fifteen thousandths can mean a lot

[murf]

i wasn't going to post the results of my 265 grain lswc bullet load in my new glock 30, but something interesting came up. a .015" change in cartridge overall length (c.o.l.) turned a garbage load into a golden load.

i purchased a used glock 30 last week. had a problem with the rear sight (fixed) but everything else is fine with the gun. so, i worked up a nice accurate 230 gn lrn load for it. then i worked up my special 265 gn lswc load. i started with a 1.160" c.o.l. and put ten rounds on target. the results were terrible: two fail-to-feeds, shots all over the paper.

the ftfs were caused by the edge of the bullet/case mouth catching on the bottom of the feed ramp which carved a chunk out of the bullet and bent the case mouth back. no wonder accuracy was all over the place.

i assumed this happened to all ten rounds, so i increased the c.o.l. .015" to 1.175" and put ten more on paper. magic ... no fail-to-feeds and very acceptable accuracy.

there are so many variables in assembling a handload that affect its performance. thought i'd share one.

caution: there is no published load data for this 265 gn load. please, do not try and duplicate this as it works in my guns only. if you do, you do so at your own risk.

so, now i have my "range cow defense" load for my g30.

murf

 

[murf]

here is a pic of the two ftfs and a pic of the 265 gn lswc bullet pulled out of the wet dirt backstop:

 

[Gottcha]

I found similar results while testing 9mm reloads. But I had better results going shorter on the COL.
It made a huge difference accuracy wise.

 

[Wreck-n-Crew]

As a personal rule for myself I start long and shorten them when it comes to pistol loads. Started with a dummy load and found my max COAL and bumped it down 10 thousandths to give a little extra room for feed and function. Then test to insure they will fit in the magazine. Till now its worked for me unless I forget to check it in the magazine. I've seen a lot of pistols where the bullet needed to be shorter to fit the magazines than the chamber.

 

[murf]

The reason I shortened the col is the longer col will "plunk" but it will not fall back out on its own. So I shortened it .

murf

 

[Gottcha]

If your plunking In your barrel that would mean the bullet was sticking in the rifling wouldn't it?

 

[Wreck-n-Crew]

The reason I shortened the col is the longer col will "plunk" but it will not fall back out on its own. So I shortened it .

murf

Good reason.

Those are some heavy pills. Are they pretty soft? They flattened out pretty good!

Edit to add: by the way not bad shooting there!

 

[Wreck-n-Crew]

If your plunking In your barrel that would mean the bullet was sticking in the rifling wouldn't it?

Yup. Raise them pressures too. Seems he was being cautious to back off and I don't blame him.

 

[murf]

gottcha,

I believe the full diameter of the bullet was just entering the throat because I could still pull the round out of the barrel with my fingers. I would not want that round any longer than 1.175" as it would jam too much bullet into the throat.

murf

 

[murf]

wreck-n-crew,

I run these loads through a chrony and note where and how far out the cases land to prevent overpressure. this load is probably plus p, but I don't think over that. I also check the primer faces and this load has flat primers, but rounded edges.

murf

 

[murf]

actually, the bullet on the right, in the picture, is the 265gn pill and is fairly hard. the other two bullets are 230gn round nose and behave like they are a bit softer. the 265gn pill went a lot deeper into the wet dirt. the 230gn pills were found just under the surface.

murf

 

[murf]

I also have to watch seating depth closely as I am at, or very close to, 100 percent powder load density. I don't want to compress the powder either.

murf

 

[murf]

WnC,

thanks for the shooting compliment. the g30 fits my hand like a glove and makes my shooting process easy.

murf

 

[illinoisburt]

In my experience with my 1911s I found better feeding and accuracy at around 1.250 to 1.260. Shorter swc lead tend to get the same hang up you were experiencing. Just goes to show why load development is so important to individual guns.

 

[murf]

I wish that load would go to 1.250" and still plunk! the 230gn round nose load for that gun has a 1.250" col.

murf

 

[KansasSasquatch]

Indeed, it can make a lot of difference. I've done plunk tests before and even manually cycled dummy rounds through a pistol that work great. Then I make test loads only to find out at the range that they don't cycle so well during live fire. Sometimes seating deeper solves the issue, and sometimes seating longer fixes it. Trial and error.