I ordered a stripped upper & lower with the intentions of building my first AR in 5.56. However I already own 2 in 5.56 & I began leaning toward a different caliber.

Please correct me if I am wrong but my understanding is that I can use this same upper & lower to build a 6.5 Grendel. All I need is a different barrel, different bolt, & different mags. Is this correct?

My upper is made by aero & has M4 feed ramps. Not all the Grendel barrels designate whether they have M4 feed ramps. Do most barrels in the 6.5 caliber have feed ramps or do I need to contact the manufacturers?

Any other special considerations I need to make for building this rifle?

There are others on this board more knowledgeable than me and they will probably be by later with info. But, I love my AR in 6.5 Grendel that Eyeguy built for me. Congratulations on taking the plunge.

It is my understanding that you are correct in that only the barrel and bcg are different. That, and you will need 6.5 mags.

The gun is excellent and is a much better shot than I am. It should be accurate to well over 600 yards. Unfortunately, I am not.

Yes, the 6.5grendel uses the same upper and lower. You are correct that the only difference is the barrel, bolt, and magazines.

I bought my barrel from Lilja, and they specified M4 feed ramps in the description. I'm not sure if others provide them as a default or not.

There are a few different magazine manufacturers out there. C-products and ASC tend to be hit or miss. I bought some ASC mags and did not have luck with them feeding. I ended up buying Elander magazines from Alexander Arms. They have cycled reliably without issue. Based on feedback I've seen, the Elander have a higher percentage of success than the ASC or C-Products. YMMV.

Whatever barrel you buy, get a matching bolt. Most barrel suppliers will either sell a matching bolt or indicate what manufacturers bolt they used for headspacing.

Ditto everything OhAggie said. Elander mags are by far the best, but you may have to wait for them from AA. Buy a cheap one now to get by, then order a couple Elanders.

When you go to AA's site and buy the mags you'll see a their barrels which are accurate and priced well. If you go that route, be aware the muzzle thread pitch is 9/16x(24 or 28?) and you'll need an adapter to install 99% of the muzzle devices on the market.

I've built 6 Grendels in the past 3-4 months and the best shooter - including a Lilja and a JP in the group - was from Odinworks.

Just what I wanted to hear. Thanks for the responses. I will soon have a new favorite hunting rifle.

Sorry for the newbie question, but I have never done a build.

Does this mean I can convert my existing 5.56 AR to 6.5G with a new barrel, BCG and mags? Is it an easy swap?

Yes on most of it...

ease of swap depends on your handguard. Some hanguards are pain to remove and reinstall but the short answer is everything is made to the same sizes so it's just swap out parts and you're good to go.

TheEyeGuy said:

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Yes on most of it...

ease of swap depends on your handguard. Some hanguards are pain to remove and reinstall but the short answer is everything is made to the same sizes so it's just swap out parts and you're good to go.

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I removed my stock handguard and replaced with a quad rail, so should be good to go!

The main issue you may run into is getting the gas block off. If it's pinned on... it may be a pain. You would also need a new gas block that isn't pinned on.

I want a 6.5 Grendel, but in the CZ 527 suppressor ready rifle. Unless I'm not seeing it, they only offer in. .300aac & 7.62x39. Of course I already have both of these in an AR. Thinking the 6.5 G would make a great youth rifle.

Only thing about the grendel is that it's not the greatest round for a suppressor. Don't get me wrong, I run a suppressor on mine, but I still use supersonic ammo.

I've got an armalite in .556 that I've never used, and won't use as a result of purchasing a DDM4. Can I convert that to something more fun? Like a .300 blackout?

Yes. IIRC, the .300 Blackout even uses the same BCG as the .223/5.56. I believe all you need is a different barrel and magazines.

Mags are the same. Just barrel.

Not always but sometimes the buffer needs to be changed when changing calibers to make it cycle correctly.

I assume that my 7.62 suppressor would work?

Even easier!

Yes

Ordered a Larue 6.5 grendel that they just released. Pretty excited about it.

03ki11erAG said:

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Ordered a Larue 6.5 grendel that they just released. Pretty excited about it.

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Talmbout!

I own a Larue in 5.56 & it is my favorite rifle. I really wanted to order one the other day but I was able to fight off the urge. You will not be disappointed.

ag0207 said:

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I own a Larue in 5.56 & it is my favorite rifle. I really wanted to order one the other day but I was able to fight off the urge. You will not be disappointed.

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They're solid rifles! Have a PredatOBR 7.62 and have had a few 5.56's come through my stores. The quality out of the box is second to none.

Preferences for barrel length?

J.D. c/o 05 said:

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Preferences for barrel length?

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I've heard the cartridge was designed for a 22" barrel. However, 20" seems to be the most popular, followed closely by 18". Shooters using it for more long range will go for a 24" barrel. All that said, if you go to 65Grendel.com, you will find guys making SBRs as well.

Makes sense, 18-20" is what I've seen the most of being sold online. I'm not one to ever be shooting extremely long distances so I might eventually settle on the 18". No Grendel SBR for me, but that might be entertaining reading.

http://www.65grendel.com/forum/forumdisplay.php?4-6-5-Grendel-Build-It-Yourself-amp-Custom-Builds

Thanks, looks like I've got my day officially killed.

These piqued my interest.

https://www.rainierarms.com/barrels/6-5-grendel-barrels/

But then my new upper setup was running up to $1500 real fast.

Deats said:

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These piqued my interest.

https://www.rainierarms.com/barrels/6-5-grendel-barrels/

But then my new upper setup was running up to $1500 real fast.

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I want heavy on a grendel because I'm going to shoot it long range, but a caliber like the grendel where you aren't going to be slamming rounds down range over and over is the one way that I really think I would be ok with having a thin barrel wrapped in an insulator. The heat build up scares me on a 5.56 or even a 300blk, but for a grendel, spc, etc, I can definitely see it being a cool combo.

Every Grendel I've ever built had/has an 18" barrel. Surprisingly the 16" barrels (and shorter) are growing in popularity and demand and you can read about why on the 6.5 Grendel forum, threads on Sniper's Hide, Arfcom, etc. People are finding that when shooting suppressed they're willing to lose a few FPS to gain better mobility and handling.

Thanks a lot for the feedback.

So given that I'll likely never shoot it suppressed or significant yardage (I may never take a shot over a few hundred yards) what would you recommend? 18"? This is really for the fun of the build (diversifying my AR collection) and maybe for a little hunting down the road. Budget isn't a huge concern, but I don't want to spend more money for capabilities I'll never use.

What is your recommendation for a 6.5 Grendel complete upper/conversion kit?

I can get 380 rounds of Hornady 6.5 Grendel and a LaRue Barrel for $450.

Am I CRAZY not to jump on this deal?? Asking for a friend.

I'd pass on that deal...pass it on over to me!

NRD09 said:

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I'd pass on that deal...pass it on over to me!

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So is it that good? I feel like I have blinders on and genuinely need a second opinion.

Grendel is going for a dollar a round right now, I'd jump on it