Issues Feeding JSP in a Larue Pred

[Nik the Greek]

Hey all,

Hoping someone can lend some insight. I own a Larue Predatar 5.56. I'm in CA, so I'm using 30 and 20 round magazines (PMAGs) blocked to 10 rounds. My practice load is prvi partisan 55 gr FMJ. For defense loads, I picked up some 5.56 mm Winchester 64 gr solid base bonded JSP (RA556B).

The soft tip on the JSPs keeps catching on the feedramp, with the bolt pressing against the round. I have to drop the magazine and pull the bolt back to clear the malfunction. All of my magazines do this at least sometimes, though usually only with the first round in the mag, though one is worse than the others and I've marked it accordingly. All my magazines feed the PPU stuff without any issues.

This is hardly ideal. Is this purely a magazine issue? Are the magazine blocks exerting too much pressure, and I could solve the issue by shaving them a bit? Any help is appreciated.

[TGS]

Nik,

This was fresh in my mind from reading DocGKR's "5.56mm Duty Loads" thread.

Whatever projectile is used, it is best with a cannelure to prevent bullet set-back in semi-auto/auto weapons. Also, be cautious with the exposed lead on some JSP designs. Often they will run great for up to 200-300 rounds, but then mysterious feeding failures will begin as a result of lead build-up on the feed ramps. I have personally seen this occur with a variety of JSP's including 55 gr, 60 gr, and 64 gr in LE training courses. As soon as FMJ or OTM was substituted, all the feeding failures ceased.

[Odin Bravo One]

In my opinion, JSP in an AR is a specific use round, and not one I'd personally choose as a defensive load unless I had specific need for it.

Take a look at Doc's list of recommended duty loads. There are many that are not JSP's, perform well, and have proven very reliable in a wide variety of AR's.

[TGS]

Take a look at Doc's list of recommended duty loads.

The best LE 5.56 mm/.223 loads for intermediate barrier penetration using 1/9 and faster twist barrels are the 5.56 mm Federal 62 gr Trophy Bonded Bear Claw (TBBC) bonded JSP (XM556FBIT3) and 5.56 mm Winchester 64 gr solid base bonded JSP (Q3313/RA556B) developed for the FBI, along with the outstanding new Black Hills 5.56 mm 50 gr TSX loading

[snip]

Most other acceptable LE barrier blind loadings are at .223 pressures, including the .223 55 & 62 gr Federal bonded JSP Tactical loads (LE223T1 & LE223T3), along with loads using Nosler 60 gr Partition JSP, Remington 62 gr Core-Lokt Ultra Bonded JSP (PRC223R4), .223 Federal 55 gr TSX (T223S), and the .223 Speer 55 & 64 gr Gold Dot JSP's (and identically constructed Federal 62 gr Fusion JSP and Federal XM223SP1 62gr Bonded JSP).

All but one of his recommended barrier blind loads are JSP.

[Odin Bravo One]

I don't like to contradict anything Doc puts out, as he approaches his work with enthusiastic scientific study and data collected according to established protocols, as well as his personal experience as a shooter and gun guy. An invaluable resource for this community, but also an outstanding personal resource I tap into regularly because he has forgotten more about ballistics than I'll ever know.

But I also don't care much for, nor see the need for a dedicated "barrier blind" cartridge. I'm all for a better mousetrap, but trading reliability for limited application performance that is only marginally better than other rounds that have proven reliable may not be the solution we are looking for. At LE/Civilian courses I have participated in as either a student or instructor, where ammo is found to be the culprit for reliability issues, the only thing that has proven to be worse than the JSP's is "Billy Joe Bob's Special Recipe" hand loads.

In most of those cases, the malfunction descriptions are identical to those listed by the OP.

As always............solely my opinion, doesn't reflect the opinions of my employer, coworkers opinions, JMB's opinion, and it is worth exactly what you paid for it.............

[GJM]

Sean, if you were to recommend a commercially available .556 load for defense around 2 and 4 leg targets, that is accurate, reliable, available and ideally not ridiculously expensive, what would it be? Extra points if there is a practice load that shoots similar POI.

[Odin Bravo One]

Black Hills 77 Sierra OTM.

Also sold as re-manufactured. Both are listed as same velocity, so while I have never fired the Re-man stuff, theory would say it should be pretty close to POI as the all new component stuff.

I have buddies who hunt Mulies with a 556/223 as it is legal in their location, and two use the 77 OTM.

I use it for sage rats and Belding's ground squirrels found in abundance in the western states.

Out of my prceision AR, I get 3/4 MOA groups out to 300. < 1/2" groups at 100 are routine, and they creep open a little bit at a time each yard line as I move back. However, I can't say that is ammo necessarily. It could very well be me, as I am not the greatest precision marksman. I do ok, but I am far from benchrest accuracy capable.


ETA........

Intermediate barrier can be a concern for some parties. If it is, then by all means, one should seek out appropriate ammunition based on their needs/perceived needs. I know that 77 OTM is not the greatest intermediate barrier round. But I also know that it is more than capable of ending fights. Quick, fast, and in a hurry. Even through intermediate barriers when applied with the proper volume and enthusiasm.

[ST911]

Umpteen JSPs through M16 and AR types, semi and select fire. Most of my AR shooting is with new or reman JSPs, primarily BHA's 55 and 60gr (and 60gr Nosler), as well as others. I've also seen some removed from human bodies, and many more removed from critters of various forms. JSPs aren't inherently a problem. They may warrant an advisory, but they are not to be poo-poo'ed.

OPs gun is GTG, his ammo is GTG, but something is amiss. OP- Call LT and see what they think.

Also of note, LT-specific... My Stealth goes quite a distance with 55 JSPs. Great varmint load. I clean the gun once a year or so.

I don't know of anyone other than the local gun shop Commando SEAL Delta Force CIA Wet Boy who would recommend a JSP in an AR...........

I'm not one for single-emoticon responses, but...

[Odin Bravo One]

I'm not one for single-emoticon responses, but...

Perhaps I was overly cynical.

Point taken. Edited original to not come off as such an ass........

[Nik the Greek]

Thanks for the information all. I'll contact LT and see what they say, but in the meantime I'll pick up some of the BH 77gr and 55gr TSX.