Mauser M 03 Part II calibres

Please note this is a three part article, you can read part one here and part three here.

Right from the start I have to say that the Mauser M 03 rifle system I have had on test for about two months is impressing me… Build quality is superb and the gun’s ability is also very high, so much so that it has - to a degree - rather turned my general view on rifle ownership on its head, as we shall see. But first calibres.

By choice I picked 223 Remington and 30-06 Springfield, to give me a fox/small deer cartridge and also a medium/large general calibre that would be good for most needs and countries. In both cases this proved to be not quite as I expected, as Mauser sees things slightly differently in terms of rifling twist. The 223 was 1-10” and the 06 1-11”, which made me re-think bullet weight and type a little, however, I have to say regardless of the pitch, both tubes proved highly accurate, once I understood what they liked.

The Goldilocks Situation

With the 1-10” .223 I was not too sure what it would like but guessed that 50-grains would be the starting point, but that proved too light, as did 55s. Going the other way I tried 64, 65 and 69-grains and they proved too heavy, in both cases the gun shot wide open groups. As luck would have it I had some old 60-grain Hornady soft tip bullets, with flat bases. I had picked them up somewhere and never used them as I prefer boat tails. With a modest load of 24.5-grains of VihtaVuori N 140 they shot stupid little groups, easily ½” if not tighter – not bad from what was a light weight 20” barrel.

I then tried some 60-grain boat tails and they did not shoot near as well, nor did some Hornady 60-grain flat base hollow points. Both these gave acceptable groups of around an inch, but not as tight as the soft points. I also tried some Sierra 55-grain, soft tip flat base and they too showed some promise at around ¾” at 100 yards. Though no expert on interior ballistics I can only conclude that the flat base style in conjunction with what is in effect a full lead core gives better stability and the full length bearing surface works with the rifling form.

However, for my needs, which is currently foxes and will soon be joined at the end of the year by muntjac and the occasional Chinese water deer - the 60-grain Hornady soft tip really does the business and I see no reason why it won’t work equally as well on the allowed deer species too. Since then I have upped the load to a maximum of 26-grains of Vit N140 and it’s averaging 2900 fps/1100 ft/lbs. Not the quickest I grant you, but easy to moderate and zeroed at 175 yards it shoots an inch high out to its zero point then an inch low at 200 yards. So from 100-200 yards I only need to compensate for an inch or aim cock on and it’s pretty much there.

150s Only

The 30-06 proved near identical in terms of experimentation and the final solution required. Though I never bothered to check its rifling twist, as I assumed it would be the industry standard 1-10”. As I said in the first article on the M 03, I had planned to use the flexibility of this big .30” cal to launch bullets from 150 out to 220-grains. So it happened I burned a fair bit of powder and a good few bullets only to realise that this was not going to work.

As soon as I discovered the barrel was 1-11” I dropped to 150-grain bullets, of which there is a good choice with Hornady SST and InterBond, A-Max, Nosler AccuBond and Sierra Game Kings. All in my favoured boat tail build, but like the 223 tube the 30-06 shot them on average into 1 – 2”. Totally acceptable, but I like things just a bit tighter.

Factory ammo proved similar with Privi Partizan (PPU), Winchester Ballistic Silver Tip, Remington Express and their Premier Sirocco Bonded all shooting acceptable groups, so no problem keeping the 06 fed. For me the solution came from a most unexpected source though a familiar name.

Having shot a 308 Winchester for a good few years and also a 300 WSM, I had all sorts of .30” cal bullets available. I had a couple of boxes of Nosler, 150-grain Partition (spire point) which I had never managed to make shoot through any .30” cal I had ever used. I thought what the hell and loaded some up with 53-grains of Vit N140 and to my surprise the barrel was shooting ½ - ¾” groups. Like the 223 the 30-06 obviously prefers a flat base design with its longer bearing surface, the full-length lead-cored build obviously giving stability with this rifling form.

The only (what I would call) modern boat tail bullet and load that showed near equal promise was, of all things, Hornady’s 150-grain InterBond. Not quite as tight, this premium projectile kept things inside the inch and though a ballistic tip I can only conclude the thicker jacket and longer lead core was approaching the stability offered by the Noslers.  So on average factory ammo can shoot 1 – 2” and reloads can get it down to sub 1 or even ¾”.

Energy to Spare

By this time I had also tried Vit N550 and 56-grains was giving an average of 2934 fps/2866 ft/lbs with the Nosler and 3016 fps/3029 ft/lbs with the InterBond. It’s here we see the improved BC of the Hornady manages to squeeze out an extra 82 fps/163 ft/lbs. Both these bullets are designed to be strong and retain their integrity, so giving good penetration and terminal effect. OK I could not have anything heavier but an average energy figure of 2900 ft/lbs is good enough for most needs and I don’t think either projectile will be found wanting on boar or big antelopes! My friend Andrew Evans-Hendricks use the Remington 150-grain Sirocco Bonded in his 30-06 and he has dropped some big Gemsbok and Kudu with that load…

The Hornady load when zeroed at 200 yards keeps it all inside an inch +/- from 100 to 225 yards, which in the majority of encounters is pretty much the distances most deer are shot in the UK. Slightly slower the Noslers gave a trajectory out to 225 of +/- 1.5” at the same zero point. Both these settings fitted in well with the Swarovski Z6i 2-12 x 50 TDS 4i scope I had on top. As I could hold pretty much dead on out to 200/225 yards then use the range marker bar (RMB) 1 to take me out to 300 yards in three increments of 250, 275 and 300.

Solids

One aspect of the 30-06 is that on a light barrel such as this, heat build-up is rapid and has a noticeable affect on group size/consistency. This will hold true for any comparable hunting rifle, so zeroing is a slow process, but then again it’s a hunting gun and not made to fire off 20-rounds strings as fast as possible. But as ever the comfort of ½ - 1” performance gives confidence.

Mauser obviously recognise this as they also offer what they call a ‘solid’ barrel. The standard M 03 profile is 17mm, the solid is thicker and more rigid at 19mm. In fact this is nothing more than a shortened Match tube with iron sights fitted, so an option worth consideration in some calibres…

Confidence Building

I have one more calibre to discuss, but first I need to talk about what the M 03 offers and can do. In the past I had never been a fan of switch barrel rifles, preferring one gun for one job and also enjoying the ownership of many different makes and types. Also I had always been cautious about having to swap scopes and barrels, which to my mind were problems just waiting to happen.

However, getting on so well with the M 03’s layout, as we will see next month in the nuts & bolts gun test, I also found that I really liked what the design had to offer. Or to put it another way; me and the Mauser were really starting to get along – accurate, nice trigger and a good detachable magazine system. Plus, with the ammunition sorted, it was now time for the gun to impress me in terms of consistency.

Here testing was simple – fire a group, scope off/scope back on, fire another group. Next the same, but take off the barrel and replace it between groups. I had to say that I was expecting some problems, but the scope mounting and barrel retention systems proved me wrong. Like any accurate gun it’s all about confidence, which gives you faith in its ability to perform. So when I have finished foxing and want to go on to larger game I now switch out the bolt head, magazine, tube and glass and I’m ready without even wondering if the rifle will shoot straight. Because I know it will!

Barrels of Fun

Perhaps you can see a pattern forming here, as pretty soon the convenience of one chassis with multiple calibres made itself apparent to me. Why had I been spending all my shooting life buying rifle after rifle and then getting them sorted so they would shoot well? Yes around £1200+ for the M 03 with a single barrel is quite an outlay. But once you are happy with it then spare barrels/bolts/magazines as required work out a lot cheaper than even a cheap new rifle, as you are still going to have to invest a few hundred quid in bedding, crowning etc…

Adding up the centrefires I have in my personal collection, all of which have been worked on/customised to make them more accurate, soon shows that a decent switch barrel is one solution to that problem. I doubt if I will get rid of all my guns, as items like the 300WSM do have a special place, but others will now see little use any more. Knowing what I know now would really make the extra outlay for a ‘transformer’ well worth serious consideration, and there are plenty of people who will tell you the same!

Reb’s 8.5x63mm

Suffice to say I will be keeping the M 03, which will allow me to add a version of a calibre that I have always considered maybe the ultimate all-rounder. Quite often we place cartridges into groups and quite rightly so – vermin, small, medium and large game species. So a 223 Remington can easily handle a roe deer, as the Scots have proved, but would you want to use it on a red? Conversely something like 375 H&H or 300 Win Mag though a good choice for buffalo or large African plains antelope are definitely over-kill for most British/European deer species, unless you have to take them at longer ranges. However, a mid-calibre bullet that offers a flexible weight range and good knock down power, yet minimum carcass damage on both large and small animals is very attractive. If so, then the 8.5x63mm created by Werner Reb looks like a plan to me.

The 8.5mm (.338”) is similar to the 35 Whelen and the 338-06, both use a 30-06 Springfield case necked up to .358” and .338” accordingly, as does the 8.5mm. It’s just that this calibre is a commercial offering by Mauser for the M 03. Given I already have a 30-06 barrel all I need is the new 8.5mm tube as both magazine and bolt head can be used.

I met Werner Reb last year at the CZ factory visit and we got talking and he was telling me about his 8.5mm saying he has shot roe with it and also taken it up against buffalo with equally good results. Obviously like 35 Whelen and 338-06 it offers good flexibility when loaded correctly. This really appealed to me, so I ordered a solid barrel at 21.5” for the M 03 with iron sights, that will give me a muntjac to boar/large game gun that might just be the last fullbore hunting rifle I ever need to buy…

Ammunition is made in Germany and fully CIP approved, dies and brass are also available, though you can make 8.5x63mm from 35 Whelen cases and some other 30-06 derivates as well as the original.

Too Much, Too Late?

I have to say that I never thought I would be that taken by a single rifle anymore, but the Mauser M 03 really floats my boat. The one downside of this sort of technology is coming to it too late in life. As hunters we all have our pet guns and, if like me you have spent a good few years and a lot of money building up your ideal hunting battery, then guns like the M 03 turn your world upside-down very quickly.

It’s pointless buying an M 03 in just one calibre, as the likelihood is that you will like it and get more. I think that if you go this route then with very few exceptions you will eventually get rid of some, if not all your fixed calibre guns and replace them with spare barrels for the Mauser. Of course the other advantage is that if you shoot a barrel out, or the rifling gets damaged and makes it unusable, then you just order another tube and fit it yourself, which takes about one minute. Rather than sending the gun to the shop and waiting for it to be re-barrelled with all the associated problems of time, cost and proof etc.

Looking at the calibre options shows that you can go from 222 Remington right up to 458 Lott, with a good choice of US and European cartridges in between. However, I would say, see what the rifling twists are before deciding, as a look at Mauser’s list shows that some of the more popular UK choices are not what we might assume. For example 308 Win is 1-11 and 223 Rem is 1-10. But there are also some useful numbers like 6mm BR, 243 Win, 25-06 Rem, 6.5x55 Swedish, 7mm-08 Rem, 7mm Rem Mag etc.

Please note this is a three part article, you can read part one here and part three here.