Problems chambering

J

jpbaker

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Hey folks,

Finally got my build together:

Savage action
270WSM Brux barrel with vias
.700" PTG Bolt Body (fluted)
PTG Bottom for AI mags

Manners T-A

and several other things but that's pretty much the nuts and bolts of it.

I duracoated it a couple weeks ago, so I went to develop and load for it today.

When determining the distance to the lands, I noticed it was hard chambering the dumbie rounds. I assumed that this was probably because I was jamming the rounds into the lands (OAL to lands had not been determined at that point).

Once I Determined the distance to lands I loaded up a dumbie round and backed it of .004" for reference (loading 150 Berger VLDs). When I went to chamber this round, there were no marks on the ogive from the lands, but it still took a lot for pressure to throw down the bolt.

I was confused, so I took some once fired brass that had been FL sized. When I tried them, some would chamber with a little to no force, some took a lot of pressure, and others felt like they were no go gauges.

I checked the OAL of the brass, some were a little long, so I trimmed them all thinking that the headspace was a little tight. I trimmed them to 2.093" since I had some brass chambering fine at 2.095". I still have the same problem, there are more that chamber, but some brass with the same OAL will not.

I rechecked the headspace again, and it was fine, but on the tighter side.

So, what is the problem here. Is it a headspace issue? I really don't want to have to reduracoat it by adjusting the headspace, but I may have to :(.



TKS
Jordan
 
The shoulder may need to be bumped back. Or possibly your chamber may be a little tight and need a small base die. I'm not experienced enough to tell your for sure if that's it.

Does it happen with new brass or factory ammo?
 
Is your expander button pulling too hard when the case is withdrawn from the die? Might be pulling the shoulder forward.
 
I had this problem when starting out reloading. It turns out the FL resize wasn't quite going all the way down the brass. A quick adjustment of the die in the breechlock nut and I was off to the races. Maybe your dummy round needs to be resized again?
 
If the rifle accepts the Go gauge, and not the No Go, it should be within spec.
If you cartridges don't chamber, then there is a compatibility issue.
How does it work with new, unfired cases?
 
Headspace has nothing to do with case length.

Headspace is checked using steel go and no go gauges that are made to an exact measurement. In the case of rimless cartridges the headspace gauge length is based at a particular diameter on the shoulder and at the rear of the gauge.

If you are using your brass to set the headspace on assembly of the barrel to the action, that is a problem unless all your brass is sized exactly the same... WSM brass is very heavy and not very uniform. Good luck with that.
 
Something is moving in your sizing process - die moving in press, lever flexing and not pushing case all the way in, Die big/chamber small.

Proper lubing will also be important.

If you size a case and you get irratic chambering, check the press, dies and how you work them.

Jerry
 
just encountered this with a different caliber..............try a different shell holder, they are not created equal, even if the dies are
 
A shell holder won't cause inconsistencies... Jerry covered it... Something is moving in your sizing process - die moving in press, lever flexing and not pushing case all the way in, Die big/chamber small.

Consistent lubing will also be important.
 
guntech said:
A shell holder won't cause inconsistencies... Jerry covered it... Something is moving in your sizing process - die moving in press, lever flexing and not pushing case all the way in, Die big/chamber small.

Consistent lubing will also be important.
Click to expand...

I beg to differ...............I have 2 rcbs shell holders, both untouched and the distance from the bottom of the brass to the top of the ear is enough to cause hard chambering when the taller of the two is used, it will not allow the shoulder to be bumped back enough to allow the case to chamber. Also confirmed this with a case gauge
 
Bump the shoulders back or FL size it with a different FL die. Very common with WSM cases. I have a 300WSM and it will not chamber brass that has been fired from the chamber with neck sizing. I know and heard from other reloaders that have the same problem. If your tight on a go gauge then try turning down your FL sizing die another turn so that your die makes full contact with the base. If not you may have to look at another FL die or body sizing die for your brass. If this is for a hunting rifle you should be FL sizing just so that there are no feeding problems in the field.
 
In theory, the dimension of the shell holder is supposed to be .100", and the ream job on the sizing die is supposed to account for that.

Sometimes the gods of tolerance stacking, pee upon what is supposed to be....

If screwing the die in a wee bit does not do it, it might be wise to start measuring.
You could also try a simple shim under the case in the holder, before you do anything permanent.

Case length is easy to measure, but if the rest of the case is not getting shaped the way it is supposed to, either from too little sizing, or being pulled out when the sizer is pulled out of the case.... Well, it needs to be watched for too.

Cheers
Trev
 
yodave said:
I beg to differ...............I have 2 rcbs shell holders, both untouched and the distance from the bottom of the brass to the top of the ear is enough to cause hard chambering when the taller of the two is used, it will not allow the shoulder to be bumped back enough to allow the case to chamber. Also confirmed this with a case gauge
Click to expand...

You are missing the point... One shell holder won't cause inconsistencies... If you don't change the shell holder, just use one shell holder ... that shell holder will not cause one brass to be sized differently than another brass. If you use more than one shell holder and they are different in dimensions, then that would cause inconsistencies. His complaint involved inconsistencies using one shell holder.
 
OK I got it fixed up.

The problem was like I mentioned in my original post. It was once fired brass, the rifle has a tighter chamber, and the Redding shellholder in my press was pretty thick and I wasn't bumping the shoulders enough. I took off several thousandths from the shellholder, and started with quarter turns, till I could lock the bolt with no effort. Problem Solved.

TKS for all the help guys!
Jordan
 
Last edited:
guntech said:
You are missing the point... One shell holder won't cause inconsistencies... If you don't change the shell holder, just use one shell holder ... that shell holder will not cause one brass to be sized differently than another brass. If you use more than one shell holder and they are different in dimensions, then that would cause inconsistencies. His complaint involved inconsistencies using one shell holder.
Click to expand...

I don't mix them, I just happened to have started out with a dud. I bought a new shell holder and experienced the problem then went through a box of old gear and happened along a old shell holder of the appropriate number, it allowed the case to be full length sized, then I measured the new shell holder and found that it was a lot taller on the ears. The new shell holder is now stored along side of the bullet seating press.
 
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