Face truing and barrel bedding?

[Chance-dg]

On my 16" GB barrel build I used all BCM upper/bolt etc and a GB barrel and am getting vertical and horizontal stringing. The barrel was a sloppy fit to the BCM upper. In my eagerness to complete this build I did not check the trueness of the face nor did I bed the barrel as I didn't know how. Now I am hoping I am able to get the very tight BCM MCMR handguard removed and rebuild this upper to correct this.

I also have a nice blue urban camo builders set from AP on hand and a Faxon 18" barrel on backorder to build as well as an AP upper with no FA and a planned 12" BAHanson barrel (not in stock yet at BA) with an Odin Ragnar handguard in the works. I do not want to make the same mistake again.

This topic has been visited previously....Would someone send me the links to this info for both the face truing and the barrel bedding??

[lazyengineer]

One clever trick I've seen someone do is to just wrap the barrel extension in a smooth cut of aluminum foil, and use that as bedding. I thought that was neat.

[A5BLASTER]

Try the custom search thing at the top of the home page. It will bring up more info on what needs to be done to your rifle then you can read in a week of nights.

I use steel shim stock to bed my barrels now. The way it works is I use a peice just thick enough that I can't get the barrel into the upper.

Then I do a compression fit by freezing the barrel and heating the upper.

I got my shim stock at a local hardware store but you can buy it online as well.

[BlakeTX]

I actually just “lapped” the face of my SOTA receiver yesterday. Took about an hour to disassemble, lap and reassemble. I got the lap tool from wheeler and it wasn’t difficult. I read mixed opinions about bedding the extension with locktite or something. Most things said that if the receiver is faced correctly and nut is torqued, then bedding shouldn’t be necessary. I don’t know how much of that is true but I didn’t bed mine.

[Chance-dg]

Thank you both for the great responses,,,,,and I am doing the search now......truly a vast amount of info there and many approaches to this issue. I thought with the BCM upper and BCM ion bonded BCG I wouldn't have this issue. I am ordering a tool from Brownells to true the receiver faces as well. All the right parts and pieces do not ensure an accurate rifle but its been a great learning experience. Now just getting the BCM handguard back off as it was a press fit with a heat gun, rubber mallet and some hand fitting around the BCM barrel nut.

[VASCAR2]

Here is a link to a custom google search for the 6.5 Grendel. Searching for the correct names or descriptions usually yield several pertinent results.

https://cse.google.com/cse?cx=016368947416500061353:paqd_0xcu1o&hl=en

I have a Friend who is a gun smith and he laps the front of my receivers with his lathe and I use blue Loctite/Permatex on my barrel extensions. I’ve been very fortunate the barrel to receiver have been tight enough I haven’t needed to shim my barrels. If there is a good tight fit between the barrel and upper receiver bedding might not help accuracy much. I’ve had very good results using blue thread locker on the barrel extension and upper receiver so I see no need to change.

[A5BLASTER]

Thank you both for the great responses,,,,,and I am doing the search now......truly a vast amount of info there and many approaches to this issue. I thought with the BCM upper and BCM ion bonded BCG I wouldn't have this issue. I am ordering a tool from Brownells to true the receiver faces as well. All the right parts and pieces do not ensure an accurate rifle but its been a great learning experience. Now just getting the BCM handguard back off as it was a press fit with a heat gun, rubber mallet and some hand fitting around the BCM barrel nut.

Keep in mind your barrel nut, gas block and muzzle device torque can and probably is playing a factor in your group sizes.

I use the accuwasher system for all muzzle devices. Lil locktite and handtight only no tools. My barrel nuts are both torqued too 35 foot pounds. And I try to not over torque the gas block screws, making sure as best I can they get run in equally.

Makes a difference.

[Chance-dg]

Thanks everyone....I am going to tear it down, true the receiver face and recheck/retorque everything to the manufactures specs from the SA adj gas block to the barrel nut....no muzzle devices on my hunting rifles....just thread protectors which are tight. using a Geissele enhanced 2 stage and AP one piece scope mount for my VX 6 2x12 and Nikon P223 3x9

[Klem]

As long as you are honest with yourself if all this messing about with the join does not work. Your horizontal and vertical stringing (large groups) might just be from an average barrel.

[Chance-dg]

Heya Klem.....I think you are right...average shooter, average barrel. every aspect is tight and right......the BCM handguard is so tight on the barrel nut it will take a bit of effort to get it removed...I don't think its worth the effort or potential damage......groups well enough for hunting to 400 yds and that's my personal limit on game. I have a new build coming along based on an 18" Wilson hunter fluted barrel with SLR adj gas block, Velocity 3LB trigger in an AP October builders set. I have noticed that if I overtighten the action screw on my AP lowers I get a bit of shift at my pivot pin...just enough to cause my stringing depending on my bag/hand positioning......I am getting about 1/8 inch space between shots just enough to bug me. I shoot from a wheel chair so my position gets changed a little as I get settled, enough to cause this. especially as I use the mag well with my support hand. I am overthinking a shooting error. and trying for one hole groups with a 3/4 " rifle

[brian y]

Chance-dg, Klem is offering sound advice and it look like you are heeding it, I just finished a build with a BCM upper not my first and will not be my last. I checked the face and like the last one I purchased from BCM it was true and did not need lapping and this was one of there blemished uppers they sell from time to time so I would work on my shooting before tearing it down, Good Luck and good grouping.