Questions for JP rifle shooters

[Nick Weidhaas]

For those of you shooting a JP rifle in Tactical I was wondering.........

1. Do you run the low mass bolt group? If yes, any problems experienced? Is it that much better than the ss standard bg? Concerned about reliablility with the LM bg.

2. With an 18" barrel, do you like the med or ultra light weight barrel?

3. Leaning toward a 1:9 twist barrel with 62-69gr. bullets. Anyone had a good experience going this route? 62gr ball is available to me for practice.

3. JP ACOG? If not, which ACOG?

4. If shooting the JP ACOG or another ACOG, what load are you using and does the BAC work out?

Thanks in advance,

Nick-

[EricW]

{I'm not a real 3-gun competitor, but I know people who are that tutor me for beer.]

1. I have ZERO experience with the JP carrier. Some people here use them with great success. Anecdotally, what I've been hearing is that the low mass aluminum carrier choked rifles left and right at the DPMS TriGun match. What I've heard one top rifle guy did (I won't drop the name) is to simply lighten up a stock steel carrier. Caveat Emptor.

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3. It took people beating me over the head with a hammer (on multiple occasions), but I now believe in the low-powered variable as THE ticket for 3 gun. There are several options for such scopes in the under $150 range. The trick is to get one that acts as a *true* 1X so you can run both eyes open and hose at the close in stuff. (Don't buy a Leupold 1-4X unless you plan to bring a monkey wrench to turn the insanely stiff mag. ring.) Benny Hill recommends the Simmons 1-5X. Apparently Bushnell has a 1-4X that is also good for 3 gun.

[Don't know what the hell I'm talking about mode /OFF]

[John Dunn]

1. No. I went with the stainless steel carrier for reliability concerns. Haven't shot the low mass. I know Zak Smith has, maybe he can comment. I know he has posted that at the ITRC this year he did not run the low mass for reliability concerns.

2. Medium

3. 1 in 9 is pretty much great unless you are going heavier than 77 gr, or shooting tracers.

3. Shot the MGM Ironman in '03 with a 4x ACOG, it was great for the long shots, a little slower on the close in stuff, especially shooting out of the back of a moving truck. I may get the Trijicon 1-4x variable Taran was using this year, because I think the variable may be the way to go, same as EricW.

4. I shoot mostly PMP 55gr factory stuff for practice, the holdover marks work pretty well for me out to 400, don't do much shooting further than that with my ARs. Don't know about the BAC, but I shoot with both eyes open for the close stuff, and it hits about where it should.

(Numbering scheme to match original post!)

[Zak Smith]

1. Yes, when I use "qualified" ammo and I can keep the gun reasonably clean. No otherwise. The Low-Mass BC is worth it when it runs, and a curse when it doesn't. At RM3G this year, I ran the low-mass bolt carrier throughout the match and it ran 100%. "Qualified ammo" for me means Black Hills 75gr.. It's consistent enough and I know the gun runs with it.

3. TA11.

4. BAC is totally worth it, it totally speeds up acquisition time. Don't worry about the BDC being off, you'll have to figure out your hold points at ranges out to 350 anyway.

-z

[Zak Smith]

Forgot to mention the JP SS carrier. It's similar in weight to a normal carrier, but slightly lighter. It's a good choice if you don't want to mess with the LW carrier, and I highly recommend keeping a spare SS carrier around even if you do use the LW carrier, so you can swap it out if your rifle starts malfing.

My Low-Mass carrier made it through Stage 3 at the ITRC this year, but got sluggish (manifest by failure to feed first few rounds) towards the end due to all the dirt/sand in the action. I switched to the SS and it ran 100%, even through the barrel-burner stage.

[George]

I like the LMOS and it runs 100% for me, but and there are a few but’s here, I control my ammo mercilessly, keep my mags in good shape and practice the “clean & lube“ drill a lot. That said, I am in need of replacing my aluminum bolt carrier because it is losing it’s plating in a number of important places. I have about 8500 some odd rounds on it and it is still running well. When I told John Gangl about it’s lifespan recently, he said they really didn’t expect the aluminum carriers to last that long in service and I should get another one real soon now ;-)

The JP lightened stainless bolt carrier is only supposed to be 4 ounces heavier than the aluminum one so it can’t be that bad of a thing, but it does require a different spring & damper setup from the lumynum one so it is not exactly the same by any means.

I will be putting another aloominium‘ carrier back into it along with a full bolt re-build. The LMOS with the aluminum carrier just works so well, when it works (just for Zak) that I have to have it. For me, it has worked 100%, but I would never recommend it for critical applications, or for anyone who isn’t into exercising proper care & feeding at all times. Hell yes it’s fussy, it’s a racing machine after all.

BTW, the ACOG with the JP reticle is fantastic, but should be coupled with a steady diet of 75, or 77 grain projectiles if you want to take advantage of it’s trajectory mapped reticle at long distances. For 55-62 grain ammo work, the standard TA11 (like Zak said) would be a better match for the trajectories involved.

For competition, I am of the opinion that a fixed magnification main optic with the JP handguard mounted iron sights for close work is the best combo for Tactical rifle division. The low powered variable is a good thing, but requires manipulation to go from mag, to no mag within an engagement sequence.

Get a 20incher, all the big dawgs (and I mean all of them) run 20’s. I’ll help you cut it if you decide I am wrong later ;-)

--

Regards,

Edited November 7, 2004 by George

[Religious Shooter]

3. Leaning toward a 1:9 twist barrel with 62-69gr. bullets. Anyone had a good experience going this route? 62gr ball is available to me for practice.

Don't have a JP. But if I got one I would get the 1x8 instead of the 1x9. The 75gr+ bullets are iffy on the 1x9 while 55-75gr+ bullets are OK with the 1x8.

[kurtm]

I love the aluminum carrier. It has been 100% for me also, like George. That being said I don't think I would run it in a "work" carbine, because those also have to be fairly court proof in the civilian world, and abuse proof in the military world. I have found that putting a drop into each vent hole in the side of the bolt between stages keep the aluminum carrier functioning flawlessly, they really like to be wet!! I have let mine go over 700 rounds between cleaning with this procedure and haven't had any problems so far.

I would stick with 20" barrels in the medium contour. I can't say for others, but the 1 in 9" barrel on mine will shoot anything that fits in the magazine sub minute, as long as it is a good reload, or good factory round.

As you may know, I am a big proponent of the TA-11, I have found that the B.C. in the scope works great with 55grs at 3200, and 69s at 3000 fps. out to 600 if the wind allows . If you plan to shoot 77gr bullets you might want to look into getting the TA-11 with a .308 Win retical, as the ballistic path of the bullet and scope B.C. are pretty much the same.

As a side note, I have the aluminum carrier in two rifles. One a J.P. and the other in a "standard" 20" iron sight rifle. Both will run with rediculesly light loads, and exhibit no pressure signs with full power reloads. They both run with full 45 round Thermould mags, full 30 rnd mags, Beta mags, etc., but you do need the J.P. hammer and trigger, of course if you buy a J.P. rifle it will already be in it. KURTM

[PacMan]

I run a LM bolt carrier in my 20" 1-8 medium contour JP. Forget the adjustable gas do-dad, I run mine in full open and it worked 100% with full 45 rounds Thermold and 30 rounds USGI mags. Just got my C-Mag and will try it out soon. Most problems with the LM bolt carrier occurred with less than full open gas system. Besides adding lube in the carrier vent holes, I use moly grease on the carrier-to-hammer contact surfaces. Shooting the regular weight carrier after shooting LM unit a while, and man, you can tell/hear/feel the heavy steel carrier working ever sooo slooowly.

55 gr. is all that I used so far, don't see any need to go with heavier bullets for what we do - and you can make the 55 gr. goes pretty fast for a flatter trajectory.

Scope wise, I'm still trying out the Trijcon 1.25-4, but the old stand by is a Leupold CQ/T.

[Nick Weidhaas]

Great info. Very helpful. If anyone has anything to add, please feel free. Thanks again.

Best,

Nick-

[smokshwn]

Nick,

I don't mean to be throwing a wrench in your decision making process, but I recently started experimenting with a low power variable. I started with an Eotech mounted on my flattop and loved it until I ran into stages with shots in the 250+ range. I bought a cheap little Tasco 1x4 shotgun scope with the Turkey reticle to play with to help decide if I wanted magnification or not. I have found that having the ability to dial up a little closeness with the magnification is absolutely necessary and the no magnification still allows for the hoser stages. Ultimately I think the setup would consist of a variable piece of glass as the main optic with either JP irons setup for limited or a red dot for open on the foregrip. As a side note I shot one of Trijicon's Accupoints this weekend and was very impressed. There is the magnification you would want and essentially what appears to your eye as a dot reticle.

Good luck, Craig

[Zak Smith]

BTW, the ACOG with the JP reticle is fantastic, but should be coupled with a steady diet of 75, or 77 grain projectiles if you want to take advantage of it’s trajectory mapped reticle at long distances. For 55-62 grain ammo work, the standard TA11 (like Zak said) would be a better match for the trajectories involved.

I disagree. The reason to get a TA11 over the TA01JP is because of the BAC feature. For 3Gun ranges (0-350 yards), the BDC differences are academic. Just figure out your hold points in the donut for 100, 200, and 300, and you're good to go. The BDC doesn't start until 400m anyway.

-z

[M.E.Anglin]

I enjoy my CQT but you need to check out the Smith& Wesson 1.5-6 shotgun black powder scope. Like 140$ delivered form CDNN Investments. I put one on my FN/FAL and really found it to be quite good has a little more power when needed, clear glass and a good retical, only problem is mounting it ,it has lots of eye relief, I am going to get another one to put on my wifes AR. I've taked to other two other shooters into them and they have no regrets.

As far as bbl. I've been running everthing from 14.5"- 20" and I really like the shorty out to 300yrds real quick handling and easy for off hand shooting. my wife has a 16" & 18" and I don't think the extra weight is worth it for 300yrds and closer and my 20" is mainly my long range gun, 600yrds +.

Just my thoughts

[George]

The reason to get a TA11 over the TA01JP is because of the BAC feature. For 3Gun ranges (0-350 yards), the BDC differences are academic

I don't disagree about 0-3sumthin', but for the record, what I really like is the fact that the reticle is spot on for 4-5-6 & 700 yard stuff ;-)

As far as donut's and pyramid shaped dayglo objects in the reticle, don't like them myself. I would have gone for a plain ole' TA01 if the JP version wasn't available. My right eye is dominant and I use the JP CTR-02 ACOG just af if it was designed for BAC. I watch through my transitions with the off eye and ignore the blur behind the reticle. As soon as I see the reticle is where it needs to be I snap focus to the strong eye and the object of desire appears behind the reticle. In real low light, the JP ACOG reticle is tritium illuminated and it delivers the same result. Works for me.

Shooting in Open division, I don't worry much about using the ACOG for close stuff, that's what I have a JPoint on the handguard for :-)

--

Regards,

[lmccrock]

When the JP Low Mass System works, it is spectacular. 223 recoil is not much, but the crosshairs did not leave the target after firing. It is like shooting a heavy .22 rimfire. "plink...plink...plink"

When it works.....

In my rifle, I could only get 30-50 rounds before it started short-stroking. That is not enough for a stage, let alone a match. I tried different lubes, no lube, a little lube, swimming in oil, a drop in the carrier holes after several rounds, 6 different kinds of ammo (a few different Black Hills, Q3131a, USA), different magazines. Oh, well. A conventional carrier works fine.

Lee

[kurtm]

Imccrock:

Does your carrier have a McFarland gas ring? If it does, take it out and replace it with standard rings. I have found that for some reason some of the ligh carriers hate them and will do EXACTLY what you describe. The standard rings work just fine and it might cure your problem. Also it might be a good idea to replace them even if they are standard rings as all rings are not alike and your set may be binding the carrier just enough when it cycles a few times. What to look for after firing 30-40 rounds is a pronounced snag just as the bolt unlocks and the carrier starts to move when cycled by hand. Hope this works for you. KURTM

[smokshwn]

As a side note, never forget to check the charging handle channel. I was experiencing occasional shortstroking, FTE's, etc. and after chasing around the gas system and bolt/bolt carrier for abnormalities, we finally found that the charging handle had an ever so slight bend. (must have bent it during malf. drills?) When the gas key would hit it jsut right it slowed the bolt carrier enough for a malfunction.

Take care, Craig

[lmccrock]

Kurt,

It was a new upper, bolt, standard rings, etc. Benny exchanged the carrier, since he built the upper. I may try a low mass carrier again someday. At the time (and now, too), I wanted a gun that ran. I will check for snags.

I will check the charging handle, too.

Lee

[MikeFoley]

1. I run the low mass bolt group, and I have had no problems whatsoever. It produces a lot less forward movement when the bolt closes, so little that you don't lose your sight picture in most cases. I am not concerned about reliability, but this is a game gun only, not one I use for anything else where reliability issues are life threatening. It has run 100% from day one.

2. I have the ultralight barrel and like it. I built one for a friend with the medium weight barrel, and it feels good too. The heavier barrel can stabilize a gun, but I prefer less weight, it barely feels like you are holding up a rifle with a scope on it.

3. No experience, I shoot 55 grains only, and have a 1 in 8 twist 18 inch.

3. I use the Trijicon Accupoint, but any Acog that fits your needs. Three factors, reticle, magnification, ability to use it up close whether occluded or through the lens. What is your maximum and minimum distance? Mine works form 0 to 300 yards. I shot it beyond that in Reno, but then you are dealing with trajectory and holdover or adjustment too.

4. BAC has worked for me in my 3X24 Compact Acog, and in my Accupoint. It worked to a lesser extent in a TA01, probably because of the busy reticle. I do not shoot occluded, though I can, I just don't need to cover the scope to eliminate the magnification. I can change my focus rapidly to do this, but understand that everyone's eyes are not the same. Also, set the eye relief to you and check it in different shooting positions.

My advice FWIW, look through every ACOG you can at actual targets, decide how much weight you can comfortably shoot as long as you need to, and get someone to show you a low mass operating system. Lock the bolt open on a LM gun and a steel carrier gun, then sight in on something, and let someone else press the bolt release, the difference will be apparent.

[hockeydadnu27]

I have had a new JP CTR-02 for one year now, 18 inch med,JP ACOG,and JPoint on the hand guard and low mass system.

I have been in 8 matches with the rifle this year and over 3500 rounds.

Had to replace carrier once so far and JP replaced at no charge. I purchased from JP a backup carrier complete Titanium carrier, works great but diffently feel the recoil compared to the low mass carrier.

With the low mass carrier must keep it wet,wet,wet,wet for reliability.

I have found after 100 rounds must pull carrier apart and lube it all up, if I don't at 125 rounds starts to short stroke, can't let it get dry.

Its like a race car, needs alot of fine tuning, but when it runs WOW!

We shoot out to 300 meters and with the ACOG I have no problems with any type of targets. I use WalMart white box Winchester 55 gr. works great for me and very accurate out to 300 meters.

I will try the new JP lite carrier stainless after my low mass carrier wears out.

This was my first season shooting action rifle and I feel because of my CTR-02

I was able to be competitive with alot of very good rifle shooters.

I hope this gives you some advise from a new rifle shooters view.

[Nick Weidhaas]

Thanks for all the great info. It is really appreciated. I've decided to go with a JP upper with the new lightened ss carrier. Barrel will be 1:9. Only hang-up now is 18" v. 20" and ultra light v. medium weight barrel. Hmmm. One thought was to get the unltra light bbl. and put a stainless steel gas block on to balance out the front end. Has anyone tried this?

Compared to a stardard factory 20" AR or 16" carbine from say BM or Colt, how does the weight of a JP medium weight barreled rifle compare? I guess I'm asking if the weight of a JP rifle with a med. weight barrel is heavier or lighter than a factory barrel? This will give me a reference.

Thanks,

Nick-

[blkbrd]

Nick: I just got my JP 18" midweight JP15 upper with the new stainless lightweight carrier and love it. I have 600 rounds through the rifle now and its been 100% no wear in was required, it eats up anything from XM-193 to Wolf with out a hickup.

The Light weight stainless carrier recoils alot less than a full weight carrier, and just a bit more than the aluminum without the wear and reliability issues. See my post and review for a picture.

Give John Paul a call and talk with him about the shooting you plan on doing, east coast close in hoser stuff or longer western matches, I went with the 18" midweight on his advice for the close in speed with the ability to reach out when I need to. He is great to talk with and he probably knows AR's for IPSC better than anyone. I shot several before ordering and the 18" midweight felt and seemed the best for me, if you live somewhere there is lots of long shots you may want the 20".

On Benny Hills advice I tried the Simmons 1.5X5X20 Pro diamond and love it, you can hose with both eyes open and drill long stuff better than the Aimpoint I was using before, and its cheap to boot. I bought mine on sale from Midway for $76, using a YHM mount and low rings to get it far enough forward. If you want a photo feel free to e-mail me and I will send some.

[Nick Weidhaas]

Thanks blkbrd. I appreciate the info.

Best,

Nick

[lucas]

I thought you couldnt use either LMOS carrier with the JP15,only the CTR-02 model?

[kimel]

It will work in any AR but you do have to replace the hammer with a JP speed hammer (and springs I think) and you loose the forward assist and dust cover functions.