6mm Grendel - Atheris Arms - Salem, Va.

[RMB]

I am in the process of purchasing my first semi-auto and wanted a 6.5 Grendel. I ran into this company and talked to the owner at length. He was very helpful. After we discussed what the rifle would be used for...mostly long range varmints (prarrie dogs in SD) he suggested the 6MM Grendel. I have done the due diligence and spoken to the diemakers, Robert Whitly's son....etc. And, I am retired so I have the time for the reloading...

So my questions are:
- what twist rate 1:8? (I will be trying the 87 grain vmax, 95 and 107 grain SMK and Berger 105 bullets)

- what barrel lenght 20" or 22? (note i will be shooting with an 8" suppressor)

I am very recoil sensitive (shoulder surgery) and this seems like a pretty effective way (27 to 28 grains of powder) to get out to 700+ yards without a larger round (i.e. more recoil). Last trip I tool my bolt 243 and after about 200 rounds my shoulder was pretty beat up. So I switched back to my 223 and the wind out there was really pushing the bullet around.

Thanks in advance for any advice.

 

[bigjake83]

I've been there and done that brother if I were you I would stick with the Grendel. I had two 6mm fat rats builds from Lee Wells absolutely extraordinary little cartridge but it just wasn't worth the work.

I had a 20" and 22" I would recommend the 22". I was getting 2870 from the 107 SMK at .5 MOA or less, and just FYI the 6mm Grendel will have a sharper recoil impulse then the Grendel.

But as stated above, Reloading is already very time consuming and the 6MM FatRat and the 6MM Grendel absolutely destroy Brass, not to mention they can be finicky when developing hand loads. With Hornady Brass I was only getting 3 reloads before having to shit can them and only 5-6 from Lapua. If you want a high-speed low-drag varmint gitter then build a .224 Valk, 22 Nosler or just stick with the Grendel.

But if you get the 6MM Grendel anyway let me know, ive got a shit ton of 95gr TMK and 107 SMKs that I need to get rid of.

 

[Scotts556]

A buddy of mine has a 22 Grendel and it is amazing. Thing shots fast, flat and bug holes. I would guess the 6mm Grendel is the same.

 

[sandwarrior]

I am in the process of purchasing my first semi-auto and wanted a 6.5 Grendel. I ran into this company and talked to the owner at length. He was very helpful. After we discussed what the rifle would be used for...mostly long range varmints (prarrie dogs in SD) he suggested the 6MM Grendel. I have done the due diligence and spoken to the diemakers, Robert Whitly's son....etc. And, I am retired so I have the time for the reloading...

So my questions are:
- what twist rate 1:8? (I will be trying the 87 grain vmax, 95 and 107 grain SMK and Berger 105 bullets)

- what barrel lenght 20" or 22? (note i will be shooting with an 8" suppressor)

I am very recoil sensitive (shoulder surgery) and this seems like a pretty effective way (27 to 28 grains of powder) to get out to 700+ yards without a larger round (i.e. more recoil). Last trip I tool my bolt 243 and after about 200 rounds my shoulder was pretty beat up. So I switched back to my 223 and the wind out there was really pushing the bullet around.

Thanks in advance for any advice.

I've had three 6.5 Grendels and have my share of hair pulling to figure things out with it. In the past bigjak83 and I have talked about him going the 6mm route instead.

As of this post, I did not know jake was having the brass issues he is having. Although, I can totally see it. More power out the barrel means more headaches getting it out there. Fireforming and reloading are time consuming, and you have to be set up to do that. Although you can get 6.5G "off the shelf", it's a lot more common you have to order it. Thus, to use it a lot I have to reload. And, I trash my share of brass with it. Added: And, I'm not even fireforming

Twist for the bullets you want to use will require a 1-8" twist. At least to get the long range capability of the 95's, 105's and 107's.

I suggest the longest barrel you can get, but they will work well down to 16". Depends on how far you want to shoot and how much velocity loss you want to accept.

 

[RMB]

Thanks...……….

 

[sam4886]

I've got a 6mm predator, same as 6mm grendel and 243 LBC. These are much easier than the fat rats, turbo 40, ect. to load for, they're just a neck down, load, and shoot. No fire forming or anything like that.

22 inch ar15. I love it. I use it to shoot paper steel, and rock chucks, and anything else that wanders by. I shoot 90 gr gamechangers at 2830 fps, easily half moa. I've got a 58 max load at 3310 too.

My original testing hornady brass lasted 4 firings. Norma and lapua have been better, haven't needed to toss them yet. Any AR is going to eat brass faster than a bolt gun.

 

[Constructor]

I am in the process of purchasing my first semi-auto and wanted a 6.5 Grendel. I ran into this company and talked to the owner at length. He was very helpful. After we discussed what the rifle would be used for...mostly long range varmints (prarrie dogs in SD) he suggested the 6MM Grendel. I have done the due diligence and spoken to the diemakers, Robert Whitly's son....etc. And, I am retired so I have the time for the reloading...

So my questions are:
- what twist rate 1:8? (I will be trying the 87 grain vmax, 95 and 107 grain SMK and Berger 105 bullets)

- what barrel lenght 20" or 22? (note i will be shooting with an 8" suppressor)

I am very recoil sensitive (shoulder surgery) and this seems like a pretty effective way (27 to 28 grains of powder) to get out to 700+ yards without a larger round (i.e. more recoil). Last trip I tool my bolt 243 and after about 200 rounds my shoulder was pretty beat up. So I switched back to my 223 and the wind out there was really pushing the bullet around.

Thanks in advance for any advice.

8 twist is good for anything 55gr -105gr, With a 22" you would gain 40-50fps over the 20".
If you push the pressure above 55000psi or resize the brass too much/overwork the brass it will shorten the life. Norma brass should last longer than the rest, it is thicker at the bottom where needed.

Any wildcat where you have to fire-form/blowout the shoulder will get old quick. I've been making wildcats since 1982 and even I hate fire-forming.

 

[steve123]

I suggest staying at 95 grains or below.
Wind drift is a wash between the 95 vs the 105 since you can drive the 95 faster and the recoil is less.
Had good brass life with Lapua brass. Imo a 107 at 2870 is getting hot in the fatrat, that's the velocity my 22" goes with 95smk and I get slight ejector swipe.

 

[Jmccracken1214]

8 twist is good for anything 55gr -105gr, With a 22" you would gain 40-50fps over the 20".
If you push the pressure above 55000psi or resize the brass too much/overwork the brass it will shorten the life. Norma brass should last longer than the rest, it is thicker at the bottom where needed.

Any wildcat where you have to fire-form/blowout the shoulder will get old quick. I've been making wildcats since 1982 and even I hate fire-forming.

Good thing you can throw a bushing in the 6.5 grendel die and just neck down your brass so there is no fire forming

 

[sam4886]

Constructor makes the 6mm predator, as in produces it, and knows exactly what it takes.

He has custom dies for it that I use too. No issues. I think he reserves those for people that buy a barrel though.

 

[RMB]

After reviewing all your input and info available on the WEB...I pulled the trigger (so to speak) on the 6mm AR. I should have the rifle in about 3 weeks....I will be posting as I get the gun up and running....

Thanks again for the input!

 

[Winny94]

I've got a 6mm predator, same as 6mm grendel and 243 LBC. These are much easier than the fat rats, turbo 40, ect. to load for, they're just a neck down, load, and shoot. No fire forming or anything like that.

22 inch ar15. I love it. I use it to shoot paper steel, and rock chucks, and anything else that wanders by. I shoot 90 gr gamechangers at 2830 fps, easily half moa. I've got a 58 max load at 3310 too.

My original testing hornady brass lasted 4 firings. Norma and lapua have been better, haven't needed to toss them yet. Any AR is going to eat brass faster than a bolt gun.

I too had a 22" 6 predator from AR15 performance. It was an accurate little thing, very litle recoil. I didnt like the startup cost of dies, but after that, it was a good little round. I ended up selling because I just didnt shoot it much and really wanted an AI (and if you havent noticed, an AI costs an arm, leg, kidney, and a 6 Predator haha)

 

[RMB]

I now have the rifle and am starting the reloading process. 20", 5R, SS T-Box barrel and will be using a GSL multi cal Suppressor. The scope is back ordered...so I will be using a Vortex HST to start.

I have the Hornady brass resized (not an issue)….. Hornady one shot lube, Redding Type S die, one pass. I have access to an optical comparator and everything looks good.

Trimmed the brass to 1.510, Chamfered ID and OD, Cleaned up primer pockets.

Going to use H4895 and 8208..What is the best starting loads...and what is the amount to step up...would .3 grains be OK...

First/starting point loads for 87 GR Vmax will be...26.9 grains/H4895 and 26.7 grains/82028

First/starting point loads for 95 GR SMK will be...26.7 grains/H4895 and 26.5 grains/82028

I will load both at 2.250" COAL and after I figure out what shoots best....then work on the seating depth.

I have used FEDERAL 205M primers for all my reloading for years and never had a problem...this has always been for bolt guns. I have used this primer on 218 bee, 223, 223AI and NEVER had and issue. And, most importantly I have never had an issue with 'supply" I did read (on another web site) that this primer is should not be used on high pressure loads...As I stated above this is my first "gas gun". Is this really the case. And if so, Should I use CCI or ???

The ultimate goal is a light weight, accurate, "walking around" rifle for "dogs" out to 500 plus yards. We go twice a year (South Dakota)....4 days in May and 3 days the end of June...and "average" about 350 rounds per day.....I just got sick of hauling around a 10 to 12 pound .243 Varmint Special rifle for part of the day. And, with all the 'talk' about bans etc..I thought I better buy one...kind of a now or never thing.

Any suggestions/comments will be greatly appreciated!

 

[sandwarrior]

I now have the rifle and am starting the reloading process. 20", 5R, SS T-Box barrel and will be using a GSL multi cal Suppressor. The scope is back ordered...so I will be using a Vortex HST to start.

I have the Hornady brass resized (not an issue)….. Hornady one shot lube, Redding Type S die, one pass. I have access to an optical comparator and everything looks good.

Trimmed the brass to 1.510, Chamfered ID and OD, Cleaned up primer pockets.

Going to use H4895 and 8208..What is the best starting loads...and what is the amount to step up...would .3 grains be OK...

First/starting point loads for 87 GR Vmax will be...26.9 grains/H4895 and 26.7 grains/82028

First/starting point loads for 95 GR SMK will be...26.7 grains/H4895 and 26.5 grains/82028

I will load both at 2.250" COAL and after I figure out what shoots best....then work on the seating depth.

I have used FEDERAL 205M primers for all my reloading for years and never had a problem...this has always been for bolt guns. I have used this primer on 218 bee, 223, 223AI and NEVER had and issue. And, most importantly I have never had an issue with 'supply" I did read (on another web site) that this primer is should not be used on high pressure loads...As I stated above this is my first "gas gun". Is this really the case. And if so, Should I use CCI or ???

The ultimate goal is a light weight, accurate, "walking around" rifle for "dogs" out to 500 plus yards. We go twice a year (South Dakota)....4 days in May and 3 days the end of June...and "average" about 350 rounds per day.....I just got sick of hauling around a 10 to 12 pound .243 Varmint Special rifle for part of the day. And, with all the 'talk' about bans etc..I thought I better buy one...kind of a now or never thing.

Any suggestions/comments will be greatly appreciated!

I think you bought it right, i.e. barrel length. Not buying all the crap to stick on it will keep it light.

Since you trimmed, did you cut the donut out?

Your starting loads look about right. With medium/fast powders like 4895 and 8208 you probably won't get "swipe" with low loads. As you move to slower, and more temp sensitive, powders you may see that. Temp sensitive powders won't necessarily work well (AA2520) as you may find you need to work up summer and winter loads. I've never tried CFE223 in my 6.5G, but several people I know say it works pretty well. It was less temp sensitive than other double based powders when I've used it in .223. I would also think Varget would give a better showing in the 6mm vs. the 6.5mm.

Remember the whole thing with loading for an AR is it's not linear like a bolt gun where you just work up with any powder. Depending on your gas port size (it should be optimized) you may have to dance around the best loads to get it to function right. Meaning the rifle will function, just your brass gets ripped up. You have 25% more capacity in a Grendel case, so it's a little trickier to get slow powders lit and burned down enough by the time they reach the gas port.

Your primers will work just fine. If you work with a double base powder, you might consider using magnum primers.

 

[RMB]

Final Update:

After some trials and tribulations (Thank you to Zach at Atheris Arms!) I have the rifle up and running. Short term I have a Vortex HST mounted, I should also mention that I have a Timney 2 stage trigger as this is on all my bolt guns.

Broke the gun in for 10 rounds and then loaded up 40 rounds of 87 grain v-max. 20 rounds of H4895 at 27 grains and 20 rounds at 28 grains, I should note that I did NOT have my bench rest bags with me. I just shot off the sh#tty range bags at the club. I was in a hurry trying to shoot before it started snowing. (gotta love Wisconsin)

Brass: Hornady 6.5 Grendel (new)
Dies: Redding Type S and Redding Seating die.
Primer: 205M
Case Trimmed
Flash holes cleaned up
Primer pockets cleaned up

27 grains H4895 - No signs of pressure or case damage
First 5 shot group (100 yards) - 1.5" without suppressor
Second 5 shot group (100 yards) - 1.5" with suppressor POI change is about 1" high and right
Third 5 shot group (100 yards) - 1.5" without suppressor
Fourth shot group (100 yards) - 1.1" with suppressor POI change is about 1" high and right

28 grains H4895 - No signs of pressure but with case damage with suppressor ('dings' on case shoulder)
First 5 shot group (100 yards) - 1.3" without suppressor
Second 5 shot group (100 yards) - 1.0" with suppressor POI change is about 1" high and right
Third 5 shot group (100 yards) - 1.3" without suppressor
Fourth shot group (100 yards) - 1.0" with suppressor POI change is about 1" high and right

So, overall I am really pleased, Based on these results (and a better optic -PST GEN 2-) I am 99% sure I can get to or below MOA, I am ordering the scope today. Next week I will start in earnest to develop the best load. I figure I have to turn down the gas port just a wee bit to eliminate the case damage/dings. One last thing to order is a brass catcher...any suggestions? I am not a big fan of crawling around looking for the brass (in the snow). The Caldwell units, do they work? Any suggestions?

I am sorry that I did not get a 'gas gun" sooner, Follow up shots are light years faster. Recoil is non existent, This firearm is a blast (pun intended)! Shoulda done this years ago! However, you can really burn though the ammo with this thing. And, gotta order 500 more pieces of brass.

Prarie Dogs look out!

Thanks for all the input and thanks to Atheris Arms!

 

[sam4886]

I've got a couple of the rail mounted caldwells that work great. Rarely a case will bounce just right and roll out between the bag and the receivers, but it drops straight down so no biggie.

 

[RMB]

I finally got some time and some 'nice' weather for Wisconsin in March...and worked up some loads in 4895. I used two bullets. The 87 grain Vmax and the 95 Grain SMK. It would seem that this rifle likes everything I tried. I am still waiting on the scope so I used a Vortex HST off another rifle.
The average of all the 5 shot groups were 1.105" (100 yards) with the best being .405". The best group was 28.8 GR of 4895 with the 95 grain SMK. The best group with the 87 grain Vmax was .505" with 28.6 grains of 4895. I did not see any case swipe and the primers looked good with these loads.
I am going to reload 10 rounds of each of the best groups with both the V-max and SMK and repeat...this time with a coronagraph.
At this point does it even pay to try another powder (like 8208 or ?)
Total rounds to date is 105 in this rifle.
Thanks in advance for any and all input.

 

[sam4886]

I really like 8208 in mine. That said, I can't find it anywhere this year, so I'm trying some other stuff. Loaded up some 90 gr gamekings with benchmark from 26ish-29ish grains. Should be able to get out this weekend and test.

 

[RMB]

Thanks, I have pounds of Benchmark as I use this as my prarrie dog round in 223...…it is an older Rem 700 Varmint Special (newer barrel with 1:9 twist) using 53 grain Vmax with 25,6 grains. Any feed back will be appreciated.

 

[sam4886]

Got some numbers with benchmark today. Seems like I can get some more velocity out of it than 8208. It's also supposed to be more temp stable than 8208 as well. I used up the last bit of my 8208 for a baseline and it was definitely slower today than it was when I was doing the initial workup last summer.

3/8/20, pulled from kestrel:
55 degrees
40% humidity
850 ft elevation
900 density altitude

6mm predator/grendel/LBC/ar

22in ar performance barrel

27.8 gr 8208xbr 2823 fps for reference

Started 26.4 gr benchmark 2751 fps
To
Ended 29.1 gr benchmark 2976 fps

No real pressure signs until about 28 grains, but I felt fine pushing to 29.

Nothing too great for groups, but the ES and SD looked great on a few so I'll play with seating depth on a few and see what happens.

 

[RMB]

And this is with the 90 grain game kings?

I am concentrating on the 87n grain Vmax and 95 gr SMK...

Best 100 yard groups so far are:
95 GR SMK 28.6 Grains of IMR 4895, Fed 205 primer, Hornady brass* 2.260 COAL = 0.557" (Shot on 2/29- 5 shot group)
87 GR Vmax 28.0 Grains of 8208, Fed 205 primer, Hornady brass* 2.188" COAL = 0.282" (Shot on 3/7- 5 shot group)

This is with the 1:8 twist and 20" barrel.
These are with an un-suppressed rifle. With the suppressor My group size increases about 20%.* * Along with the point of impact change.

I will repeat the above loads and try the Benchmark and see how this goes...It will be a week or two before I can get to this.

* - It appears that this Hornady brass will be good for a max of 4 firings.

** - I spoke to the suppressor manufacturer (GSL) and they suggested that I use the screw on adapter rather than the quick disconnect and see if the group size decreases and/or and minimizes the point of impact change.

Thanks again!!!!

 

[sam4886]

Yes, that was with the 90 gr game changers.

 

[Vodak]

I have been shooting 6.5 Grendel for quite a while now. I've had good success with 8208, CFE223, X-Terminator, and am currently working almost exclusively with H322 (which I also use for 53g SMK's in my 1-9 twist 223).

 

[LtDan47]

The 95 SMK's are working the be3st in my 6 /243 LBC

 

[RMB]

l will be using this rifle for an upcoming prarrie dog shoot the first week in May. I am leaning toward the 95 SMK due to the better BC. But...I have to verify the results...and try the above suggested powder (Benchmark) in both bullets....We are going for 4 days. I need to load up about 1,000 6mm Grendel and 1,500 223.....I am kinda running out of time. Normally we go in early June but last year it was so wet in South Dakota we are going a month early,
I have all the 243 loaded (87GR VMAX) and ready to go.