6.5 Grendel OAL Issue AR-15

james1205

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I built my Grendel around an AR Stoner 18" LBC 264 barrel. Using a Hornady OAL Guage measuring Nosler 100, 120, and Hornady 123 AMAX bullets I come up with a maximum OAL of about 2.20 for the first two and 2.239 for the 123 AMAX. The factory Horndady 123 AMAX are about 2.245 OAL. Their test data for 123 AMAX is 2.245 OAL.

Anyone else reloading Noslers or the 123 AMAX come up with similar numbers? I may very well be doing something wrong here. Any recommendations?
 

High Binder

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Re: 6.5 Grendel OAL Issue AR-15

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sundowner</div><div class="ubbcode-body"> These seem awful tight </div></div>

What do you mean by tight?
 

country888

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Re: 6.5 Grendel OAL Issue AR-15

Need more information, what powder are you using? Why do you ask? Are your loads acurate? Using different powders with different bullets you will have different OAL's. Remember that most data and posts you see on OAL is messured from case head to bullet tip. When you use a comparator like Hornadys' to messure your OAL it will be shorter than what most of your book data shows, or what people are posting because of where the comparator is measureing to. The comparator measures to the bullets ogive, not to the bullets tip. Im not sure if this is your problem or question, but I hope this helps out alittle.
 

Wannashootit

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Re: 6.5 Grendel OAL Issue AR-15

What does the powder/load have to do with the round's OAL?
You lost me there...

Sundowner,
We have the exact same barrel on a Grendel we built this summer.
Also we use the bullet comparator for all our bolt guns, but have not tried it for the 6.5 Grendel. I've always assumed that mag length is going to limit my OAL, and I won't be able to load to the lands, anyway so I haven't bothered. Usually I've found semi's are chambered so generously that loading to the lands isn't possible.

Anyway-
Your info is a bit confusing. Sounds like you set the bullet length by using the bullet comparator to measure to the ogive- then measured the overall length in "typical" fashion?

Not sure I'm following you, but that's mixing apples and oranges.
You have to make your comparisons to the ogive length given with the comparator...and completely forget about a typical OAL measurement.

So, what does the factory load measure to the ogive- and what does the comparator tell you using the modified case and the 123 A-Max bullet? Subtract the usual .01 from that length; how does it compare to the factory ammo?

If the comparator is telling you that you're jamming the bullet into the rifling, then I would agree that you have a chamber issue with the barrel. The 123 is certainly within the specs of what the 6.5 Grendel can chamber.

In fact, I have some 140's...and while they're pushing the limit, Bill Alexander has told me they will work...
 

james1205

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Re: 6.5 Grendel OAL Issue AR-15

Thanks for all your responses. All good comments. I will expand a little. I understand measuring the ogive with the comparator, with each bullet in each gun/chamber, etc.

The significance of mentioning OAL is simply to honor the 2.260-2.265 OAL restriction of the AR magazine.

All the load data I have seen, Alex Arms data on their website, the Hornady Data on their 123, load data on the 6.5 Grendel website, etc., all give OAL of 2.245, 2.260, 2.250, 2.255. I am sure you all are familiar. I will give you one example of what I discovered, and I agree powder has no relavance here.

(After extensive load development with Nosler 100 gr BT starting at 25.5 grains of BLC-2 steping .3 grains per 5 rounds loaded I settled on 26.5gr BLC-2, giving me .375" at 100yards. I used an OAL of 2.258, just like all the data showed, and no pressure signs at all.)

So what's the problem? The problem is:

While firing this excellent load at the range I had a misfire/light hit. Waited 2 min and attempted to eject the live round. The round was hard to eject. Finally, it popped out, and the bullet was way out fo the case neck. There were land marks on the bullet as if it had been driven into the lands. The 2.258 cartridge I loaded into the chamber was compressed/jammed/slammed to about 2.220, the bullet stuck in the lands, and upon manual ejection came out of the case neck far enough to be quite noticable. I found the same to be true then with 120gr BT Noslers and Hornady 123s that I had loaded to 2.260, the maximum magazine case length. Therefore, I can not load these bullets in this AR-15 Carbine anywhere approaching magazine length, in an 18" AR Stoner .264 LBC AR barrel. That is my question. Anyone else shooting this combination experienced a problem like that?

Finally, for the technicals, here are some detailed numbers to perhaps help explain. Just for 100 BT Nosler bullet. Ogive measurement is 1.694 minus .020-.040 for "jump" to lands [although Noslers like to be "snug" to the lands], puts my fully reloaded bullet length at 2.193. The maximum measured OAL in this chamber with a Nosler 100gr BT bullet is 2.233, measured about 50 to 60 times. I can not load this bullet longer than 2.233 when all the data I read says I should be able to go to 2.25-2.26.

When I measure the Hornady/Hornady 123 bullet in my chamber, the maximum OAL is 2.240. When I load the Hornady Factory 123, OAL of 2.245 and manually eject it, I have land marks on the bullet. It is jammed into the lands, albeit only .004-.005.

Anyone experience similar problems reloading for the .264 LBC AR, that is the question. Thanks again for your interest.
 

High Binder

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Re: 6.5 Grendel OAL Issue AR-15

Did the primer fire when you had this "light hit"? What I'm asking is, is it possible you missed putting powder in the case and the primer drove the bullet into the lands and it was hard to eject because you were pulling the bullet out of the rifling?

Obviously something forced the bullet forward and into the lands.
 

Tactical30

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Re: 6.5 Grendel OAL Issue AR-15

Thats the famous Grendel "Compound Throat" to where most bullets are somewhat jammed into the lands.

Google - 6.5 Grendel Compound Throat.

By the way your 100gr. Data with 25.5gr. seems kinda low to me. Im loading the 120gr. NBT with 31.4gr. of blc2.

Call or email Bill A. about your problem. I kinda ran into the same kinda problem when i started loading for the Grendel. I got it all figured out tho. I dont want to go into detail right now how cuz im on my cell and its a pain in the ass for me to type on these smart touch phones! Pm me and i will get back.
 

Tactical30

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Re: 6.5 Grendel OAL Issue AR-15

Thats the famous Grendel "Compound Throat" to where most bullets are somewhat jammed into the lands.

Google - 6.5 Grendel Compound Throat.

By the way your 100gr. Data with 25.5gr. seems kinda low to me. Im loading the 120gr. NBT with 31.4gr. of blc2.

The. 264 lbc does not have the same throat as yours. The LBC is more forgiving.

Call or email Bill A. about your problem. I kinda ran into the same kinda problem when i started loading for the Grendel. I got it all figured out tho. I dont want to go into detail right now how cuz im on my cell and its a pain in the ass for me to type on these smart touch phones! Pm me and i will get back.

I have been reloading for the Grendel for several years now.
 

Wannashootit

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Re: 6.5 Grendel OAL Issue AR-15

I hate to say it, but I can't see how it can be anything other than a badly chambered barrel.

I don't have the 6.5 Grendel modified case or I'd run it on the OAL gauge to see what I get. I can tell you that while the rifle is fairly new, we've run a few hundred rounds of the 123 Amax through it- factory and reloads at an OAL of 2.25- and have no issues.

The Stoner barrels are made by E.R. Shaw- I'd call them up and discuss the issue with them.

I thought only AA'a barrels had the "compound throat" deal...I have the same barrel as the OP and don't have a problem...
 

Muttt

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Re: 6.5 Grendel OAL Issue AR-15

Chances are when the bolt slammed that round into the chamber, the bullet started to slide out of the case from the force of the bolt ....... and stuck in the lands. I've had this happen.


Talk to the guys over on www.65grendel.com/forum/forum.php

Bill Alexander is on the forum quite frequently.


I normally use a AOL of 2.255 with my 18 inch liberty barrel. Not sure how far down the pipe your lands start in that barrel. That you'll have to measure on your own and work from there.

I did have a big problem with my reloads in the begining. I use Redding dies for my Grendel and was using a standard RCBS shell holder. I figured they were all the same. In actuality, my FL die was not going far enough down the case and was leaving the last little bit unsized. This was making my cases stick in my chamber. Eventually, I shaved down the shell holder and that fixed my problem. Turn out, the Redding shell holders are much shorter than the RCBS shell holders and that was the reason for my problems. I've since fixed that.

Both the .264 LBC and CSS use a different throat than the Alexander Arms Grendel Throat. The non Grendel throats are having some issues with some of the factory ammos. Stick with a Grendel throat and you won't have any issues.
 

james1205

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Re: 6.5 Grendel OAL Issue AR-15

Wannashootit said:
"I've always assumed that mag length is going to limit my OAL, and I won't be able to load to the lands, anyway so I haven't bothered. Usually I've found semi's are chambered so generously that loading to the lands isn't possible."

Thanks, Wannashootit. You hit the nail on the head. That is what I thought too, and what I "assumed," until that live round popped out looking like a 25-06 instead of a 6.5 Grendel. So, I took out my Hornady OAL Case Length Gauge and you know the rest of the story.

Thanks to the good responses, you all have about cleared this up for me.
 

james1205

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Re: 6.5 Grendel OAL Issue AR-15

Thanks longrange30. I took a look at the 6.5 Grendel Compound Throat articles and it is all to familiar with what I am experiencing with the Noslers.

My barrel BTW, is 18 inch, .264 LBC 1:8 from AR Stoner/ER Shaw.
Therefore, I should not be having this problem, but it is what it is.

Also, my 120 BT Nosler loads with BLC-2 are 29.2 and give me .641" at 100yds. I am really only interested in 200-500 yd accuracy and just use 100 yds to check pressure, velocity, etc.

Thanks to longrange30 and wannashootit I have a better understanding of what I am dealing with and consider this thread closed, unless someone has a real gem out there. Thanks all, and watch the wind.
 

country888

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Re: 6.5 Grendel OAL Issue AR-15

I have a 18" saturn grendel barrel. I first loaded some 95gn v-max's to try. I loaded them to mag length like everyone else. I tryed to open the bolt after loading one and couldn't. After taken a rubber hammer to get the bolt open on a side charger upper, mine did the same as yours. Then bullet had been jammed into the lands, and pulled the bullet out of the case. After measureing the OAL to the lands with a cleaning rod, I found mag length for that bullet was way to long. The OAL for 95gn V-max in mine is about .250 shorter than mag length. And they shoot great now! Now I measure for OAL for all bullets in it, and do not just set to mag length. No problems so far. But I don't go by mag length anymore, I measure all of them to the lands.

You say your giving ".20-.40 for jump"

<span style="font-weight: bold">Ogive measurement is 1.694 minus .20-.40 for "jump" to lands [although Noslers like to be "snug" to the lands], puts my fully reloaded bullet length at 2.193</span>

Is this a typo or where did you get .20-.40 for jump? I use .005-.020 for jump. This my be your problem.

Im just asking, not criticizing you.


 

Wannashootit

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Re: 6.5 Grendel OAL Issue AR-15

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: country888</div><div class="ubbcode-body">
Is this a typo or where did you get .20-.40 for jump? I use .005-.020 for jump. This my be your problem.

Im just asking, not criticizing you.

</div></div>

I saw the same thing but forgot to ask... I was assuming it was a typo and meant .02-.04..
Nearly a half inch would definitely be a problem !
 

james1205

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Re: 6.5 Grendel OAL Issue AR-15

Phat Finger error, .020 is correct. 2.220 OAL with the 100 BT Noslers manually ejected well today with no serious marks on the bullets. Thanks for your comments country888, that is exactly what happened to me, and thanks to all for your interest.