6.5 creedmoor ar10

[farmerboy78]

Neck marks look like excessive ejector pressure and a barrel extension which needs "melted". An AGB might only slightly help that issue, but the solution is really to balance your ejector and dehorn the lugs on the port side of the extension. Less gas will help with your CHS, adding some carrier or buffer weight may help too - but the AGB is the best path.

I'd never drill a hole in the side of any of my bolt gun barrels (which didn't yield compensating benefits), so I'm not a fan of off-bleed gas blocks either.

When you say to deform the port lugs, do you mean to round them over or what?

 

[Varminterror]

Yup. Get a small, fine diamond file, some popsicle sticks and wet/dry papers, and some lapping compound. Spend a half hour of your life dehorning your bottom two bolt lugs, your feed ramps, and your barrel extension lugs on the lower and port sides. Watch how the cartridge feeds into and out of the chamber, you'll see the contact points which need radiused.

 

[farmerboy78]

Hello again, I took this rifle out this evening for a good ole Arkansas deer hunt. I was using the 140gr eld match ammo and took her @ 132yds right behind the shoulder. She ran maybe 40yds and piled up! The barrel is producing 0.5" to .625" groups @ 100yds with factory ammo above, when I do my part... May not even reload for this thing when it shoots factory ammo that well! I tagged and checked her with the agfc and then gave her to a family in need!

 

[ColoradoMinuteMan]

I'm partial to SLR Rifleworks adjustable gas blocks. It's a detent style that takes down for easy cleaning if needed.

My SLR gas block has worked out really well. A really nice positive detent and comes apart so you can easily clean everything as you mentioned.

Hello again, I took this rifle out this evening for a good ole Arkansas deer hunt. I was using the 140gr eld match ammo and took her @ 132yds right behind the shoulder. She ran maybe 40yds and piled up! The barrel is producing 0.5" to .625" groups @ 100yds with factory ammo above, when I do my part... May not even reload for this thing when it shoots factory ammo that well! I tagged and checked her with the agfc and then gave her to a family in need!

Awesome, congratulations. One comment on the brass abuse. I had a similar issue with a Aero Precision / Faxon build. Faxon was very helpful and suggested polishing the edges of the ramps and lugs with Cratex on a Dremel. It worked great to nock down the sharp edges and my brass is much happier now.

https://www.cratex.com/Products/Rub...MIzMLJwMS51wIVxol-Ch0e2ADjEAQYAyABEgKFuPD_BwE

 

[farmerboy78]

Well, the creed strikes again! The rut is on here in arkansas... I took a 9 point buck this evening @ 295yds... hit him right behind the shoulder and he went tumbling after a short 75ish yd run... the eld match ammo is a buzzsaw on whitetails!

 

[farmerboy78]

Update:

I've still been shooting the hornady 140gr eld
Ammo and recently saw an issue with it once I took it to long distance. Out to 500yds the ammo is spot on. At 700yds and further I was seeing some huge velocity differences with the poa vs poi. I was consistently hitting in a moa area and suddenly rounds were hitting in a 2' area when I opened a different box of ammo. Then closed back up on another box. I didn' have a chrony to give me exact numbers, but it seemed as though there was a qc issue in there somewhere. Anyone else seen an issue like this?