.40 reload drop test

[Divedeep808]

Hey guys Ive heard some people talk about a drop test. where you take your reload and drop it in the barrel and check it. Ive been having a few .40 rounds not go into battery lately in my reloads. Im using a glock 23 kkm percision barrel and Im shoot mossouri bullet co 155 grain LSWC .401 diameter. The gun has a brand new recoil spring. There is a picture of the drop test below with one of my reloaded rounds does this look correct. Any help is appreciated.

[thai562]

That does not look correct. The rear of the case should be flushed with the barrel's hood.
Are you sure you sized the case the correctly. You can test this by taking a sized empty case and drop it in the barrel.
Maybe you flared the case's mouth too much. Or the OAL is not correct.

[Bill Steele]

The issue is a .401" bullet hanging up as it enters the throat. The shelf that is the wad cutter portion hangs up in the tight throat of the KKM barrel.

You can seat the bullet a little deeper so the bearing surface isn't going into the throat, or you can send the barrel back to KKM and have them open the throat up, or you can shoot them out of your stock barrel, which likely has a throat loose enough to accomodate the wider bullet.

[joelogic]

Are you shooting range pick up brass? Does a sized piece of brass without a bullet fit in the chamber?

Google "Glock Bulge"

I have to use a push through sizer when loading 40.

[hermosabeach]

Do you have a set of calipers?

What is the over all length?
What is the diameter at the base, 1/8" up from base and of the brass where the bullet is seated?
Last is the bullet diameter?

[Divedeep808]

Ill have to pick my calipers up from work. But the last time I measured the OAL was almost perfect to factory specs. I will have to measure the base tomorrow when I get the calipers. The bullet diameter is .401 its a LSWC, Thanks joelogic for bringing up bullet bulge I did not know about it and it seems like a likely cause. Thanks to bill steele as well I pulled out my M&P 40 and the brass all just drops into the barrel no problem, so the kkm barrel in my glock may be really snug.

[chknlyps2]

Are you shooting range pick up brass? Does a sized piece of brass without a bullet fit in the chamber?

Google "Glock Bulge"

I have to use a push through sizer when loading 40.

I also have to use a push through sizer to get the last little bit of bulge out right above the rim for my .40 reloads. I got a Lee Bulge Buster which is just a bushing that fits into a Lee Factory Crimp Die..... works great.

[Munk]

Since it's a "precision" barrel, try to segregate your brass that you use for it. Normal glock brass will likely have the bulge, common dies don't eliminate it well enough for some extra tight chambers. You may need some form of push-through solution like a bulgebuster or a smallbase die with a super thin shellholder.

There's also the issue Bill Steele brought up of bullet hitting the throat. Don't just seat your bullets to factory length, seat them to what a reloading manual recommends for your bullet's design. Ogive and cannelure can combine to give you a different required seating depth. Your recipe may have called for a shorter OAL, but you were loading to factory length anyway.

There's also the slim possibility that your barrel was made wrong, but if it fires factory ammo without issue, I highly doubt it.

[bfoosh006]

Make sure the crimp on the case mouth and bullet is within specs.....if the case mouth is to wide it will fail the drop test.

[nothing4u]

Drop the rounds in backwards, if they go in it's not the glock bulge.