Difference between .264 LBC-AR and 6.5 Grendel?

[libertyman777]

Well, it's been a while since I've been around and priced Grendel parts, uppers, etc. I have a buddy that's building me a 6.5 Creedmoor. I have a AR15 lower A2 configuration RRA with 2 stage trigger. I can't think of a better thing to do than build an upper that handles 6.5 bullets.

So, I'm looking around and see this new rendition of the 6.5. Looks like what AAC did with the .300 Whisper coming out with .300 blackout. They made a few changes but the rounds are interchangeable.

I just bought my first Grendel part, a set of Lee dies in 6.5 Grendel. I assume that if I go with the .264 LBC-AR that my dies will work?

I'd like to go with as short a barrel as possible with my rifle length tube and buffer. I believe that 18" is my limit.

I've found what looks to be a good deal on a barrel. It's here>

http://kiesfirearms.com/Parts_and_Accessories.html

It's an 18" in a SDMR/SPR profile. Threaded 1/2-28. Mid length gas system. Price is $220. I believe it will require an adjustable gas block.

But I'm open to suggestions, comments on barrels. J&T looks interesting but I'd be concerned about the weight of the 20" bull.

I'm open to a 20" rifle but no longer.

All input welcome.

Thanks,

Paul

[LRRPF52]

Who knows what chamber reamer they're using for .264 LBC-AR. Kies Firearms will have to weigh-in on that one, as we've seen all kinds of chamber variations, many of which don't eat all the factory ammo out there due to shorter throats, tighter necks, and other variables.

You really don't want a 1/x28 thread for a Grendel. It can be done, but it leaves little mass at the muzzle for accuracy, and allows unsafe muzzle devices to be installed which have tighter bores for .223 Rem. I'm guessing they more than likely use a different thread pattern.

AA fixed an upper for a forum member recently, where an unknown barrel was involved that had 1/2x28 muzzle threads. It wouldn't feed anything for love nor money, and had too large of a gas port diameter. AA pulled the barrel and installed a Grendel-chambered one, even though it wasn't theirs.

The Grendel chamber is SAAMI approved for over a year now. It has been tested with hundreds of thousands of rounds, and is a known quantity. There are a lot of unknown quantities out there, with varying results: some functional, and many not. I would urge barrel makers and shops to go with the actual Grendel chamber in an AR. For a bolt gun, it's not such a huge issue but for reliability in the AR, the Grendel chamber not only works great, but provides accuracy as well.

[VASCAR2]

The Kies barrel does not include the bolt according to what I've read on Joebob's outfitters site. The Kies barrel I looked at took a 7.62 X 39 bolt. I read on a predator forum where a customer had issues with a Kies 264 LBC. The price is not that good if you add in price of the bolt.

I have a 16" J & T and am completely satisfied and I'm seriously thinking about ordering a 20" from AA because of the profile.

[Variable]

Well, it's been a while since I've been around and priced Grendel parts, uppers, etc. I have a buddy that's building me a 6.5 Creedmoor. I have a AR15 lower A2 configuration RRA with 2 stage trigger. I can't think of a better thing to do than build an upper that handles 6.5 bullets.

So, I'm looking around and see this new rendition of the 6.5. Looks like what AAC did with the .300 Whisper coming out with .300 blackout. They made a few changes but the rounds are interchangeable.

I just bought my first Grendel part, a set of Lee dies in 6.5 Grendel. I assume that if I go with the .264 LBC-AR that my dies will work?

I'd like to go with as short a barrel as possible with my rifle length tube and buffer. I believe that 18" is my limit.

I've found what looks to be a good deal on a barrel. It's here>

http://kiesfirearms.com/Parts_and_Accessories.html

It's an 18" in a SDMR/SPR profile. Threaded 1/2-28. Mid length gas system. Price is $220. I believe it will require an adjustable gas block.

But I'm open to suggestions, comments on barrels. J&T looks interesting but I'd be concerned about the weight of the 20" bull.

I'm open to a 20" rifle but no longer.

All input welcome.

Thanks,

Paul

Not a good deal at all in my opinion. You can order a real Grendel barrel for less than that from AA directly....

http://www.shopalexanderarms.com/Rifle_Barrel_Kits-18_Lite_6.5_Grendel_Barrel.html

Either way you still need to buy a bolt. If you get a bolt and barrel together from AA you'll at least know they were actually intended for each other, and AA will stand behind it if there were any problems.

If you order from AA it might take a while (with the current election craziness), but you'd be far better of IMO to simply order from the source and get the real thing. It sucks trying to save a dime and then ending up spending a bunch of dollars on shipping back wrong stuff, aggravation over wasted ammo during function checking, ending up with things you aren't happy with, etc., etc., etc....

I also wouldn't own (or sell) a 6.5 barrel threaded in 1/2x28tpi. That is a dangerously stupid idea in my personal opinion, and should provide you with a giant "wave off" flag right there...

[Bill Alexander]

The Grendel chamber uses a 0.300" diameter neck and has a compound throat, allowing it to digest a wide variety of ammunition. It is a SAAMI standard. The 264-LBC has a tighter 0.295" diameter neck and has a conventional free bore of 0.120" length. Depending upon the version the neck length may vary and in some instances it may not allow the use of factory ammunition. The shoulder radii are also variable and may also give problems. The Grendel centers the projectile in the bore using the projectile as the reference. The LBC uses the case neck.

In deference to the LBC it will frequently match the accuracy of the Grendel with specific loads.

[libertyman777]

Thanks so much for the input. I certainly want to do what is best and what is safe (which normally is one and the same).

Most of the Grendel barrels I have seen are 9/16-24 RH. My suppressor is a .30 can that is 5/8-24 IIRC. Who would y'all recommend for an adapter?

Is the 20" barrel similar in weight to a standard HBAR 5.56 20" barrel? I'd like my build to have that kind of balance.

Also, what are considered suitable uppers? Does the upper need the M4 ramps?

[woohoo]

. The Grendel centers the projectile in the bore using the projectile as the reference. The LBC uses the case neck.
.

This is just not true.
The freebore in the 264LBC chamber is .2645 the bullet is .264. The bullet will align itself in the bore the same way it does in the Grendel chamber. The neck of 264 chamber is not small enough to touch the loaded case with a difference of .007 between them.
The only way the neck could align the cartridge is IF the 264 freebore was .007 larger than the bullet dia.

[parallax]

I shoot a 20" SAOD and the Lee dies work just fine.
I've had zero problems shooting Wolf factory ammo or Hornady Amax 123's or any of my reloads. All are accurate but the reloads using the 123 Amax's are extremely accurate when I load them over 27.7 grs of 8208 in PPU brass. I expect as good or better when I start reloading my accumulating Hornady brass.

[LRRPF52]

Which bullet will align itself in the bore of the .264 LBC chamber? VLD-types, tangential ogive types, the shorter 85-100gr varmint pills? If factory ammo is loaded for the COAL of the Grendel's compound throat, how does the .264 chamber indicate to that?

To me, it would seem that start pressure and jump characteristics would differ. The Les Baer chamber was specifically built around the 123gr SMK for target accuracy, but it seems that most Grendel owners are just as interested in hunting as they are target-shooting. A lot of folks want to be able to run the 100gr TTSX, as well as the 120gr NBT, then turn around and blast away with the 123gr factory AMAX.

With the Gendel, we can run all those pills at the same COAL.

[woohoo]

Do you load your point of tangent/ogive back in the case? I don't and don't know anyone that does. I mean maybe sure some beginner may shove the bullet back so far in the case that there is a gap between the case mouth and bullet but most have enough sense to load properly. The bullet is .264 it can only move side to side from 1/4th of 1 thou.
The freebore in the chamber starts at the same place in the Grendel and 264LBC chambers. The .2645 dia freebore in the chamber and the .264 dia of the bullet is what aligns the bullet UNLESS you stuff it in the lands and in that case they both work the same, either can be stuffed into the lands. If the bullet in either is stuffed into the lands it aligns in front of the point of tangent on the ogive instead of behind the ogive where the bullet is a full .264 like when jumping to the lands like most factory ammo is loaded.

[Bill Alexander]

The LBC chamber does not align the projectile as effectively as the Grendel chamber. It can report accuracy but is considerably more temperamental than a Grendel. Your reasoning does not account for the ogive position reference the free bore. The longer projectiles will frequently not provide a 0.264" diameter bearing surface at the position the free bore commences.

[woohoo]

If the bullets in either the Grendel or LBC chamber are not stuck into the lands the freebore aligns the bullet in the barrel. In both chambers the freebore starts apx .015 in front of the brass. Using a 45 degree angle from the outside diameter (which the Grendel is larger at .300) of the neck to the freebore diameter of .2645 the start of LBC freebore is actually closer to the case mouth supporting more of the bullet, a small amount but still closer. I don't see how one tube .2645 in dia can align a bullet better than another tube .2645 in dia.
If any bullet is loaded with the start of the ogive back in the case mouth it isn't stuffed in the lands so the lands in the throat is not supporting the ogive of the bullet or aligning it in the bore. In that case the smaller diameter of the bullet ogive would be resting on the edge of the 45 degree angle at the start of the freebore and accuracy would be terrible IMO.
I get your argument that you think after the bullet starts moving and engages the lands in the throat your compound throat works better with more bullets as an all purpose throat/chamber. That is up for debate but I understand why you say you did it.

[Overwatcher]

Not a good deal at all in my opinion. You can order a real Grendel barrel for less than that from AA directly....

http://www.shopalexanderarms.com/Rifle_Barrel_Kits-18_Lite_6.5_Grendel_Barrel.html

Either way you still need to buy a bolt. If you get a bolt and barrel together from AA you'll at least know they were actually intended for each other, and AA will stand behind it if there were any problems.

If you order from AA it might take a while (with the current election craziness), but you'd be far better of IMO to simply order from the source and get the real thing. It sucks trying to save a dime and then ending up spending a bunch of dollars on shipping back wrong stuff, aggravation over wasted ammo during function checking, ending up with things you aren't happy with, etc., etc., etc....

I also wouldn't own (or sell) a 6.5 barrel threaded in 1/2x28tpi. That is a dangerously stupid idea in my personal opinion, and should provide you with a giant "wave off" flag right there...

Firstoff I'm not trying to discourage a purchase of any AA product.
I have a KIES barrel chambered in 6x45.
Being a machinist by trade the fit and finish is superb.
On the site its also says any caliber larger then .223 is going to be 5/8-24. Mine is.
KIES also has a lifetime warranty on any of his product.
Give him a buzz super nice guy.
No sense in making claims when simply all of it is untrue.

[LRRPF52]

I like what I've seen with the Kies gas blocks, that's for sure. Good to see they're using a thread larger than 1/2x28 for the larger bores.

[Variable]

On the site its also says any caliber larger then .223 is going to be 5/8-24. Mine is.

OK, better.LOL "Wave off" flag retracted.