Hard to chamber rounds

[SS427]

I have a Remington VSSF .223 that has me stumped. I'm having a hard time closing the bolt on about half my hand loaded rounds. Here are some details:

1. The Lapua brass is always easy to extract during the prior shooting, even if the bolt was hard to close. No bolt click. No signs of pressure. Easy as can be to extract.

2. A difficult round to chamber, when removed w/o firing, shows no sign of rifling marks on the bullet. I'm seating them at the lands, but not jamming. I don't see any signs on the neck either, like if the chamber was too tight.

3. Last time I reloaded with Redding competition dies, I bumped the shoulders back .003, which I thought was a little more than needed. They still chamber hard.

4. A difficult round to chamber, when removed w/o firing, shows no marks on the shoulders to indicate that is the problem. If there is anything, there might be a slight rub mark right at the base of the neck where it connects to the shoulder. Hard to tell for sure.

Any advice?

 

[mattc]

when my case get to hard to close the bolt it is time to FL size them and cut the case down some. The brass will start to move to the neck if you just neck size and make it hard to close the bolt.


matt

 

[gunplumber]

You might try checking over all case length. Any case that is too long will jam against the end of the chamber regardless of where the neck seats. All cases should have the same case length for optimum accuracy anyway.

 

[SS427]

The Redding bump die I use essentially FL sizes them, except for the neck.

Double checked the length, and while they are getting close, all of them are less than the 1.760 maximum length. Most measure between 1.756 and 1.757. I don't see any signs of them getting jammed into the throat. I think I would see signs of pressure if that was the case anyway.

 

[gunplumber]

Have you kept track of the hard to chamber cases and are they the same every time? Do the affected cases keep rounds in the same group as easily chambered rounds or do they produce fliers?

 

[SS427]

No, I don't track them. It wasn't really bad until a couple reloadings ago. I figured bumping them back .003 would fix the problem but it didn't.

Actually, if I have a good group going, and the next round is hard to chamber, I know it will be in the group. They are more accurate than less, and I don't ever recall one being a flyer.

 

[bglenn]

After the case is fired, can you put the fired case back in the chamber and close the bolt easily - after 5 minutes from firing or more? :-\ How do you measure your shoulder set back?

Glenn

 

[SS427]

Yes. They seem to chamber as easily as they eject. I've only tried a few though.

I use calipers and the Hornady lock-n-load headspace tools for measuring the shoulders. Not the most accurate, but I can clearly feel the the body die resizing the case.

 

[DOGCAPPER]

Check just above the haed...hot loads will give extraction/loading problems here..dont ask how i know.

 

[bheadboy]

after a number of loadings, some cases weaken at the junction of the sholder and case body, a presure ring forms when sized showing .002-3" ring, this causes the case to be hard to chamber.
this can also happen when the sized case neck walls are thick enough to cause bullet seating to be too tight and when the bullet is seated it pushes the shoulder back against the body causing this ring, check neck wall thickness after sizing, sort by thickness, load the try chambering the thick ones vs the thinner ones

Bob

 

[SS427]

It does appear there are scuff marks just above the extraction groove. Nothing dramatic, but they look different than the cases for my other .223s.

I take it the bump die is pushing the shoulder back enough, but it is not reaching down far enough on the case to resize the lower part of the case? I will try my RCBS FL sizing die on a few rounds and see if that fixes the problem.

This is not a hot load though. 25.3 grains of Varget, which puts it right in the middle of the Sierra min/max range. (Sorry, 55 grain bullets)

 

[jo191145]

If the web was blown out as some suggest they would not extract easily.

I would bet some of the shoulders are not being set back enough during FL sizing. Upon firing the undersized (FL sized) body fills the chamber drawing back the shoulders allowing easy extraction.

Thats the only plausible scenario for hard chambering easy extraction. Unless the FL die is a totally wrong fit for the chamber that is.

 

[SS427]

If they all went through the same body die bumping back .003, how could some of the shoulders not be set back as far as the others? I don't measure everyone of them, but the first five or so out of the press I check and they were uniformly set back. Could the brass be springing back more on some of the cases?

 

[jo191145]

Well used brass can bump back different lengths depending on hardness.
Gotta admit if your truly bumping back .003 I myself would find that much variation hard to believe.

#4 of your original post states a possible rub mark at neck shoulder junction.
Perhaps a defect or terrible mismatch between your die and chamber.

Blown webs extract hard. A 6ppc is known for warning shooters of oversized webs. Even with a custom action you'll feel the extra extraction force required and the "click". Very common in the 6ppc using high end nodes.

Fire a piece of hard to chamber brass. Extact and rechamber. If it rechambers easily after firing its not the web that cannot be resized causing you the trouble.

 

[bheadboy]

Otter, less likely the press springing, more likely the brass -

if the neck tension is high after sizing, yours seems to be, the bullet on seating can push the shoulder back (the seating dies is not firm against the body of the case) and cause a pressure ring at the shoulder body junction. take calipers and measure the dia. of the body at this junction on a tight round.

you may find a .001-.003 increase in body diameter which would cause hard chambering,on firing the case expands to the chamber and extracts easily
Bob

 

[infantrytrophy]

If they all went through the same body die bumping back .003, how could some of the shoulders not be set back as far as the others? I don't measure everyone of them, but the first five or so out of the press I check and they were uniformly set back. Could the brass be springing back more on some of the cases?

Otter,

Yes. Strange as it may seem, there is a lot of variation in the amount of shoulder "bump", even with the same die setting. You should check the "case headspace" of a substantial number of cases to determine this. This variation depends on a number of factors, including how much any given case has been previously sized back and then "stretched" by firing. Even within the same lot, different pieces of brass will spring back more or less.

You can even see this happen: size a case, then size it again with the same die setting. Frequently there will be even more shoulder setback.

This is not an exact science. Set your die and make your measurements based on averages of large samples.

Randy Sikes

 

[SS427]

One more item I should have mentioned. I use the same Redding dies to reload for two other .223s. One is a Wby Vanguard sub moa and the other is a Savage LRPV. Neither of these rifles exibit a similar problem.

I have a couple things to try now. I have some factory spec reloaded rounds I will try to chamber. And I will do some measuring. If I find anything out of the ordinary, I will post it.

 

[SS427]

The other ammo that I have, which have the shoulders set back .020 more than my reloads, chamber the same way. Some are easy, some are hard, but not as hard as my own reloads.

My fired brass is on average .003 longer than my reloaded brass. Basically it is the same length as before I bumped it back last time. I tried chambering some of this fired brass and while they didn't seem to chamber as hard as the loaded ones, some were tougher than others. Once I got them chambered, I could start to extract, and then re-chamber, and they chambered with relative ease.

Could the resistance I feel be the extraction claw fitting over the rim? A slightly thicker rim gives more resistance? Also of note, this gun has always stuggled to eject inexpensive brass. Winchester brass never would eject well. It was like the claw was losing it's grip just before it ejected. Once I got Lapua brass this problem went away. (I don't recall the Winchester brass chambering hard....only used it a couple times and then move it into rotation for a different .223 .)

 

[jo191145]

Otter

I've never owned a Rem action so............

You may be on to something tho. When chambering a round with resistance does the bolt handle lower into battery easily?
With oversize brass the handle should lower with resistance. If its an issue with the extractor its quite conceivable to feel resistance chambering but the bolt lowers easily.
I've never had this issue so thats pure conjecture on my part

Compare the case head diameter and rim thickness of your Lapua and old lot of Winchester.

Undersized case heads are a "contributing" factor to Savages failure to eject properly.
There can be some big discrepencys between specs on brass.
In my limited expierience Winchester can be very small in Saami specs while Lapua can sometimes be oversized.
I'm working with a lot of 6BR lapua now that has some rim thicknesses large enough to not fit in a shellholder.