Reforming Dutch manufactured .303British to 6.5 Dutch

[Dutch Mosin]

This is my first post in here, so I thought I might as well post about a Dutch rifle and "Dutch" ammo.


Dutch Steyr Mannlicher M95 rifle with early bayonet.

This post is about reloading for my Dutch Steyr Mannlicher M95 rifle again.
I usually use .303 British Boxer cases and reform them to 6.5x53.5R.
This time however I decided to try the Dutch .303 British cases.
These were manufactured by AI (Artillerie Inrichtingen) in 1959.
AI was the Dutch State Weapons and Ammunition Factory.
The quality of the brass is great.
Problem is that these are Berdan cases and don’t use the 5.5mm (0.220”) Berdan primer, but the larger 6.34mm (0.250”)Berdan primer.


Uncleaned Berdan primer pockets of the Dutch .303Br brass

Not only the 6.34mm, but also the slightly larger 6.45mm (0.254”) Berdan primer fit in this primer pocket.
You not only have to check the diameter, but the height of the primer is important too.
Both Berdan primers have a different height, but both fit the primer pocket of the Dutch AI case.
I already reformed the cases and trimmed them back to 53.45mm (2.104”).
The Dutch AI cases didn't fit the chamber so I had to adapt the diameter just above the rim by 0.06mm.


6.45mm Berdan.


6.34mm Berdan.
The guy who sold these to me used the primers for his Lee Enfield.

After that it’s priming the cases.
Because of the size of the primers I have to use an adapted shell holder and an handmade primer device .
A good friend from the US made these for me a couple of years ago for which I’m still grateful.


Adapted shell holder and handmade primer device.


Left: Dutch .303Br parent case.
Right: Reformed to 6.5x53.5R Dutch (notice the adjusted diameter above the rim)


Time to prime the cases.

From here it’s just business as usual.
Fill up the case, place the bullet and off to the range.


Ready to go to the range.

Here’s the loading data:
Brass: Dutch Berdan .303British reformed to 6.5x53.5R
Primer: 6.34mm and 6.45mm Berdan primers by Dynamit Nobel
Powder: 13.8 grains of VihtaVuori N110 (reduced load)
Bullet: 160 grains cast bullet in cal .266

Met vriendelijke groet,

Martin

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[xa-coupe]

Very ingenious ! I am impressed with your dedication and workmanship. I'll be interested to hear how it shoots.

[Dutch Mosin]

Very ingenious ! I am impressed with your dedication and workmanship. I'll be interested to hear how it shoots.

Thanks and no problem letting you know how this ammo performed.

I had to fireform the cases first so IMHO these results are not bad at all.

Take a look at this picture.
From left to right you see a Dutch .303 case, a .303 reformed to 6.5x53.5R and a fire formed 6.5x53.5R.
It looks like the reformed case has a split neck, but it disappeared after fire forming.
These so called oil dents are created by to much lube while reforming.
Sometimes they don't disappear and most of the time the neck splits at these places after about 5 to 6 times reloading.
Check the shoulder of the fire formed case.
It fits the chamber of my Dutch Steyr Mannlicher perfectly now.



Here's a picture of the target.
My goal for that day was fire forming the cases, but IMHO this target doesn't look bad at all.
First shot was way too low(not on target), second one still too low, third shot was too high but the rest looks OK to me.
I have to adjust the front sight a bit, but the ammo performs great.



Met vriendelijke groet,

Martin

[xa-coupe]

Excellent work. I am surprised you have managed to get the 303Br case to undergo such a change. The ones I have ( S&B ) are quite thinck and brittle and are a pain to just trim to size.
Target looks good. Once you sort out all the sighting I think it's going to be a winner.

[Dutch Mosin]

Excellent work. I am surprised you have managed to get the 303Br case to undergo such a change. The ones I have ( S&B ) are quite thinck and brittle and are a pain to just trim to size.
Target looks good. Once you sort out all the sighting I think it's going to be a winner.

Thanks.
I know what you mean.
Compared to the Dutch manufactured .303 cases the S&B cases are of a lesser quality.

I managed to prolong the life of my S&B cases though.
I use the S&B cases in my Mosin Nagant M91/30.
Instead of FL sizing them I just neck size them.
Next to this I don't use a full load, but shoot with a so called reduced load.
So....instead of 46 grains of VihtaVuori N140 and a FMJ bullet I use 18 grains of VihtaVuori N110 and a casted bullet.

Here's a picture of the casted bullets I use.
The cal .313 fits my Mosin Nagant M91/30, the .311 my Mosin Nagant M39


Cal .311(top) and .313(bottom) casted bullet.


Not a perfectly casted bullet, but they fly great.

Met vriendelijke groet,

Martin

[xa-coupe]

The results speak for themselves. I used to FLR everything but as it is getting more expensive to buy things I am going to have to work on prolonging case life, so neck sizing will be on the cards. I will have to start separating the cases so I don't mix them between rifles. That or cough up for some remington brass and a few O rings How much brass are you taking off the bottom of the case? It is very hard to tell from pictures.
I used to be all about the shooting of the firearms, now I get off as much on the ingenuity shown by various individuals filling a gap for which there is no commercial equivalent, not to mention the manufacturers/designers way back when.

[Patrick Chadwick]

Congratulations on your work, Martin. It is good to see someone taking some trouble to get the old bangers banging again.

I used to FLR everything but as it is getting more expensive to buy things I am going to have to work on prolonging case life, so neck sizing will be on the cards. I will have to start separating the cases so I don't mix them between rifles.

Neck sizing not only prolongs case life - it also often makes these old rifles shoot better! Resizing dies have to be made so that the die + manufacturing tolerance still produces cases that will chamber in the minimum chamber as per CIP or SAAMI. If you look around the forums, you will find many instances of shooters complaining that the dies are too tight for the bullet diameters that they need for optimum performance in their rifles. So I sometimes use a die for a different caliber to get a better neck size than the "official" set.

The best for maximum case life AND performance would be if your optimum bullet requires a neck size that is exactly that which you get from the spring-back of the neck after firing - the benchrest ideal - then you would need not sizing at all, as the brass would be working within its elastic limit all the time! We are using old service rifles, not benchrest equipment, so it is not possible to do this with all rifles - but the closer you can get, the better.

Patrick

[smellie]

Gentlemen, five points:

1. The best military .303 brass I have ever encountered is the Canadian Defence Industries brass. It is getting old now (all mfd during WW2) and often can benefit from a mild annealing, but it is fine bras to work with. Headstamp commonly was just DI and the date, as 1944 and the letter Z, these at noon, 4 and 8 o'clock. The ammunition was Boxer primed, noncorrosive and nonmercuric so, if you run into some, don't be afaid to shoot it. I have run into a bit of this brass in the last few years and generally hoard it, but it IS truly excellent.

2. Neck-sizing is fine, lubing the insides of the case-necks before FL OR neck-sizing is even better, but I am told now that the BEST thing available is that new LEE Collet Die, which is not expensive at all. The idea is good: case-mouths compressed against a ground mandrel, so zero 'drag' and thus zero stretch.

3. For fresh brass, Ed's Famous O-Rings really work! If you are worried about bolt pre-load, go to your local dollar store and get a bag of pony-tail ties from the girls' department: do the same job, hold your brass central and not as heavy as an O-ring and a lot cheaper (I got 100 of them for a buck).

4. Given that the Dutch and the Romanian Mannlichers used ammunition that was VERY nearly perfectly interchangeable, this solution should work if you have one of those (very darned scarce) Romanian rifles that you really want to shoot.

5. There are a lot of forums out there where fellows come just to milk folks for whatever they can learn, just so they can sell their stuff at higher prices, based on someone else's hard work. THIS forum is what it SHOULD be: collectors working together and sharing their hard-won knowledge in order to benefit the shooting community as a whole. I am very happy that this forum exists... and I salute every one of you. YOU are COLLECTORS and STUDENTS.... and there aren't enough.

One final point: have fun! That's what it's all about.
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