What does the gas port size have to do with it, when the majority of us use adj gas blocks?
Magnum AR Project
- Thread starter Masczek
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I have agb's on both, but it's the 1st restriction. 1 would think it doesn't make a difference, but it does. If it's undergassed (port size to small) you need more to cycle (that's the case in more felt recoil). Overgassed usually requires more buffering weight (bcg, buffer or more spring pressure) that translates into more cyclic mass that has more felt recoil.
Yes, I get all of that...
under gassed..you can't open the AGB enough to get it to cycle...drill out the gas port
over sized gas port...turn the AGB down...
Right?
Yes, you can do all of that and get it to cycle reliably, but why have more cyclic weight than necessary. Probably need to start another thread as not to derail this any more than we have. Always willing to discuss the subject.
What is the buffer weight, and bolt carrier group weight of the KT10?
What performance are you getting out of the 6.5 PRC, and 300 WSM?
What performance are you getting out of the 6.5 PRC, and 300 WSM?
Curious myself on that! I think he's using a standard (non-a5) carbine tube and buffer. As most AR's go, you usually have less fps than if it were a bolt gun.
Masczek
Well-Known Member
No worries about getting slightly off topic, I'll touch on the port size since it was something I wasn't thinking much on when I started. My first prototype barrels both where drilled with a "slightly" larger gas ports (.114") because I was using adjustable gas blocks. Once I tested them out I obviously had dial the gas down since it was way too much. The problem I ran into was the gas blocks I was using didn't have enough "fine" adjustment in them, one click was either too much gas or not enough to cycle reliably. I was surprised that changing the buffer weight didn't help get it where I wanted it either. But once I got the gas port size dialed in, it was a lot easier to fine tune the gas system with the adjustable gas block. And since I was messing with the gas port size, I decided to make it work with a standard 3.5 oz carbine buffer.
Masczek
Well-Known Member
Buffer is 3.5 oz and BCG is 1 lbs 2 oz.
I honestly don't have a lot of performance data on the 6.5 PRC, I'm working on getting that soon. I do know that both my hand loads and factory ammo where functioning flawlessly in the 6.5 PRC prototype. At the time, hunting season was right around the corner, so I needed (and wanted) to get my 300 WSM upper dialed in. I'm averaging about 2815fps out of a 22" barrel. I'm using Norma brass, 190gr Berger VLD and 61.5gr of H4350.
I'm not the best shot, but I can manage just under an inch at 100 yards with the 300 WSM, when I have more time I'm going to try different seating depths to see if I can tighten the groups.
I've got a little over an inch with the 6.5 PRC using factory ammo. I'm betting that I can get slightly better groups with handloads, but that will be something I'll do once spring comes. I am going to take it back out soon to get some velocity readings though, I'm kinda curious on that.
Masczek
Well-Known Member
They're on the website, feel free to PM me for more details.
PM me or contact me through the website, I'm always willing to work something out.
precisionobsession
Active Member
Interesting thread. I have always been interested in building a 300wsm gas gun as I am weirdly obsessed with the caliber. Just never pulled the trigger.
wvbearhunter
Well-Known Member
The KAK one I had was a lot of fun and ran pretty well but would ocassionally choke. I think 300 saum or 300rcm would work better due to the shoulder angles involved
