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  1. #11
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    Quote Originally Posted by Nehalemguy View Post
    I gotta ask.......does this mean she is out of spec and needs replacing or just adjusting?
    Maybe she needs oversized rollers. GARY.
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  2. #12
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    Quote Originally Posted by N4KVE View Post
    Maybe she needs oversized rollers. GARY.
    If I don't get my caloric intake and caloric burn ratio back to the early March number I am going to be an oversized roller.

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    Quote Originally Posted by Tug View Post
    If I don't get my caloric intake and caloric burn ratio back to the early March number I am going to be an oversized roller.
    Well that sounds like the reason she didnít bring you the beer!
    Sounds like she is in spec, looking after your azz!
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  5. #14
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    Just for the record (future search purposes), on DRLB systems headspace is set when the chamber is cut. It is determined by the amount of cartridge sticking out from the chamber face. This amount should be equivalent to the depth of the bolt face counterbore plus .009" (ish). This amount creates a gap between the bolt face and chamber face when a cartridge is in the chamber, keeping the brass pressed firmly in the chamber shoulder. Once headspace is set, it does not change on the HK platform.

    Bolt gap is irrelevant to headspace. Bolt gap sets the placement of the bolt locking lever on the bolt head when the rollers are seated in the trunnion. The gap width tolerance (.004"~.02") controls the delay of opening (timing) after firing. Gaps too large open too soon. Every component in your rifle has a manufacturing tolerance. When made to specifications the parts typically work well in any rifle. HK is very good at making their parts right. Aftermarket vendors, not so much. As parts wear, different size rollers are used to keep the gap in spec.

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    Quote Originally Posted by Holescreek View Post
    Just for the record (future search purposes), on DRLB systems headspace is set when the chamber is cut. It is determined by the amount of cartridge sticking out from the chamber face. This amount should be equivalent to the depth of the bolt face counterbore plus .009" (ish). This amount creates a gap between the bolt face and chamber face when a cartridge is in the chamber, keeping the brass pressed firmly in the chamber shoulder. Once headspace is set, it does not change on the HK platform.

    Bolt gap is irrelevant to headspace. Bolt gap sets the placement of the bolt locking lever on the bolt head when the rollers are seated in the trunnion. The gap width tolerance (.004"~.02") controls the delay of opening (timing) after firing. Gaps too large open too soon. Every component in your rifle has a manufacturing tolerance. When made to specifications the parts typically work well in any rifle. HK is very good at making their parts right. Aftermarket vendors, not so much. As parts wear, different size rollers are used to keep the gap in spec.
    So I have a question.
    If the rifle has no bolt gap. Could that cause the rollers not to protrude far enough into the trunnion and create excessive head space?

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    Quote Originally Posted by HD Bee View Post
    So I have a question.
    If the rifle has no bolt gap. Could that cause the rollers not to protrude far enough into the trunnion and create excessive head space?
    Headspace is not effected because the pressure from the recoil spring is still forcing the bolt head into the rear of the cartridge and it is still seated firmly on the chamber shoulder.

    However, because your rollers aren't firmly locked in the triangle (because the bolt locking lever is not on the bolt ramp) you will experience violent recoil as the pressure forces the bolt head rearward until the rollers make contact and squeeze the locking piece and carrier rearward. It's a good way to damage the bolt face windows.

  8. #17
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    Quote Originally Posted by Holescreek View Post
    Headspace is not effected because the pressure from the recoil spring is still forcing the bolt head into the rear of the cartridge and it is still seated firmly on the chamber shoulder.

    However, because your rollers aren't firmly locked in the triangle (because the bolt locking lever is not on the bolt ramp) you will experience violent recoil as the pressure forces the bolt head rearward until the rollers make contact and squeeze the locking piece and carrier rearward. It's a good way to damage the bolt face windows.
    There is no 308 that relies on spring pressure to maintain head space. You would need a gorilla to cock the gun.
    On a pistol round not a rifle round.
    They either have locking lugs, locking shoulder or a mechanical or gas delayed system to hold against the initial pressure of the fired cartridge.

    The locking lever holds the bolt and carrier compressed together. Itís the amount of protrusion of the locking piece into the bolt that pushes the rollers out to engage the trunnion. If there is no bolt gap then the locking piece canít push the rollers out far enough to fully engage the trunnion. Which would cause the bolt to not lock up tight in the trunnion with a cartridge in the chamber.
    The same as excessive headspace in any other 308 rifle.
    You would most likely bulge or rupture the back of the case.
    Last edited by HD Bee; 04-28-2020 at 01:06 PM.

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    Quote Originally Posted by HD Bee View Post
    There is no 308 that relies on spring pressure to maintain head space. You would need a gorilla to cock the gun.
    On a pistol round not a rifle round.
    They either have locking lugs, locking shoulder or a mechanical or gas delayed system to hold against the initial pressure of the fired cartridge.

    The locking lever holds the bolt and carrier compressed together. It’s the amount of protrusion of the locking piece into the bolt that pushes the rollers out to engage the trunnion. If there is no bolt gap then the locking piece can’t push the rollers out far enough to fully engage the trunnion. Which would cause the bolt to not lock up tight in the trunnion with a cartridge in the chamber.
    The same as excessive headspace in any other 308 rifle.
    You would most likely bulge or rupture the back of the case.
    I never said that the headspace was "maintained", I said it wasn't affected.
    Headspace (in this platform) is not set with the bolt locked as with those you mentioned. It's a delayed blowback rifle. You could remove the rollers completely and the headspace remains the same.
    .

  10. #19
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    Quote Originally Posted by Holescreek View Post
    I never said that the headspace was "maintained", I said it wasn't affected.
    Headspace (in this platform) is not set with the bolt locked as with those you mentioned. It's a delayed blowback rifle. You could remove the rollers completely and the headspace remains the same.
    .
    The M1 Garand and M14 are headspaced by reaming the chamber also. You could remove the bolt locking lugs and maintain headspace by spring pressure. Just like removing the rollers on a roller locker.
    Are they safe to fire? NO

    I think most gunsmithís definition of headspace is the bolts free play in a locked position with a cartridge inserted in the chamber.
    With the bolt and carrier compressed the rollers are pushed out by the locking piece and the bolt is temporarily locked in the trunnion.
    Any adjustment by changing the rollers or locking piece would change the free play of the bolt in the trunnion and change the bolt gap.
    But YMMV.

  11. #20
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    You guys are starting to hurt my head space. Yeesh.

    -E-

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