ftf cci short range greens

[jlash4488]

I tore my m4 carbine down last night and im at my dads sighting it in and ive gotten a few ftf's. After inspection,  ive noticed the bolt isn't fully seated and causes the ftf.. I sprayed some rem lube around the bolt housing but hasnt helped.. this ammo is 1640 fps and I have my spring set @ 4 turns in from flush.. any ideas?  I just turned it in another two, and am going to try it again...

[techmike]

Next time you have the bolt out, try dropping a round into the chamber. It should drop in and fully seat, if it does not, try the same test with a different brand/flavor of ammunition. If it still doesn't fall in, scrub the chamber with a phosphor/bronze brush. Also, does the bolt go into battery without a round in the gun?

In an email from Colt/Umarex, I was told that the recoil spring should be flush for standard velocity ammo, and in 4 turns for high velocity ammo. The muzzle velocity of 1640 fps that you stated is well into the hyper velocity range, and the Colt is not designed for that type of ammo.

Pg11. owner's manual:

"Attention:

.22 L.R. caliber cartridges have a wide range of loads, from very weak for sport shooting and maximum precision to very powerful for a high projectile velocity. To ensure reliable operation, a semi-automatic firearm must be matched to a certain cartridge load. For this reason the cal. .22 L.R. Colt M16 / M4 has been designed for high-quality standard ammunition and HV (High Velocity) ammunition, and one can be sure of trouble-free operation only with these types. Please note that these rifles are not designed for the use of cal. .22 extra long ammunition."

So, you might want to try some high velocity ammo and see how that works.

TM

[jlash4488]

I noticed that sometimes it wont and almost feels lile something may be catching. I took it to the local gunsmith and told him of the ftf.. a week later I got the rifle back dirty as heck and he said he never had a problem firing it (chsrged me for two boxes of ammo @ $9.99/box).. he never even took it apart.. I bought a box of the rounds he used and I had 1 ftf out of ten.. needless to say.. I am pretty upset with that shop..

[techmike]

I didn't notice that you posted SR Green CCIs, I was focused on the velocity, my bad. Yeah these won't be reliable in the Colt. Reasons are - 21 grain projectile it is too light to reliably cycle the action - before the gas can push the bolt all the way back, the projectile has left the barrel, pressure drops and the action is short cycling, hence your FTFs. You will have a better shooting experience if you can get some quality standard or high velocity ammo. Might need to run through 500 rounds before the rifle will "settle in". And remember, .22 semi autos can be finicky about their diets. I think I tried 4 or 5 different brands before I settled on Federal ammo for mine.

TM

PS - From CCI's website:

CCI Short Range Greens

"Accurate to 50 yards. Maximum range 3/4 mile. Use in ANSI sporting chambers only - Do Not Use in match chambers. May not function in all semi-automatic firearms. Use only in firearms having standard ANSI sporting barrel/chamber dimensions.

1260 fps in handguns "

[jlash4488]

Which federals are you running? Im having trouble finding .22s around here.

[techmike]

Well, I cheated. I started buying "extra" .22lr when It was cheap and plentiful, so now I have a bit on the shelf. My go to plinking ammo is Federal Bulk. Used to buy it at WalMart in the 550 boxes for $18. It's pretty good general plinking ammo for the Colt for ranges out to 50 - 60 yards. It has a 36 grain bullet, and my experience with the Colt M4 is that 36 grain bullets start to drift at around 70 to 75 yards. I can still hit targets at 100 yards, just not exactly where I want to.  I also use Federal Blue Box, it is 40 grain round nose. I do like Federal, they stand behind their products. Winchester Super X works great, as does BVAC. Also have Win Dynapoint and some CCI "AR Tactical" which is excellent ammo, but was pricey even before the current crunch.

Question: Have you contacted Umarex customer service about your issue? If your Colt is a new rifle, you should consider getting it looked at while it is under warranty.

[jlash4488]

Unfortunately it Is not new. I never really shot it much new.. was working too much to ever get out.. and now im scratching my head..

[techmike]

One thing that almost always gets overlooked when this issue happens is the magazine. If you have only one mag, I would suggest getting another one before you start swapping out parts. At least inspect the lips, and clean it. If you have more than one, label them with numbers so that if one mag becomes a problem, you can identify which one it is. And if possible, try to stick with one brand/flavor of ammo while you track down the problem.

[jlash4488]

Thank you for all the info mike! I've been wanting to pick up a few 20 round mags.

[techmike]

Anytime buddy, let us know how it goes.

TM