Accuracy of 20" Wilson Arms 6.5 Grendel Hbar Stainless Steel barrel

[Beowulf3]

Looking at this upper for sale locally for $610. First, is it a good deal? Secondly, what kind of accuracy can I expect from Wilson HBar SS? Is it ia match barrel?



NEW Custom 6.5 Grendel Complete Upper Double Fluted

Wilson SS Barrel 1/8 Twist

20" Wilson Arms 6.5 Hbar Stainless Steel
* Profile – Hbar
* Chamber - 6.5 Grendel (Compound Throat (SAAMI Spec) .125 Bolt Face Depth)
* Barrel Thread - 5/8x24
* Barrel Twist - 1x8
* Barrel Steel - 416R Stainless Steel
* Barrel Finish –Stainless Steel
* Fluted - Yes
* Gas System - Rifle Length Gas System
* Gas Block Platform - .750 Gas Block platform
* Sight Tower Type - NA
* Feed Ramp - M4 Feed Ramps
Mega Arms AR15 SBU Billet Upper Receiver . The stout octagonal shaped profile provides increased strength and stress resistance and works great in long barrel applications.
Machined from billet 7075-T6 aluminum vs. the more commonly used 6061 for a 70% increase in strength. Black Hard anodized with a surface hardness of 60 Rockwell. Works great in long barrel applications. Weight 12.7 oz

[Redraider]

Hi,

If it were me.........I'd walk. That .125 face depth breeds problems, in my opinion. The experts will be along soon.

Redraider

[hikfromstik]

Buy it and get a saami bolt , simple fix . My friend has 3 mega upper lower matching sets . One of those are the Maten (ar10) it's definitely the nicest billet upper lower I've ever seen . Wilson makes blanks for a number of high end manufactures like white oak arms , JP ( I think ), and a couple of others . You should get match accuracy .

[rabiddawg]

Buy it and get a saami bolt , simple fix .
.

I don't think it is that simple. I thought the headspace was set when the extension is installed on the barrel. Hopefully an expert will chime in on this.

[Joseph5]

headspace is set for the bolt so you can not just swap out a 0.136 depth bolt for a 0.125 depth bolt.

[Kilco]

For that kind of money steer way clear..

Run with a JP 22" system if you want top dog. Everyone who has one on here is getting 1/2 groups from a variety of loads. Cryogenic heat treated barrels with their super slick bolts, proper SAAMI spec and the proper. 136 bolt depth.

Also if you want a complete upper you can roll with AA roughly the same price..

[Beowulf3]

For that kind of money steer way clear..

Run with a JP 22" system if you want top dog. Everyone who has one on here is getting 1/2 groups from a variety of loads. Xrtogenic heat treated barrels with their super slick bolts, proper SAAMI spec and the proper. 136 bolt depth.

Also if you want a complete upper you can roll with AA roughly the same price..

Something like this?

https://tacticalgunreview.com/jp-ctr-02-...el-review/

[Kilco]

Something like this?

https://tacticalgunreview.com/jp-ctr-02-...el-review/

If you wanted to stay in the 6-700 price range for a complete upper, I'd look into AA. If you were looking to spend more, or buying a barrel bolt combo for that price then building on, JP gets my vote.

The .125 bolt on the Wilson setup makes me cringe.

[Lone Hunter]

Why does no one like the .125 bolt depth??

[Beowulf3]

I see...

[just_john]

There is no real issue with a .125 bolt as long as that is the right one for the chamber cut it is being matched with.

[rabiddawg]

Why does no one like the .125 bolt depth??

Because it is not the one designed for the 6.5 Grendel. The .125 bolt is a 7.62x39 bolt that is used in place of the correct bolt. Simple as that.

Here ha go. Sticky thread link

http://www.65grendel.com/forum/showthrea...endel-bolt

[Lone Hunter]

So it looks like a .125 bolt is really designed for a 5.56 depth and the .136 is designed for the 7.62x39/220 Russian/Grendel based case. Why are they building.125 depth bolts? Since they are lighter seems like they would fail easier. I have always been a bolt gun guy and really liking the AR especially the Grendel.

[rabiddawg]

Where are you getting your info lone hunter?

Why build a .125? Because it is intended for 762x39 but works with 6.5 G

read Bwaites' article I linked. it says, and I'm paraphrasing

Colt looked at x39 and saw the lip was thicker than that of 556 so they made the .125 FOR THE X39. Then Bill A looked at colts work and designed the .136 for Grendel.

.125 is a 762x39 bolt. Some use this in their Grendels
.136 is the bolt that was designed for the 6.5 Grendel.

I don't know any simpler way to say it.

[Lone Hunter]

Rabiddawg,look at the link you posted. I got my info from your link. Look at the picture of the 5.56 and the picture of the 6.5 Grendel. Shows .125 for the 5.56 and .136 for the Grendel. This is from BFT post with pics. This is my reason for asking questions. Not an expert by any means,hell,not even a novice either. Got a long way to go on learning but the only way to learn is to ask questions. I can get around with bolt guns but AR's are new to me. I wanted to know why some companies like BHW recommend.125 instead of .136? To me a .136 seems beefier and would be the way to go. I have a 20" .264 LBC BHW Barrel with a .125 bolt. This is what they recommended.So, I ask questions to find out.

[Lone Hunter]

Also it seems to me that a .125 bolt as BW says is just not as strong as the .136 and I can see why. Just can't figure why BHW said to use the .125 instead of the .136. It shoots great but now I wonder how long it will hold up. I am not hard on my weapons but don't need any breakages either.

[NugginFutz]

Chill, folks. No need to get short.

LH - To answer your question, BHW said to use a .125" bolt because that is what their barrels are now exclusively cut for.

Like many barrel makers, BHW began using the .125's at the time because of availability, and little else. They also cut chambers head spaced for the .136" bolts, and applied the now infamous "Type I / Type II" nomenclature to distinguish between the two. Only recently have they dropped the .136" variations, but only to simplify and reduce their tooling costs.

I have two BHW 264 LBC's, both head spaced at .136". I also have a Larue 6.5 Grendel, head spaced at .136". At any time, I can interchange bolts without concern.

There is also some competing anecdotal information about the advantages to either extractor thickness.

In the .125" camp, there is the claim that there is less unsupported case wall extending from the chamber. This is really a minor point, in my opinion, due to the lower case pressures of the Grendel cartridge.

In the .136" camp, you have the fact that the Grendel was originally designed for the .136" bolt face, with the extractor being a stronger, better fit for the Grendel's case lip.

The odds of your BHW with the .125" becoming a problem are affected by metalurgy, round count, and how hot your loads are. Statistically, you likely won't have an issue.

For those buying a new setup, the tried and true advice has been to stick with SAAMI, and .136" to avoid questionable performance, functionality and durability.

Apologies to the OP for semi-hijacking the thread. Hopefully, it goes back on track, now.

[Lone Hunter]

Thank You for the info. NF and RD. I apologize for hijacking the thread but you can't learn if you don't ask.

[rabiddawg]

I wasn't trying to be rude I just couldn't put it any other way.

I did go get my glasses and look at the graphic from the link. The only thing I can see that would be confusing is the wording that leads you to believe the x39 bolt face depth is the same as a 6.5 Grendel. That contradicts everything I have learned about the two.

[LRRPF52]

So it looks like a .125 bolt is really designed for a 5.56 depth and the .136 is designed for the 7.62x39/220 Russian/Grendel based case. Why are they building.125 depth bolts? Since they are lighter seems like they would fail easier. I have always been a bolt gun guy and really liking the AR especially the Grendel.

Most of the companies making 7.62x39 never did the engineering work on how to make it work in the AR15, and ignored everything Colt did when it was a funded program.

Bolt face depth and extractor lip thickness are two of the main differences between a 5.56 bolt and a well-engineered 7.62x39 bolt, since the rim thickness is a lot more than 5.56/.223Rem.

When Bill A. was researching how to make a good bolt for the .50 Beowulf, he looked at the work on that project and how they solved a lot of the problems with getting a 7.62x39 to work in the AR15.

A deeper bolt face was one of the solutions to accommodate an extractor with sufficient lip thickness.

A .125" bolt face depth doesn't allow a lot of lip thickness for a rim like you find on x39 and Grendel, yet everyone in the industry makes x39 bolts and chambers set up for .125" face depth, and extractors fail left and right as a result. Their answer is to just replace them when they break.

If I had a .125" face depth chamber, I would personally use the LMT enhanced 7.62x39 bolt, but those extractors have broken on people too in full auto guns that are tortured. The bolts hold up better than anything out there in the x39 world because they're made from AerMet alloy, which is twice the cost of 8620 or 9310.