"lobster Tail" Bolts And Lightened Carriers

[uscbigdawg]

So in my down time here in the ROK I spend A LOT of time cruising the net and shopping for parts/guns when I get back home. D & L Sports and Lewis Machine & Tool (a.k.a. LMT) have a similar bolt design wherein the extractor has a "lobster tail" that in theory makes it more reliable, stronger, etc. Anyone try this? Good, bad, solution to a problem that doesn't exist? Any input is appreciated. A big negative that I find is not knowing if it'll run with a standard extractor (which it appears that it should). Man would that be a bear if it went down and didn't.

Lastly, other than the JP-LMOS, has anyone run their stainless lightened carrier and compared the two? Too, I though MSTN was going to come up with a skeletonized carrier. Any word on these? I love my JP-LMOS, just don't like cleaning the rifle!

Thanks in advance and Merry Christmas!!!

SPC Richard A. White, Senior Medic

249th MP Detachment (EACF)

Camp Humphreys, ROK

[Religious Shooter]

Lastly, other than the JP-LMOS, has anyone run their stainless lightened carrier and compared the two? Too, I though MSTN was going to come up with a skeletonized carrier. Any word on these?

I bought a lightened carrier from MSTN a couple of months ago at RM3G. I think it was around $150. To my untrained eye it looks like it is hardchromed. The MSTN carrier retains the teeth on the side so that the forward assist can be used. I believe the JP doesn't have teeth.

I don't have a JP-LMOS. But comparing it to my full-sized bolt I got "typical" results. The gun "recoils" less and it is less reliable (or more finicky).

In the beginning the recoil was so noticeably less that when I did controlled pairs during a stage at Area 1 it felt like the gun had jammed and I actually paused to see if anything was wrong.

In addition the gun is less reliable in that the gun's window of tolerance for different loads is less. I may just need to get a lighter buffer spring to make that window a little bit wider. For example Wolf 62's won't drive the gun anymore. My 55 reloads @ 3100 fps (16") drive the gun fine.

[uscbigdawg]

I have the LMOS but am considering getting the lightened stainless carrier, or one from MSTN, just 'cause as much as I love my LMOS, I'm not the most prudent when it comes to cleaning the rifle.

RS. I know what you mean about the reduced impulse. Run the JP reduced buffer and it should fix the problems you're having. After that, it's just getting used to the greatly reduced impulse/recoil and not thinking that the rifle has jammed.

SPC Richard A. White, Senior Medic

249th MP Detachment (EACF)

Camp Humphreys, ROK

[Bronco]

Richard, I have always used a mil-spec carrier group in my match AR as I've seen the LMOS bite people in the ass when shooting prone and with what I suspect is a less than clean rifle. At RM3G I got a lightened stainless JP carrier and buffer kit and put the carrier in a 20" upper attached to a CAV Arms lower. As you may know CAV arms lowers use a CAR buffer so the one supplied by JP was to long, I weighed the two and found the CAR buffer only 1 gram more than the JP so left it in. To date there has been 500 rounds through the rifle with no failures and not cleaned yet. I like this setup and plan to use it next year. It has shot 50 gr. to 77 gr. loads. The impulse is noticeably less and very sweet to shoot. I think you would like it. Keith

[Wakal]

Just switched to a JP stainless lightweight carrier (and matching buffer) in my Open AR. Ended up fitting an adjustable gas tube to the rifle, as it was cycling a bit faster than it really needed to.

Easy enough to replicate, though. Just mill three ounces off a standard carrier, and pull an ounce of weight out of a standard buffer

Alex

[TMC]

Hi Rich,

When I got my 18" JP with the stainless low mass I shot it side by side with the 20" with the alum. low mass. Not much difference between the two. If you starting from square one, I recommend the stainless low mass, about the same recoil impluse and more durable, no more peck marks on the bottom of the carrier.

Merry Christmas,

Todd

[John Dunn]

I think the D & L bolt is the LMT bolt, but I don't know for sure. There are a couple threads over on Arfcom that they may increase reliability in M4s, but I think the general consensus is they probably aren't any better than a D-Fender or O-ring to increase extractor tension, and may not be any better in other barrel lengths or semi-autos. Don't know if a regular extractor would work with that bolt or not. I'd give Dave Lauck or MSTN a call.

[Carlos]

John Dunn wrote:

"but I think the general consensus is they probably aren't any better than a D-Fender or O-ring to increase extractor tension, and may not be any better in other barrel lengths or semi-autos"

I have seen the "D-Fender" or "D" shaped o-rings at the gun shows (only $15) and they are supposed to work; but

-what about the "O" ring you mentioned? How much does it cost & where to buy? Thanks.

[John Dunn]

John Dunn wrote:

"but I think the general consensus is they probably aren't any better than a D-Fender or O-ring to increase extractor tension, and may not be any better in other barrel lengths or semi-autos"

I have seen the "D-Fender" or "D" shaped o-rings at the gun shows (only $15) and they are supposed to work; but

-what about the "O" ring you mentioned? How much does it cost & where to buy? Thanks.

It's the -006 size O-ring, Viton was recommended to me for it's solvent and temperature resistance. The dimensions are 1/4" OD, 1/8" ID, 1/16" thick. I picked up a bag of 25 or 50 O-rings (can't remember) at some online auto parts store for less than one D-fender. You could probably get them at home Depot. AR15.com probably has a million threads on this, so you might try a search over there if you run into any problems.