6.5 Grendel velocity

[cshooter]

Ive been trying to do some research on barrels for my new build and was wondering what velocity's you all are getting with deferent length barrels. I know you load specific for the barrel length, and that you don't want to load to hot, but was just wondering how much more velocity is gained with the 24" and even 28" if any one has one over say a 18 or 20.
Cedrake

 

[Drifter™]

Re: 6.5 Grendel velocity

I don't know how accurate this data is, but here's a link to data on AA's website that shows ballistics for various barrel lengths:

http://www.alexanderarms.com/grendel_ballistics.pdf

 

[eleaf]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Drifter_1</div><div class="ubbcode-body">I don't know how accurate this data is, but here's a link to data on AA's website that shows ballistics for various barrel lengths:

http://www.alexanderarms.com/grendel_ballistics.pdf </div></div>

That's probably not far off with the Lapua 123 and a 19.5" barrel.

Don't get hung up on velocity with the Grendel. The entire philosophy behind the design of the round is "Start slow, finish fast".

Muzzle velocity is NOT the best indicator of performance when dealing with the awesome bullets available for it.

I wouldn't go with anything longer than a 24", and personally I wouldn't even go that long. 18 or 19.5" will get you where you want to go with this round without issue. No need to add significant weight and bulk for minimal performance gains.

 

[FCS]

Re: 6.5 Grendel velocity

20" with rifle length gas system is about ideal.

Friend has an 18" with mid, 120 A-max at 2400 fps.

I'm getting 2620 from 21" barrel with 120 Berger.

Another friend has a 24" Satern barrel with extended gas system and he is in the 2600 fps range also. However, he has a very short lead and is unable to get enough powder in case to get more velocity. Barrel is being adjusted and I expect he'll be able to get 2650 to 2700 afterwards.

 

[sititunga]

Re: 6.5 Grendel velocity

Max velocity for the Grendel is achieved in the 22 - 24 inch range. The only thing to be gained by going longer is a longer sight radius.

 

[cshooter]

Re: 6.5 Grendel velocity

thanks guys I think i get the idea now. there is just so much information out on the net about this cartridge that seems to contradict its self. Im just trying to do all my reaserch before I give Satern a call


also have another dumb question would it be better to have the barrel threaded or just have it stop at the crown
Cedrake

 

[Mschloss]

Re: 6.5 Grendel velocity

I have mine threaded for my AAC M4-2000 (months and months away). Until then, I am using a brake from Alexander Arms. Most Grendel threading seems to be 9/16 x 24 tpi.

 

[eleaf]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cshooter</div><div class="ubbcode-body">thanks guys I think i get the idea now. there is just so much information out on the net about this cartridge that seems to contradict its self. Im just trying to do all my reaserch before I give Satern a call


also have another dumb question would it be better to have the barrel threaded or just have it stop at the crown
Cedrake </div></div>

Do you want to install a muzzle brake, flash suppressor, or sound suppressor at some point?

If so, then having it threaded is a very good idea.

 

[Scottmilk9]

Re: 6.5 Grendel velocity

I got all messed up thinking i had to get 2600 or so out of my gun, but once i realized the accuracy, my 20" barrel with a 85Sierra HP is about 2560 and getting 1/2-3/4" groups consistantly.

 

[steve123]

Re: 6.5 Grendel velocity

Scott,

Which would you rather use for comps ? You're 6.5G or you're POF 6.5 Creed.Why ?

 

[FCS]

Re: 6.5 Grendel velocity

What bullet are you planning on using?
Punching paper/ringing steel or other end use?

 

[cshooter]

Re: 6.5 Grendel velocity

punching paper and hopefully f class when i get to that level of shooting skill. I don't plan to hunt with it so weight is not a concern. I was thinking about using a longer barrel to stabilize the larger bullets better (130's), but with what has been said in some of the other threads. I am wondering if bigger is really better. I will have all of the other components for the rifle, as soon as the brown truck gives me my ops-4. just trying to make the right call on the barrel before I spend the money.
Cedrake

also has anyone heard any more about the brass discrepancy that was being discussed a little while ago

 

[BERTMAN77MK2]

Re: 6.5 Grendel velocity

special forces snipers use Satern's 24 incher in 6.5 Grendel
and have made recorded kills beyond 1000---so if weight doesn't
matter I'd get at least 24"

 

[eleaf]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BERTMAN77MK2</div><div class="ubbcode-body">special forces snipers use Satern's 24 incher in 6.5 Grendel
and have made recorded kills beyond 1000---so if weight doesn't
matter I'd get at least 24" </div></div>

I wouldn't go any bigger than 24" as there is no real performance gain. And I would likely never want to go any bigger than 20". The difference is ~40-60 fps at the muzzle, and only 30 fps at 1000 yards. Delivered energy is also negligible at 100 yards as well, with both falling under the magic 500 ft/pounds shortly after 900 yards.

The only REAL performance difference between the 24" and 19.5" is academic, and the weight/portability difference is HUGE. The only difference between the two will be slightly different dope.

Go with the 19.5".

 

[aqualung]

Re: 6.5 Grendel velocity

Not being funny, but a longer barrel will NOT stabilise a heavier bullet. That's down to rifling twist/bullet velocity.
A longer barrel will NOT give you the additional velocity needed if bullet stability is marginal. If you want to stabilise heavy for calibre bullets, you need a faster rifling twist.

Check out what Frank has been doing with an 18" .308 barrel (There's a video clip from maybe 2 years back). Go short, fast twist if you want to shoot heavy bullets.

Just my 0.02c.

N

 

[eleaf]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Paduan Learner</div><div class="ubbcode-body">Not being funny, but a longer barrel will NOT stabilise a heavier bullet. That's down to rifling twist/bullet velocity.
A longer barrel will NOT give you the additional velocity needed if bullet stability is marginal. If you want to stabilise heavy for calibre bullets, you need a faster rifling twist.

Check out what Frank has been doing with an 18" .308 barrel (There's a video clip from maybe 2 years back). Go short, fast twist if you want to shoot heavy bullets.

Just my 0.02c.

N </div></div>

You can't really shoot much anything larger than the 130s with ANY twist in the Grendel because one generally runs in to mag length issues first (find a bolt action Grendel is rare indeed). And the 130s shoot fine with the 1:9 twist barrels (the slowest twist I've seen on any Grendel).

 

[Jon A]

Re: 6.5 Grendel velocity

There are a lot of 1:8 twists out there. They shoot 140's beautifully.

 

[Scottmilk9]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steve123</div><div class="ubbcode-body">Scott,

Which would you rather use for comps ? You're 6.5G or you're POF 6.5 Creed.Why ?
</div></div>

It depends on the match, matches like we run in phoenix where we only go to 700yds and we make the shooting more dynamic, uncomfortable positions, etc... I would rather use my grendel for the lighter weight, more maneuverability.

The Creedmoor is definitly a long range gun and its heavy. I think it would make a good prone and F-class semi-auto. Not to say it wouldn't compete, because Nomad got first place and i was 12-13 last year at oregon sniper match.

 

[FCS]

Re: 6.5 Grendel velocity

22 to 24" barrel from Satern, +2 gas system, "small" gas port, 8 or 8.5 twist and you'll be able to run pretty much any bullet you desire.
If you are not going with extended gas system, stick to a 20" barrel IMHO.

Single loading the 130s would be hard to beat.
Out of magazine the 120s are best bet for beating wind.

AA / Laupa brass would be my first choice. Buddy has used some Hornady but case mouth required extra attention as it had pretty large burr. If your time is worth anything, AA/Laupa is the safer and cheaper option long term.

Longer barrel will pick you up a bit in velocity but not enough to stabilize a bullet. 9 twist will probably work with all but the heaviest of 6.5mm bullets but an 8 twist won't hurt you any either. See Satern has some 8.75 twist barrels in stock. 120 and under, 9 twist will do just fine. Plan on running anything larger, I'd go 8.5 minimum and prefer an 8 twist.

Problem with the bigger, longer bullets is you lose a fair bit of case capacity when running OTM, if single loading than not as big a deal. 120 Sierra and 120 Berger Match BT are nice OTM bullets. 130 JLK is great single load bullet but you'll be about 2.475" OAL.

 

[cshooter]

Re: 6.5 Grendel velocity

Thanks guys this has answered a lot of questions and added some more.
Cedrake

 

[sititunga]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BERTMAN77MK2</div><div class="ubbcode-body">special forces snipers use Satern's 24 incher in 6.5 Grendel
and have made recorded kills beyond 1000---so if weight doesn't
matter I'd get at least 24" </div></div>

I didn't think the 6.5 Grendel had been deployed. Who's using it?

 

[eleaf]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jon A</div><div class="ubbcode-body">There are a lot of 1:8 twists out there. They shoot 140's beautifully. </div></div>

I have a 1:8 twist. All of AA's 19.5" barrels are 1:8.

I didn't think that the 140s could fit well in the magazine without pushing them in too far for great performance.

 

[eleaf]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sititunga1</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BERTMAN77MK2</div><div class="ubbcode-body">special forces snipers use Satern's 24 incher in 6.5 Grendel
and have made recorded kills beyond 1000---so if weight doesn't
matter I'd get at least 24" </div></div>

I didn't think the 6.5 Grendel had been deployed. Who's using it? </div></div>

From what I understand, there MAY BE a couple of SF units using them in an effort to evaluate them for further use.

MAY BE.

Or maybe not.

I doubt very many people know how many have been used and to what effect, if it's been used at all.

That said, it doesn't surprise me in the least that the Grendel would give similar performance to the 7.62 in the field. It's probably a better bet than using the .308 SASS in so far as it's a much smaller and lighter platform.


Same/negligibly similar performance + smaller + lighter + can carry more ammo = WIN

Plus, you won't have to carry a completely separate weapon for security purposes when long range gun is a disadvantage. All you would need is a separate upper and magazines. It sure beats the hell out of carrying an M4 AND the AR 10 (or .308 bolt gun).

 

[cshooter]

Re: 6.5 Grendel velocity

I'm pretty certin that most of the 140s are hand feed.
Cedrake

 

[Jon A]

Re: 6.5 Grendel velocity

140's work fine from mag length (Berger VLD and A-Max). Yes, they take up some case capacity so you don't gain as much as you do with heavier bullets in bigger rounds, but they still work well. A tad less drift in the wind and they bang the steel a little harder.

 

[FCS]

Re: 6.5 Grendel velocity

What are you getting for velocity with the 140s?

Powder used?

 

[Jon A]

Re: 6.5 Grendel velocity

I run them in the 2300-2350 range out of my 24". Some have pushed them to 2400+ with even shorter barrels but I like to run this gun mild for long brass life and no broken bolts.

Also 2520 will give more velocity but I like to use TAC. I only load the 123's to the 2500-2550 range, so figure around 200 fps less than whatever you run 123's at.

I think the factory 123 ammo that's 2600+ uses better powders than we have access to for handloading; I wouldn't handload them that fast. It really makes the factory stuff hard to beat ballistically, if you can afford to keep buying it.

 

[steve123]

Re: 6.5 Grendel velocity

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Scottmilk9</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steve123</div><div class="ubbcode-body">Scott,

Which would you rather use for comps ? You're 6.5G or you're POF 6.5 Creed.Why ?
</div></div>

It depends on the match, matches like we run in phoenix where we only go to 700yds and we make the shooting more dynamic, uncomfortable positions, etc... I would rather use my grendel for the lighter weight, more maneuverability.


The Creedmoor is definitly a long range gun and its heavy. I think it would make a good prone and F-class semi-auto. Not to say it wouldn't compete, because Nomad got first place and i was 12-13 last year at oregon sniper match.
</div></div>

Good to know.Thanks Scott!

My 6x47L bolt gun isn't going to be ready for the TPRC so I'm gonna be using the AR/6mmART40.

 

[Scottmilk9]

Re: 6.5 Grendel velocity

We'll see you in a few weeks.

I never used anything heavier than a 124 in mine. But used the new IMR 8208 XBR and getting great groups.

 

[Mgordon]

Re: 6.5 Grendel velocity

I was running the 123 Lapua Scenar bullet in my 22" Grendel and I was getting around 2510 FPS.

Mark

 

[sititunga]

Re: 6.5 Grendel velocity

120 gr Berger Match bullets run at about 2540 fps out of my 22 inch. Sadly it's only supersonic to about 900 yds. I've found the 120 Berger more accurate than the 123 Lapua out of my JP.