Is there a huge difference in quality  in say a SOL .625 gas block and a larue .625 gas block?

$50 vs $100

You have to make that determination for yourself. Research the specs, design, and materials. I use BCM gas blocks. If you look at the description, you know exactly what you are getting.

Types of steel and adherence to specs can be the difference between cheap and expensive gas blocks.  That said, unless the thing cooks you breakfast in the morning, cures male pattern baldness, and splits the atom, $100 is overkill for a standard gas block.  On the flip side a $10 usually sucks from the quality and fit standpoint.  Roll pin holes out of spec.  Loose fit to the barrel. etc...   Go with a happy medium.

The $25 ones are functionally the same as expensive ones in my trials. Many brands are just resellers where the most they do is get their logo etched on some mass OEM part and upcharge 60% while pretending to do some extra QC.

I can grab an Expo arms or Dirty Bird item which are just the bulk oem brands from PA and AR15 discounts and they work every bit as well as Badger, DD, BCM, etc.

BCM blem gas block

$20

@greenranger

As far as basic LPGBs....I've used $12 offerings and $70 offerings without issue.

I'm sure there are plenty of turds out there for sale though.

Same here. I have never had a properly installed one fail. It is a simple part. I like BCM for the tight fit and the knurled screws.

Thanks

Thanks for the replies so far. Helps me decide on what I’m gonna put on this build —which will be the first total build for me.

Really hard to beat Wojtek gas blocks if you want an adjustable option.  They're all I use anymore.

https://www.wojtekweaponry.com/product-category/firearm-parts/badass-adjustable-gas-blocks/

This.

SLR Rifleworks makes a damn nice GB OP.

FIFY

I bought a BCM blem charging handle and blem pistol grip, but the grip wouldn't seat all the way. There was almost 1/4" gap and it needed some sanding that didn't get done.

Two other grips fit the same lower just fine.

I'm now a little bit leary of what "blem" means, especially on polymer products.

I can never find the cheap blems when I need a gas block!

I build a lot of uppers

I have had dimensional issues you wouldn't expect with even some quite expensive blocks

I've taken to buying several at a time, and doing my own qc.  And sending the culls back

There are no $100 blocks I would consider at the moment outside of adjustable units.  Dimensional analysis of a new block isn't terribly complicated

Yes, you can go too cheap. You will get poor dimensions and weak steel. I don't have time to go into the whole story, but I once bought a Sadlak low profile SPR gas block from Brownells to see if going as cheap as possible had any negatives. It did. But this was an under $20 gasblock.

Cheapest quality gas block is probably BCM, but they use the same external body/profile on .625 and .750 so the .625 is heavier and makes no sense for you.

The Larue is designed with a longer shank for covering up the blemished, unparked sections when you remove a fixed gas block. A normal SPR short profile won't and it won't cover the front pin hole in the barrel left from removing a fixed gss block. It is a specialty item. Midwest Industries makes one that is heavier but only $45 that accomplishes the same thing.

If I was spending up to $100 on a low profile gas block, I would get a Superlative Arms adjustable set screw gas block. They are $100 retail and if you are LE they are about 20% off. They will sell you a gas tube that is specially bent for their gas block which is slightly higher than SPR spec. Worth the few dollars more to get  it if you go this route.

To piggy back off of this, DSArms has a quality offering similar.
DSA AR15 Extended Length Low Profile Steel Gas Block - .750"

Well worth the price and free ship for Arfcom members.

My 2 were interference fit on Colt barrels requiring slight heating. I'd wager that they wouldn't move if ran w/o set screws. (3 set screws per GB, for the record.)

I wonder if there was a run of them with undersized bores. I had one that wouldn't go on a Ballistic Advantage barrel even with heating, DSA replaced it and the new one went on without issue.

I was hoping it was a perk and not a flaw.

I would imagine your goal would be for the gas block to last as long as the barrel would. With that said, I imagine a difference in steel and component would play into the gas block port opening up and that rate would go up or down depending on how quickly it reaches high temps and for how long it is exposed to that high heat.

The question is if that makes any sort of difference in the life expectancy. I would say it does but the difference would be so small that it would make no statistical difference.

So are yall saying with a LaRue barrel I need the longer gas block? Or would the shorter ones suffice ?

If you're not attempting to cover previously drilled taper pin channels from a FSB then no.

These are all I have used for years.  They are machined exceptionally well, seem to have a better overall fit (tend to be tight) and are reasonably priced.  I’ve used some GB’s in the past that fit more loosely than I wanted, prefer a tight fit.