All purpose "Help me build my AR" thread.

[williaty]

It seems like 1:9 used to be the most common, since it shoots such a wide range of bullet lengths, until the .mil started using 1:7 and now everyone has to be like .mil or they aren't cool.

"Heavy" is a barrel profile. Considerable extra weight, especially at the muzzle, heats up slower but takes longer to cool off.

Hammer forged is a way of making a barrel. Generally considered to be a desirable feature.

Not sure about CL. Possibly carbine length?

MP is usually MPI. Magnetic Particle Inspection is a way of making sure there's no flaws in the metal. Generally considered to be a desirable feature.

[kbilly84]

Not sure about CL. Possibly carbine length?

Chrome Lined. Unless it's stainless (those are never CL, as I understand it), CL is a must-have.

I've wondered why barrels are MP and bolts are MPI, when both mean Magnetic Particle Inspected. I've found that odd.

Anyone out there can explain - metallurically - why Hammer-Forged is better? I used have a vague idea, but now it's more of an "accepted fact"

[thebigstick]

hey folks.
putting together my first ar and I've come to the rear sight, and now I have a few questions.

are all rear sights created equal?
what should I look for in a rear sight?
and would you recommend a manufacturer over any other?

thanks in advance

[RickOShea]

hey folks.
putting together my first ar and I've come to the rear sight, and now I have a few questions.

are all rear sights created equal?
what should I look for in a rear sight?
and would you recommend a manufacturer over any other?

Most have dual flip apertures. Usually one of the "peep holes" is larger (for close in/quick use) while the other is smaller (for longer range/more precise aiming).

BUT....Some rear sights have both apertures on the "same plane", so that your point-of-aim/point-of-impact is the same no matter which one you're using. While others have the apertures on different planes. IIRC, on those you'd sight the small one in at 300 yards/meters, and that would give you a "battle zero" from 0-200 yards/meters with the larger one.

Now, what type of rear sight are you looking for, a fixed or folding one?

[nimdabew]

I've wondered why barrels are MP and bolts are MPI, when both mean Magnetic Particle Inspected. I've found that odd.

MP is batched tested and MPI is individual tested.

[thebigstick]

hey folks.
putting together my first ar and I've come to the rear sight, and now I have a few questions.

are all rear sights created equal?
what should I look for in a rear sight?
and would you recommend a manufacturer over any other?

Most have dual flip apertures. Usually one of the "peep holes" is larger (for close in/quick use) while the other is smaller (for longer range/more precise aiming).

BUT....Some rear sights have both apertures on the "same plane", so that your point-of-aim/point-of-impact is the same no matter which one you're using. While others have the apertures on different planes. IIRC, on those you'd sight the small one in at 300 yards/meters, and that would give you a "battle zero" from 0-200 yards/meters with the larger one.

Now, what type of rear sight are you looking for, a fixed or folding one?

fixed.
I'm also saving up to get an eotech or similar sort of red dot and I'd like to co-witness.
quality wise if I stick to the major manufacturers are they all about the same? (the rear sight I mean)

[williaty]

Anyone out there can explain - metallurically - why Hammer-Forged is better? I used have a vague idea, but now it's more of an "accepted fact"

The way you turn a big bar o' steel into a finished product has a major effect on the final grain structure of the metal. Grain structure is sort of like what shape of snowflake the steel made as it crystalized. Some snowflakes are stronger, tougher, or in some way different than other snowflakes. Hammer forging is one process that tends to result in snowflakes that are both strong and tough, which is what is required for durability.

[mk_ultra]

I have a Larue fixed . If it was out at the time I bought mine , I would have gotten the Daniel Defense .

Can't go wrong with either of those or an LMT as well as far as fixed BUIS go .

[kbilly84]

Nim & WIlliaty, Thanks for the info.

Big Stick, I've got a DD a1.5 on mine and love it. Really, any of the reputable manufacturers are GTG.

ETA: didn't Dave or someone do a write-up on sights for AR's a while back?

[nimdabew]

Anyone out there can explain - metallurically - why Hammer-Forged is better? I used have a vague idea, but now it's more of an "accepted fact"

The way you turn a big bar o' steel into a finished product has a major effect on the final grain structure of the metal. Grain structure is sort of like what shape of snowflake the steel made as it crystalized. Some snowflakes are stronger, tougher, or in some way different than other snowflakes. Hammer forging is one process that tends to result in snowflakes that are both strong and tough, which is what is required for durability.

http://bettincustomguns.com/Technical%2 ... niques.htm

[JTNieman]

Hammer forging is good because it's cheap.

If you want a match grade, uber accurate barrel, you get button rifling.

[majorhavoc]

ETA (6/12/12): Now out of stock; no backorder

SI Defense Bolt Carrier Assembly Mil-Spec AR-15 223:

http://www.midwayusa.com/product/811336 ... gton-matte



In stock and with $15 off using coupon code AR15615, it checks in at under $100 ($95.63). In the current market conditions, that's not a bad deal these days.

Specs:
SI Defense AR-15 bolt carrier groups are 100% mil-spec, fully assembled and ready to be dropped in. The carrier body is machined from 8620 steel, heat treated, MP inspected and then Mil-DTL-16232G manganese phosphated. The carrier's bore is hard chromed for increased corrosion resistance and reliability. The bolt is machined from Carpenter 158 steel, shot peened, MP inspected and manganese phosphated per Mil-DTL-16232G. SI Defense Bolt Carrier Groups feature a gas key tube that is hard chromed and properly torqued and staked. .

[TheLastOne]

meh a new thread would be stupid, and most of the people I'd like to hear answers from read this thread, so:

Recommend me a shot timer. Had a blast in Dave's sub-group this weekend working on transitions, splits etc, and with the disruption drill. I think Doc had a Competition Electronics (CED) brand?

I don't know shit about these things, but I want adjustable delay start (because I shoot by myself for the most part), able to display time between multiple shots, time between first and last shots. Pretty sure that is all standard, but there you go.

Thanks

[nimdabew]

http://pact.com/index.php?option=com_co ... &Itemid=63

Get that one.

[RickOShea]

I use "Ole Blue"....But it's kinda bulky compared to some of the newer timers.

http://www.midwayusa.com/product/1810132542


I like the smaller size of this one, but I don't have any experience with 'em.

http://www.midwayusa.com/product/759103

[TheLastOne]

http://pact.com/index.php?option=com_content&task=view&id=17&Itemid=63

Get that one.

Have you used that one? I'd trust your personal opinion of it. There are a lot of shitty reviews in that link, but I know that can often mean jack shit.

I use "Ole Blue"....But it's kinda bulky compared to some of the newer timers.

http://www.midwayusa.com/product/1810132542


I like the smaller size of this one, but I don't have any experience with 'em.

http://www.midwayusa.com/product/759103

I think that first one is what Dave and Doc66 have. Probably my best bet.

Second one looks great except for the non replaceable battery situation. I'm all for rechargable, but I'd rather it didn't work because I forgot a 9v versus it lost its charge and I have no method to charge at the range and/or it not working/battery broke and I have to send the fucker off to the factory...

[Dave_M]

meh a new thread would be stupid, and most of the people I'd like to hear answers from read this thread, so:

Recommend me a shot timer. Had a blast in Dave's sub-group this weekend working on transitions, splits etc, and with the disruption drill. I think Doc had a Competition Electronics (CED) brand?

I don't know shit about these things, but I want adjustable delay start (because I shoot by myself for the most part), able to display time between multiple shots, time between first and last shots. Pretty sure that is all standard, but there you go.

Thanks

We use Pocket Pro II's

[0122358]

do you guys think a Fenix LD10 would work as a firearm light? and what is a good mount? All ive got is the standard carbine handguards with after market screw in piccitanny rails on the top and bottom.? was thinking somthing like a VTAC light mount.

ETA...does anyone use Streamlight lights?

[hatchtrikk]

Can you guys give your recommendations as to which muzzle device would be best for a RECCE style build? I'm leaning towards a regular old A2.

It'll have a 16"bbl.

[Regular Guy]

Can you guys give your recommendations as to which muzzle device would be best for a RECCE style build? I'm leaning towards a regular old A2.

It'll have a 16"bbl.

VLTOR A2.

[majorhavoc]

Damn. PSA AR barrels in light, mid and heavy weight profiles, midlength gas systems, $123.95 with free shipping for the month of June.

http://palmettostatearmory.com/index.php/ar-15-05/barrel-clearance.html

16", Chrome Moly Vanadium Steel, 5.56 NATO Chamber, 1 in 7 inch twist, Chrome-Lined Bore and Chamber, Mid-length gas system, 1/2-28 Muzzle thread, .750 Gas Block Diameter, High Pressure Tested, Magnetic Particle Inspected, Black Phosphate coated.

I swear to god I'm not a shill for PSA. I don't even haunt their website. But this shit keeps showing up on Slickguns.com. Somebody out there must be in the middle of a build and looking for a decent barrel.

Note these are not the hammer forged barrels, so I don't know if they're FN. It's super easy to do a hell of a lot worse if you're in the market for an AR barrel, but you'll have to look far and wide to find a better deal at the moment.

They also have special prices on 14.7" light profile in 5.56 and 16" CMV 6.8 SPC II with a 1:11 twist. Hope this helps somebody.

[hatchtrikk]

Can you guys give your recommendations as to which muzzle device would be best for a RECCE style build? I'm leaning towards a regular old A2.

It'll have a 16"bbl.

VLTOR A2.

What are the benefits over the standard A2? I like the look of it, so I'll probably end up with it anyway. Just wondering.


LOL at the new smilies. I'm so excite!

[Regular Guy]

Can you guys give your recommendations as to which muzzle device would be best for a RECCE style build? I'm leaning towards a regular old A2.

It'll have a 16"bbl.

VLTOR A2.

What are the benefits over the standard A2? I like the look of it, so I'll probably end up with it anyway. Just wondering.


LOL at the new smilies. I'm so excite!

It doesn't do the sparky like the A2 does. The Vltor is spark free and does a damn good job of flash suppression. The A2, not so much.

[Regular Guy]

Damn. PSA AR barrels in light, mid and heavy weight profiles, midlength gas systems, $123.95 with free shipping for the month of June.

http://palmettostatearmory.com/index.php/ar-15-05/barrel-clearance.html

16", Chrome Moly Vanadium Steel, 5.56 NATO Chamber, 1 in 7 inch twist, Chrome-Lined Bore and Chamber, Mid-length gas system, 1/2-28 Muzzle thread, .750 Gas Block Diameter, High Pressure Tested, Magnetic Particle Inspected, Black Phosphate coated.

I swear to god I'm not a shill for PSA. I don't even haunt their website. But this shit keeps showing up on Slickguns.com. Somebody out there must be in the middle of a build and looking for a decent barrel.

I'm not a shill either but how can you argue with that price. Yes, they are FN barrels, just not CHF but made from the same metal.