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Hey guys. So I'm finally getting my 18" upper built. I have an 18" Satern barrel that came with a "matched bolt". I'm not sure who makes their bolts but, to my untrained eye, it looks like a regular bolt. I'm using a JP FMOS bolt carrier and it came with a bolt that looks pretty trick, and is made from Carpenter 158.
My question is how "matched" are Saterns bolts to their barrels, and am i better off using their bolt over the JP unit?
Thanks
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First of all, assume nothing!
The most important question in this is which bolt face depth is the barrel head-spaced upon? There are 2 bolt face depths in the Grendel:
1. the standard Grendel bolt which has a 0.136" depth.
2. The other type has a 0.125" depth.
You can measure both bolts if they are in your possession but whatever the barrel was head-spaced for, that's the depth of bolt you need to go with.
Depths are typically +/- 0.001"
Example: on the Brownells site for 18" Satern barrel, they have this description, notice it says 0.136" face depth:
"...Muzzle is threaded 5/8"-24 and the gas shoulder accepts 0.750" gas block. Chamber is 6.5 Grendel II. Opposite side of gas port features a dimple for a gas block set screw. A 6.5 Grendel bolt is included with each barrel. Bolt is machined from 9310 steel with a bolt face depth of .136". Barrel extension is M4 feed ramp style."
If the 2 bolts are the same depth and the barrel was head-spaced for that depth, consider yourself lucky, use 1 and keep the other as a spare.
But I would assume nothing. Check the literature/specs of your Satern barrel to ensure which depth it set for.
There are several threads on here about bolts and barrels and head spacing... Mix and match in this arena is bad joo-joo.
"Down the floor, out the door, Go Brandon Go!!!!!"
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Grayfox,
Both are .136
Thanks
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Matched bolt, both .136.
GTG then looks like.
Shoot safely!
"Down the floor, out the door, Go Brandon Go!!!!!"
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Use the JP and keep the Satern as a spare. The JP is the best bolt out there, but even if anyone wants to debate that, there is no bolt that easier to clean than a JP.
Let's go Brandon!
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StoneHendge Wrote:Use the JP and keep the Satern as a spare. The JP is the best bolt out there, but even if anyone wants to debate that, there is no bolt that easier to clean than a JP.
I have a JP bolt and have no issues with it, but i haven’t really noticed it being any easier to clean. I also notice that their gas ring design is looser than others but I haven’t had any reliability issues either. I’d use the JP primarily and spare with the saturn just because the JP should be a better bolt IMO. I have JP, hardened arms, alexander Arms, and group buy bolts. So far no issues with any.
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Maxim firearms makes a really nice bolt also.
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Joseph5 Wrote:Maxim firearms makes a really nice bolt also.
+1 . They are are good bolt for hot reloads too. Tough as nails
