benelli m4 slug cycle issues,, help please

[rockwind1]

just got a almost new m4, 240 rds thru it with no problems. started using royal star low recoil rifled slugs, 2 3/4 1 1/8 oz 1200 fps. sighting in at 50 yards, i think 1 out of 25 actually cycled. the royal star buckshot cycled fine, also low recoil and federal target load 7 1/2 shot low recoil cycled great.

i am puzzled and worried,,, i have a class coming up and i bought ALOT of these slugs.

sighted in the iron stock sights first and then put on my H2 aimpoint and sighted it in. what sort of groups should i expect? 4 or 5" at 50 yds? from a bench rest on a sandbag?

i noticed my cheek is not resting much on cheek pad, but the slugs did the same no matter what. standing or bench.

thanks for any advice

[mavericksun]

Had another student with a cycling problem at the frontsight shotgun class. The instructor basically said it was a problem where the shooter did not brace himself for the recoil and some of the energy that would have been used to cycle the round was used instead to push the person back. sort of an inertia issue. The student brace himself better and the problem went away. It's an issue with very low velocity rounds. I tend to use things with at least velocity of 1350 to avoid the problem completely.

[rockwind1]

I am fine with trying that but I do think that it seems unusual that the the other low recoil rounds, which have 1200 fps or 1250 fps with the same weight projectiles all cycle fine. the buckshot has about the same recoil and seems to cycle fine. would like any alternative ideas/solutions in order to try several options next time at the range.

[CandG]

Had another student with a cycling problem at the frontsight shotgun class. The instructor basically said it was a problem where the shooter did not brace himself for the recoil and some of the energy that would have been used to cycle the round was used instead to push the person back. sort of an inertia issue. The student brace himself better and the problem went away. It's an issue with very low velocity rounds. I tend to use things with at least velocity of 1350 to avoid the problem completely.

That doesn't sound right to me.... The M4 isn't an intertia/recoil operated action. It's gas operated - the gas pressure in the bore (between the empty shell and the projectile) forces 2 pistons rearward which cycles the action. The problem could really only be the result of low gas pressure - how you hold the weapon should be irrelevant.

OP, I have not fired Royal Star low-recoil slugs in my M4 personally, but I have seen that other members here shoot them in their M4's without issue. What I can tell you is that the M4 likes to shoot full-power loads. I always have issues shooting #8 birdshot/practice loads with mine, though slugs and buckshot have never been a problem.

My 2 recommendations are:

1) Disassemble your ARGO pistons, and give them a proper cleaning and lubrication.

2) If that doesn't fix it, sell the remainder of your low-recoil slugs, and buy some full-power slugs instead. Maybe try these: http://www.ammosupplywarehouse.com/c...TGUN-SLUG.html (the product at the very bottom of the list...$138.99/250). Don't be afraid of full-power slugs with the M4. As I'm sure you've noticed, the recoil of an M4 is completely manageable with any ammo. These aren't your granddaddy's pump-action shotguns.

[BigFatGuy]

Since it's a fairly low-round-count gun, perhaps a heavy oiling? Or fire some cheap, high power bird shot to wear it in?

[splithoof]

Since it's a fairly low-round-count gun, perhaps a heavy oiling? Or fire some cheap, high power bird shot to wear it in?

No to that. Never "heavy oil" anything but a drill bit in steel.
Give it a cleaning, and try another brand of standard velocity/recoil slugs. My $$ says it's the ammunition or shooters technique, not the weapon.

[NYT]

did you clean the m4 before using it? a thorough cleaning? did you use the lube that they supply or your own?

i use vital shok truball low recoil slugs for killing feral hogs. i have no issues cycling the rounds.

[lindawcca]

I'm with Cockedandglock. Clean your ARGO Pistons and reassemble according to instructions. Check for any leaks. My M4 has performed flawlessly with cheap and low recoil without any issue. I agree the shooter's position should have no bearing on the cycle function as the M4 is designed to be operational from any platform, angle or shooting position. I have probably over 2500-3000 slugs through mine of every kind I could get my hand and no cycle failures. I am a stickler for running a clean well inspected weapon every time but again the M4 is designed to run in the harshest of elements. Good luck.

[70 blazer]

I've shot plenty of low recoil through mine when new no problems . I would clean it and try again

[CandG]

As a general point for all firearms, you should always clean and lube it before you shoot it the first time, because you have no idea what kind of gunk/crud (technical terms) is in there. Then, clean/lube it again after your first range trip, even if 1000 calgunners proclaim that your particular gun "almost never needs to be cleaned". Breaking it in with your first range trip will often result in lots of little metal particles. Kind of like a brand new car engine.

Most guns don't come with lube, but the M4 does, so you should use their lube at least until you run out of it. They thought it was important enough to use whatever that lube is that they gave you a free tube of it, so you should probably take their word for it.

Don't overlube it. The ARGO system doesn't need much, just enough to keep the metal friction down. If you flood it with lube, it can affect the movement in a bad way.

Did you install an aftermarket top rail? For example, a sidesaddle? Sometimes, the screws that come with those can make contact with the bolt... not good. So check that as well, if applicable.

Where are you located? Odds are, there's a calgunner with M4 experience that would come take a look at it for you. If you're near Sac, I'd happily check it out for you.

[BigFatGuy]

No to that. Never "heavy oil" anything but a drill bit in steel.
Give it a cleaning, and try another brand of standard velocity/recoil slugs. My $$ says it's the ammunition or shooters technique, not the weapon.

What can I say, I'm used to pump guns. :-)

[j6p2004]

Try a bit more lube at the rail for the bolt carrier and also the recoil spring and see if it helps.

[jeffrice6]

"Break in" with heavy loads ~ 250 rds of cheap(er) estate or what not & try leaving the action locked back for a week or so....... Works for the SLP

[Sheepdog1968]

At some class I took, an individual was having issues with one specific brand on slugs in his semi auto. He switched to a different brand of slugs and the problem disappeared.