Honestly, I wouldn't worry about it. My main issue was hangfires. If they fire then just clean as for corrosive and go on...
Printable View
So those primers were HARD!
I had no problem getting a LC 308 and German Polte primer to pop, in the case, by whacking on the back of an M1903 bolt with a rubber mallet (mainspring removed). Those are both military cases for MG use. Not soft Federal primers.
For this .303 I was using a spare k98k firing pin and a rough jig to align everything. 2X harder strike force and just a modest dent. Finally had to deprime the case and just smash the primer on the steel.
It had a healthy bang and looks eager to rust. So we know that. But I am thinking with primers this hard, FTFs could be mechanical in some guns.
My question becomes is this what the customer wanted? Would assume so. Only to find that rifles with tired springs experienced no joy perhaps, and hence the reputation?
We will see if they go bang as-is first before swapping primers. Looking for rounds that can shoot well in a wartime expedient '42 Maltby with a short throat but that awful 2-groove barrel.
Maaaaybe let some fly in my all-original (T) but inclined to approach that one carefully as it is worth a real penny. Hand loads into Prvi brass.
What's wrong with a two-groove barrel? Is it rusty or shot out? If it isn't, and passes the gauging standards, it should perform every bit as well as a five or six groove barrel. They wouldn't have been adopted if they performed worse than other barrels. The same holds true for the 1903A3 Springfield and other military rifles.
Two skinny channels into which jacket material has to move in order for meaningful twist to impart upon the projectile. With BT bullets, there is insufficient contact area for that to happen. One has to have bullets that are both flat base AND open base to hope for meaningful engagement.
These Winchester bullets have that which is why I bought this ammo.
I have some modern 180gr SP with a flat (but closed) base. I will also see how they do.
In an 03A3 the groove/land ratio is about 50/50. In the No. 4 2-groove it is about 10/90.
The No.4 5-groove rifling also appears about 50/50.
It was a wartime expedient so I'm not hating on the production people. It was on the winning end of the war and did its part. But that doesn't make the No. 4 2 groove a great performer in 2025.
On the plus side it's a fun challenge to overcome the various obstacles.
Mk.8z ammo with the 174 grain boat tail projectile was produced for the Vickers MMG. As BAR says, rifles were designed around the Mk.7 flat base projectile. Many rifles with otherwise excellent barrels regardless of the groove count that have seen a diet of cordite loaded Mk.7 won't stabilize boat tail projectiles. Unless you're shooting a fresh, out of the wrap, 1955 Fazakerley No.4 or an SMLE of No.4 rifle rebarreled with a new military or commercial barrel, boat tail projectiles like the Sierra Matchking are a waste of money. They are worth a try as every barrel is different but the 180 grain Pro Hunter is a much better option as well as other manufacturers flat base hunting bullets. I know this doesn't help our brothers in the UK and elsewhere around the globe as they aren't allowed to use hunting ammo for target shooting. Unfortunately, the cheapest loaded FMJ fodder for range time these days is Czech S&B and Croatian PPU. Both are loaded to Mk.8z spec with boat tail projectiles so it's MG ammo. I don't know why companies like Winchester or Remington don't offer new cartridges built to Mk.7z specification. I know I'm repeating myself here but it's not like they don't know how or haven't got the machinery. Both companies have been loading .303 British ammo since the First World War. Maybe there isn't enough demand in their eyes. I see these problems so much that I find that to be strange. If someone would produce quality Mk.7z ammo at a reasonable price, I'd think it would be flying off the shelves by the case. Just my two cents having worked on these rifles a bit in the past 30 years.
How does one properly sight in for hunting unless one shoots those hunting rounds at targets? This makes no objective sense, but that's par for the course with firearms laws.