Tight chambering brass

[AckleyHunter]

Looking for someone who has any idea what is going on here. I have a lot of starline brass for my 7mm-08 that is hard/tight to chamber after firing. The virgin brass chambers great. But after full length resizing it is hard to close the bolt on. The strange part is it chambers fine if you just put the spent case back in the chamber. It appears the resizing is what makes it hard to chamber. They are properly trimmed to length so I don't believe that is the problem. A lot of Hornady brass has no problem chambering after resizing. Same for some random federal and remington brass I have from old factory loads. Seems specific to the starline brass.

 

[rookhawk]

Looking for someone who has any idea what is going on here. I have a lot of starline brass for my 7mm-08 that is hard/tight to chamber after firing. The virgin brass chambers great. But after full length resizing it is hard to close the bolt on. The strange part is it chambers fine if you just put the spent case back in the chamber. It appears the resizing is what makes it hard to chamber. They are properly trimmed to length so I don't believe that is the problem. A lot of Hornady brass has no problem chambering after resizing. Same for some random federal and remington brass I have from old factory loads. Seems specific to the starline brass.

Could lack of lube in the case mouth be compressing the case a bit, causing a bulge in chamber? Have you tried backing out the die to neck-bump the case rather than full length sizing?

Every case brand is unique as evidenced by their different H20 capacity. It could be that the Starline has more or less brass in a particular area of the case causing your phenomenon.

 

[AckleyHunter]

Could lack of lube in the case mouth be compressing the case a bit, causing a bulge in chamber? Have you tried backing out the die to neck-bump the case rather than full length sizing?

Every case brand is unique as evidenced by their different H20 capacity. It could be that the Starline has more or less brass in a particular area of the case causing your phenomenon.

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.

 

[Wyatt Smith]

Are bullets seated when you try to chamber?

 

[skydiver386]

Have you inside or outside turned any of the case necks?

Usually neck thickness becomes an issue after a few firing and sizing cycles, but with certain brands of cases and certain calibers it can rear it's head at any time. The 243 Win is especially notorious for this in my experience.

 

[Wyatt Smith]

Also was the brass fired in the same rifle as you are trying to chamber it in now?

 

[AckleyHunter]

Also was the brass fired in the same rifle as you are trying to chamber it in now?

Bullet or no bullet, still tight.

Yes, same rifle.

 

[AckleyHunter]

Have you inside or outside turned any of the case necks?

Usually neck thickness becomes an issue after a few firing and sizing cycles, but with certain brands of cases and certain calibers it can rear it's head at any time. The 243 Win is especially notorious for this in my experience.

Neck thickness is not something I usually check. Has not been a problem in the past. Outside thickness is the same between brass manufactures and chambering with no bullet is still tight.

But it might be something to look into more carefully.

 

[Paul K]

Are you setting up your FL die correctly? Run die to the shell holder and then another 1/8 or a 1/4 turn till you feel it cam over.

Paul

 

[Daggaboy375]

How do the resized case dimensions compare to the
virgin brass?

 

[AckleyHunter]

How do the resized case dimensions compare to the
virgin brass?

They are longer, but I trim them back to suggested trim length. Chamfer and debur. Outside neck diameter is the same as the unfired. If there is a difference somewhere my calipers can't find it.

 

[AckleyHunter]

Are you setting up your FL die correctly? Run die to the shell holder and then another 1/8 or a 1/4 turn till you feel it cam over.

Paul

Setup correctly. Even took it apart and cleaned to make sure some gunk was not changing the size.

But, 'is your computer plugged in' is still the no 1 solution to tech support.

 

[Paul K]

Yep. Just curious, did you weigh any of the Starline brass and compare it to your other brands ?

 

[Rafiki]

Strange indeed. I'm wondering about the shoulder, could that be the issue? These would headspace on the shoulder. Some chambers may be more forgiving than others.

 

[uplander01]

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.

 

[Grumpy gumpy]

Do you have a micrometer, if so measure a fired case , before resizing, and then a reloaded case, pay particular attention to the shoulder/body junction area. It could be that as you push the projectile into the case it’s ever so slightly deforming the body at that point, also the area just above the head of the case. You may find that the rifle has a tight chamber and that slight deformation is what is causing the issue.
Gumpy

 

[Paul K]

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

 

[Smitty]

I have had this problem with 2 rifles lately. First with a 6.5 creedmoor and also with a 6.5 x47 Lapua. Long story short, with today's tight chambers, it is more common to have dies that fail to re-size enough from mid case down to base. You can order a "small base die" from Redding or RCBS in 7mm-08. This should take care of the problem. I did that for the Creedmoor, but I can't find a 6.5 x47 small base die, so I tried a different brand full length sizing die and it did the trick. Be aware, the first time I used it, the die was very snug. I used imperial die sizing wax and would lower the ram a small amount, back up and lower again till I was able to seat it all the way. No problems since. Please feel free to shoot me a DM if you have any questions. I hope this helps.

 

[Smitty]

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

Good Idea.

 

[MauserDuff]

I had the same problem with a Kimber 280 AI. I used two sets of Hornady dies (and talking to Hornady tech), multiple depths of sizing (to FL), and a chamber polish from the GS. Nope. I had to grind down the shell holder a bit to allow deeper seating into the die, apparently bumping the shoulder back a few thousandths. That worked. Prior to this, with my old 8x57, I only had to neck size. I guess I just had a tight chamber.