Tight chambering brass

[Paul K]

Redding makes a shell holder set for just that purpose.

Paul

 

[JimP]

Get your magic marker out and blacken the whole case, gently chamber it and look for scuff marks. The magic marker wipes off with rubbing alcohol or Hoppes.
Paul

You can also use the soot off of a candle flame

 

[MauserDuff]

Redding makes a shell holder set for just that purpose.

Paul

That's great--Redding shell holders. See page 20. I did it the cheap-ass way (with my 50 yo Lyman shell holder). Whoops--re-read the description. These all INCREASE the headspace, not decrease which grinding the shell holder does, and which seems to be what is warranted here.

 

[AckleyHunter]

Sounds to me like there is something going on at the bottom of the case by the case head during FL sizing...the cam over advice is good. The other thing that could be happening is your internal sizing button on the way out could be pulling the shoulder forward and you are pushing the shoulder of the case tight against the chamber. Try pulling your sizing button out and run and case through and try it.

Tried that, without the button the bolt wouldn't close at all. But again, only for the starline brass. Used the hornady as a control.

 

[Paul K]

Run that die down a little farther till it cams over harder. Just try it on one case that you have already sized. Keep turning the die down a little at a time and trying in the rifle till you can't cam the press over.

Paul

 

[mdwest]

One of my christensens had a tight/sticky chamber… I just polished it a bit by putting a tiny bit of bore polish on a copper chamber brush that I chocked up in a cordless drill… ran it in and out of the chamber for maybe 15-20 seconds total… and it completely solved my problem..

 

[Roosterlund]

I’ve heard Starline brass is very hard. Should try to anneal a couple. Resize and try. If you don’t have an annealer you can do by hand with propane torch. Only doing one or two. Seems like you’ve tried everything else.

 

[AckleyHunter]

I swapped the shell holder in my trimmer. It was just thin enough to bump the shoulder back. Tight, tight tolerances. Thanks for all the suggestions!

 

[fourfive8]

Full length dies don’t really size full length. They size down to the web area just above the base. Your rifle may have a slightly tight chamber in that area. You might need a small base die for that family of cartridges.

 

[Wyatt Smith]

It sounds as if you have been pretty thorough, my guess is pile be that the star line brass has a bit more “spring back” than your others. I would try a different brand of die and see if you get lucky.

 

[fourfive8]

I swapped the shell holder in my trimmer. It was just thin enough to bump the shoulder back. Tight, tight tolerances. Thanks for all the suggestions!

Good outcome with simple fix. Usually it works the other way with FL sizer setting shoulder back too far and shortening case life.

 

[longrangehunterII]

Since other brass worked well in the same F/L die it’s the brass thickness of the Starline brass.

Do you think it’s the neck size that’s the problem?

Or shoulder bump not being enough?

Do you have a Match Chamber? Those tend to be tight especially if the gunsmith is on top of his measurements when cutting the chamber.

i.e. I have more than a few chambers in various calibers that even brand new brass will fit like a custom made leather glove. After firing they can even come out smaller! i.e. shoulder length. Or neck chambers that are minimum spec for the various manufacturers of brass and their neck thickness. i.e. ADG, Lapua, Peterson, all have thicker necks than Winchester, or Remington.

Lapua 308 Winchester uses a .335” bushing vs .329 for Winchester brass, Federal is .333” bushing. Just depends on the brass and the cartridge and who makes it or the lot!

Or in some cases it’s the die that is making the case grow in length and/or your chamber specs.

It’s clearly something happening since the fired cases will rechamber fine, but after sizing you run into issues….. Firm to unable to close your bolt down on a resized piece of brass. (which is the cause of the issue). It’s growing in some way.

In the end, most manufacturers will just ask you to send them (10) Ten 2-4x fired pieces of brass from your weapon and they will fix the problem!

Hope that makes sense, and/or helps. BTW I’ve sent in more than a few dies to have that done, so it’s more common than you might think.

 

[fourfive8]

If chambering interference can be ID’d as caused by shoulder contact (headspace) and not excess diameter of neck or body, it’s not difficult to either grind down shell holder or grind down length of sizing die. I prefer “shaving” some off bottom of the sizing die. Another possibility, albeit very rare, would be tight headspace caused by belt contact in a belted chamber. If that’s the case, time to tweak the chamber with a chamber reamer.

 

[Rare Breed]

Good thread and following closely. My MRC in 404 J using new Hornady ammo cycles and loads beautifully and smoothly. However when I fire it takes about anywhere from 30-60 seconds for the bolt to release letting me eject the shell. No problem raising the bolt just does not retract. I did what @mdwest did with my drill and it did not help but did give me a clean barrel like never before lol! It is now with Tipton Burns in TX along with 40 rounds of new Hornady ammo to get it fixed. I am a reloader but this is factory ammo again never fired. We will see. Love the rifle it is gorgeous. It is my second MRC 404 with the first one performing flawlessly and very accurate. I should have never sold it!!!!

 

[fsrmg1]

Try neck sizing alone and see if it still does it, if it does, it is likely that when the shoulder is being pushed back, it is ever so slightly belling out and expanding the case just under the shoulder. You can measure this to verify. Cause is that the sizing die is a bit oversized below the shoulder.

 

[MacJenkins]

How much are you bumping the shoulder? If the fired brass chambers fine before sizing then this should be farly easy to measure on the brass what is happening after sizing.

 

[Fryeguy]

A lot of good advice here. I had a 6.5 creedmoor that was funny like this. Several things here I also did. I usually set up my sizer so that it sizes the case just enough to chamber easily so as to not over-work the brass, it also fits chamber a little better. Lots of articles on this so no need to repeat it all. My creedmoor was exactly as yours. Fired cases would chamber easily. I would start with FL die turned out a 1/2 turn or so, sizing case until shoulder was contacted. As soon as I touched shoulder and set it back just a few thou they chambered tight. I slowly turned die in small increments until they chambered easily. My particular rifle I had to take to a cam over way more than I would have expected. I think the die had a little bit larger diameter should area. So with a slight shoulder bump it bulged out some, which was proven with marking the outside of the case some. I have a couple of creedmoors, both tikka. Both rifles had a different die setting. I bought another die for each gun. I also just set the other one up so that it barely sizes case and it has worked fine with no issues.

 

[Rare Breed]

Try neck sizing alone and see if it still does it, if it does, it is likely that when the shoulder is being pushed back, it is ever so slightly belling out and expanding the case just under the shoulder. You can measure this to verify. Cause is that the sizing die is a bit oversized below the shoulder.

Thanks but you would think with factory loaded ammo that would not be the cause

 

[Bob Nelson 35Whelen]

It is full length. I have mulitple rifles chambered in 7mm-08 so to avoid any mix ups, I set everything back to full length spec.

To add to the mystery, they chamber fine in other rifles. Seems to be rifle specific.

Probably just a starline/rifle specific problem. They still chamber and shoot well. But it takes enough force to close, I just don't like it. And I would like to fix it because I have lots of starline brass and I am cheap.

@AckleyHunter
To me it sounds like a case of minimum chamber with maximum brass
Have you tried a different set of dies. Uncommon problem but it does happen now and then.
If the brass fits other rifles I would say you have a minimum spec chamber.
Bob