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Posted: 11/12/2005 7:03:32 PM EDT
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Problem is not so much the rifle, but the rifle/mags combo. For the most part, the rifle cycles with authority, which translates to the buffer making it back to strike the back of the receiver extension and cause both a good dead blow effect of the buffer, and the jolt to the mag to allow it to recover/get the top round fully up tight against the feed lips for a clean bolt strip off the mag on the forward stroke. But, every one in a while as you have noted, the rifle may semi soft stroke, which does not transfer a good impact pulse into the mag to allow it to recover. A couple of solutions would be to check the USGI mags to insure that they are clean, the inside of the bodies’ bur free (including checking the followers for molding burs), and that the springs are in good working order. As for the rifle, making sure that it/the bearing surfaces are correctly lubed (including the receiver extension assembly), and to either allow the rifle enough time to self polish if new, or if the rifle is broken in, then to keep the rifle lubed as the rifle is ran (read a few drops of CLP into the exhaust ports to allow the lube/cleaner to migrate threw out the rifle to replenish the lube, and to break down any fouling that may be building up to the point that it may slowing the cycle stroke down). Also to point out if the rifle is correctly stroking threw out the mag run, check to make sure that the mag catch is correctly tensioned, hence if needed, add a wind or two to mag catch to correctly retain the mag (threaded section of the catch should be flush with the face of the button, but an extra turn may resolve the problem if mag retention turns out to be the antagonist to the problem at hand) One of the areas that you have not touched on is ammo choice. Often the thought of under power ammo comes to mind when thought of short stroking. Although true, the same can happen when ammo that is too hot, or wrong for the rifle being used as well. Here, the hotter ammo (or say 5.56 Nato ammo using in a tighter 223 chamber or a chamber that is short throated) will over pressure bind the spent case to the chamber side walls, and the extra needed force of the action/bolt to strip the round out of the chamber will cause too much reduction is cycle energy to allow a healthy cycle stroke. To sum it up, strip the mags down and give them a good cleaning. Since this is an intermediate problem, best guess is that the mags/springs/follower are in good working order. If this is a new rifle, allow it time to self-polish threw live fire, remembering to keep the bearing surfaces well lubed with CLP. Lastly, remember that every few hundred rounds, adding a little extra CLP to the rifle, may just be the deciding factor that allows the rifle to cycle cleanly. As for adding/correcting the feed ramps, this solution is best reserved for problem caused by ammo this is outside of the norm for the rifle, and since not stated, It very unlikely that you have encountered such problems. |
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tnx for the reply. What is CLP by the way? The rifle is not new and ammo is factory ammo we use on our SWAT team. Ill try the mag cleaning to see if that was the issue. Otherwise, nice answer, very complete. I have a few questions about "CLP into the exhaust ports to allow the lube/cleaner to migrate threw out the rifle to replenish the lube, and to break down any fouling that may be building up to the point that it may slowing the cycle stroke down" Which ports? where are they? oN the bolt? |
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The easiest form to buy CLP is BreakfreeCLP. On the carrier with the port cover open, you will see two holes in the indent of the carrier. These are the gas section exhaust holes. Slightly pull back on the charging handle, and you will see the gas rings move forward of these holes (really just the bolt rotating and the carrier moving back with the rings staying stationary). With the rings forward of the holes, add a few drops (or quick squirt of CLP since the 16oz spray can is the best way to go) to re-lube the rifle after a few hundreds rounds of use (read cycle the rifle a few times, and then the gas pressure of the rifle being fired with migrate the fresh CLP throughout the upper). As for cleaning and lubing the rifle, a Copper removal solvent should be used to clean the bore, but any remaining traces of it should be flushed out with CLP as you use the CLP to clean, and then lube the rest of the rifle (read the upper bearing surfaces (including the receiver extension parts)). Also. keep in mind that if CLP mixes with coper solvent or other oils, it just turn into a sticky mess. FYI: Cleaner Lubrication Protection ( from rust) www.ar15.com/content/guides/maintenance/ |
| HI, I had the same problem with my new bush master V MATCH 16 INCH, I tried all types of mags in my collection, all types of USGI brands, with the black and green followers, I pollished up my feed ramp area to a shine and then re blued, and the best move I made was I put in the MAGPUL FOLLOWERS , also once I put in the followers I took a dowell rod about 1 foot long made a small point on the one end. I put the point of the dowell into the area of the follower were you can see the spring in the square area in the top of the follower and worked it up and down a few times, it helps work and set the spring. As you do this you will feel the spring and follower smooth out.. really try the magpul followers, I have 45 different USGI mags I put magpul followers in all my mags. I took 60 rounds to the range 2 weeks ago before the new followers, the rifle jammed on the feed ramp 25 times, after the new followers I took 120 rounds to the range this past saturday, and NOT ONE JAM ON THE FEED AREA! I told my navy seal friend about them, so I sent him 6 magpul followers to test, he wrote back and told me they were 80% better then the light green followers that are in the mags he uses. He said send him more so off to war more go! i hope this helps some? great forum great people lots of good help mike b.. |
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