pnutty

I have a few questions for you, if you dont mind. Is it worth it to use a muzzle brake on a hunting rifle, and regarding the cantilever mount, is that a Leupold mark ar mount? If so how do you like it, I have seen them go for a pretty good price so I was suspicious about the quality.

Nice elk 👍 Could you share the build details?

I visited my lgs and he had one more aero m5 upper hidden away that he let me purchase. I already built an upper just for steel targets so I thought maybe I could build this upper for hunting whitetails and the occasional coyote that gets in the way. Has anyone successfully used a large ar platform for hunting and if so, how is it set up? I was thinking 7mm-08 for the caliber with a 16”-18” lightweight barrel, but im open to any and all suggestions!

I did put a box of S&B 140g fmj through it and no pressure signs I saw except some but not all of the primers are flattened. One thing I noticed is compared to my bolt 6.5CM (I know apples to oranges) is that the firing pin indent is much deeper, I don’t know what the spec is for large frame ar’s but I measured using a depth micrometer and from front of bolt to bolt face is .125” and front to the tip of the firing pin when engaged is .076” so that’s a .049” protrusion. Possibly this could be an issue as well? One last thing is that I do have srp 6.5 brass for my other gun as well, would that have any advantages to use with a gas gun?

I will, I ran this load in a bolt gun with no problems but that’s a different animal.

It was a handload, 40.2g of imr4451 over 140g sst. Primers are cci #34

Hello everyone, I finally taken my first large frame 6.5cm build to the range and everything worked great. Put 70 rounds through it and no issues functioning but I was puncturing primers. (Indoor ranges aren't ideal but it was good enough for a function test and scope zero) When I got home and started to clean it, I couldn't remove the cotter pin at all. I had to clamp onto the round part of the cotter pin with the corner of the vise and yank it out that way. Once I got it out I found the pin was bent to hell, I also noticed a few pieces of primers that came out when I finally got the bolt apart. (Primer pieces are at very top of the photo) From my research, the primer issue is because of excessive clearance between the firing pin and hole. I measured my firing pin hole at .082” and the firing pin tip at .077”, I found that cmmg makes a .08” firing pin for their mk3 model rifles. My questions are if the cmmg firing pin will work in my dpms bcg and if the primer cups getting lodged in the bcg are the reason the cotter pin bent. Specs are m5 receiver sets cmmg lpk armalite recoil setup dpms bcg ba 6.5cm 20” barrel rifle gas length

Absolutely, I was stalking this place for awhile before making an account. I wanted the entire Armalite recoil setup but the tube and buffer seem to not be available anymore.

Hello from another ban state dweller as well ,as I am in the peoples republic of NY. Just curious how you made yours "compliant" as in Ny, the most common thing to do is pin the mag which is what I did.

Ended up getting the barrel installed, gas tube looks is right in the middle of the cam cutout and I used the bore scope to make sure the gas block was aligned. Just waiting on a few more parts to finish it up.

Good points on everything, the rods put the torquing stress on the steel barrel/extension instead of the aluminum upper receiver. I do have to ask, have you ever had the index pin slot deform or get damaged using the action rod method? I read some stories about that happening but they were with the smaller platform and not the larger platform.

That was an experience I bet, what is your suggested way of installing and removing barrels on these 308 uppers?

Perfect, thanks for all the help you’ve given me. With any luck the rest of the parts should be here by this weekend and I will do a range report. Just one other question, when installing the barrel nut on ar15’s I always clamped the barrel in a barrel vice and tightened the nut that way. With the larger 308 platform, would it be better to sandwich the top and bottom ends of the receiver in a vice and tighten the nut that way?

I am building on a aero m5 receiver kit with a BA 6.5cm barrel, a local gun shop is selling DPMS 308 bcg for a good price. Is it required to have the “high pressure” dual ejector bolt with smaller firing pin for the 6.5cm round or would I be ok with the 308 bcg?

Great! I did fire off an email to them last night and they spec’d the port diameter to .0785.