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Got mine, along with my two bolts. They look great.
That being said, has anyone had any issues with gas blocks fitting? I've tried three, and they don't want to slip on at all. Two Sadlak and one Geissele.
Got mine, along with my two bolts. They look great.
That being said, has anyone had any issues with gas blocks fitting? I've tried three, and they don't want to slip on at all. Two Sadlak and one Geissele.
I had to ever so slightly hold open my clamp on superlative GB to get it to slide over so that tells me most of these profiles are right at the 0.750" diameter specified.
I tried heating the gas block up, got it about halfway on, and it stuck solid. Nothing was moving it. Stuck the whole assembly in the freezer. Pulled it out after a couple of hours, hit the gas block with a propane blowtorch, and it still wouldn't move. I finally resorted to grinding the side of the gas block off, which allowed me to get it off the barrel.
I used my reloading calipers to measure the journal diameter, and it is coming up at 0.751-0.752" toward the shoulder. I was getting some slightly higher measurements toward the front.
Got mine, along with my two bolts. They look great.
That being said, has anyone had any issues with gas blocks fitting? I've tried three, and they don't want to slip on at all. Two Sadlak and one Geissele.
Measure your IDs and distance to ports from the barrel shoulder and the back of the gas block to the center of the gas block ports.
I often have to heat up my Sadlak blocks to press-fit them to the journal. You can also freeze the barrel and heat the block, then quickly slip the gas block over the journal to the correct position for alignment.
The biggest mistake I see a lot of people making is assuming that the gas block should touch the shoulder of the barrel/journal junction, as most new AR15 owners didn't grow up with the handguard cap. Most barrel profiles are cut to accept the handguard cap between the FSB and the shoulder, even though most everyone has been using free float for many years now.
There are some low profile gas blocks that will actually align with a shoulder abutment, but most require stand-off equivalent to the thickness of the handguard cap.
Use calipers and measure.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
There are some low profile gas blocks that will actually align with a shoulder abutment, but most require stand-off equivalent to the thickness of the handguard cap.
You happen to know the thickness of a handguard cap? I think I'll change my barrel drawing specifications to allow the block to abut the shoulder directly and assume no handguard caps will be used.
:: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets
Modernizing the Grrr barrel. I like it. My low profile adjustable lined up with no setback so not sure how it would have worked if you make these changes? Why can't everything just be standard.
You happen to know the thickness of a handguard cap? I think I'll change my barrel drawing specifications to allow the block to abut the shoulder directly and assume no handguard caps will be used.
Be careful. If you change the barrel spec to account for the cap thickness, then gas blocks that are designed to butt against the shoulder won't work on those barrels. Here's an excerpt from the installation instructions for a YHM clamp on block:
7. If using a standard forearm slide the gas block all the way on until it hits the metal forearm cup.
If you are using an aftermarket forearm DO NOT PUSH THE GAS BLOCK AGAINST THE
SHOULDER OF THE BARREL! You must leave a 1/32” gap between the shoulder of the
barrel and the gas block. *::Exception::* The YHM-9384 gas block should not have a gap
between the shoulder on the barrel and the gas block.
a small oring behind the gas block works as well, i typically just put a sharpie dot at 6 oclock to the gas port and line it up with the hole in the bottom used to drill the gas port in the gas block then if i am using a set screw style gas block i place a #8 lead shot in each set screw hole and then torque the screws down on them such as to make a better contact and not marr the barrel or create a pressure point
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