04-20-2014, 02:01 AM
(This post was last modified: 04-20-2014, 05:29 AM by NugginFutz.)
I found this posted recently by Arne Brennan, one of the co-developers of the Grendel. It is a very candid assessment of what he referred to as the Grendel v1.0, now called the Grendel II by Steve Satern.
It should serve to enlighten any with questions regarding what the GII is capable of, and why Arne and Bill A decided to employ the compound throat in what we now know as the SAAMI Grendel.
This all dovetails quite neatly with a posting here on this board.
http://www.65grendel.com/forum/showthrea...nt-history
The short version? With mag length as a governing factor, certain bullets will not perform to their capability in a conventional .300" throat. That was why the compound throat was introduced. It allowed more bullets to be shot accurately when loaded at or less than magazine length. The GII is not a magic chamber, by any stretch of the imagination. Nor was the v 1.0 "better" than its successor, the 6.5 Grendel. It clearly had its own shortcomings.
While there is speculation that this variant will allow heavier bullets to be shot at higher velocities, there is no basis to this, given the above constraints. As a gas gun goes, there are just so many things you can do, before you start to exceed safe limits and start breaking things, or worse. You need look no further than the .264 LBC as proof of this. There are no quantum leaps in performance with it. Why, then, would a GII be able to achieve them?
As I previously stated, I believe that in the final analysis, whether this new (old) variant performs up to its maker's expectations, the net result is more demand for Grendel ammunition. That demand should translate into greater recognition in the industry and, hopeful, result in increased production of the ammunition. Everyone wins, as I see it.
[SIZE="1"]ETA: The quote from Mr. Brennan was taken from the same site owned by the ex-member who has been promoting the GII for the last few months.[/SIZE]
It should serve to enlighten any with questions regarding what the GII is capable of, and why Arne and Bill A decided to employ the compound throat in what we now know as the SAAMI Grendel.
Quote:Actually, the Grendel V 1.0 was a 1.5 degree .120 freebore. It worked well with Nosler 120 Ballistic Tips, Sierra 107 and 120 Matchkings and the Hornady 129 SST seated magazine. I still have a couple of the barrels sitting in my garage.
...
Some questions that have been emailed to me during the past few weeks:
...
So why the compound angle throat?
A colleague of mine and I took a few rifles out in May of 2004 and we were loading at the range. The Lapua Scenar did not shoot to our expectations with a .300" neck 1.5 degree .120 freebore when seated to magazine length. As we tested out and learned shooting other 6.5mm cartridges including the 6.5 PPC, 6.5 BR, 6.5x47 Lapua and 6.5-.284, the 108 and 123 scenar achieved their best accuracy with less than .005" jump to the lands. In a nutshell, the Compound Angle throat was a compromise to still let the Nosler 120 Ballistic Tips, Sierra 107 and 120 Matchkings and the Hornady 129 SST shoot well without generating unacceptable pressure levels and "trick" the 108 and 123 Lapua Scenar into shooting better.
Which will shoot better?
Depends what bullets you are going to shoot.
Will you notice a difference in accuracy?
Depends what level of accuracy you are capable of.
Will the removal of the .5 degree result in decreased chamber pressure?
Again, depends on the bullet, but I would not deviate from published load data and pump up the volume based on an assumption that the single angle .120" freebore will result in less pressure.
...
I would caution people not to try to push the heavier bullets because pressures can climb very quickly. Every person I saw who broke a bolt did so trying to shoot 130 grain and heavier bullets and trying to push them.
I remember shooting the 140 Partition at right around 2300 fps and that was about the practical limit without spiking pressure.
This all dovetails quite neatly with a posting here on this board.
http://www.65grendel.com/forum/showthrea...nt-history
The short version? With mag length as a governing factor, certain bullets will not perform to their capability in a conventional .300" throat. That was why the compound throat was introduced. It allowed more bullets to be shot accurately when loaded at or less than magazine length. The GII is not a magic chamber, by any stretch of the imagination. Nor was the v 1.0 "better" than its successor, the 6.5 Grendel. It clearly had its own shortcomings.
While there is speculation that this variant will allow heavier bullets to be shot at higher velocities, there is no basis to this, given the above constraints. As a gas gun goes, there are just so many things you can do, before you start to exceed safe limits and start breaking things, or worse. You need look no further than the .264 LBC as proof of this. There are no quantum leaps in performance with it. Why, then, would a GII be able to achieve them?
As I previously stated, I believe that in the final analysis, whether this new (old) variant performs up to its maker's expectations, the net result is more demand for Grendel ammunition. That demand should translate into greater recognition in the industry and, hopeful, result in increased production of the ammunition. Everyone wins, as I see it.
[SIZE="1"]ETA: The quote from Mr. Brennan was taken from the same site owned by the ex-member who has been promoting the GII for the last few months.[/SIZE]