Experienced Opinions - Short Stroke? Bolt Overrun? BAD?

AR/M4 AR Technical Discussion
1

Shot a carbine match yesterday and this happened to me three times with three different mags. All PMags. Approx. 75rds fired in the match.
Racked the charging handle and the round went into battery.

Short stroke? Mag overrun? BAD Lever on new Noveske lower?

Specs on carbine:
Gen II Noveske lower w/ BAD lever
H buffer
Blue Sprinco spring
14.5" DD midlength
IMI M193 ammo

This only started occurring when I mated the new Noveske lower to the upper. I know…I know…I should have run it more prior to the match. Just didn’t see this coming.
My LMT lower with BAD has never had this issue with all things being the same. Buffer, spring, etc.
I’ll be pissed if this is a lower / BAD issue and it may very well be.
I intend to take the BAD off and see what happens.

If not the lower/BAD combo, what direction in buffer, spring should I go? Lighter, heavier, combination of the two?

What is the experienced opinion of the house?

2

scoby, i’m having trouble seeing everything in the pic. are you saying that when you charged the weapon the bolt DID or DID NOT strip a round into the chamber? if i’m reading your post correctly, it sounds like the weapon chambered the initial round appropriately. if that is the case, when this malfunction occurs, does the spent casing get extracted/ejected? have you noticed the bolt locking back after the last round?

3

just realized… this is your 666th post. spooky.

4

Kyle, you’re right…should have clarified this.

It happened once on a mag change. Hit the BAD and the bolt didn’t catch the round.
Happened twice during firing.
Each time I checked the chamber, saw what happened, worked the CH and continued.

I’m thinking the BAD, but don’t know…yet.

5

Damn…didn’t notice.
Thanks for getting me off it. :wink:

6

haha… no problem. so it WAS extracting every time, just failing to chamber the subsequent round, right? and was the round that failed to chamber still completely seated in the mag?

7

It’s all guesswork, however I would do a search about the BAD lever and read some of the various malfunctions people seemed to encounter after installation.

8

No extraction problems.
The round looked just like what is shown in the pic. The round was not completely seated in the mag. It was like the bolt never picked up the round and ran over it but, pushed it forward just alittle.

9

A lot of different issues going on here so you will want to minimize everything.

First, load one round into a mag. Fire. Did the bolt lock back? If yes, do it ten more times and see if it does it every time.

If it does not, put a regular carbine spring in the gun and try the test again.

C4

10

I’ve read all of them at some point. Probably should go back and take a look.

I’ll get it figured out eventually, just hoping someone may save me some time and ammo.

11

I’ll be willing to bet, that if you remove it everything will be fine.

12

I’ll give this a try.
I have the BAD on two other guns and its’ use is ingrained in my brain.
I really hope that it is not the BAD.

By the way, thanks for the lower and the good service.

13

i was about to suggest the same as grant. if the bolt is completely failing to pick up the next round, it might be outrunning your mag. see what happens. i’m not too familiar with the BAD lever, but have read about people having some issues. weather or not they were the same issue, i couldn’t tell ya.

14

.

I have seen one gun where the Bolt Catch locked the BCG back on the Bolt Carrier body and not in front of the Bolt Face. This caused a similar looking feed to what you have.

I can’t get my rifle to duplicate catching on the BCG body, so it might have been a BCG issue.

Try using the BAD to catch the BCG by intentionally “miss” catching the Bolt but still applying pressure on the BAD to see if it can make the BC catch the front BCG shoulder.

Just a thought…

.

15

If I had to bet on it…I’d say you were right.

If it wasn’t pouring down rain right now, I’d be trying to figure it out this very minute.

16

WEAK! :smiley:

17

Just gave this a try. Bolt catch will not engage the carrier and hold it back.
Thanks for eliminating one possibility.

18

I know…I’m not the man I used to be. :cool:

19

It sounds like the new upper has an oversized gas hole to me. What weight buffer do you have, the h? Cheap to get a heavier one (h2) and try it out. I would loan you mine, but i’m in AZ. I know this video is for a piston setup, but I saw it on one of the topics the other day. Good cut out animations.
http://www.youtube.com/watch?v=2LltApvOC0U
skip to 4:27
it sounds like your problem to the T.

20

Most people are going to point to the BAD lever because… well they just will. Until you take it off and shoot the gun, and try the test Grant mentions, it’s kind of pointless to speculate and it’s going to be hard for people to get over the BAD.