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HK 51000384 UPPER RECEIVER KIT MR556A4 16.5" 13% Off w/ Free S&H

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HK 51000384 UPPER RECEIVER KIT MR556A4 16.5
HK 51000384 UPPER RECEIVER KIT MR556A4 16.5
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HK 51000384 UPPER RECEIVER KIT MR556A4 16.5

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Questions & Answers
Don you have to use the Geissele mr556 trigger for the new A4 variant or can you use other Geissele triggers like the SD-E?

No it takes a specialized trigger with a slightly longer hammer . i googled that and learned in less than 5 seconds.

by Sonofmk12, Verified Owner, January 24, 2026
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Code: 13-UPK-51000384

MPN: 51000384

UPC: 642230270213

List: $2,499.00Save 13%
$2,179.00

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OP Bucks$43.58

Product Info for HK 51000384 UPPER RECEIVER KIT MR556A4 16.5"

HK 51000384 UPPER RECEIVER KIT MR556A4 16.5" -image

WARNING: California`s Proposition 65

HK 51000384 UPPER RECEIVER KIT MR556A4 16.5"

HK 51000384 UPPER RECEIVER KIT MR556A4 16.5" Orderable Models

List of Orderable Models

  • HK 51000384 UPPER RECEIVER KIT MR556A4 16.5'' , MPN: 51000384 , UPC: 642230270213 , Code: 13-UPK-51000384
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