JAMMED BOLT - 300 BLK AR-15

**StanCT** · 09-09-2018, 15:56

Before I take my rifle to a gunsmith (and perhaps you can steer me towards a reputable one in the Cape Town Southern Suburbs), are there any opinions on the possible cause of a jammed BCG?

The round fired, but the action did not cycle & upon closer inspection, it appears that locking lugs of the bolt have not rotated sufficiently to disengage from the lugs of the barrel extension.

Could this be caused by an excessively hot reload?

Before firing this round, I chambered and manually extracted it and it was a bit tight, although it did pass case gauge.

I am hoping that nothing is broken.

Edit: looking at the previously fired case, there were definite signs of pressure on the primer, with the ejector pin also leaving its mark on the head.

Here's a pic of the case, compared to normal factory case;

**Vaal** · 09-09-2018, 16:08

Have you tried to gently, tap the empty case out with a cleaning rod, from the muzle end? Be carefull not to damage the muzle crown.

**StanCT** · 09-09-2018, 16:17

Thanks, Ja that case is not going to unchamber until the locking lugs can unlock.

**Chris8** · 09-09-2018, 16:26

If you are 10000% sure it fired.

Point rifle barrel up.

Spray oil down barrel.

Leave for 15/20 min.

Collapse the stock.

Pull charging handle down while smacking the butt on the floor.

Put a towl down so you dont damage the stock.

Make sure the stock is collapsed.

**Chris8** · 09-09-2018, 16:30

Again I wouldn't even try it if I wasn't 10000% sure it fired.

**TRG** · 09-09-2018, 17:44

Jrrre how much was your load & OAL?
Seriously overcharged.
Any velocity readings?
Did you use S265?
Normally it is already a compressed charge with 110g

**Chris8** · 09-09-2018, 17:55

Would like to know as well.

Originally Posted by TRG

Jrrre how much was your load & OAL?
Seriously overcharged.
Any velocity readings?
Did you use S265?
Normally it is already a compressed charge with 110g

**StanCT** · 09-09-2018, 18:34

how much was your load & OAL? - 8.1 grn & 57.4mm (max)
Any velocity readings? - 1010fps
Did you use S265? - Lil' Gun
Normally it is already a compressed charge with 110g - 250 grn

**Stevin** · 09-09-2018, 18:46

I would try and mortar it as a poster above mentioned. I would try it without the oil first personally, but it comes down to how comfortable you are.

The load doesn't seem that excessive but it is 0.1gr below the max load for a 230gr projectile on the Hodgdon website. The case though does seem to exhibit signs of pretty high pressure tho.

**StanCT** · 09-09-2018, 19:09

Thanks guys, so ... I successfully "mortared" the stuck case out, as outlined above.

The primer had been severely flattened & blown out. This case looked even worse than the one pictured above.

How can a subsonic round develop such dangerous pressures?