Installing Yankee Hill Low Pro Gas Block On Spr barrel

[burgess65]

Hey,

Anyone have any tricks on how to install the YHM low pro gas block on a bison spr barrel? I cannot seem to get it any where close.

Thanks for the help!

[WASSMAN]

I take it you got a set screw type gas block. If so good luck.

[Nswish]

We're going to need more info than that. In what way isn't it getting close?
It isn't going to butt up against the barrel shoulder tightly, there will be a slight gap for a traditional handguard endcap.
There should be a dimple in the barrel diresctly under the gas port, that dimple should line up perfectly with the rear most set screw for the gas block. That rear set screw is posistioned so it should line the ports up perfectly.

[burgess65]

We're going to need more info than that. In what way isn't it getting close?
It isn't going to butt up against the barrel shoulder tightly, there will be a slight gap for a traditional handguard endcap.
There should be a dimple in the barrel diresctly under the gas port, that dimple should line up perfectly with the rear most set screw for the gas block. That rear set screw is posistioned so it should line the ports up perfectly.

I think i received the wrong diameter gas block. It slides over the first few inches of the barrel with out any problem. But once it gets to the first hump at the front of the barrel, it wont go any further. I dont want to hammer it on for fear of completely screwing up my finish. For the record, the set screws are completely removed so that cannot be an issue.

For the record, I purchased it along with my barrel from bison. I would have assumed the diameter would have been correct. If i cant come up with a solution here, i'll be sure to give bison a call tomorrow.

[WASSMAN]

If you have a set of dial calipers on hand you can measure the O.D of the barrel and the I.D. of the gas block. That will tell you how far off you are.

YHM has been know in the past to be off of their measurements, just ask H. I had a spector gas block from YHM and I had to ream the gas tube hole a little so the tube would slide into it. It seems YHM has been a hit and miss for me. FYI the last Upper Receiver spec out fine.

[Nswish]

That makes it sound like you had the barrel coated. If thats the case, the finish is too thick. There are only a few sizes of gas blocks so if it looks close its the right one. The GB should measure .75" as should the barrel. It the barrel is a hair too thick from the finish try some sand paper inside the gas block to open it up just a bit. Either that, or email Ben and see what he says.
Personally, I'd open up the gas block but thats not really something you should have to do for an assembly.

[burgess65]

Ok, i'll definitely call him tomorrow. I wish the fix would be as easy as sanding the inside of the block but it's so tight around the barel to begin with, it's almost too much for the finish to be the issue.

Edit:

According to the YH's website, for the YHM-9383 gasblock, the ID should be .750...

hmmm..

[JDeere7296]

Ok, i'll definitely call him tomorrow. I wish the fix would be as easy as sanding the inside of the block but it's so tight around the barel to begin with, it's almost too much for the finish to be the issue.Edit:According to the YH's website, for the YHM-9383 gasblock, the ID should be .750... hmmm..

I doubt the finish is that thick, I've refinished many barrels and never had one that tight. More than likely the gas block may be out of spec

[mrosbro]

the last three gas blocks i have used,1 YHM and 2 VLTOR all were undersized by about .003. just enough to keepthem from sliding on. i just used a dremel and opened them up. it takes time and alot of fitting but it works.havent had any problems or gas leaks.

[burgess65]

Dremel option Is going to be my plan. I'll let you all know how it goes. Pics will be up soon too!