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JP LOW MASS CARRIER - Read Before Buying

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I had a discussion with JP Rifles about many things today. The first of which is the JP LOW MASS CARRIER. It is Important to note that the carrier is expected to be used with their adjustable gas block. They are a complimentary system.

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I installed a low mass bolt carrier (not JP's I used the Young's super lite) in my 300. It is my understanding that the idea is to have the minimum weight moving back and forth so as to disrupt the shooters sight picture less for faster follow up shots. As Imschur stated, your supposed to use an adjustable GB and tune the gas impulse so as to use just enough gas to cycle the action , and it should be understood that with the lighter BCG weight along with the reduced gas impulse, a gun so equipped may possibly be more sensitive to fouling and would not be an ideal choice for a defensive or combat application. In fact JP sells an extra power buffer spring (+7%) for the very purpose of helping the lighter BCG to strip and chamber the round. I think that this is more competition directed than real world intended. I'm still trying to learn about this but the Tubbs CWS , and the Xheavy buffer that many people use to slow or delay the bolt unlocking or rearwad travel of the bolt/bcg, and that many people claim gives them less perceived recoil, I think are more useful on a gun without an adjustable gas system which may be oergassed,if the gun is intended for tactical purposes.

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In my experience , the lighter weight BC's ,only add problems to a gas operated system. Unless the system was designed around it .

Some people over analyze there gas operating systems. The piston systems can benefit from a simple gas regulating system , but not to control how easy felt recoil is .

If you look at some of the good designed gas regulating systems are used ( FN -FAL ), they are used to operate the system with a certain cartridge or make sure they work with extreme fouling from combat or extended shooting extremes .

The whole purpose of the BC is to not just slow the unlocking of the bolt for proper function , but to also make sure there is enough inertia to strip the next round from the mag. & also have enough to lock the bolt .

Striping a round from a mag. , slows the BCG down ,quite a bit , I 've seen some stop the BCG in its forward motion completely .

The buffer spring buffers the rearward travel of the recoiling BCG & on doing so uses its compressed spring to launch the BCG back into battery.

By lightening the weight of the BCG , you will lose a lot of inertia & that can cause feeding problems.

In the same sense , the lighter weight can also cause extraction & ejection problems. ( unlocking prematurely )

These components are miss matched more than any parts on an AR type rifle .

I went to a Tubbs spring because I thought I was having problems with a specific brand of ammo , come to find it wasn't the spring , but the brand mag. & lower receiver tolerance stacking. The brand mag ,just doesn't work with this receiver , where all others do.

I can say the Tubbs spring ,does help in the recoil , a little &  keeps a longer lock time ,which may help if you think you have an over gassed system. ( that also opens another can of worms )

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Although I have yet to experiment with the CWS (only so much time to play, I mean test new things) I have installed Clint''s extra heavy car buffers in both my Mega and my Kaiser .308. Now, I realize that all this is subjective, but when I shoot my .308 AR's and then try friends .308's I think mine seem as though they have less Felt recoil. I realize that  the guns are all configured differently, so some of it may be weight or muzzle device related, but I choose to believe that the heavier buffers are at least partially involved. When I get a chance, I plan to buy one of those lighter weight buffers of the same size as my CAR buffer, and do a range session to see if I can actually tell the difference when I switch out the XH for a standard weight (which is around 3 oz lighter)

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If you think some thing makes you feel less recoil , than go for it . Nothing wrong with that ,that's for sure .

The problem I see as I have already stated ,is that once you fine tun the rifle for perceived recoil , you run a large risk of function problems .

Of course most of the rifles here will never see combat , some may see hunting conditions & if its going to go wrong ,it will when your out there in adverse conditions.

A safe queen or Sunday target plinker , well probably not give you much problems. They are generally cleaned & are used in a controlled environment.

I  have never used any thing , but stock type buffers & springs in any AR ,being a select fire or semi auto , in any rifle I have built .

The std DPMS , 308, carbine buffer I have in my 308 carbine , works with the std 308 spring or the Tubbs spring . I can say I believe it is smoother functioning with the Tubbs spring in there , but I have never had a problem with std springs or buffers .

I only use M16 BC 's in the AR15's ,I build. If you look at the 308 BC , its just a large M16 look a-like.

I like the Superior shooting systems spring (Tubbs ),It has some features that should be in any recoil spring ,that's used in all types of rifles that use them.

As an example:

I wish they made them for my REM. 1100. I have a heavy recoil spring in there for slugs & 00. With that spring in there ,I can't use much other ammo , it will fail to extract , but felt recoil is lessened with slugs & high pressure loads  & I know its not scientific ,but others with similar shotguns say they can feel it less with it .

That shows I have made this shotgun very ammo specific . It was my goal , to keep from punishing an old shotgun & still being able to use it for hunting . This is no longer my primary hunting weapon, she's a back up .

Since we don't have the specialized equipment , all we can go by is how it feels when changing from one spring/buffer to the other .

The more you lighten these rifles up , the more felt recoil they will have .

I always think about that when I shoot my M1 Garand(wish it was heaver-er,LOL.

I for one will buy & use more Tubbs springs.

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Drew, you should post the whole writeup that you received from JP, if it's alright with them.  That's some good info for the masses.  <thumbsup>

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