JP ENHANCED EXTRACTOR JPEB-308EX 308 AR

by Donald Sullivan | Apr 24, 2016 | 308AR Bolt Carrier | AR-10 Bolt Carrier | AR308 Bolt Carrier | 1 comment

JP 308 AR ENHANCED EXTRACTOR JPEB-308EX

JP 308 AR ENHANCED EXTRACTOR JPEB-308EX – This replacement extractor for DPMS 308AR AR308 pattern .308 bolt assemblies includes our extractor spring/rubber core. JP 308 AR ENHANCED EXTRACTOR JPEB-308EX provides a great upgrade over existing over factory 308 AR extractors.  JP completely redesigned the extractor, using improved materials and heat treatment processes.  This extractor will hold up for thousands of rounds, instead of encountering extraction issues after a few hundred.  Fits DPMS pattern 308 bolts.  Includes extractor and spring.

JP 308 AR ENHANCED EXTRACTOR

Installation Instructions
Engineered to provide a much longer service life than standard extractors, the JP .308 Enhanced Extractor is an easily swappable component for any DPMS pattern bolt to eliminate extraction problems, premature extractor failure and other malfunctions resulting from the extractor not clearing the case rim. While designed to remedy these extractor‐specific problems, the JP Enhanced Extractor will not solve issues stemming from poor chambering or over‐gassing. If your rifle continues to experience extraction issues with this component installed, the problem lies elsewhere. Refer to the section below regarding such failures.
To remove your existing extractor, use an appropriately sized punch to drive out the extractor pin. On all current JP EnhancedBolts, this pin can be inserted/removed in only one direction. With the pin out, the extractor will then be easily removable and should retain the extractor spring, which need not be removed from the extractor. Install the JP Enhanced Extractor in the same manner making sure that the extractor spring with rubber insert and the O‐ring remain in assembly.

ADDITIONAL EXTRACTION ISSUES
Although much development, thought and testing have been put into optimizing the performance and durability of this extractor, it is important to know that other factors enter into an extraction failure and some of these are beyond the ability of any extractor to overcome. If you have a rifle that has extraction issues, it is important to find and address the root causes that may not be related to design deficiencies of the extractor itself.

Note that if you see the rim of fired cases slightly bent to the rear from extraction, this is an indication that your rifle is on the verge of not extracting or breaking the rim off the case. These cases should then be discarded and not reloaded. The cause of this should then be determined and addressed.

1. Over‐pressured ammunition causes the case to extrude into every minor imperfection in
   the walls of the chamber. The case will then stick and fail to release from the chamber during
   the firing process. For reliable extraction, the case must relax and release the chamber
   during the firing cycle.
2. Port pressure that is too high or too sudden will cause the extractor to break the rim off the
   case before it has a chance to release the chamber. Excessive port pressure causes too rapid
   a pressurization of the bolt/carrier assembly, which in turn attempts to extract the case too
   quickly before it is “ready” to come out. If the port is close to the chamber as in the carbine
   port position, this exacerbates the problem further. An adjustable gas system can usually
   solve this issue.
3. Micro flaws in the chamber of any self‐loading rifle are an invitation for a malfunction. If the
   chamber has reamer marks, scratches from sand or grit, rust pits or any negative features
   into which brass from the casing can extrude during the firing process, this will literally lock
   the case in the chamber and defeat the best of extractors. If these anomalies are not overly
   severe, the chamber may be recoverable with a good polish. Rust pits, however, usually
   spell the end of a good barrel. A ring depression from a bad or fouled reamer is also not
   recoverable, and the upper will have to be re‐barreled.

JP 308 AR ENHANCED EXTRACTOR JPEB-308EX

DPMS 308 Bolt Carrier Exploded View

by Donald Sullivan | May 9, 2015 | 308AR Bolt Carrier | AR-10 Bolt Carrier | AR308 Bolt Carrier | 4 comments

Exploded View – DPMS LR-308 Bolt Carrier Group

DPMS .308 bolt carrier parts list and image. This 308 Bolt Carrier is also the same as the Fulton Armory 308 Bolt Carrier Group

DPMS LR-308 Bolt Carrier Group

DPMS LR-308 Bolt Carrier Group Parts

Below is the parts needed to assemble a DPMS LR-308 Bolt Carrier Group. DPMS and part suppliers omit the 308 portion of the part numbers. Example : Bolt Carrier BT-12

• 308-BT-16 – Firing Pin Retaining Ring
• 308-BT-12 – Bolt Carrier
• 308-BT-03 – Extractor Pin
• 308_BT-17 – Cam Pin
• 308-BT-02 – Bolt
• 308-BT-14 – Firing Pin
• BT-11 – Bolt Carrier Key
• BT-10 – Bolt Carrier Key Screw
• 308-BT-07 – Extractor
• 308-BT-08 – Extractor with Extractor Spring

DPMS LR-308 Bolt

• 308-BTASSY – .308 Assembled Bolt
• 308-BT-02 – .308 Bolt (Stripped)
• 308-BP-01 – .308 Bolt Component Pack

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