Fail to fire, hammer drops

[chadjetlag]

I built a 6.5 with a bolt from a group buy here and a double star barrel. If I load the rifle from a magazine, even using the forward assist, the hammer will drop and will not even put a mark on the primer. If I drop a round into the chamber it will fire and eject as advertised, the next round from the magazine will not fire. I assume it is not going fully into battery for some reason

[NightFisher]

That is the most likely reason. You using factory loads or reloads? Have you tried different ammo?

[Rangerofthenorth]

Are you "riding" the charging handle? If not, maybe try a stronger spring like a JP tuned spring.

[bj139]

Clean the chamber real well with solvent and a wire brush. Sometimes there is manufacturing oil or something dried in the chamber preventing full chambering. I had several like that.

[FRB6.5]

Using a standard AR15/M16 firing pin or a short one made for the other bolt type?

Nvm missed that it did fire if dropped one in.

[grendelnubi]

Your recoil spring may be weak? When pushing the round out of a mag, it may not have enough force to push the round all of the way into the chamber. Are yo using an adjustable gas block? Could the bolt be short stroked? Check to make sure it holds open on an empty magazine. If not, increase gas till it locks.
You may have already quantified this using the forward assist but needs to be considered anyway.

The other issues could be related to ammo. Factory or reload? If reload it could be resizing issues, check your case specs, length, diameters etc... I have seen excessive cartridge headspace resulting in cartridges that will not fire, hard to remove from the chamber etc..... Typically I resize mine to 1.211. Factory ammo generally run to about 1.209.

You may want to check your chamber specs, like headspace tolerances using a go or no go gauge. If you take an chamber a round using your hand, finger to push it into the chamber, does it fall out when you tilt the barrel up?

Not going into battery is a real issue and can be dangerous if it actually fired while not in full battery. I believe that is what is occuring, it not going into battery. I would check the lugs on the bolt also to see if they have any signs that may indicate what is going on. For example, excessive wear on the back side of the lugs. I realize this is a new build but you never know.

Check your firing pin to make sure it is the right length.

[Mad Charlie]

When I read his post this morning, the first thing I thought was short pin in long bolt. Then I saw that it would fire when he dropped the bolt on a chambered cartridge, I dunno...

[LtDan]

Is the bullet going in to the lands (aka short freebore), take a magic marker and color the bullet then chamber it and eject it carefully. Check to see if bullet is contacting the lands there will be marks around the circumference if so that barrel has a problem. If the bolt does not go all the way into battery that is a big problem. One other thought is the hammer spring on the hammer the correct way, I saw this last weekend at my range and the guy was bummed because that was his birthday present and it didn't work. I took a look and reinstalled the hammer spring and he was all cheeks after that.

[chadjetlag]

I will check some of the advice and follow up. It does it with factory and reload ammo. Going to verify bullet depth to lands and grooves, gas block, bolt and see whats next

Thanks

[chadjetlag]

I checked my handloads, they are touching the lands and grooves, I will look at seating depth. I was pretty sure it was happening with factory ammo, now I’m not sure so I have to get some more.

Thanks

[LtDan]

You have a barrel with short freebore which was a big problem back a ways. I think you need to contact the barrel maker on this. I know Satern had issues and so sis others. Do a google search on 6.5 Grendel short chambers for some interesting readings.