Reloading barrel check question?

[Utah Shooter]

Not finding any info on this so what the hell. I am reloading some ammo in 40 S&W and when I am doing the barrel check I am finding 2 different length boolits and passing at roughly the same point.

!. At an OAL of 1.145
116983
2. At an OAL of 1.20
116984
Why is this? Is perhaps the case stopping on the lip where the barrel starts (sorry I do not know the terms)?
116985116986

[LUBEDUDE]

The answer is yes. You answered your own question with your last statement, which is called " headspacing on the case mouth".
This is why both bullets worked.

But such is not always the case. If you had a bullet with a large ogive, (fat cone area) it may not go past the chamber into the rifling. Thus, not chamber.
Also, if you had a mega taper crimp, the cartridge may not headspace and slip deep into the chamber. Then the firing pin may not reach the primer.

This is why many of us do the "plunk" test - with our barrels or case gauges.

[Utah Shooter]

I am such an idiot.

[LUBEDUDE]

Not at all man.

That is how we learn. People teach me a lot here.

That's why this is one of the best sites on the web.

[Weaponologist]

Definitely get yourself some Case gage's. There very inexpensive. I have them in all the caliber I run..

[troyboy]

Now that you are aware they will chamber,check the magazine fit.

[str8wal]

Now that you are aware they will chamber,check the magazine fit.


And see if they cycle.....

[Minerat]

I am such an idiot.

Most of the auto pistol rounds head space on the shell mouth not on the rim. That is why it is important to check the overall case length (OCL). Most manuals have a listing of the max case length and trim length suggestions, so as long as your cases fall between the two you're fine. Too long and it will not chamber, too short and you may not get a good strike on the primer. Then the over all length (OAL) to make sure the cartridge will fit the mag and not extend into the refiling. The more uniform the case length the easier it will be to get a more uniform taper crimp.

As for your self analysis. There is no stupid question when reloading and you were smart enough to ask on this forum. So good on you.

[BNE]

Been there and done that sir. Only mine was in the fat. One no-fit category.

[arclight]

You can also have a case that fails if there is a shaving of lead resting on the mouth of the case. This usually happens if you don't bell the case mouth sufficiently.

Arclight

[twc1964]

No matter how long we reload and cast, there will come a time when we all get stumped. We all need help or a different perspective to push our brain into gear lol.

[Utah Shooter]

Funny thing is I knew that. I have not reloaded pistol in a couple of years. I just do not want to blow my hand off.