they perform out to 300M for our Combined Service Rifle competitions.
From what I gather I should be able to easily work with velocities of around the 2000fps mark.

[Wilderness]

My load came straight out of the Norma manual of the time - 150 gn Norma SP at 2700 fps. Powder was almost certainly Norma 201.

Our 2206H powder is sold by Hodgdon in U.S. as H4895. What's more, the factory is busy churning it out this year, though the pistol/shotgun powders and Trail Boss are reportedly on hold.

[Rapier]

If you powder coat, nose down with a plain base, it will hold without leading to 2,600-2,700. I do so in my 358 guns using the RCBS 200 plain base. I use a 1/4” hardware cloth box with the sides laced together using stainless steel wire, then turned up side down, as a standing tray in a convection oven. Very accurate, 3/10 inch at 100 yards, and flame/gas erosion resistant for me. The alloy I use is very hard, 7-2-1 (WW-L-CLS).