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I'm nearly finished with my build. I have one last question. I'm using a Lilja AR24 barrel and a Precision Firearms NiB BCG from the group buy of last year. Will I need to do a head space check on this set up? If I remember correctly Lilja used the Precision Firearms Bolt to design their barrel. Can anyone verify this for my? I just don't want buy head space guages for a one time use. Thanks
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Lilja used whichever bolt you asked your barrel to be headspaced to. I know there were at least options for LBC, PF, and AA, possibly more. I think the normal production run barrels are using PF or maybe Maxim.
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If this is all new equipment from quality vendors, which I believe Lilja and Precision Firearms are and it's assembled correctly, I wouldn't worry about it.
Shoot it, watch for pressure signs, if you see a problem then it's time for gauges.
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I asked Daniel Lilja the same question. His reply was "You want the type 2 bolt with .136” depth". His website says:
"The 6.5 Grendel barrels are headspaced using a Maxim Firearms bolt. Headspace may not be correct with our barrel using an Alexander Arms or LBC bolt. Bolts are not included. We suggest contacting Maxim Firearms for an MF bolt at 928-486-2296".
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If you've already bought the bolt from Precision drop Mark an email at
pf15@pf15.com and ask him for his take. He'll be able to tell you exactly what to do.
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A Wilson case gauge has two steps. The lower can be used to adjust the sizer die and the higher one can verify that the headspace is in the ballpark.
I use these on my 223, 300 Blackout and 308, have never bought one for the Grendel, but need to I guess.
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The Wilson gauge is good to have. I also think the head space comparator is handy too. With the gauge, you can confirm that the case will fit in the minimum chamber. With the comparator, you can measure the size of fired cases and adjust your sizing die to bump the shoulder just enough to reliably cycle in your gun. Your brass will last longer.
Last time I checked, Maxim machines the bolts for PF. PF does a different surface treatment and slicks up the extractor. I have one of each. Both are very nice and work well.
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Since it is a finished barrel with the barrel extension already on it you would not be able to adjust the headspace. Iy your bolts closes on a factory round that is all you need to know.
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Thanks for all the help guys. I'll post some pict's and a range report when I get it out this spring.
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gooffy140 Wrote:when I get it out this spring.
Ugh, how can you stand to wait? It might be a little nippy on some some range days, but we can shoot about every week of the year down here. I guess the advantage is that you can get a lot of ammo loaded up and stockpiled, whereas, most of my buddys load some and shoot some and never seem to have any loaded rounds on hand. Come on down south for a while!
"This mornin', I shot six holes in my freezer I think I got cabin fever Somebody sound the alarm"
Jimmy Buffett - "Boat Drinks"
My "6.5" = 24" AA Overwatch upper 1/9 twist, NC based US Tactical lower, standard A4 6 position stock, AR Gold Trigger, JPS SCS buffer, Vortex 6-24 x 50 FFP PST with EBR-2C MOA reticle