AR Rounds stuck in chamber

[91Eunozs]

If not the case, I’d suspect a tight chamber; cut with a worn reamer. Or more likely, tolerance stacking between that and very slightly over-length cases.

 

[Valkyrie1776]

Several years ago when we had a 2 year long debate about SB dies on another forum I called the die manufacturing companies. I asked what their planned design was. Redding would not answer at all. Hornady said all of their dies are designed to be .004" in diameter under the minimum chamber size. RCBS said their small base die diameters are .004" under minimum chamber size and the FL are .002" under, there is no difference in length or headspace adj. Forster and Lee said the same as RCBS. From this it looks like all of Hornady dies are small base whether they say it or not.
Everything manufactured has tolerances, even the reamers used to make the dies have tolerances usually +-.001".

ETA- no dies are designed to resize brass smaller than factory made brass.

Several years ago when we had a 2 year long debate about SB dies on another forum I called the die manufacturing companies. I asked what their planned design was. Redding would not answer at all. Hornady said all of their dies are designed to be .004" in diameter under the minimum chamber size. RCBS said their small base die diameters are .004" under minimum chamber size and the FL are .002" under, there is no difference in length or headspace adj. Forster and Lee said the same as RCBS. From this it looks like all of Hornady dies are small base whether they say it or not.
Everything manufactured has tolerances, even the reamers used to make the dies have tolerances usually +-.001".

ETA- no dies are designed to resize brass smaller than factory made brass.

I was using a Hornady FL die. My cases were .002 larger than Hornady factory loads, as measured just above the groove. Now I’m using an RCBS SB die and my cases are exactly the same diameter as the factory loads. And best of all, I’m able to cycle my AR with no issues anymore.

Problem solved. Thanks everyone.

 

[Rocketvapor]

Now to find your datum to base dimension that is right for your chamber.

 

[Yondering]

I agree to a point, the heavier military type cases need over camming. I shoot 243wsm, 6x6.8, and a 20x6.8. They all need that extra pressure to cycle in an ar. It is similar to what you say without trimming the bottom of the die.

Still no, not really. Sizing to the correct dimensions is needed. Small base dies and/or camming the press over are not necessarily required to do that, and in most cases small base dies are NOT needed.

As you said yourself - if the bottom of the die were trimmed, camming wouldn't be necessary with your dies, for your rifles, with your brass. Carry that thought a little further - obviously there are a lot of cases where correct sizing can be achieved without small base dies or camming over. The goal isn't to cam over the press, it's to size brass correctly. My objection is simply that you're conflating the goal of what's needed with what your particular setups require to get there. I will add that I shoot about 3 times that many different AR cartridges, and none of them require small base dies. Some do have the press camming over, and some do not; there are a lot of factors in play there. Heck there are differences there just between my different 5.56 rifles and the brass I'm using at the time, and it's condition, even if I'm using the same die set and press, not to mention the different presses and dies.

 

[Yondering]

I was using a Hornady FL die. My cases were .002 larger than Hornady factory loads, as measured just above the groove. Now I’m using an RCBS SB die and my cases are exactly the same diameter as the factory loads. And best of all, I’m able to cycle my AR with no issues anymore.

Problem solved. Thanks everyone.

So, you set up a new sizing die, again without measuring shoulder bump but chasing factory dimensions instead, and then concluded SB dies fixed your problem without actually knowing what changed except one dimension. This is exactly what I pointed out earlier, and how the "SB dies are necessary for semi-autos" myth keeps being perpetuated. What's really necessary is knowing how to measure the dimensions you actually need, and sizing to those dimensions.