Successful Reloading

[Nicholas]

Hi guys,

I have been successfully reloading for my 308 win for the last few months, and my loads have been excellent out to 1000 yards.

I would like to thank everyone for their help and advice and at the same time discuss another issue I am having.

I am using a relatively light load of 43 grains of Varget with 175 grain Sierra's.

Some of my Lapua brass that has been loaded five times is starting to cause the bolt to stick upon ejection. Eight out of the eleven shots I fired with the brass was sticky. I also shot a bunch of other Lapua brass that had been loaded less than 5 times without any problems?

I am wondering what is causing this? There are no cracks in the case and the primer pockets are okay. Before I loaded them I checked to see if there was a donut forming inside the neck but couldn't see any. Although I didn't see a donut in the cases I believe that there could be one forming that is causing the excess pressure, what do you guys think??

[ 09-13-2002: Message edited by: sr90 ]

 

[Mysticplayer]

Are you experiencing any difficulties chambering the case that have been fired more then 5 times? how are you sizing the cases? Have you measured the muzzle vel to compare new vs old cases? How large are the cases about 1/8" in front of the extractor groove, new vs old?

More info might give light to the problem. I suspect that the chamber is a little large at the base and the cases are growing to fit. After a few firings, the brass is work hardening and not releasing from the chamber walls. headspace will also play a role in this. Is this a factory rifle?

Answers to the questions above will help solve your problem. if you can, try some other brass like Fed Gold medal, and see if you have the same problem.

Good luck...

Jerry

 

[Nicholas]

My rifle is a Robar SR90 with a custom chamber, not tight necked though.

I just happened to full length size all my brass before I fired it this time because I had fired some of it in my friends 308 win, duh, I forgot I did that. My friend has a Robar like mine though. I realize that the chambers aren't exactly the same. However, I don't think that caused the problem because the measurements all look ok?

Here are the measurement I got:

Case Head thickness
new case = .4675
twice fired = .4710
once fired case head = .4705
5-times fired = .4715

Oal of brass (chamber will accomodate 2.04)
new case = 2.0095
3-times fired = 2.01
5-times fired = 2.015

Shoulder Headspace measured with Stoney point gauge. (I zeroed the caliper on the gauge)

New Case = 1.6215
once-fired = 1.623
5-times fired = 1.623

Neck thickness
new brass = .015
5-times fired = .0145

Rim thickness measurement
new case = .4695
5-times fired = .4705

[ 09-13-2002: Message edited by: sr90 ]

[ 09-13-2002: Message edited by: sr90 ]

 

[FatBoy...]

SR-90,

Light load for sure,, I shoot 45gr under a 175, but I'm sure my chamber is larger than yours. I get 2700 to 2730fps from a 26" factory tube.

Did the cases cause any sticking after you FL sized them? I generally just neck size and they get tight after 4 or 5 firing. After 6 or 7, they NEED to be FL sized. If you can still open the bolt without forcing it, this may just be normal case expansion.

I did notice that I got unusual expansion on occasion if the bullet was into the lands .

If you don't neck turn, I wouldn't think you'd have a doughnut. As I understand it, that only happens in neck turned brass but I may be FOS on that one, so best to double check.

FatBoy...

 

[Nicholas]

It was easy to lift the bolt the first 3/4 the way up but the top 1/4 was pretty sticky for a the rounds I'm talking about. I did let the rifle get pretty dirty, fired 60 rounds without any cleaning.

FatBoy

It is a light load for sure I have tried 45 grains with the 175's too without any pressure signs. I got 2770 fps with 45 grains out of my 24" Schneider fluted barrel

. I decided to use the light 43 grain load because accuracy was really good and I am getting 2650 fps which is all I really need. Plus since I am a newby reloader I wanted to take it easy for a while.

[ 09-13-2002: Message edited by: sr90 ]

 

[FatBoy...]

SR90,

If your chamber was clean and dry when you started, 60 rounds should be nothing for a 308 with Varget. I've shot 150+ with no trouble.

If you're just feeling a tight bolt (maybe a slight hanging) for the final 1/4 of the ejection throw,, that doesn't sound like a big problem to me. It's hard to say, not actually being there.

When you have to beat the handle up with the palm of your hand,, it's too tight

BTDT

2650fps MV for such a light load is GREAT, no need for more speed. I needed to go to 45gr to get these **** Lapua cases shooting for me. I had to turn the wick up to group under 1moa at 100/200 yards,, but the extra velocity has helped at 1K. I've had my best luck with Winchester brass and 44.2gr Varget, but my misses bought me 200 Lapua cases per my request for Christmas last year,, so they WILL be used.

FatBoy...

 

[Nicholas]

Didn't have to bang the bolt handle with my palm but a few of them were pretty close.

 

[FatBoy...]

SR90,

Were they close after you full length sized them and then re-fired? If they were JUST fl sized and gave you a sticking bolt the first firing after a FL sizing, they may have a problem. If you've got a couple or more firings with just a neck size,, it's normal to have some tight ones.

FatBoy...

 

[Nicholas]

I full length sized them with .002 smaller than chamber headspace, and I neck sized them to .3065 inside diameter.

I am stumped? I got 3 reloadings before I full length sized the first time. I didn't have to full length size yet but I did because I could tell the headspace getting long when I closed the bolt.

 

[daveosok]

You may need to get a set of small base dies for brass that has been fired 5 times.

 

[FatBoy...]

SR90,

Also,, I'd trim to 2.000" or to 2.005". The lead may not be as long as you think. Especially if the rounds haven't been trimmed in a couple firings. Trim them up before you spend any cash and see how a couple of them do.

Oh, and don't worry about the small base die messing with your POI/POA... that's BS unless you're a serious BR shooter. I doubt you'll notice any difference in a tac rig, maybe 30 fps difference from a FF case.

FatBoy...

 

[Nicholas]

I got one of Sinclairs oal gauges to measure maximum neck length to get the 2.04 figure I rechecked it last night and it was 2.038 with the dirty chamber.

I think I will try trimming the cases like you said though.

What is a small base die. I assume that it sizes the case head??

 

[FatBoy...]

sr90,

a small base die will bring the case down to original specifications or slightly smaller. It is needed for tight chambers and some autoloaders with other than large chambers.

You're correct, it works the case head more than a standard FL die. I recommend the redding body die in small base form because you can use it and not have to worry about messing with your neck and, though they don't recommend it, you can size loaded ammo in a pinch,,, just make **** sure it's lubed up good.

FatBoy...