Gas block jig.

[raptrbreth]

Just wondering if anyone has used a jig to dimple the barrel. I was watching YouTube videos about attaching gas blocks and came across this:
Gas Block Dimple Jig | BRD ENGINEERING

Thoughts?

I am new to AR building but want to put together as much as possible in a home shop. I understand that it can be done without the jig but seems that it would be so much more repeatable with the jig. I plan, if the first works out, to build at least two more.

 

[1911ly]

I've never bought a barrel that the gas block hole wasn't drilled. You might check with a barrel manufacturer to see if you even need it.

 

[raptrbreth]

I've never bought a barrel that the gas block hole wasn't drilled. You might check with a barrel manufacturer to see if you even need it.

No this is for the gas blocks that use set screws instead of clamping. The jig cuts dimples to allow the set screws to get a firm hold.

 

[bstewrat3]

I don't think the spacing for the set screws is a standard dimension. I have changed blocks before and ended up with marks in different spots. I have never dimpled though so it didn't affect me.

 

[USMC-Johnson]

seems silly to not have an indexing pin of some sort for the gas port.

 

[rob63]

At $60, wouldn't it be cheaper to just buy a cheap gas block, drill out the threads and use it as a jig?

On a related note, has anybody ever used one of these to make sure the gas block is aligned properly? There is a video at the bottom of the page that explains how it works. It's a neat idea and cheap, but I'm just not sure getting it aligned properly is really enough of a problem to justify any expense at all.
https://hbindustries.net/store/shop/ar15-gas-block-aligner-5-56mm/

 

[padawan]

At $60, wouldn't it be cheaper to just buy a cheap gas block, drill out the threads and use it as a jig?

On a related note, has anybody ever used one of these to make sure the gas block is aligned properly? There is a video at the bottom of the page that explains how it works. It's a neat idea and cheap, but I'm just not sure getting it aligned properly is really enough of a problem to justify any expense at all.
https://hbindustries.net/store/shop/ar15-gas-block-aligner-5-56mm/

Take your set screws out, slide gas block on bbl, align gas block, use a transfer punch to mark your dimple locations, drill carefully. Now the dimples are exactly where they should be.

 

[sig1473]

seems silly to not have an indexing pin of some sort for the gas port.

There is. That is what the pointed set screw is for as it goes over your gas port.

To the OP, I have purchased one from BRD. I was like you and was wondering if it was 'worth it'. I can answer that easily with a "yes they are". I purchased the jig for the Geissele gas block. I took my time and now my gas block is perfectly aligned. I rest easily knowing it is aligned rather than eyeballing. When it comes to building ARs, I have learned you get what you pay for and it is sometimes pricey. I have upgraded all my tools such as using a Geissele Reaction Rod, MagPul Armorer's wrench, quality torque wrench, quality punches, etc. Like I said it is pricey, but that is the price you must be willing to play the game correctly.

 

[raptrbreth]

There is. That is what the pointed set screw is for as it goes over your gas port.

To the OP, I have purchased one from BRD. I was like you and was wondering if it was 'worth it'. I can answer that easily with a "yes they are". I purchased the jig for the Geissele gas block. I took my time and now my gas block is perfectly aligned. I rest easily knowing it is aligned rather than eyeballing. When it comes to building ARs, I have learned you get what you pay for and it is sometimes pricey. I have upgraded all my tools such as using a Geissele Reaction Rod, MagPul Armorer's wrench, quality torque wrench, quality punches, etc. Like I said it is pricey, but that is the price you must be willing to play the game correctly.

The Geissele Reaction Rod was on the list next. Thanks everyone for the input. I just worry about buying a single jig when companies use differing hole offset. Guess I will buy the one that seems to fit the most number of companies gas blocks.

 

[USMC-Johnson]

http://www.brownells.com/gunsmith-t...-torque-tools-prod27452.aspx?avs|Make_3=AR-15

Quite a bit cheaper than the geissele reaction rod and works just as well. I've got them in the ar15 and ar10 configurations and they work great and hold up great. The only thing i did was have a friend machine some flats on them so they get held in my inexpensive vise better.

 

[sig1473]

I just worry about buying a single jig when companies use differing hole offset. Guess I will buy the one that seems to fit the most number of companies gas blocks.

Me too. Just remember though that the gas port dimple that you drill will always be in the same spot no matter the gas block.