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All the 223/556 bolts I have seen are not flat like the 91 or 94 bolts. When the brass after shooting is inspected you see that the bolt has almost crimped the primer into the brass causing you to have to swage the brass in order to reload it. My question is has anyone removed the raised area and what was the result. Thanks Mel
 

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I wouldn't change it.

HK Germany designed it that way for a reason, and while I can only speculate on the purpose, it seems that the roller delayed locking mechanism would allow some of the pressure from firing to exert itself on the inside of the primer cup. Seems to me, that the raised portion on the breech face would cause the brass to crimp slightly against the primer cup helping to hold it into place until the pressure dropped and the rollers were unlocked to start the extraction cycle.

While this may be inconvenient for reloading, I'd be hesitant to just get an end mill and grind it down.

The 94 bolt heads operate at much lower pressures than 5.56, but this doesn't explain the '91 bolt head being flat, if that's the case (I don't have one to compare with).
 

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The 91/G3 carrier doesn't have a similar annular ring. But I'm with Longduck - they put it there for a reason, and it would have required either special tooling or a more complicated toolpath to do it, so I'm thinking it should stay.

You might want to check with some of the clone makers' 5.56 bolt heads and see if they all have the same thing. I know at least some of them do, I've seen them.
 

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The 91/G3 carrier doesn't have a similar annular ring. But I'm with Longduck - they put it there for a reason, and it would have required either special tooling or a more complicated toolpath to do it, so I'm thinking it should stay.

You might want to check with some of the clone makers' 5.56 bolt heads and see if they all have the same thing. I know at least some of them do, I've seen them.
The Vector 93 has the raised primer nub surrounding the firing pin hole in the bolt face. I've been told that these rifles will shed their primers during firing if that is removed. Too, if you remove that you immediately made your firing pin way too long, wouldn't you?

While it is a happy coincidence, I'm glad my Dillon Super 1050 has the primer crimp swage at station 2. :D
 

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You'll ruin your bolt. I have not done it, but trust me, you'll ruin it. As said above, Hk designed the bolt correctly. This is a combat rifle and they were absolutely not concerned with re-loading brass. Where they come from, brass is not an issue.
 
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