The Now .260Rem Build Pt. 2
It has been quite a while since my last blog introducing the AR10 precision rifle platform. Originally I had my mind set on the 6.5 Creedmor. However, I decided to go with the .260Remington instead.
The barrel is made by Proof Research, and this is their carbon fiber AR barrel. If their suppliers don't have a barrel in stock, you will have to wait a few months for your barrel to be made as I had to. So far, the barrel was worth the wait! Hence why this "part 2" of this blog has taken a little while to report.
The components that I have added and were not listed in Part 1 are:
- Proof Research 20" carbon fiber barrel
- JP LMOS bolt carrier
- JP Gen 2 Heavy AR10 silent captured spring
- BCM Gunfighter charging handle
- Atlas bipod
- JP High Pressure bolt (was head-spaced by Proof upon barrel completion)
- Wilson Combat rifle length gas tube
Once I put the rifle together, I purchased a box of Remington Premier Accutip ammunition to use for the initial firing of the rifle. Little did I know, this would start a rabbit hole of "issues". I loaded the magazine with (1) round and attempted to load that round from the magazine into the chamber. Before firing, I looked to verify if the rifle was in battery and it was not. I tried to pull on the charging handle to extract the round, and I had to "pogo" the rifle to get the round out.
I looked at the ammunition and noticed that the bullet seating depth wasn't exactly consistent. I picked a round that appeared where the bullet was seated deeper thinking that maybe the COAL (cartridge overall length) was just barely too long for this chamber. That round was stuck and not fully into battery as well. I cleared the rifle, packed it up, and took it back home for further inspection.
I thought head-spacing could be off just a touch. Sean, the owner and gunsmith at Dunaway Custom Arms verified that the head-spacing was good. Although, he did noticed some light burs on the extractor that came with my JP HP bolt. So he cleaned that up to help the round seat more smoothly into the bolt face. I contacted Proof Research and they said it's most likely the ammunition needing a shoulder bump because their chamber tolerances are very tight. That is what I would like to hear instead of "the chamber was cut improperly". Tight tolerances is a good thing!
I spent a small fortune to buy 100 cases of Lapua brass, Winchester Large rifle primers, (1) pound of Varget, 100 123gr SMK BTHP bullets, and a set of Redding top notch match dies. This was not a cheap typical reloading re-supply trip. I put together a basic load according to my components and what was listed in the Sierra reloading guide. Chambering problem solved! To clear the rifle without firing the round, pulling on the charging handle was still a little sticky to extract the round. However, I didn't need to pogo the rifle to do so. I am sure once the rifle breaks in, this wont be an issue anymore. I tried multiple rounds in the magazine after the successful firing of only a single round in the magazine each time. It cycled without any issues.
Stay tuned for Part 3.
