6mm grendel VS 6br

[skeetlee]

I was wondering about the little grendel case necking it down to 6mm. I know nothing about it personally as i dont even think i have seen one. Anyway how much smaller is the grendel case compared to a BR case or is it smaller? Anyone shooting 105-108 in the grendel case? I have a little BAT action that has a ppc bolt face and i may sometime down the road put a 8.5 twist brux 6mm barrel on it. Whats the general thinking or ideas behind necking down the 6.5 grendel? Lee

 

[CJ6]

pretty much a 6PPC as that is what the Grendle is based on, ppc necked up to 6.5 with a few minor changes.

 

[MarkS]

Lee,

I have seen a few guys shooting them in 600 yds benchrest It is real close to the 6BR in speed. Most of the guys shooting them are using them on ppc bench gun, just like you are talking about. The 6 Grendel looks like a small 6BRX. The general idea is to use your current benchrest gun, and be able to shoot long range.

Mark Schronce

 

[distinguished]

Robert Whitley made the 6mm AR from the 6.5 Grendel. Check out 6mmAR.com.

 

[Laurie]

Lee,

the Grendel is basically the PPC case necked-up to 6.5mm and throated to suit AR15 magazine length COALs of 2.26" or thereabouts with bullet weights up to 123gn or maybe 130gn for reduced wind drift compared to .22 cal bullets. At the rear end, it uses the standard PPC / 7.62X39 Soviet 0.445" case-head diameter for which AR15 bolts are readily available. Comparing drawings in loading manuals, they aren't identical but are so close this may well be only the difference between fired cases from different chambers.

If you neck it down to 6mm for use in your bolt-action rifle, you're back to the 6PPC-USA, so you might as well start with PPC brass either in USA or necked-up, turned and fireformed .220 Russian forms depending on the application - unless of course Grendel brass is cheaper or more readily available.

Laurie,
York, England

 

[skeetlee]

thanks fellas i didnt realise the grendel was so close to a ppc. seems a little small for a 123gr bullet, maybe even a 105?? How fast is a 6mm grendel with a 105? 2650?? Interesting!! Lee

 

[JERRYHM]

The 6MM Grendel can approach the 6BR's velocity if the case is blown out 0.10" with a 40 degee shoulder.
Listing the results of both the 6 grendel and the 6 grendel turbo 40.

Some results shoot the 6MM Grendlel in a AR-15 upper build by
Robert Whitley

The 6mm Grindel in a bolt rifle may have 100 to 200 fps over the AR15 upper.

High powder is Standing at 200 yards, RF sitting at 200 yards, RF prone at 300 yards and SF prone at 600 yards.

May – California State HP Rifle Championships

5-2-2008 Warm up club match – 80 shots
189-2X, 200-9X, 197-7X, 197-9X = 783-27X Match Winner

5-3-2008 State Championship – 80 shots
185-2X, 198-9X, 195-2X, 196-5X = 774-18X 6th place
(got my days mixed, club match score would have won)

5-4-2008 Team match – 50 shots
93-3X, 99-5X, 95-0X, 198-12X = 485-20X Hi Individual score
Coach missed the wind at 300 yards, but was on at 600 yards in a difficult switching wind.

5-29-08 Practice Sac: 100-3X, 99-7X, 98-2X, 189-7X = 486-19X
6-05-08 Practice Sac: 97-2X, 100-5X, 98-1X, 196-9X = 491-17X

6-12-08 Practice Sac: 97-3X, 99-4X, 98-2X, 195-6X = 489-15X

6-14-08 Sac: 80 shot 189-3X. 197-5X, 200-11X, 198-13X = 784-33X MW
The 300 RF prone 200-11 and the 784-33X are new Grand Senior National Records.

6-15-08 Sac: 80 shots 192-3X, 200-8X, 199-9X, 199-10X = 790-30X MW
The 200 RF sitting 200-8X and the 790-30X are new Grand Senior National Records.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

6MMAR Turbo 40 --- Grindel neck down to 6mm blown forward 0.100" with a 40 degree shoulder.

August 16, 2008 Sacramento 100 yard Bench Rest IRON SIGHTS Five Shot Groups

Powder – Load – Bullet –-- OAL –- MV – ES – SD - Group
RL15 30.1 -- B105s -- 2.443” –2882 – 05 –02 ---- 0.305”
RL15 30.4 – B105s -- 2.443” –2907 – 27 –09 ---- 0.545”
RL15 30.1 -- B108s -- 2.320” –2862 – 19 –07 ---- 0.475”
RL15 30.4 – B108s -- 2.320” –2896 – 07 –02 ---- 0.461” ************** #1-600 Yard Load
H4895 28.5 – B90s ---- 2.270” –2876 – 20 –08 ---- 0.721”
H4895 29.0 – B90s ---- 2.270” –2922 – 13 –05 ---- 0.378” ************* 200 Load with 90 and 95s
H4895 28.5 – B105s -- 2.443” –2808 – 11 –04 ---- 0.504”
H4895 29.0 – B105s -- 2.443” –2847 – 21 –07 ---- 0.848”
H4895 28.5 – B108s -- 2.320” –2780 – 07 –02 ---- 0.458” *************** 300 & #2-600 Yard Load
H4895 29.0 – B108s -- 2.320” –2814 – 19 –07 ---- 0.550”

Feb 13 2010 Sac Match
Rapid fire prone at 300 yards = 200-11X, Slow fire prone at 600 yards = 200-10 X

 

[JMC]

Skeetlee,
I have been shooting the 6 Grendel for a year and a half and have extensive experience with the Grendel in a custom bolt gun shooting 600 and 1000 yds with it. The Grendel is not just another PPC case the shoulder on the Grendel case is blown 0.070" forward the shoulder angle is 30 deg and the body taper is the same as the 6 PPC as is the case head diameter. If you try and use a 6PPC or 220 Russian case it will end up with the neck being much shorter than if use a 6.5 Grendel case and neck it down and fire form.

The difference between a 6 Grendel and a 6 BR is 2 grains of water filled to the top of the neck but keep in mind the neck shoulder junction on the Grendel is roughly 0.120" longer than a 6 BR case neck shoulder junction. On my Grendel I have a long throat on it which enables me to put the powder charge I like behind the bullet and keep the bullet out of the area in the case neck where the donut may form.

I can easily shoot a 105gr bullet around 3000 fps after going through 4 barrels I have the data to back up the velocity. When I want to push 95 gr bullets through it 3200 fps is not out of the question. This year at the 600 yd NBRSA nationals I shot a Light Gun 3 target agg of 1.980" and was the smallest LG 3 target agg shot. I made a few mistakes at the NBRSA Nationals but was still able to come in 9 in the grand so the little cartridge does shoot. The little Grendel case gives nothing up to a BR and may actually be closer to the 6 Dasher in performance. The same rifle shot a 660 yd LG 3 target score in Ojai that was a 146 score and it also shot the small group which was 1.800” in Ojai.

Keep in mind this is in a bolt gun and not an AR, because the Grendel is also shot in an AR platform I will not post the loads I use as they would destroy an AR that works on a much lower pressure platform. One person I shoot with in Sacramento who was instrumental in developing the 6 AR and the turbo 40 can push a 105 gr bullet a little above 2800 FPS out of a 6 Grendel case in an AR, a lot of the reloading data at 6mmar.com he supplied look for test data shot in Sacramento. The performance really steps up when you have a bolt gun.

If you would like more information contact me off line. At benchrest.com you also asked who made the stock on my rifle and here is that thread

http://benchrest.com/forums/showthread.php?t=69300

and yes the barrel has been coated with "Isonite QPQ process" by Joel Kendrick.

John

Here is the link to Ojai

http://benchrest.com/forums/showthread.php?t=68398

Here is the 600 yd nationals

http://benchrest.com/forums/showthread.php?t=69057

 

[BlackHawk95]

I have a .22AR from Robert Whitley. its based on a necked down 6.5 Grendal. It shoots the 75gr VLD extremely well at 3100fps. its managed 10 shot groups at 380yd right at .60 moa. Its an AR-15 also.

I chose it over the 6mm Grendel, and it absolutely does a number on varmints too.

Jerid