SBR AR15 is jamming - HELP ME

[44 MAGNUM SHOOTER]

What changed since last year when it ran fine?

Only the TTO Muzzle Bralke..


Got home late last nite, completly tool it apart and cleaned it up really good. I will add a xtra power wolf buffer spring and see if that won't slow things down a bit. The bolt at times sees to grab midway on a round in the magazine causing it come flip upwards, jamming it between the bolt and chamber as in the pics above. It is ejecting the fired round just fine, although it's throwing the cases in front of me a mile away about the 2 o'clock position

Plan to shoot it again in a couple of weeks to test

 

[jeffers_mz]

I've spent a lot of time thinking about this, because I have a BAR-10 that does the same thing. Problem IDs as identified so far:

1. Not enough gas.
1A. Port too small
1B. Gas tube obstruction (debris)
1C. Gas tube obstruction (kink)
1D. Gas tube obstruction (tube/key misalignment)
1E. Ring containment issue as bolt rotates

2. Buffer spring too powerful

3. Magazine seats too low in magwell, top cartridge not high enough for bolt to catch on way forward
3A. Magazine spring slow to push next round up

4. Feed lip issue, cartridge "porpoises" as bullet tip rides over magazine front edge, allowing bolt to slip over edge of casing

That's all I've got so far, no solution yet, watching this thread for resolution.

 

[SKSnut]

PROBLEM SOLVED

Funny, i was thinking the same thing!

 

[44 MAGNUM SHOOTER]

Cleaned her up, had a smith tear it apart piece by piece, could not find anything wrong but did say the buffer spring was pretty heavy. I will put a lighter one in and test it out here in a few days. May just trim a few coils though instead. Also told me to stop using Mobil 1 as a lube and gave me some stuff called Slip 2000 EWL. Heard good things about this oil. Now to pray if works..

 

[shooter521]

Also told me to stop using Mobil 1 as a lube and gave me some stuff called Slip 2000 EWL.

LOL. SLIP2000 Gun Lube and EWL are both great products. I've been using EWL exclusively for about the last year.

 

[gtmerkley]

Every 10th round is not that bad for an ar15.

 

[shooter521]

Every 10th round is not that bad for an ar15.

You either forgot the purple text (sarcasm), or you're basing your comments on some POS ARs...

 

[44 MAGNUM SHOOTER]

Every 10th round is not that bad for an ar15.

What planet are you on buddy?

 

[Travis Daniel]

i have always heard that there were a lot of troubles like this with the short barrel ARs.

 

[shooter521]

i have always heard that there were a lot of troubles like this with the short barrel ARs.

Dropping below a 14.5" barrel does require a little bit more attention to detail when setting the gun up. Dropping below 10.5", even more so. That said, a properly set up shorty will run with the best of 'em.

 

[44 MAGNUM SHOOTER]

After trimming a few coils on the buffer spring and installing a BCM extractor spring, had 7 jams out of 200 rounds.. Getting much better, but not quite there yet. And boy, did that freaking thing run hot, could hardly hold it at the end of my shooting session. Gas piston system is looking better and better these days....

 

[44 MAGNUM SHOOTER]

After trying n trying n trying to get this dang thing to run right.. Decided to give up on her. Ended up parting it out and ran across an new and unfired POF 11.5" Gas Piston Upper with the MMR 9X Rail on a Colorado gun forum. After talking to this guy for a week, I got it shipped for $800.00. This was down from his original asking of $1100. He bought it from POF but then had an unexpect bill come up. Seems like alot of $$ but the POF uppers are going for $1275+. oh well. It should run like a sewing machine. With the money I got for my parts it ended up costing me $500.00 billz.

Thanks again to all that helped !

 

[300sx]

hope your problem is solved..looks good..

 

[Tireburner Turner]

Yeah the new gun looks good brother, sorry to hear about the old SBR. I have heard those 10.5's can be finicky if they arent dialed in just right. Let us know how the new one shoots!

 

[44 MAGNUM SHOOTER]

Yeah the new gun looks good brother, sorry to hear about the old SBR. I have heard those 10.5's can be finicky if they arent dialed in just right. Let us know how the new one shoots!

Shot it today and it ran like a sewing machine. 600 rounds and still clean as a whistle inside.. so far very happy.

 

[loony1]

good to hear, problem solved

 

[Tireburner Turner]

thats awesome man! Glad to hear its doing its job, but next time your at the range take your camera so we can see that puppy in action!

 

[Bull13]

I am having a similiar problem with my Olympic. I beleive it was I that caused it, but it might be a clue to your issue. I messed with my gas block, and had bleed off causing a poorly ejected shell (I understand that's not your issue) and then in the same chamber cycle would jam a new round and crush the case, just like yours shows.

Check our General Firearms Discussion: AR-15 Question, if interested.

I am heading out here shortly to test my rooky fixes.

Good luck with your problem, it is frustrating.

 

[44 MAGNUM SHOOTER]

it is frustrating.

That is an understatement my friend

 

[Nsw550]

Gas piston AR15's are the way to go these days. That looks bada$$