Christmas present to myself .... a 6.5 Creedmoor barrel.

[MCMXI]

After a lot of thought and some amount of trepidation I ordered a 6.5 Creedmoor barrel for my AI AW currently chambered in .308 Win. The rifle is so good in .308 Win format that in all honesty I wish I could keep the .308 Win as is and buy another AI in 6.5 Creedmoor, but I simply can't justify that kind of expense at the moment. I used the AI for hunting this fall with good success and will most likely use it for coyotes and paper punching with the 6.5 CM barrel. It takes about 10 minutes to swap the barrel, maybe less, so I could realistically switch between the two if the need arises. I plan on buying a SANDMAN-L suppressor from Dead Air Armament to test out their QD system. I'll use it with the new barrel that ships with 5/8-24 threads on the muzzle rather than AI's standard M18x1.5 threads. My biggest concern is handloading since I plan to work up a match load in 6.5 CM. Taliv and others have mentioned the firing pin/primer issue with AIs but MHSA has indicated that they might soon offer a firing pin "bushing" service .... factory approved I would assume. Either way it should be fun to see what the AI is capable of with the new barrel. My gf has a tack driver of a rifle chambered in 6.5 x 47 Lapua so I might be able to keep up with her now with the 6.5 Creedmoor.

 

[txblackout]

me too. I ended up ordering a remage criterion barrel to replace a 308 barrel on a rem 700 in a mcmillan stock.

Cheapest way to try out 6.5 creedmoor.

 

[MCMXI]

I received the new barrel from Mile High earlier in January but with two work-related trips and a week in Hawaii in January I never got around to swapping the barrels on my AI until today. In truth I needed a distraction since one of my Rottweilers passed away on Saturday and it's been an emotional roller coaster since then. Swapping the barrels and shooting a couple of groups helped me to focus on something else for a few hours at least. My mind was wandering and that's probably why I used Hornady 120gr GMX for the first five shots with less than stellar results. After cleaning the barrel with foaming bore cleaner and making a windage correction on the scope I shot five more rounds. For the second group I used Hornady 140gr A-MAX (the ammunition I meant to use from the start) with encouraging results.

I'll be working up two loads for this barrel. A match load using 130gr Berger VLD bullets and a hunting load using Barnes 120gr TTSX bullets. I'll use the same powder for both to negate the need to "season" the barrel when switching between the two. The Bartlein barrel has two odd flats near the muzzle which according to MHSA were required for the PSR contract. I have "legacy" AIs so the flats are redundant. It's odd that the flats don't index at 12 and 6, or 3 and 9 but accuracy seems to be good regardless.

 

[MCMXI]

The group above was shot with the thread protector installed. The next group (when the snow stops) will be shot with a Dead Air KEYMOUNT brake attached since that's what I'll be using with or without a SANDMAN-L or - S, both of which will be arriving shortly. I've used the DA brake on other rifles so don't expect any issues.

 

[MCMXI]

More results with the new barrel. I shot the targets on the left and bottom on Monday. The Hornady GMX load didn't perform that well but the 140gr A-MAX is a very good factory load for this rifle with all three 5-shot groups around 0.5 moa. Today I shot the top target first with no scope correction followed by the target on the right with the Dead Air brake attached (hand tight). The mirage off the barrel for the second group was bad since it was 30F in my shooting room! I made a scope adjustment for the group on the right. If it wasn't for the one messed up shot in the top group I would have had a 5-shot group in the .2s! I'm fairly sure that these groups will shrink once the suppressor is here.

 

[Corn-Picker]

How does the AI barrel attach to the receiver (headspace)? I have a TC Dimension swap barrel, there is a barrel nut and the bolt lugs lock in the barrel -- no headpsacing necessary. It looks like AI uses a different system but doesn't require head spacing. Impressive shooting.

 

[MCMXI]

Corn-Picker, I have the "legacy" AIs so the barrel is removed and installed using an action wrench that fits inside the receiver. The receiver unscrews from the barrel and the shoulder on the barrel tenon controls headspace so you can imagine how tight the machining tolerances have to be. Every AI barrel and bolt (for the same family of cartridges) are interchangeable. I find this amazing given that they don't use a barrel nut system like Savage. These rifles are easy to shoot so decent groups are the norm.

 

[MCMXI]

After measuring once and twice fired (neck-sized only) cases from this barrel, and buying a NO-GO gage, it was clear that the barrel was at the upper end of the SAAMI chamber spec. I sent it back to MHSA and one of their gunsmiths took .005" off the shoulder that butts up to the receiver. I got the barrel back earlier in the week and put the barrel back on yesterday. I shot a couple of groups (44.0gr and 44.3gr of Reloder 17) to make sure that the barrel is still shooting well. Clearly it is, and now the chamber at the shoulder datum is around .002" over a PT&G GO gage. Once fired new Hornday cases grow at the shoulder from -.0035" to .0010". Twice fired cases (neck-sized only) grow from .0010" to .0020". They were growing to +.008" before! 44.0gr is a real sweet spot for this barrel. If 44.6gr shoots well and to the same group center location I'll call it good and then start playing a little with bullet seating depth. The bullet is currently about .020" off the lands, virtually the same length OAL (within .0015") as factory Hornady 140gr A-MAX match ammunition.