resizing 300 WSM

[born to hunt]

Need some guidance here.

I'm on my 5th loading of my 300 wsm brass and I notice the bolt is becoming "snug" to close. (Tikka T3stainless) I've only neck sized to this point, with only one round of trimming to length. Last night I FL resized one case andit chambered easily again. My question: is there a way to measure how far back I need to bump the shoulders, or should I just FL size all and start over? If I do FL size all, how much of a difference have you notiiced on your neck sized VS. full length sized reloads? I have the load where I want it (under 3" at 310 yards) and I'm worried FL sizing will screw it up.
My load is 168 barnes TTSX on top of 70 grains of RL22 at 3080fps.
Thanks!
bob

 

[ironworkerwill]

Nah, it will not hurt to FL. I have a rifle with a min comp chamber and it needs to be FL'd after every shot(< .002 of a full bump) I'm on 8 reloads in ppu brass and 10 in norma. I do anneal often.

 

[gahunter12]

You only want to bump the shoulder back about .002" at most for a bolt rifle. There's numerous tools that will measure the head space. I have they Hornady Head Space kit myself, and have been pleased with it. I make sure the cases is clean, and get a measurement, then set my FL die to only bump back .002". To be honest I FL size all my bolt brass since they are used for hunting, and I don't want to take any chances of having a problem in the field. I have never had a problem with case life doing this.

 

[born to hunt]

Having not measured .002" bump, can I do the same thing with a dial caliper? or is it just a matter of incrementally adjusting your die until the shell just chambers easily?

Thanks for the reply

 

[ironworkerwill]

Yeah, if you don't have the tools- It's a bit of a guessing game, but it can be done.

Run the FL die untill it touches the ram at top dead center. Back the die off untill you see a sliver of daylight. Here you will not be close to a full bump but after painting a case and chambering your round you'll be able to adjust your head space.

I shoot for a snug shoulder while chambering. What ever "feel" you like is up to you. I like to feel a little drag while closing the bolt.

You don't have to create .002'' of head space.

The die will also add more taper to the "blown out" case that will benefit case extraction.

 

[gahunter12]

Here's the head space tool I use. It mounts to your calipers.
http://www.amazon.com/gp/aw/d/B000PD5VN8?pc_redir=1405530196&robot_redir=1

 

[born to hunt]

That was the answer I was looking for. I had never heard of "bump sizing" vs. FL or neck sizing.

I will do this and compare groups. I just hated to think of having to FL size the tighter brass and lose the full advantage of fire sized brass. I'm probably splitting hairs, and the loads are for hunting, and an inch larger groups make little difference, but...at longer ranges, this guy needs all the help he can get.

 

[FROGO207]

I need to bump back my 300 WSM brass every 4 or so firings so that they chamber OK when neck sizing the other times. Case life is 15-18 reloads before I split necks or loose primer pockets on average. YMMV

 

[Walkalong]

There are lots of ways to measure where the shoulder is and how much you move it.

http://www.thehighroad.org/showthread.php?p=6270171#post6270171

http://www.thehighroad.org/showthread.php?t=734058

 

[born to hunt]

Walkaolng-

That was a teriffic thread...I learned a lot. What do you think my chances are of convincing my wife I need a lathe? I only have 8 kids 12 and under, so I have plenty of spare time...

Thanks again for the guidance.
bob

 

[Walkalong]

Glad it was helpful. Chances on the lathe sound slim.....

 

[ironworkerwill]

Aw heck, Walkalong is just showing off.

 

[Poper]

Here's what I use to precisely measure the shoulder set-back:
http://www.sinclairintl.com/reloadi...291_a_7c1020_a_7c749006292_d_749006314_d_5599

Made by RCBS, it is a great tool and easy to use. It also comes with the goodies to be able to precisely set your bullet seating depth, too. They come in a wide variety of calibers.

 

[rogn]

One little curiosity you may find with the full length sizing is that the case volume may decrease enough its hard to get the same amt of RE22 in the cases w/o compression. Not a safety factor just a problem at times.