To bed or not to bed

[JustBC]

I am putting the finishing touches on a 16" AR15. I'm using Aero receivers and a White Oak SDM barrel. I've heard that bedding the barrel extension with Loctite may increase accuracy. The downside is it will be a PITA to remove. Is it worth the hassle? Am I going to pick up significant accuracy? Also which Loctite to use? Am I going to get the same benefit from low strength as I would from red?
Thanks.

 

[mpncc]

I don't know about whether that will really boost your accuracy or not but I wouldn't personally do it. But there are tools now to true AR receivers which could add a little accuracy without adding an hour to pull your barrel

 

[bigjake83]

Yes it will help with accuracy, and dampen Barrel harmonics. I use red Loctite and if you do it correctly it will not be a pain to remove your Barrel later on. what you want to do is lightly buff the inside of the upper receiver where the barrel extension slides into with some light fine grit sandpaper, then clean the area with strong alcohol or carburetor cleaner. Lightly coat the barrel extension with a light weight oil like WD-40. Before you apply the red Loctite install your barrel and season the threads you want to tighten the barrel nut back and forth to about 40 to 60 foot pounds 4 - 5 times. Once that is done clean the upper receiver Barrel Extension Channel again with some alcohol then apply a liberal amount of red Loctite inside the barrel extension channel of your upper receiver and install your Barrel, tighten your barrel nut and remove all excess Loctite from inside your upper receiver. Next you want to place the barreled receiver pointing up and allow it to cure for 24 hours.

by slightly sanding the barrel extension channel of your upper receiver and cleaning it with alcohol the red Loctite will adhere to the inside of your upper receiver and not to your Barrel extension due to the fact you applied a loght coat of oil so when it comes time for you to remove your Barrel it should slide out with just a few taps and the red Loctite will adhere to the inside of your upper receiver, and not the barrel extension..

Hope this helps.. on a side note, that is a very good Barrel that you chosen for your build I would recommend you buying a higher quality upper receiver my recommendations would be a VLTOR, you can usually get them for about $160 off of Joe Bob's Outfitters in my experience they have proven to be extremely high quality, the BCG Channel isn't sloppy and the face of the receivers have all been Square.

 

[JustBC]

That is exactly what I needed to know. I hadn't thought about using a release agent on the barrel extension, that's a great idea. Beds it nice and I can change the barrel later.
I was going to lap the face of the receiver and be done with it but I will think about the VLTOR. Thanks for the advice!

 

[Downtown]

Some barrels fit so tight that heat must be applied to fit the extention into the receiver. Bravo Company is one that comes to mind. Would loctite bedding still improve on a fit like that?

 

[bigjake83]

Some barrels fit so tight that heat must be applied to fit the extention into the receiver. Bravo Company is one that comes to mind. Would loctite bedding still improve on a fit like that? [/QUOTE

Even if I have to Thermofit the barrel I still use Red Loctite..

 

[Shoots 700's]

I did it with a Noveske 12.5" Barrel. That with the Vltor upper it shoots great!

 

[Pan]

Barrels with fail zero barrel extensions usually fit extremely tight as is

 

[BarrettBoy]

I wouldn't do it.
I don't think it will yield any significant improvements or changes, but will definitely create a major hassle if you want to remove it.

 

[padom]

I strictly use BCM uppers and thermofit my barrels. Accuracy is sub .5moa and my results are all over the forum if you want to look at the accuracy I get. I never lapped a receiver face or bed a barrel in my life.

Just built a Precision SPR AR for a forum member a few weeks ago. He texted me the other night to tell me gow accurate the gun was just shooting Freedom 60vmax.

Sent from my SM-G935P using Tapatalk

 

[CNJarvis]

I'm planning on doing this on my current build using Loctite 609.

 

[bigjake83]

I strictly use BCM uppers and thermofit my barrels. Accuracy is sub .5moa and my results are all over the forum if you want to look at the accuracy I get. I never lapped a receiver face or bed a barrel in my life.

Just built a Precision SPR AR for a forum member a few weeks ago. He texted me the other night to tell me gow accurate the gun was just shooting Freedom 60vmax.

Sent from my SM-G935P using Tapatalk

Are you going to be competing in round 4 of the 100yrd shootout???, I haven't see anything from you other then that one 5x8 you post all the time...

 

[padom]

Are you going to be competing in round 4 of the 100yrd shootout???, I haven't see anything from you other then that one 5x8 you post all the time...

Look a little harder. Target after target in the Rainier Ultramatch review thread, 6.5cm Bartlein custom build thread, multiple White Oak threads but specifically the 20" SDM thread. 10.5" 5.56 sbr build thread, All sub 0.5moa groups...

Also that 8x5 300blk target you reference was a Aero Precision upper, no thermofitting, no receiver face truing, no bedding, no magical pixy dust.

If bedding and truing receiver faces gives you peace of mind then you're gonna do it but its far from necessary when quality uppers are used...This isnt coming from just me, numerous top AR builders have echoed these same words.

Sent from my SM-G935P using Tapatalk

 

[bigjake83]

Look a little harder. Target after target in the Rainier Ultramatch review thread, 6.5cm Bartlein custom build thread, multiple White Oak threads but specifically the 20" SDM thread. 10.5" 5.56 sbr build thread, All sub 0.5moa groups...

Also that 8x5 300blk target you reference was a Aero Precision upper, no thermofitting, no receiver face truing, no bedding, no magical pixy dust.

If bedding and truing receiver faces gives you peace of mind then you're gonna do it but its far from necessary when quality uppers are used...This isnt coming from just me, numerous top AR builders have echoed these same words.

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Just trying to incite some friendly competition...

 

[JustBC]

I looked at the sleeve retaining compound too. I went with Loctite red since I had some. It was a bit messy but cleaned up fine. Does 609 have a high enough temp rating? I would think 620 would be better.
I ended up staying with the Aero upper, again because I had it. I went to lap it but it turns out the mating surface on the M4E1 is machined, not forged. I discovered this after I had a lapping tool turned down to fit.
I will post some groups when I get around to it.

 

[The King]

Group testing with several uppers in a before/after fashion with loctite, loctite and shims, and heat fit barrels showed that if the barrel interface was loose you get 18% accuracy gains from loctite, and 35% from shims and loctite. Again, if you aren't press/heat fit already.

I have just disassembled a 2014 vintage JP factory upper and it had a shim. This gun shoots lights out, and JP's are known for doing so. Just a note.

 

[Greg Langelius *]

When I built my first (and so far, only..., but probably not for much longer) upper, I bedded the extension with Red LocTite.

My reasoning was that the likelihood of my ever shooting out the barrel was appreciably zero, and that if I did, a stripped upper was certainly well enough within my budgetary restrictions to make the barrel replacement as painless as possible.

I do not pinch my pennies quite enough to get them to scream... In my estimation, barrels are just another wear item, and maybe stripped upper receivers ought to be, too.

IMHO, that would be my own most practical consideration.

Greg

 

[2ndamendfan]

loctite 620 fit the bill the best and seems to be the most recommended. It is thicker so much easier to work with as it doesn't run all over while you are trying to get stuff assembled. It has a release of 450 degrees. If for some reason it would ever need to come apart (other than barrel replacement) hit it with a heat gun and apply some pulling force (not a lot) when it hits 450 your likely to hit yourself in the face with the barrel. Amazing engineering.

 

[Greg Langelius *]

Thank you, my next upper will be bedded using loctite 620. It just makes no sense to me to built an unbedded upper when stuff like this is available.

 

[MarkCO]

Thermofitting and or shims are the best best after just getting an upper receiver (7075 is also a good idea) that has a slightly tighter extension. Locktite on passivated metals (which the extension of both the receiver and barrel both are) won't do much if any good. You end up with a little material, but material which is not solidified no bonded. Given the right sequence of heat cycles, it can result in worse thermal shift than having nothing. If you activate the metals by sanding and exposing, then it becomes a much harder process to rebarrel as you will have pits and peaks in the receiver due to the corrosion process of the Loctite.

When the thermo-fitting (or even shims and heat, or just heat) is used and applied to quality components, it "just makes no sense" to do something else that is marginal at best and can ruin an upper.

 

[SgtDog0311]

Resurrection Alert!
Just fit a barrel on an AERO Enhanced in .308. At the last minute I decided against the loctite because I decided instead to order a Bat extension and replace the one on the barrel after I shoot it. I thought that way I could test for groups, then order a custom fit extension and test again.

Now my question is this: If you wanted to do a thermal fit, how much expansion could you expect. Meaning, let's say my receiver measured 1.189-1.1895 (measured across three planes) then what size extension would be appropriate to order?

I've never tried slipping an exact one-for-one OD into an ID, so don't know if you look for an exact fit for thermal fit or go one thousands over or what to expect from expansion.

 

[Merle]

Resurrection Alert!
Just fit a barrel on an AERO Enhanced in .308. At the last minute I decided against the loctite because I decided instead to order a Bat extension and replace the one on the barrel after I shoot it. I thought that way I could test for groups, then order a custom fit extension and test again.

Now my question is this: If you wanted to do a thermal fit, how much expansion could you expect. Meaning, let's say my receiver measured 1.189-1.1895 (measured across three planes) then what size extension would be appropriate to order?

I've never tried slipping an exact one-for-one OD into an ID, so don't know if you look for an exact fit for thermal fit or go one thousands over or what to expect from expansion.

Good luck with replacing a barrel extension on a finished barrel that already has the gas port drilled.

 

[SgtDog0311]

First build so that would tell you there is a lot of down-stream thinking I'm gonna miss. I HAVE inquired with a barrel maker to see if they would put my extension on a barrel I ordered. No reply yet.

Since you didn't answer the question I hope someone chimes in who can.

 

[Merle]

First build so that would tell you there is a lot of down-stream thinking I'm gonna miss. I HAVE inquired with a barrel maker to see if they would put my extension on a barrel I ordered. No reply yet.

Since you didn't answer the question I hope someone chimes in who can.

The barrel extension is installed on a barrel before the chamber is finish reamed and before the gas port is drilled. If you want a certain maker's barrel extension installed on your barrel you have the barrel made with that extension. Chances are the gas port won't be at the 12 o'clock position or the head spacing be correct if you swap extensions. I'm sure it can be done but it probably will require machining and is probably more trouble than it's worth.

 

[SgtDog0311]

Good to know Merle. I compete in the BPCR & BPTR world which is all-together different being in my case vintage single shots. I was not thinking at all of the sequence all of that is to goes into the final product but as soon as you said "good luck with that" I realized the roll stamp, gas port and the alignment pin are all top-dead-center (at least on my Criterion - for the roll stamp) so I got your meaning right away. Albeit with some disappointment. So I'll back the truck up there. I do think a Bat custom fit barrel extension is a nice idea, though I wouldn't know what size to request. My .308 receiver measures 1.190 so I'm thinking at least a half thousands smaller would be advisable unless I wanted to do a thermo-fit. And if a thermo-fit, then still same question... how much expansion can I count on? But good catch on your part. Need to first find out how hard it would be to get a barrel maker I chose to take a barrel extension from me and turn that around. Appreciate the response - almost called Bat and ordered and extension before your post.

 

[SgtDog0311]

btw... still think I'll shoot this existing barrel to record group sizes before pulling it to shim and bed. Will be interesting to see if it makes a difference or not.

 

[Constructor]

I am putting the finishing touches on a 16" AR15. I'm using Aero receivers and a White Oak SDM barrel. I've heard that bedding the barrel extension with Loctite may increase accuracy. The downside is it will be a PITA to remove. Is it worth the hassle? Am I going to pick up significant accuracy? Also which Loctite to use? Am I going to get the same benefit from low strength as I would from red?
Thanks.

It isn't a pain in the ass to remove, anyone that says it is has never done it. We have been bedding receivers to increase the rigidity of the connection since the 80s. To get the barrel out stick a wood dowel in the back and tap it out, takes about 10 seconds.
Use plain old blue locktite, you aren't trying to glue the pieces together just filling the voids.

 

[Constructor]

The barrel extension is installed on a barrel before the chamber is finish reamed and before the gas port is drilled. If you want a certain maker's barrel extension installed on your barrel you have the barrel made with that extension. Chances are the gas port won't be at the 12 o'clock position or the head spacing be correct if you swap extensions. I'm sure it can be done but it probably will require machining and is probably more trouble than it's worth.

No one I know installs the extension before chambering the barrel but you are correct if you change the extension it will not align with the port.

 

[RyanScott]

Short chambering or final chambering?

 

[black max]

No one I know installs the extension before chambering the barrel but you are correct if you change the extension it will not align with the port.

How do they check headspace without the extension?

 

[Constructor]

How do they check headspace without the extension?

We measure the stickout of the go gauge.

 

[DRAM40A1]

I’ve never had an issue removing a barrel I’ve bedded with 271. Just stick a dowel inside the receiver and drive it out. All the Loctite stays on the barrel extension.

 

[MontanaMan]

I strictly use BCM uppers and thermofit my barrels. Accuracy is sub .5moa and my results are all over the forum if you want to look at the accuracy I get. I never lapped a receiver face or bed a barrel in my life.

Just built a Precision SPR AR for a forum member a few weeks ago. He texted me the other night to tell me gow accurate the gun was just shooting Freedom 60vmax.

Sent from my SM-G935P using Tapatalk

Padom,

I know this is an older post above, & as I remember from some of your more recent posts (maybe the Ranier barrel series?) it seem as if you were more recently using some AERO uppers??

If that's correct, which version & how was the barrel extension fit on those?

Thanks.

MM

 

[Precision Underground]

Are you going to be competing in round 4 of the 100yrd shootout???, I haven't see anything from you other then that one 5x8 you post all the time...

Where is this 100 yard challenge..... sounds like something I would enjoy wasting ammo on!

edit....Never mind. I got bit by a zombie thread. Carry on lol.

 

[padom]

Padom,

I know this is an older post above, & as I remember from some of your more recent posts (maybe the Ranier barrel series?) it seem as if you were more recently using some AERO uppers??

If that's correct, which version & how was the barrel extension fit on those?

Thanks.

MM

No, that was many years ago. I stopped using Aero uppers for quite some time now. BCM only when using forged uppers. Aero stuff was great for years. When I tested Rainier Ultramatch Gen1's I used Aero uppers some 5+ yr ago.. stopped when I got a few small and large frame upper/lowers out of spec, mags falling out, not fitting together and their CS was non-existent. Promises of replacements, no comes for.months, told employees handling my casr quit and nothing could be found to finally receive new parts. Never again I said, too many good companies out there to deal with that.

Aero uppers never had tight fitting barrel.extensions like BCM and MEGA....

 

[Stavey]

I’ve had fantastic results with aero recievers but I’ve only assembled 10 or 15 this year . Not 1 has been out of spec. If barrel isn’t tight than address it with shims or loctite or both . Problem solved. Same results in the end.

 

[padom]

I’ve had fantastic results with aero recievers but I’ve only assembled 10 or 15 this year . Not 1 has been out of spec. If barrel isn’t tight than address it with shims or loctite or both . Problem solved. Same results in the end.

Its actually not the same result in the end... it helps, but not the same. JP covers this and why in their recent video about their new uppers...

 

[Stavey]

Of course they do . They want to sell you an upper. I honestly don’t think I would gain anything by using a bcm , jp , or any other overpriced reciever. Compass Lake Engineering uses aero Precision upper recievers. Ever seen a complaint regarding their accuracy. I rest my case
That’s just 1 example.

 

[padom]

Of course they do . They want to sell you an upper. I honestly don’t think I would gain anything by using a bcm , jp , or any other overpriced reciever. Compass Lake Engineering uses aero Precision upper recievers. Ever seen a complaint regarding their accuracy. I rest my case
That’s just 1 example.

Lol. No Seekins covered this as well which Frank posted about when reviewing their rifle. Yep, myself and @lennyo3034 both had accuracy issues which were replaced. Mine replaced twice. Your sample size is WAY smaller than mine....

 

[Stavey]

What about Compass lakes sample size ?
It’s your money
Probably better spent on ammo or a shooting class

 

[padom]

Lol. No Seekins covered this as well which Frank posted about when reviewing their rifle. Yep, myself and @lennyo3034 both had accuracy issues which were replaced. Mine replaced twice. Your sample size is WAY smaller than mine....

You sure arent loosing anything having a thermo fit BCM upper with door and forward assist for $59.99. Buy it over an Aero all day every day and on Sunday.

 

[MontanaMan]

Yeah, for sure, at that price, I just bought 3 of them.

MM

 

[Stavey]

Those are blemished scratch and dent for $59 let’s be clear

 

[MontanaMan]

True, but nothing that affects function; a little paint covers pretty much all the sins on the ones I've used previously.

MM

 

[Stavey]

I picked a couple up to play with . I have a white oak predator barrel in the way so why not give them a try.

 

[padom]

Those are blemished scratch and dent for $59 let’s be clear

You have never bought them but know you know what your buying?? Myself and many on here have bought many 100's. They ARE NOT blems... They MAY have a scratch on them from being handled but only one out of over a 100 came with a mark on it. All the rest brand new in a box with not a mark on it.

 

[Stavey]

You have never bought them but know you know what your buying?? Myself and many on here have bought many 100's. They ARE NOT blems... They MAY have a scratch on them from being handled but only one out of over a 100 came with a mark on it. All the rest brand new in a box with not a mark on it.

No clue what you are even talking about. I stated a fact . That is that the $60 uppers are scratch and dent. This is info rite from their site .

 

[redneckbmxer24]

Aero makes good receivers for the $$, in the rare event I use a standard mil spec receiver they're my go to if I'm assembling vs buying, and what I recommend to people when a stiff walled upper isn't needed.

To pretend all uppers are created equal, and premium uppers like JP and the like are just "overpriced" and you're not getting a performance difference for the added cost is ignorant. If you're building a precision upper having a stiff walled upper built to high tolerances is 100% worth it and even Aero's "enhanced" receivers aren't as stiff as other's out their, let alone their standard mil spec receivers.

My first 224V was put together on a Aero mil spec receiver. It was supposed to be on a Seekins IRMT, but the receiver I got was out of spec, and then the replacement was out of spec too, so I put it together while I was waiting. Craddock Rock Creek barrel, Seekins BCG and Seekins SP3R forend were put together. The setup was accurate but was the first time I really noticed a upper stringing the more I loaded into the bipod... RECEIVER FLEX... I removed the barrel reinstalled into another mil spec receiver which I believe was an LMT... same result. Then I ordered a VLTOR MUR and not only did the POI shift when loading the bipod go away 100%, but the overall accuracy tightened up even more too. I had an upper consistently shooting in the .1's and .2's at 100.

So tell me how that is if a $59 Aero mil spec receiver is as good as any other receivers? Same parts just on 3 different receivers. Barrels bedded with red loctite on all 3 receivers, the Aero required some .001" shim stock too since it was about .003" over what the barrel extension measured.

I tested several other receivers in the same way on other setups and came to the same conclusion. The receiver and your assembly process DOES make a difference.

 

[redneckbmxer24]

No clue what you are even talking about. I stated a fact . That is that the $60 uppers are scratch and dent. This is info rite from their site . View attachment 7218646

I'll take Aero's over BCM for milspec. Every BCM I've had (have one sitting here as we speak) has had an incredibly sloppy fit on lowers. The one that's sitting here was actually off of one of their SPR uppers too, it got yanked as soon as I got it because of the slop which I was already aware would probably be the case.

Still doesn't change the fact that a thick walled upper is superior in every way for a precision build.

 

[Greg Langelius *]

Two 6.5 Grendel Uppers.

One AR Stoner factory, unbedded as received from Midway. The other, AR Stoner components, refaced/trued and bedded with Loc-Tite Red.

Once loads are finalized and accuracy benchmarked, the barrel will be removed; then the refacing/truing and bedding will be performed and performance will be reassessed/compared.

This is near the top of the project list for resolution early this year.

Greg