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Alexander Arms DIY Kit - Printable Version

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Alexander Arms DIY Kit - MeatySweats - 03-05-2020

I'm looking at kits and uppers along with barrel/bolt combos and I came across this one AA's sale page:

http://www.shopalexanderarms.com/DIY_Parts_Components-Alexander_Arms_6_5_Grendel_Upper_Kit.html

Is there a reason why its $300 versus the regular $600+ ones? I could see that the threading and gas blocks are different, is the barrel difference worth the $300?

Alexander Arms DIY Kit - Shooterrex - 03-05-2020

1/9 twist for lighter bullets

Alexander Arms DIY Kit - grayfox - 03-05-2020

Not a fan of the 9/16 thread styles... very few options go with that.

Alexander Arms DIY Kit - ricsmall - 03-05-2020

I’d bet that barrel would shoot up to 115-120gr pills other than a vld. If I bought one I’d thread to 1/2-28, and screw on a piece of cut off SS barrel threaded 1/2-28 internal, turn down and thread to 5/8-24 while barrel was still in lathe, eliminating any concentricity issues. Good value.

Alexander Arms DIY Kit - lazyengineer - 03-05-2020

The barrel is also a steal. As to 1/9, I did some Google searching on that, and Bill Alaxender, on this very forum hasd some very interesting commentary on that. That was a very consciously researched and selected twist. My own ballistic calculations show that 129+ is suboptimmally too heavy. 123 has better ballistics and hits harder, by the numbers. 129+ is just too slow, and will end up going subsonic at a shorter range than a 123 does . As to 1/9, in a 20", Bill picked that spec because he found that very forgiving to Grendel accuracy, while 1/8 was a lot more finicky.

I included their $60 overpriced flash hider in my order, and still feel it's a great price for a top shelf name brand BBL from the masters of Grendel.

FWIW the cotrovertial RedX has extended A2' FH for $10 as well, in the 9/16.

Alexander Arms DIY Kit - LRRPF52 - 03-06-2020

grayfox Wrote:Not a fan of the 9/16 thread styles... very few options go with that.

Every reputable muzzle device manufacturer has been making 9/16x24 devices for a long time, many well over 10 years.

I think the price is based on ditching 9/16x24 though, since so many people read comments like this and believe them.

Even when Grendel first came out, there were plenty of options.

Alexander Arms DIY Kit - lazyengineer - 03-06-2020

LRRPF52 Wrote:Every reputable muzzle device manufacturer has been making 9/16x24 devices for a long time, many well over 10 years.

I think the price is based on ditching 9/16x24 though, since so many people read comments like this and believe them.

Even when Grendel first came out, there were plenty of options.
That wasn't my experience in 2020. I spent a week looking for a basic A2, for basic A2 price, failed and gave up.

Alexander Arms DIY Kit - brian y - 03-06-2020

I picked up a 24" barrel and bolt from them it has the 1/9 twist and it has shot 123gn ammo very well, I have had it out to 800yds with no problems. That is a great price for that combo.

Alexander Arms DIY Kit - Harpoon1 - 03-06-2020

I purchased a 16” 1/7.5 twist barrel from them a couple of years ago. I wanted to try a tighter twist and this was the only option I could find at the time. I had always thought their stuff appeared a little substandard, “dated” and overpriced but, they invented and developed the cartridge, so, I took a chance. I should have tried dropping a factory spec round in the chamber before installing it, as a quick check. Won’t do that again.

I had to all but “pound”on the forward asssist to get the bolt to go into battery using Hornady 123 American Gunner. On the third or fourth round I never could get it to go into battery and went to pull the round out with the charging handle. The bullet was stuck far enough in the lands that it pulled itself from the case, dumping powder everywhere inside the lower.

This was a brand new barrel, right from the factory mind you. OTOT, the woman I dealt with at AA was all but belligerent and insistent that their barrel could NOT be the problem.

That did it for me, it’ll be a long time, if ever, before I purchase anything else from Alexander Arms.


Caveat Emptor

Alexander Arms DIY Kit - lazyengineer - 03-10-2020

My 20" Alexander Arms 1/9 BBL came today. Man, I have to say there's almost nothing standard on this thing. The gas-block portion of the barrel is of non-standard dimensions, the muzzle-device cut is of non-standard threads - sure am glad I bought their gas-block and flash-hider to match. There won't be any swapping stuff around!

It's heavy, I'll say that. At close to 3 lb just for the BBL. the PSA 20" A2 BBl is close to 2 lb 3 oz, and the Team Monster BBL is closer to 2lb 8oz or so. So it's not crazy-heavier than Team, but it is heavier.

I haven't decided my opinion on the gas-block portion of the BBL. By being a lot thicker, that should mean it's less sensitive to torques and such, and so inherently more accurate. It's a lot of mass at that part of the BBL though.

I bore-scoped it. The gas-port hole has burrs inside the barrel, which isn't a big turn-on. Kind of sloppy. I'm guessing that will go away pretty quick with usage, and will run about 40 rounds or so of Wolf Steel through it, to let those steel jackets have a whack at it.

Still, not a great start.

For the flash-hider, I'm not a huge fan of the A1 style bird-cage design, as I will get some blast down on the ground when shooting prone (which I do), but here we are. Timing is easy, since there are 5 equal rotation positions to choose from. I didn't bother with the crush-washer, but just put some blue-loctite and some mild torque on it. I don't really plan on running it hot enough to mess up the blue loctite, and by the time I do, it will have enough carbon deposits to seal it in place that way anyway - is my expectation.

The crown has a light 45 degree crown on it, that's only land's deep - but looks uniform enough.

The throat and chamber reamer maybe is different than the team barrel, with a little bit of run before the lands start. Where the Team Monster barrel lands start right away. When I ran a Hornady gage, I found the throat about 0.010" longer than the Monster Team Barrel, for bullet seating; which is pretty close. Barrel interior was smooth and the rifling looked well cut.

We'll see how it shoots, I mounted it last night to 40 ft' lb's torque on the barrel nut.

Alexander Arms DIY Kit - VASCAR2 - 03-11-2020

I have a 1:9 twist Shilen 6.5 Grendel that has proven accurate for me but I haven’t shot very many 129 grain bullets. I think Bill A. mentioned the longer barrels did well with 1:9 twist. The 1:9 twist was the traditional twist for the 264 Winchester Magnum and I believe the 6.5x55 Swedish Mauser plus Mannlicher–Schoenauer 6.5×54mm used 1:9 twist. The 6.5x54 M/S used some pretty long bullets. If I had the option of buying my Shilen with 1:8 twist in 2012 I would’ve bought it instead of the 1:9. Back then you were lucky to find any 6.5 Grendel barrels in stock. There are way more options today.

I bought one of the Group Buy 12 inch barrels with the fast 1:7.5 twist just because I was curious how it would compare to my PSA 1:8 twist barrel. Be sure to let us know how your AA 1:9 twist barrel shoots.

Alexander Arms DIY Kit - Jakal - 03-11-2020

I've got an AA 16" 1/7.5 twist and with Barnes 100 grain TTSX, I'm running 2725fps w/CFE223. Damn accurate and never had any problems with it. Dedicated Nightvision rig.

Alexander Arms DIY Kit - lazyengineer - 03-12-2020

The barrel did pretty good. Not amazing, but the best results so far, and I'm still breaking it in.


As typical, the 90 gr TNT's just shoot great in everything, and here come in at sub MOA performance, which is a good start:
[Image: Screenshot-20200311-210631-Range-Buddy.jpg]


GreenBox 107 SMK's. Decent, at 1.1 MOA. Not amazing, but that's pretty good at 200 yards.
[Image: Screenshot-20200311-205640-Range-Buddy.jpg]

The 107 SMK 2nds at Powder Valley for about 20 cents a bullet. TIGHT group, and a darned flyer that really opened it up.
[Image: Screenshot-20200311-211132-Range-Buddy.jpg]


Here's how it did with Federal's 120 gr Fusion factory ammo. This is actually pretty good for that load, as non of my other Grendel barrels would get anywhere close to 2 MOA with this ammo, and the Alexander BBL is down to 1.6 MOA, which is actually a real improvement.
[Image: Screenshot-20200311-204628-Range-Buddy.jpg]

Alexander Arms DIY Kit - lazyengineer - 03-12-2020

The real wildcard though was the 129gr SST's. Which supposedly are not fully stabilized in a 1/9 twist barrel. And so of course, shot my best group of the day somehow.
[Image: Screenshot-20200311-212828-Range-Buddy.jpg]


Some of the loads did open up bigger than this. With the 100 gr Noslers shooting closer to 1.6 MOA. Wolf Steel was around 2.2 MOA, which is pretty good. No jams or other issues. Overall, the accuracy is pretty good, and it was also pretty consistent. Almost nothing other than Wolf Steel broke over 2 MOA. Most loads were in the 1.0 to 1.5 MOA range, which isn't bad at all. Best I've had yet, at least.

Alexander Arms DIY Kit - MeatySweats - 03-12-2020

Thanks for the data! I bought a bunch of wolf, american gunner, PPU and some ELD to try out and I'm hoping they'll group well.

I just got my kit today, but no magazine. I'll call them up tomorrow and ask if they forgot about it because I'm lacking mags at the moment.

Alexander Arms DIY Kit - joedirt199 - 03-12-2020

I bought an adaptor to change the thread pitch to the more standard 5/8 to open up the choices of muzzle devices. Barely adds any length. Saw those barrels and they do try to get you to buy their parts. Other companies offer gas blocks in those diameter so an adjustable one can be had for less.

Alexander Arms DIY Kit - VASCAR2 - 03-12-2020

Most AR-15 6.5 Grendels will feed four or five rounds out of a 5.56/223 Pmag if you don’t have access to a 6.5 Grendel mag.


Thanks for the update Op. I’ve been reading this forum for several years before buying my first 6.5 Grendel and joining the forum. When there were fewer vendors/manufacturers of 6.5 Grendel barrels the majority of barrels on the market tended to be of good quality. Most of the rack grade barrels tended to be pretty respectable and generally accuracy problems were related to optics, trigger or interference with the barrel harmonics.

There just wasn’t the knowledge base when other manufacturers started turning out 6.5 Grendel barrels and that was when I started seeing significant number of barrels with QC and accuracy issues. There can be QC or manufacturing problem with any manufacturer but the number of these problems and the manner in which the vendor/manufacturer deal with the problem is what is important to me. Buying a high quality (generally more expensive) barrel is the key to getting consistent accuracy. Rack grade barrels really boils down to luck of the draw but your chances of getting lucky is better with certain manufacturers and worse with others.

Alexander Arms DIY Kit - lazyengineer - 03-15-2020

Set up with the bipod at 200 yards to do some more testing.
The 107 SMK green box shot amazing today, sub MOA, with perfomance as good as 1/2 MOA:
[Image: Screenshot-20200315-091345-Range-Buddy.jpg]

The 107 Factory Seconds at powder valley did good as well, giving sub MOA performance
[Image: Screenshot-20200315-000055-Range-Buddy.jpg]

Nosler bullets be it 100 or 123, generally struggled more, and were typically in the 1.5 ish MOA range, with some groups opening up more. My overall experience with Nosler and 6.5 just hasnt been good.
[Image: Screenshot-20200315-115359-Range-Buddy.jpg]

Hornady 100 gr did better, generally running in the 1 MOA range or better.
[Image: Screenshot-20200315-114331-Range-Buddy.jpg]

Alexander Arms DIY Kit - lazyengineer - 03-15-2020

All in all, I'm pretty darned happy with the barrel and build - at last.
[Image: 20200314-210155.jpg]

It's been a long ride trying to get a Grendel capable of sub-MOA level performance. My goal was to get a rig I could use in the AR Tactical catagory for 600 yard midrange matches, and fire it from a bipod. My prior attempts with other barrels had not gone well, but this one should do much better. Here is a 99/100 score (with a crazy 9 I didn't call, so not perfect).

[Image: Screenshot-20200315-124209-Range-Buddy.jpg]


Heck, it even shoots Wolf Steel half-decent, at around 2.5 MOA or better most of the time.

Alexander Arms DIY Kit - VASCAR2 - 03-15-2020

I’m not surprised your barrel shoots 129 grain bullets pretty well. My Son in Law has a Lothar Walther 22” 6.5 CSS barrel with 1:9 twist. The 6.5 CSS uses a 2.95 neck but a compound throat chamber that shoots 6.5 Grendel ammunition. His barrel is picky on which bullets will chamber without seating real deep. He pretty much settled on Hornady 129 grain SP and 129 grain SST. These two bullets shot real well in his L/W barrel.

A Friend has a 24” AA CMV 1:9 twist barrel which shoots very good and he has used it to take numerous antelope in Wy. After seeing how my 1:9 Shilen shoots I can live with 1:9 twist 6.5 Grendel barrels.