My first 6.5mm Grendel Project - after 3 .223 Rem AR-15s

[45r]

A very accurate load I've been using is 27.6 grains AR-comp under 123SST's and rem 7 1/2 primers.
AR-comp is made in Sweden for Alliant.
It is similar to RE-15 and optimized for AR's.
It shoots sub MOA in my Grendel and 264LBC.

[Kohoki]

[KentuckyBuddha]

Thanks! That is interesting. I have also been considering a Geisele S3G as well. I am probably ok with the stuff I have though. LOL

[Kohoki]

I am facing precision troubles, the best groups I was able to realize with my setup were about 24mm/ 0.98" with

Lapua Brass
27 grs XBR 8208
123 grs Lapua Scenar
57.1 mm C.O.A.L.
CCI 450 Primer

I used a benchrest rifle rest setup like these: Benchrest rifle rest

This setup usually enables me to realize 5 shot groups of sub moa size with all my rifles.

What do you guys suggest?

[JDub]

If you have not been measuring and recording your velocities with a chronograph, that would be the next step.

You are so close. The difference between .98in. and what your rifle is truly capable of may come down to shooting conditions or other external conditions not related to your load.

[Kohoki]

Hmmm...I have to admit, that a five shot group @100m with a diameter of .98"/24mm is not what I am about to accept. I am able to compare that rifle with my Sabre Defence XR-15 M5 in .223, this rifle produces 12 - 18mm groups with almost every 52 grs. or 55 grs HPBT ammo on the market (preferably Remington Premier Match or GECO). I am expecting this also from my Grendel but we tried about 20 different loads up to now with 24mm as top load...

[A.D.D. AR]

Kohoki- have you gone above 27.0 grains XBR in your load testing? If not , I would try working up in .2 grain increments to about 28.0 grains, somewhere in that range is where most guys see their best accuracy with 123gr bullets.
But once you go past 28.0 grains, pressure can spike quickly, so be careful.
-hope this helps,
mike

[Kohoki]

Hornady OAL Gaugefree travel of about 0.1488"

Hornady recommends a free travel of 0.040" - everything longer than that should result in a loss of accuracy.

I think I found the root cause for the lack of precision - what is your free travel? Does anyone of you has this kind of long free travel space and is able to create sub moa groups?

[Kohoki]

See also the


Share your max. C.O.A.L. thread...

[Kohoki]

Hi guys,

the results of my tests reached thoughtful ears, I will receive a new barrel with minimal free travel/jump. Awesome customer service @LW in Germany!!

[Kohoki]

It is done!

Guys, I made it,...my gun made it into the German CALIBER magazine! The February issue will have an 8 page special about the gun I build up. As soon as I am allowed to post pics you will get them!

Just for your information: the best group we were finally able to produce was 8 mm wide!!! Cheers to Dave Manson from Manson Reamers, he made it possible!

[NugginFutz]

Excellent news, and congratulations!!

We'll be waiting with anticipation for your pictures. Does CALIBER have an online presence? I was unsuccessful in looking them up.

[KentuckyBuddha]

Excellent job!! For my fellow 'murricans that have not spent years in the company of our Euro brethren that is 'bout 1/3 moa.

[Kohoki]

Ok guys, the magazine has been released and I have the permission to post pics online - sorry for the crappy quality, I will add HiQuality Wallpaper stuff later:

http://s34.photobucket.com/user/kohoki/slideshow/6-5%20GRENDEL%20AR-15

[KentuckyBuddha]

That is awesome sir!! The A-10 nose art is a great touch. : )

So many parts to be jealous of. Congratulations on a great job!