Accuracy of a wide range of bullets

[rickOshay]

I wanted to post some pics of results I've obtained with a wide variety of bullets for the Grendel. I know BWAITES has done similar recently, and hope he posts a link.

I will admit in advance, that these pictures are single groups, and sometimes only three. So they do not represent true accuracy. But they do indicate that accurate loads could be developed that achieve these results on a consistent basis. My point is that this wide range of bullets is shown to group well out of a 6.5 Grendel Chamber - I'm assuming its SAAMI based on OAL measurements (see below).

Here is a pic of the variety of bullets I've tried. Not a complete list, but certain a variety of sizes and shapes.


L to R: 85 gr Sierra; 120 gr Berger BT; 120 gr North Fork Tech; 120 gr GMX; 123 gr A-MAX; 130 gr TSX; and 140 gr Naturalis


Rifle used:
- 24" Satern cut-rifled match barrel. (OAL: 123 A-MAX = 2.273"; 123 SST = 2.254")
- MEGA billet receiver
- Geissele Hi-Speed National Match trigger
- Vortex Viper PST 6-24x50 FFP




I've included pictures of results of other bullets not in the group photo, but this gives you a feel for the variety of shapes and sizes - all shooting well.

Here we go:

The 85 gr Sierra - 5 shot group at 100 yards. Square is 1"


And the other extreme just to get to the point quickly: 140 gr Naturalis - 3 shot group 100 yards. Squares are 1"


This photo goes with the thread on N530 powder: http://www.65grendel.com/forum/showt...-bullets/page2

[rickOshay]

Of course we should all know the commercial Hornady 123 gr A-MAX shoots well:

6 shot group into 1" square


And the commercial 123 gr SST shoots just as well, even if the shooter pulled one shot high:



But what about the relatively fat 120 gr Northfork Technologies premium bullet? Well, here's a pic of an OCW of 3 charges of AA2520


And you would expect the long slender 120 gr Berger BT to do well, and it really does. Here is an OCW done at 300 meters (circle is one inch)

[rickOshay]

Didn't really have a good picture of a single group with the 107 SMK, I'm still working on it. But here's a ladder done at 300 meters - that's at 3" black circle.


Here's one of the 95 gr VMAX


I've posted this pic of the 120 gr GMX


And the same for the 130 TSX - this is a ladder of loads, the circle is 1.84"

[explorecaves]

Any pics of the loaded rounds?

[LR1955]

Guys:

If the point is that given enough load development, almost any bullet can be made to shoot well out of a Grendel SAAMI chamber. The exact same can be said for the variations of SAAMI Grendel chambers. Probably a bigger issue is the quality of the barrel, no matter how the throat is designed. If you have a poor barrel, it won't shoot anything well. A very good barrel will probably shoot everything well with some much better.

A better way to try and prove one was more versatile than the other would be to use only factory loads and run a real test that would take about a hundred rounds of each factory load, fired at 300 and 600 yards as distances and under uniform environmental conditions.

LR55

[JASmith]

The reports we have seen would suggest that tests like this were done during the Grendel development phase and the classic parallel throats were found wanting given the constraints placed on the cartridge by the AR15 platform.

The suggestion to do a shoot-off with several flavors of factory ammunition could help verify that development experience. Going to 300 and 600 yards is an excellent way to ferret out differences in accuracy. The challenge is that wind becomes an important factor at these ranges, meaning that one could argue the test would have to be done more as a true shootoff where rifles with the various chambers a shot side-by-side on a particular range.

It would also be best done with several different sets of rifles to minimize the effect individual rifle quirks even in nominally identical chambers.

Referring again the previous post, LR points out that factory ammunition is a better choice. That is because the seating depth can be readily changed in handloaded ammunition. This means that most, but not all, bullets can be seated far enough out to attain the optimum jump for most throats.

• The first exceptions are short bullets without enough shank length to allow seating far enough out.
• The second exception is long-nosed bullets where the magazine limits the overal length,

[jluck]

What do you think of the North Fork bullets? I know they design for hunting with little concern for BC numbers or long range shooting but they are literally just down the road from me and have yet to try them.