.40 case gauging with BBI bullets

[Logisticsnightmare]

Just recently received my STI DVC Limited gun and started loading some ammo this morning. Got about two hundred loaded and decided to check the ammo by dropping them in the chamber. In the first hundred, only 41 of them fit without a problem. The rest would only go half way before stopping.

I'm new to reloading 40 but not reloading in general. I could understand 10 or so but 59 out of 100 is a little much. Any idea what is causing this? No coating or lead is being shaved off.

Usually load 9mm with bullets from Bayou Bullets and never have that many per 100.

Current reloading set up:

Dillon 650

EGW Undersizing die

Dillon Powder measure

Dillon bullet seater and crimp dies.

Bullets are Black Bullet International 180 gr flat point. Any help would be appreciated.

[FortyOverUnder]

That U-die should be enough to remove Glock bulge. It is for me. I've put away my push through for the EGW U-die. So this does sound interesting.

To follow through: you are sizing as low as you can, right?

[superdude]

First, determine WHERE they do not fit. Do the plunk and rotate test described here: http://www.shootingtimes.com/reloading/reloading-tips-the-plunk-test/

[Logisticsnightmare]

That U-die should be enough to remove Glock bulge. It is for me. I've put away my push through for the EGW U-die. So this does sound interesting.

To follow through: you are sizing as low as you can, right?

Yes, put it in according to the instructions. I'm gonna try the permanent marker and then try backing off the crimp.

Never truly thought about over crimping till I read that article.

[Logisticsnightmare]

Here is what they are doing

[Steve RA]

Does look like the problem is in the crimp area. Compare and measure one such as in the picture and one that did chamber and see exactly where the difference is. Then you will know what needs to be done to correct the problem.

[Rustygun]

Does look like the problem is in the crimp area. Compare and measure one such as in the picture and one that did chamber and see exactly where the difference is. Then you will know what needs to be done to correct the problem.

I had a similar problem and found that I was over crimping ever so slightly on some cases that were a few thousands longer. Seems to have caused a slight bulge or wrinkle in the case below the bullet seating depth that would interfere with chambering. For those that know more about this subject is this a possible cause for the original posters problem?

[Steve RA]

Very well may be.

[pbcaster45]

I was having a similar problem with my Edge and Glock 35 (Lone Wolf Barrel) when I first tried using Blue Bullets. I'd been using plated bullets before that and I'd backed off my crimp die too much (to avoid over-crimping). I had to increased the taper crimp to 0.421 - 0.4215. I switched to Remington 40 S&W brass with PC bullets since it's a little thinner.

The tighter crimp had no effect on the accuracy of my plated loads - you live and learn!

Edited December 6, 2015 by pbcaster45

[Sandbagger123]

you probably don't have enough crimp. brass varies quiet a bit in length. just grab a handful and measure them and you will see. when setting up the crimp die use the shortest one. this way the shorter ones will get enough and the longer ones just a little more. the bad ones you have are probably the shorter ones ,

i crimp to .420 with the BBI and they work great

[noylj]

Run your finger down the bullet ogive to the case mouth. Do you feel the case mouth sticking out and "catching" your finger?

Per Ramshot:

"SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”

It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must be seen as a guideline only.

The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.

This parameter is determined by various dimensions such as

1) magazine length (space),

2) freebore-lead dimensions of the barrel,

3) ogive or profile of the projectile and

4) position of cannelure or crimp groove.

• Always begin loading at the minimum "Start Load".

• Increase in 2% increments towards the Maximum Load.

• Watch for signs of excessive pressure.

• Never exceed the Maximum Load."

Your COL (OAL) is determined by your barrel (chamber and throat dimensions) and your gun (feed ramp) and your magazine (COL that fits magazine and when the magazine lips release the round for feeding) and the PARTICULAR bullet you are using. What worked in a pressure barrel or the lab's gun or in my gun has very little to do with what will work best in your gun.

Take the barrel out of the gun. Create two inert dummy rounds (no powder or primer) at max COL and remove enough case mouth flare for rounds to chamber (you can achieve this by using a sized case—expand-and-flare it, and remove the flare just until the case "plunks" in the barrel).

Drop the inert rounds in and decrease the COL until they chamber completely. This will be your "max" effective COL. I prefer to have the case head flush with the barrel hood. After this, place the inert rounds in the magazine and be sure they fit the magazine and feed and chamber.

You can also do this for any chambering problems you have. Remove the barrel and drop rounds in until you find one that won't chamber. Take that round and "paint" the bullet and case black with Magic Marker or other marker. Drop round in barrel (or gage) and rotate it back-and-forth.

Remove and inspect the round:

1) scratches on bullet--COL is too long

2) scratches on edge of the case mouth--insufficient crimp

3) scratches just below the case mouth--too much crimp, you're crushing the case

4) scratches on case at base of bullet--bullet seated crooked due to insufficient case expansion (not case mouth flare) or improper seating stem fit

5) scratches on case just above extractor groove--case bulge not removed during sizing. May need a bulge buster.

[redial]

This ^^^

My Bullseye 1911s and my 10mm Lone Wolf are VERY tight chambers - the crimp has to be perfect to pass the *plunk* test.

Maek

[Logisticsnightmare]

After playing with it a little more yesterday, found that the crimp die had backed off too far and wasnt crimping. Got it set back and locked down. 400 rounds later have no issues. Shot it this morning and didn't have a problem. Thanks for the help guys!