6 Creedmoor AR10 building now just random questions.

[Defender32]

I am trying to utilize an older 308 AR I had and make it my coyote rig for night hunting.

PSA upper and lower, Timney Trigger, KAK Industries BCG, KAK K Spec 5.3oz buffer and spring assemble.

Barrel is Rainer Arms 22" +2 gas system, Adjustable gas block and it will be shot suppressed.

What are some things I need to look for besides blown primers and NASTY brass when adjusting the gas block? I have not had to use one on any of my rifles yet. I just ordered one for this one due to all the stories I have read and issues.

My plan for this build is 58g-90g projectiles. H4350 will be powder of choice as I have 16+ lbs of it.

 

[Gohring65]

I’d order a high pressure bolt before starting any load work up. Trust me, you’ll be dealing with pierced primers and beat up brass with a standard bolt and high port pressure cartridges. Arm or Ally had the tool craft high pressure 6.5 creed bolt carrier group on sale for 140$, not sure if they still do or not, but that’ll be the best 140$ you’ll spend on this project.

 

[Defender32]

I will look into it. My bolt is currently in a buddy's 6.5 creed because he was having blown primers with his JP BCG and mine wasn't blowing them. It never hurts to have a spare though.

 

[Defender32]

I’d order a high pressure bolt before starting any load work up. Trust me, you’ll be dealing with pierced primers and beat up brass with a standard bolt and high port pressure cartridges. Arm or Ally had the tool craft high pressure 6.5 creed bolt carrier group on sale for 140$, not sure if they still do or not, but that’ll be the best 140$ you’ll spend on this project.

Toolcraft 6.5 Creedmoor Double Ejector BCG

Toolcraft 6.5 Creedmoor Double Ejector BCG - dual ejectors add reliability to your AR with consistent, powerful ejection. The largest Toolcraft dealer!

www.armorally.com

This the one you are referring to?

 

[Gohring65]

I will look into it. My bolt is currently in a buddy's 6.5 creed because he was having blown primers with his JP BCG and mine wasn't blowing them. It never hurts to have a spare though.

If yours is working in a creed you’ll probably be fine with it.

 

[Gohring65]

Toolcraft 6.5 Creedmoor Double Ejector BCG

Toolcraft 6.5 Creedmoor Double Ejector BCG - dual ejectors add reliability to your AR with consistent, powerful ejection. The largest Toolcraft dealer!

www.armorally.com

This the one you are referring to?

Yes

 

[Dogtown]

I’d order a high pressure bolt before starting any load work up.

This.
I swapped out a 16" .308WIN barrel I had for a long time with a 16" 6mm Creedmoor barrel and on the second shot the bolt broke (severely over gassed). A high pressure bolt swap and adjustable gas block installation and it's been running like a champ since.

And for loads, I'm running 95 VLDs, initially with H4350 but now N160.

 

[msgriff]

JP offers two different bolts, their standard "EnhancedBolt" and their "EnhancedBoltHP". Some confuse the two when ordering, JP even gets them confused in some of their product descriptions. The biggest difference being the firing pin tip diameter. Just a "heads up".

"Blown primers" can mean a couple things. Cratered/pierced vs popped primers can be caused be different issues.

 

[Defender32]

His is a JP and my current BCG is a KAK Industries.

Mine is running in his rifle. His was blowing primers totally out of the pocket. Most of that mom was 120g Hornady loads.

 

[Kinked_Chrome]

For gas block adjustment, start with it closed and open it up little by little until it just holds the bolt open on an empty mag. If you shoot in varying conditions a lot, maybe a few clicks passed that. With 6cm and a can, youll have a ton of gas so it might only be a few clicks passed closed to cycle your gun well.

 

[Defender32]

Appreciate that info. I will give it a go.

New BCG on order just incase it is needed. It dont hurt to have a spare either.

 

[Namekagon]

Any downside to using a HP bolt on a 308 build? I'm thinking of building a large frame 308, but might convert it to 6.5 Creed or something like that later.

 

[Gohring65]

Any downside to using a HP bolt on a 308 build? I'm thinking of building a large frame 308, but might convert it to 6.5 Creed or something like that later.

Not at all. Run it!

 

[msgriff]

Any downside to using a HP bolt on a 308 build? I'm thinking of building a large frame 308, but might convert it to 6.5 Creed or something like that later.

My opinion is that beyond just the firing pin tip diameter, the difference between the tip diameter and the bolt face orifice is of equal or more importance. The greater the area of the annulus, the more likely that you will have issues, particularly with higher pressure cartridges. These dimensions can vary greatly between manufacturers, even those who market their bolts as "HP".

 

[Top O' Texas]

Here's the difference between the hp and non pins.
L) non
R) hp
The non WILL NOT fit into a non hp bolt due to the angle. KAK uses hp pins (at least in their magnum bolts) and be aware from other sites that state hp firing pins as every one I've ordered from ISN'T a hp pin. HP pin per bolt compatibility is check your bolt and old pin, but aero precision DOES use these pins in their bolts and bcg's (at least the last 6 I've bought). Brownells site is WRONG on their so-called hp pin sales according to reviews. Even JP's can be misleading. JP hp pin on R and other hp pin on L. L pin is used by a few other mfgrs.

 

[Top O' Texas]

I have had 3 JP hp pins fail badly.

 

[Top O' Texas]

I would add the extra tungsten before shooting!

 

[Defender32]

I would add the extra tungsten before shooting!

Extra Tungsten to the buffer? 5.3oz buffer and heavy spring isn't enough??

 

[Top O' Texas]

Extra Tungsten to the buffer? 5.3oz buffer and heavy spring isn't enough??

Then you'll need to go with a rifle length buffer and add even more weight IF you gas port isn't sized correctly? I have no experience with a 6creed, only a 243win 22" w/standard length gas. If not wanting to go rifle, then you'll need an A5 tube, AR10 rifle spring and an AR15 carbine buffer. With an adjustable 3 weighted heavy body buffer you can go as high as 7.51ozs (from what I've tested). IF your gas is shut way down and primers are still popping it might take a heavier bcg, but that'll add to the recoil.

 

[Defender32]

Then you'll need to go with a rifle length buffer and add even more weight IF you gas port isn't sized correctly? I have no experience with a 6creed, only a 243win 22" w/standard length gas. If not wanting to go rifle, then you'll need an A5 tube, AR10 rifle spring and an AR15 carbine buffer. With an adjustable 3 weighted heavy body buffer you can go as high as 7.51ozs (from what I've tested). IF your gas is shut way down and primers are still popping it might take a heavier bcg, but that'll add to the recoil.

I have *NO* Primers popping in my system. I was asking questions on this particular build as it was prior a 308. My BCG is running flawless in a 6.5creed and MagPul UBR system. It is a standard stuff.

My Upgrades are as follows.

+2" 6 Creed 22' barrel
Adjustable Gas Block
KAK Industries Carbine buffer tube, Spring and Buffer 5.3OZ ( K-Spec Enhanced system )

 

[Top O' Texas]

I have *NO* Primers popping in my system. I was asking questions on this particular build as it was prior a 308. My BCG is running flawless in a 6.5creed and MagPul UBR system. It is a standard stuff.

My Upgrades are as follows.

+2" 6 Creed 22' barrel
Adjustable Gas Block
KAK Industries Carbine buffer tube, Spring and Buffer 5.3OZ ( K-Spec Enhanced system )

With the creed cases being the same from 22-6.5 and as the bore goes smaller the pressure at the port will be higher (powder dependent) and should need more gas choked off if the port size is the same? At least you're not having primer issues, so that help.

 

[Defender32]

Build is now complete and running beautifully. Brass does not come out Bolt Gun clean but it's not nasty as the ground either. It absolutely hammers with Factory 103 ELDX. Recoil is very mild and a dream to shoot. I did shoot it with both BCG's I have a both of them were flawless. All in all I am 100% pleased I made the swap. Coyote Rig is now complete. Time to work on a 75g V-Max load.

PSA Upper & Lower
Timney Trigger
KAK Industries K Series buffer tube kit w/ 5.3 oz buffer
Rainer Arms 22' 6 Creed Barrel +2 Gas
Superlative Arms bleed off gas block
MagPul PRS Lite
Ergo Straight grip
Midwest Industries 15" Slim forearm
PTP Master Chief suppressor and Rauch Precision suppressor cover
Pulsar Thermion DUO 50 optic. * Love the day time and thermal options of this optic *

 

[Defender32]