Grendel definition and contempories.

[Von Gruff]

I know there are a couple of reamer specs for the Grendel with the double angle of the AA origonal and the saami spec single angle throat.
In New Zealand there is a straight necking down of the 7.62x39 to 6.5x39.I have sample
The 6.5x39 case measures at 1.552 where the Grendel measures 1.512.
There is a base to shoulder difference of 1.212 (6.5x39)to 1.156 (Grendel)for them as well.
The 6.5x39 case is not improved like the Grendel and the shoulder angle is unchanged from the parent case although they are loaded to the same oal.

The 6.5x39 seems to be the common chambering in New Zealand with reamers and loading dies etc on the shelf.

I havent been able to get a shooting comparison between the two and wondered it there had been a test done. Is it purely the case improvements that have led to the exceptional results and ready exceptance of the Grendel as without pulling the only sample of each that I have down to do a volume comparison.

Von Gruff.

[GWH]

Von, i will be interested to see the responses you get to this.

[bwaites]

Von,

The SAAMI Grendel chamber is the AA chamber with a compound throat. Unfortunately, SAAMI takes a while to publish the chambers online, but it is the same chamber and throat design as used on all AR15's built by Alexander Arms.

The Grendel brass has several grains more capacity than the 6.5x39. Even x39 brass fire formed to Grendel is usually about 2 grains down in capacity vs. the Lapua and Hornady brass.

I don't know of any direct comparisons in the two, most likely because the 6.5x39 suffers from feeding issues in the AR chassis, and with readily available Grendel brass, I simply don't think anyone has ever tested it.

As for acceptance, there are several things that have played a part:

1) Factory loaded ammo from multiple sources.
2) Case design which allows feeding in the AR15.
3) Multiple suppliers of factory ammo.
4) Exceptional accuracy, with almost every Grendel rifle shooting sub MOA groups with at least one load, and most with multiple different loads.
5) Good support from the originator of the cartridge.

Thats just to name the ones I can think of easily!

[Von Gruff]

That all makes sense although there are a couple of factors that may have influenced the 6.5x39 use in NZ. The first being the relative scarcity of AR type rifles so most builds will be on the bolt rifle. The small population meaning the less mainstream cartridges and component brass are not as readily available whereas the x39 brass is widespread. For many here it is availability that promotes exceptance. The shooting uses in the two countries differ with shooters in general here maintaining the tried and true cartridges of general hunting (223, 243, 260, 708, 7x57 and 308)
This part of you answer is most telling and generally answers my initial question
The Grendel brass has several grains more capacity than the 6.5x39. Even x39 brass fire formed to Grendel is usually about 2 grains down in capacity vs. the Lapua and Hornady brass.

That and the ppc shape is a fine reason for the Grendel's sucess.

Von Gruff.