ar15 loading issue - Page 3

HiBC · August 24, 2020, 07:15 PM

As I said,I don't.

Metal god · August 24, 2020, 07:45 PM

Yeah IMR 4320 is a real case filler , 55gr bullets can be slightly compressed at 5.56 pressures . It’s really about stick powders and how they may bridge in the case when you drop the powder in quickly . I’ve been loading IMR 4895 and I thought seating was going well but several bullets were seated .010+ longer then what most were or intended . Turns out the powder was bridging just right and not allowing the bullet to seat to the intended depth .

I had to go to a solid seating stem when seating my 162gr AP 308 bullets because my floating seater stem die like Redding comp seater die would not seat them deep enough do to the compressed load .

It’s not a daily thing but I do shoot a lot of heavy/long for cartridge bullets so compressed loads are not uncommon for me . The ball powders that are compressed are the worst IMO because the powders settles in the case well and there’s not much allowable space left for the powder to compress into . The bullet almost feel like it hits a stop and the bullet just pushes back out what ever amount the powder wants it to . To be honest I don’t know if the bullet gets pushed back out or the press just flexes similar to When sizing a case and the bullet just stops being seated deeper even though the die is set up to do so . In those circumstances you’ve got to be careful because you could bulge the brass by overly compressing the powder .

lordmorgul · August 24, 2020, 09:22 PM

Accurate LT-32 is an extruded powder that is chopped about 1/3 the length of H4895 and Varget. Similar in appearance but shorter, and fills cases less because there is less wasted volume, more similar to ball powder.

Andrew - Lancaster, CA
NRA Life Member, CRPA member, Calguns.net contributor, CGF / SAF / FPC / CCRKBA / GOA / NAGR / NRA-ILA contributor, USCCA member - Support your defenders!

Metal god · August 24, 2020, 10:27 PM

That’s a real nice size powder should be really good for metering and as you say fill rate . It appears to be a relatively fast buring powder for the cartridge , somewhere in the IMR 4198 / H-322 area . Which is fine in general but may be a bit fast for the 77gr bullets . Not that you can’t use it just that it’s not really optimal.

olduser · August 24, 2020, 11:02 PM

I had the same problem as you. Some times the bolt would not go fully into battery. Try loading a resized case with no bullet and see if it will chamber. If resized cases will work but loaded ones do not you have a bullet seating problem. Probably the shoulder collapse pointed out by others. Flat based bullets can be hard to start some times and are more prone to this. I invested in an RCBS Precision MIC. Used properly it allows you to see just how the chamber of you gun allows the cases to lengthen. The RCBS Mic allows you to see just how much you are setting the shoulder back during resizing. My goal is to size to give me 0.002 to 0.003 clearence.

August 24, 2020, 07:45 PM	#52
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 7,134	Yeah IMR 4320 is a real case filler , 55gr bullets can be slightly compressed at 5.56 pressures . It’s really about stick powders and how they may bridge in the case when you drop the powder in quickly . I’ve been loading IMR 4895 and I thought seating was going well but several bullets were seated .010+ longer then what most were or intended . Turns out the powder was bridging just right and not allowing the bullet to seat to the intended depth . I had to go to a solid seating stem when seating my 162gr AP 308 bullets because my floating seater stem die like Redding comp seater die would not seat them deep enough do to the compressed load . It’s not a daily thing but I do shoot a lot of heavy/long for cartridge bullets so compressed loads are not uncommon for me . The ball powders that are compressed are the worst IMO because the powders settles in the case well and there’s not much allowable space left for the powder to compress into . The bullet almost feel like it hits a stop and the bullet just pushes back out what ever amount the powder wants it to . To be honest I don’t know if the bullet gets pushed back out or the press just flexes similar to When sizing a case and the bullet just stops being seated deeper even though the die is set up to do so . In those circumstances you’ve got to be careful because you could bulge the brass by overly compressing the powder . __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

August 24, 2020, 10:27 PM	#54
Metal god Senior Member Join Date: April 10, 2012 Location: San Diego CA Posts: 7,134	That’s a real nice size powder should be really good for metering and as you say fill rate . It appears to be a relatively fast buring powder for the cartridge , somewhere in the IMR 4198 / H-322 area . Which is fine in general but may be a bit fast for the 77gr bullets . Not that you can’t use it just that it’s not really optimal. __________________ If Jesus had a gun , he'd probably still be alive ! I almost always write my posts regardless of content in a jovial manor and intent . If that's not how you took it , please try again .

August 24, 2020, 07:15 PM	#51
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,350	As I said,I don't.

August 24, 2020, 09:22 PM	#53
lordmorgul Senior Member Join Date: August 18, 2016 Posts: 206	Accurate LT-32 is an extruded powder that is chopped about 1/3 the length of H4895 and Varget. Similar in appearance but shorter, and fills cases less because there is less wasted volume, more similar to ball powder. Andrew - Lancaster, CA NRA Life Member, CRPA member, Calguns.net contributor, CGF / SAF / FPC / CCRKBA / GOA / NAGR / NRA-ILA contributor, USCCA member - Support your defenders!

August 24, 2020, 11:02 PM	#55
olduser Senior Member Join Date: August 10, 2020 Posts: 115	I had the same problem as you. Some times the bolt would not go fully into battery. Try loading a resized case with no bullet and see if it will chamber. If resized cases will work but loaded ones do not you have a bullet seating problem. Probably the shoulder collapse pointed out by others. Flat based bullets can be hard to start some times and are more prone to this. I invested in an RCBS Precision MIC. Used properly it allows you to see just how the chamber of you gun allows the cases to lengthen. The RCBS Mic allows you to see just how much you are setting the shoulder back during resizing. My goal is to size to give me 0.002 to 0.003 clearence.