45-200 SWC - Confirming what I think I read

[silverjay]

Loaded some 45 acp with 50/50 air dropped 45-200 SWC from the rcbs mold. Used 5.2 grains unique and seated so the shoulder on the SWC was 0.020" beyond the brass. Cartridge oal was 1.761. Shot, cycled, and grouped well for the 100 rounds I took. When dropping the slide I could feel a catch just before the slide seated. From what I have read here this was the shoulder on the SWC head spacing before the brass. Is this correct?

[Fluxed]

That might be correct.
Have you tried the "plunk test" where you take the barrel out and use it as a gage for the cartridge?

[prs]

It probably is the foreward edge of the full diameter part of the boolit catching the leade. You can confirm with the plunk test. I am kinda green with ACP reloading and have had that happen from over doing it with a roll crimper, poocing that leading edge. Got best feed with flush seating and just enough "crimp" to return case wall to parallel, ie, close the bell. On those rounds were I have pooched the leading edge like I explained, I also got a lot of barrel leading in the rear of the barrel, evidently from that pooched area being sheared off and over riden by the boolit. I still have some large amount of those and I am shooting them and cleaning the barrel every 100 rounds with bronze wool and Kroil. With rounds I loaded the other way, no leading.

prs

[williamwaco]

Loaded some 45 acp with 50/50 air dropped 45-200 SWC from the rcbs mold. Used 5.2 grains unique and seated so the shoulder on the SWC was 0.020" beyond the brass. Cartridge oal was 1.761. Shot, cycled, and grouped well for the 100 rounds I took. When dropping the slide I could feel a catch just before the slide seated. From what I have read here this was the shoulder on the SWC head spacing before the brass. Is this correct?

Eject an unfired cartridge.

If the catch you feel is what you expect, the lead at the shoulder will show a scraping from the edge of the front of the chanber. Some times you can even see markings from the rifling.

If this is the case you need to seat deeper.

Use the test described by fluxed.
It should take no more than the force of gravity for the cartridge to seat flush.

[gray wolf]

I doubt your brass was head spacing on the end of the brass, try this;
measure the distance from the end of the barrel hood to the rim inside the chamber, do it with the long end of your caliper. record the measurement, then measure some of your brass and see how many achieve this same measurement. Or drop some empty brass into the chamber and see how many come to rest at the end of the barrel hood, I venture to say not many will.
Seat one of your SWC bullets long with just a little crimp, just enough so the bullet will go easily into the chamber. Then slowly keep seating it deeper until the back of the case is even or about .005 below the barrel hood. That's your OAL for that bullet.

Cartridge OAL was 1.761
That sounds way long for a SWC bullet, I load a ball profile 225 grain round nose to 1.165
I think your bullet may have been crashing into the barrel lead.
5.2 Unique is a nice easy soft load 5 grains puts the brass at my feet and hardly works the slide.

[silverjay]

With the original oal a few would hang. Shortened it 0.010 and they all drop with a satisfying thunk. Thanks.

[huntrick64]

Get it to pass the "plunk" test first, then increase taper crimp a little at a time until they feed consistently without catching the brass on the lip.

[runfiverun]

yes it is.

[jonp]

That sounds a little long. I resorted to what gray wolf said to do and solved my problem along with adjustng the taper crimp. I was crimping too much

[runfiverun]

the plunk test is a good rule to follow, except everybody does it with the barrel facing down.
try it with the barrel horizontal so gravity can assist the mouth/edge of the boolit in engaging the end of the chamber.
if everything works freely in slow motion with light finger pressure then the return spring can do the same thing.

[MtGun44]

Are you taper crimping as a separate step? This is necessary and could
account for your issue.

Dismount barrel and chamber drop as a test of LOA and taper crimp.

Bill