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+--- Thread: 6.5 Grendel Max (/showthread.php?tid=12662)
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6.5 Grendel Max - s3silver - 02-04-2017
I was browsing the net and came across this forum. 6.5 grendel with shoulder blown forward. Anyone else done this? Seems interesting in a bolt gun setup.
http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/7351896/Re_My_6_5_Grendel_Max_Maybe_th
6.5 Grendel Max - JASmith - 02-04-2017
Von Gruff developed a cartridge with that Nickname and shared with us both the development of the wildcat and a bullet mould to go with it. The first thread is http://www.65grendel.com/forum/showthread.php?3002-Bolt-rifle-for-dedicated-handloaders&highlight=Grendel+Max.
He had reamers and mould built, the posted who he got tuhem from so others could try the cartridge too.
6.5 Grendel Max - sneaky one - 02-05-2017
S3S--- it is a cool bolt gun round. I'm working on an AR version- about a 75% gain as to the bolt gun gain. I'll have more data this spring.
6.5 Grendel Max - s3silver - 02-06-2017
JAS - thanks for the link. Very good and interesting read.
Sneaky - an ar version sounds even cooler. Can wait to see your results.
Grendel is such an efficient and accurate round.
6.5 Grendel Max - Drift - 02-06-2017
Would someone please remind me. If I get a Grendel rechambered into a Grendel Max and then shoot regular factory ammo out of that, "How much velocity can I expect to loose compared to a standard Grendel?"
6.5 Grendel Max - Drillboss - 02-07-2017
Nope, the Grendel Max chamber won't fire factory Grendel ammo. He's blown the shoulder forward such that the headspace won't allow the shorter SAAMI cartridge.
6.5 Grendel Max - sneaky one - 02-09-2017
Drill, it will fire, and fireform the rounds in the Max chamber. The bolt lugs hold the round in place. Von Gruff & I talked about this as he asked for my input, and a few others-- to get the reamer print done. 3 years ago...
He used Factory Hornady cases to fireform to the Max. case. So it's a duh, on that . I have done a many here in testing also.
Revisit the Max- reamer print- - it's reamed .050 longer
He sent me a dozen retired Max cases , from NZ- for me to measure upon. It's my goal to make a Max lite version for AR's.
6.5 Grendel Max - s3silver - 02-09-2017
That's what I thought from the read. He used factory cases to fireform since it was the same grendel specs, just .050 longer.
Sneaky - can't wait to see your results. What's your timeline?
6.5 Grendel Max - Drillboss - 02-09-2017
I stand corrected. My answer was based on what Von Gruff told me once:
Giday Drillbos and no the factory ammo cant because of the headspace which is .050 longer with the GM. I did get a couple of boxes of Hornady ammo when I first built the rifle more to get the brass than anything else and debulleted, saved the powder in another set of cases, expanded the neck to 30 cal then necked back down in the Grendel dies with a .05 spacer glued to the shell holder which is a permanent fixture that stays with the Grendel dies. This is how all reloading is done but for the first necking down I added a .006 shim to give me a crush fit in the chamber, added the powder backinto the cases and seated the same bullet to an OAL of 2.405. The GM case gives me a near 10% case capacity advantage but with the bullet seated long it opens up more space for the powder so that with 32.6gn CFE223 under the 123gn bullet I get 2700fps from my 21 in barrel and at just 53K psi. The 100gn ttsx gets 2950 but the 123gn has a better long range performance with less elevation and windage drift.
Without a doubt the most efficient and usable rifle I have built (other than a little 20 VarTarg that is)
6.5 Grendel Max - Rickc - 02-09-2017
Wonder what the velocity gain would be with an ackley improved grendel
My 6mm turbo 40 has a blown out shoulder of 40 degrees and a much shorter neck than the original grendel case
Suprised someone hasn't already done it
6.5 Grendel Max - ricsmall - 02-09-2017
Rickc Wrote:Wonder what the velocity gain would be with an ackley improved grendel
My 6mm turbo 40 has a blown out shoulder of 40 degrees and a much shorter neck than the original grendel case
Suprised someone hasn't already done it
I've thought on it some!! Lol. I love an AI cartridge. I don't think the factory ammo will fire in the max chamber. Seems to me gruff was necking up then back down to 6.5 leaving .050" of neck to act as a false shoulder.
Richard
6.5 Grendel Max - JASmith - 02-09-2017
Rickc Wrote:Wonder what the velocity gain would be with an ackley improved grendelRun, or get a buddy to run, the 6.5 Grendel with a powder like H335 in QuickLoad. Do this at the suggested 50ksi for AR bolt happiness, then repeat at the pressure YOU THINK might be OK for your rifle.
My 6mm turbo 40 has a blown out shoulder of 40 degrees and a much shorter neck than the original grendel case
Suprised someone hasn't already done it
Then, morph the Grendel case into the configuration you are thinking about and repeat with the same. Pressure levels and powder.
You will have four muzzle velocities to plug into your favorite exterior ballistics calculator.
Do this and see what the cihange in wind drift at the ranges you are interested in. Is the gain more or less than 1 moa? 1/2 moa? Or 1/4 moa?
The answer combined with how well you believe you can shoot will tell you whether the exercise is worth the bother.
I have done exercises similar to this for a couple of wildcats and haven't yet convinced myself that the blown forward, blown out, higher pressure combiniation will make a real difference in my ability to hit at range.
Nonetheless, like any choice of cartridge, rifle, or bff, the resulting state of mind may be enough. Most of us will not criticize your chosen path if for no other reason than curosity to see how it works out!
VonGruff has done us a real favor by already having done the experiment. It definitely seems to have worked well for him and we learned a bit too.
6.5 Grendel Max - D.Davis - 02-09-2017
I shoot a 20 Grendel AI in a CZ 527. I like it in a bolt gun, but for feeding reasons in a semi I think the shoulder angle should be left alone. Dave.
6.5 Grendel Max - sneaky one - 02-09-2017
S3--- Von and I went around a bit on the AI- I wanted it- he strongly recommended against it.
Timeline will be spring this year- a few more numbers to go through, Need to check the viability of this project again. I gained plenty of deer harvesting usage, by going lighter in all copper pill wts., to get my dream gun done, in std. Grrr trim- chambers with awesome results.
Maybe Jasmith can email me a reason to skip the idea...
Joe Joe,,,?
6.5 Grendel Max - Rickc - 02-09-2017
D.Davis Wrote:I shoot a 20 Grendel AI in a CZ 527. I like it in a bolt gun, but for feeding reasons in a semi I think the shoulder angle should be left alone. Dave.
I have the turbo 40 improved. It feeds flawlessly
See pic below beside its parent case the 6.5 grendel. There is 1 gr of h20 capacity gain between the grendel and the Ackley Improved. Does that equate to 100 to 150 fps velocity increase with the 123's?
[IMG]
![[Image: 20170209_181902_zpsedqcrr68.jpg]](http://s1056.photobucket.com/user/rcoody1/media/20170209_181902_zpsedqcrr68.jpg.html)
[/IMG]
6.5 Grendel Max - s3silver - 02-11-2017
Drillboss Wrote:I stand corrected. My answer was based on what Von Gruff told me once:
...The 100gn ttsx gets 2950 but the 123gn has a better long range performance with less elevation and windage drift.
Without a doubt the most efficient and usable rifle I have built (other than a little 20 VarTarg that is)
No problem.
The 100 ttsx at 2950 should be interesting. Currently, I have the same pill going at ~2800 out of my 22" AR and it's already a performer. Have you taken anything with that load?
6.5 Grendel Max - s3silver - 02-11-2017
Rickc Wrote:I have the turbo 40 improved. It feeds flawlessly
See pic below beside its parent case the 6.5 grendel. There is 1 gr of h20 capacity gain between the grendel and the Ackley Improved. Does that equate to 100 to 150 fps velocity increase with the 123's?
[IMG][/IMG]
Probably not, but we gotta squeeze every last ounce of efficiency from this great little case...haha.
That AI case does look pretty cool though.
6.5 Grendel Max - Drillboss - 02-11-2017
s3silver Wrote:No problem.
The 100 ttsx at 2950 should be interesting. Currently, I have the same pill going at ~2800 out of my 22" AR and it's already a performer. Have you taken anything with that load?
Not me, I was just quoting the gentleman that designed the cartridge. Like Will Rogers once said, "all I know is what I read in the newspapers".
6.5 Grendel Max - Rickc - 02-11-2017
s3silver Wrote:Probably not, but we gotta squeeze every last ounce of efficiency from this great little case...haha.
That AI case does look pretty cool though.
Wildcatting is fun!
That AI is a grendel necked down to 6mm. Pushing berger 105's at.2850.
Another 100 fps out of the grendel with 123's sure would be nice
6.5 Grendel Max - Drift - 02-12-2017
Another 100 fps with 123's would be nice indeed! Or the same velocity with 130's for us hunters. I was hoping some super powder would suffice... But if I'll have to keep my eye on this thread to see where the G Max goes.