Precision and high velocity:

7mm Blaser Magnum in Blaser R8!

Is there a real need for more hunting cartridges, more 7 mm cartridges or even more magnum cartridges? No, not at all. Is there still room for new, precise, flat shooting hunting cartridges? Yes, if the new cartridge are able to perform better than the old cartridges. Especially when better performance means higher precision!


If maximum precision and high velocity is important, it may be worth taking a closer look at the 7 mm Blaser Magnum, which in this test delivers accuracy at the very top of all magnum cartridges I have tested. And absolutely the best of the relatively few 7 mm magnum cartridges and rifles I have tested. Which, to tell the truth, have varied a lot when it comes to precision! 

Now you might well say that I am spending far too much time, column-space, too many bullets, powder and loading in testing such an unusual cartridge as the 7 mm Blaser Magnum. From the outset, I had no intention of loading so many different bullets – the idea was to collect data for some of the most common and best 7 mm hunting bullets. 

This test started with the old reliable 160 grain Sierra GameKing, mostly because the 160 grain GameKing is a simple and uncomplicated lead-tipped bullet that has delivered top precision over the years in most 7 mm rifles and cartridges. But when 160 grain Sierra GameKing delivered small groups from the first three-shot, the plan had to be changed to test a wide range of 7 mm hunting bullets charged with an appropriate amount of gunpowder. As many as possible new 7 mm hunting bullets, good hunting bullets, high BC bullets and suitable homogeneous hunting bullets. The 180 grain Lapua ScenarL was loaded only to find out if such a long matchbullet can be accurate in the 7 mm Blaser Magnum with 1-10 twist in a 65 cm R8 barrel.

Precision.

Most bullets and loads achieved good to exellent precision in the 7 mm Blaser Magnum Blaser R8 Ultimate! The only two exceptions were the 168 grain Nosler AccuBond LR with mediocre precision and the 160 grain Swift A-Frame with a three-shot grouping of around five cm at 100 meters. However, this is just further proof that even a super accurate rifle cannot deliver small groups when the Swift A-Frame does not want to cooperate!

As mentioned previously, the 160 grain Sierra GameKing was the most accurate, especially loaded with the most slow-burning gunpowder like Norma 217. Out of twelve loads with the 160 GameKing, seven three-shot were better then 10 mm at 100 meters, the “worst” three-shot was 15 mm! Most of the other big game bullets were accurate, like 160 grain Nosler AccuBond with all groups under 20 mm and the 170 grain Norma Oryx with six out of eight three-shot under 20 mm. For those who want to hunt with homogeneous lead-free bullets, this was the first test of the 7 mm 140 grain Norma ECOSTRIKE, which should be compared with the Barnes TSX/TTSX. The difference is small, but Norma ECOSTRIKE is at least as accurate as Barnes TSX in this rifle. Norma 204 gave the smallest groups with 140 grain ECOSTRIKE.

Due to both time and barrel wear, loading and shooting were limited to one three-shot group for each charge. For this reason, individual series need to be taken with one pinch of gunpowder. The best way to determine the accuracy of any single bullet is to take the average of all three-shot groups with that bullet. The same for gunpowder to find witch one that gives the highest velocity, or best accuracy.

Loading

The 7 mm Blaser Magnum is simple and easy to reload. With a reasonable case volume and slow-burning gunpowder, there were no surprises. Two cases were reloaded ten times with 160 grain Sierra GameKing and 65 grain MRP without cracks or loose primer pocket, and a measurement of five case before the first load and after six reloads showed that the case length had not increased more than 0.1 mm.

Everything was loaded in a Norma cases with a Triebel die set, something that may be a disadvantage compared with a more normal 7 mm magnum. Only Norma makes 7 mm Blaser Magnum cases, and Norma cases are among the best –if not exactly cheap. The same goes for die set from Triebel.

Shooting

If loading the 7 mm Blaser Magnum has been simple and straightforward, shooting it was a real pleasure! Mostly because of top accuracy from the first three-shot grouping, but also because of the same point of impact with just about everything of bullets, gunpowder and charge weight from the first to the last series. Whatever is the most important is up to you. I say: yes thanks, I will take both!

And recoil – or rather lack of it! Irrespective of the great number of shots, recoil is almost a non-issue in this test. The R8 Ultimate 7 mm Blaser Magnum is very recoil-friendly – friendlier than expected given the bullet weight and speed. An A-Tec silencer is one reason for that; the fact that the Blaser R8 Ultimate is basically a heavy object is another. However, regardless of silencer, rifle weight and stock shape, the 7 mm Blaser Magnum was a pleasure to shoot. Not just as far as the recoil was concerned, but also the same point of impact, accuracy, and no surprises in the form of unexpectedly high pressure in first-time testing of new loads.

All in all, the entire test of the 7 mm Blaser Magnum was so positive that I might have to consider having a 7 mm Blaser Magnum as my own hunting rifle. With quick and easy barrel change, any hunter who have a Blaser R8 can hunt with the 7 mm Blaser Magnum. But what about this flatshooting, accurate and recoilfriendly cartridge in a custombuilt, light hunting rifle made for stalking and long walks in the mountains? Maybe that project is worth a closer look…

7 mm Blaser Magnum

The story of the 7 mm Blaser Magnum began when Bernhard Knöbel as the former CEO of Blaser, found out that Blaser as one of the leading rifle manufacturers of Europe needed to have its own line of Blaser Magnum cartridges. An idea that took shape in a meeting with Hartmut Liedtke from Blaser and Christer Larsson from Norma Åmotfors in a hotel room in Las Vegas during the 2007 SHOT Show. The family of Blaser Magnum in 7 mm, 300, 338 and 375 calibre should all have the same basic case, 30 degree shoulder angle and case neck with 1.1 caliber length. As with many other new magnum cartridges, the 404 Jeffery was the mother case for the four Blaser Magnum, but with a slightly more conical case body than some of the other new, beltless magnums like WSM. And for better feeding and function, it should have a slightly lower working pressure.

Due to the experience Norma have had with varying precision in 7 mm magnum cartridges, the case length and volume for the 7 mm Blaser Magnum were specially adapted to MRP to achieve the best results. In other words, not entirely unlike Norma's old 7 mm super-cartridge, the 7 mm S&H, or 7 mm Super as it has been called in later years.

7 mm Blaser Magnum 

Test-firing from a shooting bench, distance 100 meters. Test rifle Blaser R8 Ultimate with 65 cm barrel, Blaser 4-20x58 and A-Tec silencer. 

Velocity and 3 shots are the average of three series with factory cartridge, and one three-shot series with homemade cartridges.

 

Factory cartridge     velocity 3 shot
7 mm Blaser Magnum 139 grain Hornady InterLock      971 m/s 29mm
         
Loaded in Norma cases with RWS 5333 primers        
Bullet gunpowder weight velocity 3 shot
127 grain RWS EVO Green cartridge overall length 81 mm
MRP65 grain918 m/s19 mm
7098313
139 grain Hornady GMX cartridge overall length 81.5 mm
N 56062885 m/s 25 mm
6593227
MRP6286815
6692922
140 grain Barnes TSXcartridge overall length 79 mm
N 56062872 m/s 23
6693124
MRP 6286615
6792523
140 grain Norma ECOSTRIKEcartridge overall length 81 mm
20460 grain889 m/s8 mm
6392214
N 5606287722
6693817
MRP6285512
6792220
N 56572 k92325
150 grain Nosler Ballistic Tip cartridge overall length 81 mm
N 56062846 m/s 15 mm
6589019
MRP6283310
6689911
150 grain Swift Scirocco IIcartridge overall length 82 mm
MRP62 grain864 m/s15 mm
6590321
N 1656282618
6687133
156 grain Norma Oryx cartridge overall length 76 mm
MRP62 grain839 m/s19 mm
6587914
N 1656279710
6687729
2176884520
7086429
159 grain RWS EVO cartridge overall length 79 mm
MRP60 grain828 m/s15 mm
6387113
N 1656082624
6386714
160 grain Nosler AccuBond cartridge overall length 81 mm
N 56062852 m/s 17 mm
6487612
MRP6282914
6587212
2176885017
7086519
160 grain Sierra GameKingcartridge overall length 79 mm
N 56062854 m/s 13 mm
6588113
MRP6283612
6587315
N 565658488
688819
7090311
N 165628079
668528
688738
217688498
708677
160 grain Swift A-Frame cartridge overall length 79 mm
N 56565 grain841 m/s45 mm
6787947
2176884251
7086554
165 grain Sierra Gamechanger cartridge overall length 82 mm
N 56062843 m/s 10 mm
6487518
MRP6283810
6487115
N 1656279712
6685219
2176884920
7086825
168 grain Nosler AccuBond LR cartridge overall length 83 mm
N 56565 grain826 m/s23 mm
6786227
2176882830
7085718
170 grain Norma Oryx cartridge overall length 78 mm
N 56062 grain829 m/s17 mm
6486817
MRP62 82410
6586414
N 5656584519
6787612
2176884920
7086922
180 grain Lapua ScenarLcartridge overall length 83 mm
N 56564 grain829 m/s 11 mm
6685418
N 1656279512
6482017
6684419
2176884614
7086914

 

 

 


About the Author

Jakt

We thank the Norwegian hunting magazine Jakt and the author Jørund Lien for the possibility to share the article here. Takk!

The view of the author are his/her own and do not necessarily represent the views of the company.

 

Die Blog-Beiträge geben stets ausschließlich die Meinung des jeweiligen Autors, der jeweiligen Autorin wieder, und nicht unbedingt die Ansichten von Blaser.

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