Maple Ridge Armoury AR10 Barrels. Shot targets added post #75 Nov 16th

[Bonjour43ma]

And.. International barrels initially told me no when I emailed asking for a barrel with the above specs.. Glad to see you guys providing a barrel with true 308 military precision rifle specs. Thank you!

If you want to tighten those groups up give 175 smk with 43.4 of varget or 44 grains of varget a try. The Federal Gold 175 is a bit slow and with the 18.6" length you're likely just a bit slow to hit the optimum accuracy. The 20" version will likely correct that for off the shelf match ammo while still shooting the above formula like a laser.

Waiting for the 20" version SPR....

Even with the 1:11.25 twist rate? What about shooting something lighter like a 168gr proj ?

[Epoxy7]

Even with the 1:11.25 twist rate? What about shooting something lighter like a 168gr proj ?

Yes I68 is a better bet for off the shelf match ammo due to FPS and the accuracy node . As is 167 Lapua. For reloads I use the same varget formula for both 168 and 175. Also I’ve had excellent results with 155 using this twist rate but in a longer barrel.

I suspect the reason the shown groups on this thread were as good as they were in that 18.6" barrel is due to a few combinations but predominantly the 5R rifling which does tend to give better velocity vs a non 5R rifled barrel. The twist rate is optimized for 167-178 rounds. The M118LR chamber is also excellent for these rounds. When they announced this project it's why I asked for those specs. When the KAC SR25 won the M110 contract they were actually using Remington 5R barrels and in 20". When you buy a LMT MWS 20" barrel it's also 1:11.25 twist as was the Canadian military AR10t with it's 24" barrel. These specs have been used for AR10/AR308 rifles in military applications since early 2000. Read up on the success that Remington 5R milspec owners have had which have this twist rate and have barrels based on recountoured M24 barrels.

Keep in mind that most off the shelf match ammo with Federal Gold being the standard are for a 20-26” barrel. With an 18.6” barrel some tweaking might be required. Federal gold is the civilian version of the Military round and military rifles are predominantly 1:11.25 twist rates.

A Federal gold clone round load is 43 grains of varget with 168 or 175 SMK bullet. A bit hotter at 43.4 or even 44 seems to be the ticket. I find it shoots a bit tighter even in guns that love Federal gold.

The results posted with these barrels at 18.6” and with 175 Federal off the shelf match ammo are exactly what I would expect, which is a good thing. They should be fairly easy to really dial in. Even easier in the 20” version which I’m waiting for.
Also I would suspect that 168 Federal Gold off the shelf match ammo might be even tighter shooting than that 175 Federal.

[Bonjour43ma]

Here's an interesting video on Faxon's pencil barrel. Supposedly with "proper stress relief"

Would your pencil barrels be similar to that claim?

[playinghooky]

Are these 308 barrels shipping this week?

[Maple Ridge Armourer]

Are these 308 barrels shipping this week?

Assembling and shipping all SPR barrels this week. Assembling and shipping all Pencil barrels next week. Then 6.5 Creedmoor barrels begin production.

I apologize for the delay, its not for lack of effort.

[playinghooky]

Assembling and shipping all SPR barrels this week. Assembling and shipping all Pencil barrels next week. Then 6.5 Creedmoor barrels begin production.

I apologize for the delay, its not for lack of effort.

Cool. Thanks

[Maple Ridge Armourer]

Here's an interesting video on Faxon's pencil barrel. Supposedly with "proper stress relief"

Would your pencil barrels be similar to that claim?

Interesting. The IBI blanks are properly stress relieved. We will run a test similar to this and post the results here.

For the 308 Pencil barrels we will burn 20 rounds between 5 shot groups. This should be sufficient to heat up the barrel since the wall thickness is similar to that of the 223 barrels but there is greater pressure and heat from the round. For the 223 Pencil barrels, we will do a 30 round dump as in this video.

Stay tuned!

[Bonjour43ma]

Wow looking forward to it! I'm still undecided between the .308 SPR or the pencil and your test will be awesome to help make that decision.

[RKRZ]

Finally received mine. Won't get a chance to shoot it until after the new year when the rest of my parts arrive from the US, so the only thing I can do is look at it.

Which leads me to notice this: while the barrel index pin and gas port are aligned with each other, they are misaligned with the fluting on the barrel. The asymmetry is unfortunate from an aesthetics standpoint. Not sure if there are any implications as to barrel harmonics.

[Epoxy7]

I should ask if the nitride process for the barrels is SAE standard AMS-2753? Also any issues with the heat of the process and the temper (heat stressing) of the barrel blanks?