Round Chambering Issue

[myn0ck]

So I'm having a little round chambering issue.

 

My anecdotal experience is that this only happens with a newly inserted 33rd factory Glock mag that is fully loaded (or close to it).  If I only put 15-20 rounds in the mag, I do not recall this happening. 

 

It has happened with at least 2 different mags and whether I'm using the Federal Syntech or a round-nose round.

 

I'm planning to do a little polishing of the barrel, but any other ideas?

 

Barrel: KVP

Upper:  QC10 Side Charging

Bolt:  Taccom

 

Thanks!

 

[Flatland Shooter]

I recently resolved this issue by installing a Taccom 9mm feed ramp.  It only happened with an extended magazine but looked just like your jam.  

 

They are not that expensive or hard to install but it got my PCC into running at 100% again.

[Nugget]

The ramp works but you can also change your bullet to a round nose profile to get it to feed. Worked for me.

[MikieM]

You didn't say, but your buffer spring could be too strong. If this is a new gun, or a new build, then try a standard spring until you get a couple of hundred rounds down the barrel.

First, and foremost however, be sure and check your ammo and magazines. 

 

+1 on the RN bullets.

Edited April 1, 2018 by MikieM

[myn0ck]

9 minutes ago, MikieM said:

You didn't say, but your buffer spring could be too strong. If this is a new gun, or a new build, then try a standard spring until you get a couple of hundred rounds down the barrel.

First, and foremost however, be sure and check your ammo and magazines. 

 

+1 on the RN bullets.

It is new.  With my factory ammo comparisons, optic sighting and today's match, I'm probably around 500-600 rounds total.

 

I'm also using the Taccom buffer with whatever springs come with it.

 

It also happened with RN bullets.  :-/

 

18 minutes ago, Flatland Shooter said:

I recently resolved this issue by installing a Taccom 9mm feed ramp.  It only happened with an extended magazine but looked just like your jam.  

 

They are not that expensive or hard to install but it got my PCC into running at 100% again.

 

Is that the feed ramp that requires cutting space into the receiver to fit?  I can see that working... I just don't like the idea of irreversible mods to things.  I'd almost rather get the ramped tension barrel.  :-/

[TRUBL]

the chamfer on the barrel....your bullet profile....both suck. The recoil spring is fine.

our ramp will help a lot....with what you got.

RN profile will help 

the barrel chamfer.....let the experts screw with that

[myn0ck]

1 minute ago, TRUBL said:

the chamfer on the barrel....your bullet profile....both suck. The recoil spring is fine.

our ramp will help a lot....with what you got.

RN profile will help 

the barrel chamfer.....let the experts screw with that

 

When do you expect your (expert) ramped tension barrel back in stock?  :-)

[TRUBL]

15 minutes ago, myn0ck said:

 

When do you expect your (expert) ramped tension barrel back in stock?  :-)

good question......better be damn soon!!! We just ran out, but they were being made

[longbeard]

I had the same issue. Use RN and install the feed ramp. It's not a big deal to install. A file and some jb weld and you're set. Cheaper than a new barrel as well.

Don't forget that if you go with Tim's ramped barrel you need the shortened bolt or you'll have to mod the one you bought.

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[Patrick Scott]

Taccom ramp will help, it did for me.
We have to remember that the 9X19 case is tapered, so the more rounds in the mag the lower the angle of bullet presentation to the chamber which is probably why it runs better as the round count in the mag drops. 

[myn0ck]

37 minutes ago, longbeard said:

Don't forget that if you go with Tim's ramped barrel you need the shortened bolt or you'll have to mod the one you bought.
 

I already have Tim's bolt and buffer... I suppose completing things with his barrel could be considered fate.  ;-)

 

2 minutes ago, Patrick Scott said:

We have to remember that the 9X19 case is tapered, so the more rounds in the mag the lower the angle of bullet presentation to the chamber which is probably why it runs better as the round count in the mag drops. 

Thank you!  This is the first time I've heard that explanation for my experience.  I guess I need to get this fixed before I start running with a mag extension then!

[Patrick Scott]

5 minutes ago, myn0ck said:

I already have Tim's bolt and buffer... I suppose completing things with his barrel could be considered fate.  ;-)

 

Thank you!  This is the first time I've heard that explanation for my experience.  I guess I need to get this fixed before I start running with a mag extension then!

There is a reason lots of from the ground up designed sub guns with high capacity run curved mags. 

 

[Flatland Shooter]

16 hours ago, myn0ck said:

Is that the feed ramp that requires cutting space into the receiver to fit?  I can see that working... I just don't like the idea of irreversible mods to things.  I'd almost rather get the ramped tension barrel.  :-/

 

I felt the same way about modifying my upper receiver.  I bought the ramp back around Thanksgiving and had it handy "just in case".  When out of the blue I started having feeding problems with large capacity magazines, I tried just about everything I could.  None helped.  And it cost me dearly at a few matches.

 

Fitting the ramp only required taking out a small bit of material and was not noticeable unless you were really looking for it.  On mine, I touched up the ends of the ramp with a black magic marker making even less noticeable.   I did file the notch where the ramp was a "press fit" but it became loose in time.   I just need to be careful when I open up the receivers so I do not lose the small part.

 

[MikieM]

You didn't say what brand your lower receiver was but some may be dimensionally different than others.

Insert a magazine with one round in it, and with the bolt locked back, see where the nose of the bullet is pointed. It should be on, or very near the centerline of the bore.

You'll notice that you can, at this point, rock the magazine back and forth (fore and aft) a small amount. Rock it back and forth and see if there are any changes to where the bullet nose is pointing. Regardless, it should always point to somewhere within the bevelled circle (the ramp) at the back of the barrel.

Although bullet seating depth could play a role here, I'm thinking your magwell is a bit too far away from the breech, or the magwell is a bit large for your mag and is allowing it to rotate back and forth a little too much.

Having said all that, I agree with Flats, and recommend you install a ramp to assist the one that is machined into the barrel. 

[ChuckS]

On 3/31/2018 at 5:50 PM, myn0ck said:

So I'm having a little round chambering issue.

 

My anecdotal experience is that this only happens with a newly inserted 33rd factory Glock mag that is fully loaded (or close to it).  If I only put 15-20 rounds in the mag, I do not recall this happening. 

 

It has happened with at least 2 different mags and whether I'm using the Federal Syntech or a round-nose round.

 

I'm planning to do a little polishing of the barrel, but any other ideas?

 

Barrel: KVP

Upper:  QC10 Side Charging

Bolt:  Taccom

 

Thanks!

 

 

Load your mags fully an take a picture of them from the front so you can see the top round and the next round down and post it.  If the rounds are not stacking correctly, the top round may dip and miss the barrel bevel with the bolt push. Mag sitting too low can do this also...

[myn0ck]

10 hours ago, ChuckS said:

Load your mags fully an take a picture of them from the front so you can see the top round and the next round down and post it.  If the rounds are not stacking correctly, the top round may dip and miss the barrel bevel with the bolt push. Mag sitting too low can do this also...

Mag on the left has 5 rounds, on the right, fully loaded at 33.  

 

The rounds on the right look just a tad lower.

[myn0ck]

11 hours ago, MikieM said:

You didn't say what brand your lower receiver was but some may be dimensionally different than others. 

I went the non-easy route and got an 80% lower from Iconic Industries, the 9mm Instigator Ultralite.

[ChuckS]

1 hour ago, myn0ck said:

Mag on the left has 5 rounds, on the right, fully loaded at 33.  

 

The rounds on the right look just a tad lower.

 

It sort of looks like the rounds may be too long for the mags.  See if you could post a side view and top view. Measure a couple rounds also.

[1911luvr]

The super easy answer is a Taccom ramped barrel. Mine shoots every thing from a 1.085 to 1.160 OAL.


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[ALauFirearmsTraining]

On 3/31/2018 at 9:12 PM, Flatland Shooter said:

I recently resolved this issue by installing a Taccom 9mm feed ramp.  It only happened with an extended magazine but looked just like your jam.  

 

They are not that expensive or hard to install but it got my PCC into running at 100% again.

so I was reading on Taccom's website that the feed ramp only works with Lowers that doesn't have the bolt open option, do you happen to have any experience with that?