My First Spacegun Build And Am Getting Reamed

[Nitroman]

I posted my new build on 24-hour and Falfiles and am getting slammed because I wanted to use a twist rate that'll allow for the use of the Barnes 63-grain and lighter bullets. I guess this is beyond most peoples' comphrehension? I dunno. From almost all the reply's I glean I need to find a narrow range of bullets weights and then...that's it bey-beh. Not like using a bolt gun where you can experiement throughout what's available. And the big point is my desire to use a 1:9 twist. This just has some people burning UP I tell you. I wanted that twist with a short throat to seat the bullets to the lands, a longer bullet I'll just seat deeper into the case. What the hell is wrong with people? Geez, you'd think I just propositioned their 12 YO daughter or something.

So here is what I decided to get. I WAS pretty **** excited about it until today.
I have just now mailed a cashiers check to cover the cost of a build to Mike Millie of Dedicated Technology. Everything I have seen posted on various forums about this fellow shows him to be upright and a righteous builder of extremely accurate AR's.
http://www.dtechsuperstore.com

I decided to using the Shilen select match barrel since it is probably one of the five best barrels being made today on this planet. It will be 24 inches in length, as large a diameter as will fit under Millie's own free-float handguard and through his Picatinney gasblock. (I stressed I was going to use the mangonel-style flip up front and rear sights for emergency use.)

I asked for a reamer with the tightest chamber and neck that will allow the use of commercial ammo without me having to turn the necks (of brass). And throated for use with the 63 grain Barnes TSX. This is the heaviest bullet I will shoot. My expectations are nothing further than a 500 yard shot. I was looking at a 1:9 twist, but Millie told me he doesn't recommend a short throat with a 1:9 twist, only his 1:12 and 1:14 barrels. He has a reamer he calls a "Heavy Match" that is very tight in the body and neck, but has a throat that allows seating of any bullet out to magazine length. Does this sound like a good one? I was looking at the tighter twist due to most of my shooting in the wintertime cold temps in dense air; the extra stabilization might be necessary?

Trigger will be the Geissel NM set to 1.75 pound first stage with a 0.5 pound second stage (I really am ready FTR_Shooter).

The upper, lower and barrel will be done in Norrel Moly-Resin Olive Drab. The small parts, ejection port cover, gasblock and handguard/mount will all be Norrel Flat Black.

The average annual temperature for Southwestern Alaska is +29*F. We do get some days that are +70*F and over, but this is rare. Most of the time in the summer it's +60*F and cooler. So I need a quicker rate of twist, but not so quick it'll blow up lighter, faster bullets like a 40 grain Nosler BT.
Oh, I got slammed about wanting to have back-up-iron-sights or BUIS (I didn't even know AR weenies had an acronym for that). Being as this rifle may weigh around 11-12 pounds ready to run, I was told the BUIS are a joke for SHTF and runnin' and gunnin'. WTH? Is everyone a tactikewl mall ninja?

 

[Korhil78]

How about build how you want it and enjoy it? They arn't shooting it so don't worry about them. Enjoy your gun. Congrats!

 

[Nitroman]

How about build how you want it and enjoy it? They arn't shooting it so don't worry about them. Enjoy your gun. Congrats!

Thanks. You are right. I have never built an AR so was looking for insight from those who have. I need to call the builder next week and have a good talk with him, and ask him to send me copies of his chamber prints to see which one I think will work for me.

 

[Korhil78]

I would say you are on the right track. Just get with your smith and see what he recommends. The 1:9 twist will allow you to shoot heavier bullets, not lighter ones. The lower twist stabilizes heavier bullets. I shoot 55 gr bullets out of my 220 swift and it has a 1:12 twist.

All the rest of your ideas sound good. I dont have iron sights on my AR because I have a variable power scope on it so if I have my scope power on the lowest setting until I get to where I am going. You dont really need the iron sights on it if you are going to varmint hunt with it. It will make your line of sight so high because you scope will have to be mounted above the line of sight of the iron sights.

 

[HARPERC]

How about build how you want it and enjoy it? They arn't shooting it so don't worry about them. Enjoy your gun. Congrats!

I would second this, but temper it with the thought if you've done a good job picking the smith, and communicating your needs as you initially posted, consider giving a little of the decision making to the builder. This has worked for me on bolt rifles, don't have any knowledge of AR's like you just starting to intrigue me.

 

[SLOAN]

You did two things right. you called mike an you listen to your self..Be safe have fun an aalways shoot center mass.SLOANgun)

 

[msalm]

1-9 and 1-8 twists shoot light bullets extremely well, and will handle the longer bullets up to the 69gr... Don't sweat your twist selection, the 1-9 works very well.

 

[rdsii64]

When they are paying for the build then they can tell you how to build it. do the research make an informed decision build it how you want it. THEN SHOOT IT LIKE YOU MEAN IT.

 

[Stormrider]

It will be 24 inches in length, as large a diameter as will fit under Millie's own free-float handguard and through his Picatinney gasblock.

I did the same thing some time ago so I will offer this for your consideration... I found that the rifle was front heavy (just plain heavy!) and only suitable for shooting off a bipod or rest. It was however, extremely accurate. If you plan on carrying it much while hunting, I would suggest a thinner diameter barrel to reduce the weight (might even consider fluting it) and put a heavier stock on it, like the Magpul PRS. It will help the balance a lot.
As far as the twist rate is concerned, you can shoot pretty much anything you want to include the Hornady 75g BTHP. You probably won't be able to use the 75 AMAX out of the magazine because of the length of the ogive. It causes the bullet to be seated a little below the top of the neck, however I would expect that it would work well single loaded. The 77g SMKs should work too.
I would listen to the 'smith about the chamber dimensions very closely. AR's will generate a lot of fouling and that fouling will find it's way into the chamber. If you have too close a fit it will cause malfunctions. One more thing, Never, Never neck size the cases. That WILL cause you problems.
Good luck on your build. Hope you have a great time with it.

 

[SBruce]

Absolutely nothing wrong with a 9 twist. The Bushmaster Varmint comes with a 9 twist (or used to, not sure if it's still made). Personally, I'd go with the smiths' recomendation on the chamber and throat. Just let him know what you intend on shooting and the guns' intended use and that you want the best precision/most accuracy that you can get out of an AR platform.

I'd be curious to hear why your builder/smith doesn't recommend a short throat with a 9 twist. He probably has a very good reason, I just don't know what it is.

My build was an 8 twist just because I wanted both of my uppers (one is a factory Bushmaster Predator) to have the same twist rate. My barrel is 22" long and measures .850 at the muzzle. It's fluted fore and aft of the gas block and it's actually a pretty heavy little rifle.

It's got a Sierra Precision grip and a Rite-Pull grip extension and Magpul stock (I absolutely love the stock). Nightforce Unimount above the flat top reciever. Jewell Trigger set at 1.5 lbs.

The group is the best I got with Varget powder and Sierra 60 grn HP at 200 yds. Varget is the only powder I tried so far and I haven't done any adjustment of seating depths. The gun shot some other 1/2 minute groups at 200, but not as pretty as this one (wish the flyer wasn't there!)

Good Luck on your project and don't let the others bother you about shooting light bullets and a twist slower than 7 or 8. There's alot better cartridges/rifles out there than a magazine length dependant 223 if we want to shoot 75 grn and heavier bullets.

 

[Nitroman]

Gentlemen,

Thank you fr your opinions and recommendations.

I spoke to Mike Millie about the rifle. He will make the barrel 22". About 1" under the handguard, and 0.936" after the front gasblock. He will use his reamer he calls the "Heavy Match". It is a PTG reamer with 0.069" freebore to load long bullets. The diameter of the free bore is 0.2245". He told me no-one has had any complaints so I'll go with that. I chose to go with a 1:8 twist. The .223 Remmie isn't fawst enough to blow up small bullets (I hope), so this should work well with virtually everything I try to throw down the tube.

Looking forward to this. I even thought about having him make an upper in .243 WSSM at the same time. I have a couple months to decide this.

Thanks again for the information and opinions.

 

[brentc]

Nitroman, you've chosen well with Mike Milli. He creates a fantastic product. 1x8 is a good choice, and will work great with about anything you feed it.

 

[Buccaneerfan]

I just got my first ar with a heavy barrel and 1-9 twist as well. I have been getting reamed as well from all the tacticool guys as well but who cares? We each build our rifles for different uses and if you are not a SHTF type of guy, you simply don't need the same things. I totally get what you are trying to do. Good luck and let us know how it shoots! Don't sweat the people you will never meet!