Thread: Rounds jamming into lands

Evening guys, ran into a problem this afternoon with a few rounds jamming into the rifling. I rechecked the coal and ojive measurements and they match near perfect with the rounds that are chambering fine.
I've done a jam measurement in the past and they're seated 25 thou off jam. Brass was all necksized then sorted to right length.
I fired a couple and the bolt was stiff to lift, is this indicaticating a problem in the neck or shoulder?

I'm new to reloading so won't be surprised if I'm missing something pretty obvious, any help or thoughts would be great.
Cheers

In addition to the above... neck tension may not be enough also.

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What is your indicaction they were jamming into lands? did you stick a round in the chamber and try to eject a live round and have the bullet stick in the barrel?
Your lands dont move back and forward so something in your measurements is asmiss.

Need more information.

are you 100% positive its projectile jamming into rifling???? eg did you open bolt and find marks on projectile or COULD it be the sizing die loosened slightly and case is tighter than normal somewhere else,eg shoulder is rubbing.....
Ive been caught by it before is why I mention it.

Heavy bolt lift is probably due to those rounds being over-pressure, due to the projectile being jammed (so higher pressures being generated before the projectile will move).

But my first question is...How do you know the rounds are jamming into the rifling?

Ok jammed causing the high pressure males sense to me

It is plainly obvious. He is not shooting a .308

Originally Posted by kayneb

Attachment 178618

I dunno what that is but it is not a mark from your lands.
Looks like a dent?

Take a fired case that chambers easily and one of the ones that was stiff to open and measure them both on the shoulder....you could use say the 45 cal comparitor or whatever just use the same on each.
Set up fl die to just bump back to the lenght of the fired case that chambers easily to up to minus 2 or 3 thou less max.

nah...felt tip pen a tight round..chamber it a few times and see where its touching..

now try the body of case...... there is one clear patch of diagonal rubbing there,but it goes too far forward to be rifling alone.

How many times have you neck sized the same piece of brass.

I used to neck size as that was what came with the rifle, now I neck size Nothing. Full length everything.

If you colour one of the cases incl projectile with a sharpie and carefully try chambering it then carefully remove it you should be able to see where its sticking as it were

Oh I see you have tried. Is that tip deforemed?? Are you dropping straight into chamber or feeding thru a mag to chamber?

Is it a new batch of projectiles? If so, could it be a different ogive?