SAUM and WSM Shooters reloading Question

[youngtrout]

Hello

Really trying to wrap up my 7saum build. Getting close. Still in breaking in, load development, and stock finishing.

My question is this, how many of you guys are full length resizing VS neck sizing? I'm currently necking down 300saum Norma brass. Will chamber after resizing just fine, virgin brass. After firing, the brass is chambering pretty hard, but will chamber. This is after running it through a Redding neck sizer to give the proper neck clearance. If it was my .260, I'd be running it through a body die or FL sizer just from the feel.

For background, this was a custom reamer, it is a match or a tight chambered reamer. I realize the short magnums are operating at higher pressures, wondering if this is part of my issue.

My powder I'm currently working with is H4831SC and running 160 Nolser accubonds.

So whats everyone else doing? Always needing to FL Size? If you are neck sizing, how many loads are you getting before needing to FL or body size, etc. Anyone running a similar chamber? Match, etc? So far I've had a few issues getting this one running

Thanks for any feedback!

 

[J E Custom]

Hello

Really trying to wrap up my 7saum build. Getting close. Still in breaking in, load development, and stock finishing.

My question is this, how many of you guys are full length resizing VS neck sizing? I'm currently necking down 300saum Norma brass. Will chamber after resizing just fine, virgin brass. After firing, the brass is chambering pretty hard, but will chamber. This is after running it through a Redding neck sizer to give the proper neck clearance. If it was my .260, I'd be running it through a body die or FL sizer just from the feel.

For background, this was a custom reamer, it is a match or a tight chambered reamer. I realize the short magnums are operating at higher pressures, wondering if this is part of my issue.

My powder I'm currently working with is H4831SC and running 160 Nolser accubonds.

So whats everyone else doing? Always needing to FL Size? If you are neck sizing, how many loads are you getting before needing to FL or body size, etc. Anyone running a similar chamber? Match, etc? So far I've had a few issues getting this one running

Thanks for any feedback!

Sounds like you all ready have it figured out.

Neck size until it gets tight, then size only enough to fit nice in the chamber. I anneal the necks
or the brass after 3 firings in high pressure loads just to make the bullet grip consistent and increase
brass life. (This also makes bumping the shoulder easer when necessary).

To much sizing only increases head space, so size only what you have to.

Just my opinion

J E CUSTOM

 

[youngtrout]

I guess I'm more concerned that the brass needs to be FL sized after one firing. I wondering how common this is among the short mag folks. In my 300wm I'm getting around three before having to fl size

 

[MontanaRifleman]

My philosophy in handloading is to be consistent. That is why I FL size every go around. I used to neck size my 300 WSM and RUM brass and after about 3 firings it needed body sizing. IME, this process is contrary to the idea of consistency. Every load is different from the previous and next.

Also, a FL die is a better tool for uniformity (reduced runout). I have had good success in using RCBS, Redding and Hornady FL dies to produce consistent cases with about .001-.0015 runout, if I keep the dies clean, lube the cases properly (not too much or little) and use slow steady strokes.

I FL size just enough for the case to fit the chamber and lock the bolt down easily.

 

[Shortmagman]

One of the things that the people that first reloaded the Short mags found was that they seemed to move the shoulder of the cases more that most rounds. As a result the shoulder must be moved back a few thousands before they would chamber in the gun that they were fired in. I am sure that with a load that is not full tilt would move the shoulder less and would not need to be moved back, but high pressure loads do move the shoulder.

Because of this I have always full sized my 300 WSM's, 270 WSM, and 7 mm SAUM.

 

[youngtrout]

Sounds good. Just picked up a Hordany headspace gauge. I'll get some measurements tonight.

Currently have the Redding bushing neck sizer. Need to either pick up a body die or the FL bushing sizer. Plan to set back the 2-3 thousands.

Also picked up some barnes 150's to give a go. Really do like the accubond but shop was out, the barnes 180 is my go to in my 300. Would like to try the LR Accubonds but sounds like they wont be out in time.

Only one hunting trip this year for this rifle, a late aug. caribou trip with a good chance at an interior grizzly, so really need to stick (IMO) to the premiums, especially with the 7mm. Both bullets listed above have done well for me in the past. A long shot in this area for caribou is around 400-500. And any bears would be taken at 200 or less.

Thanks!

 

[4bycamper]

Havn't full length sized yet with my 7 saum.
But then I'm not going for every last fps.

Didn't get best results with H 4831.
Usually best loads for me are 57 1/2gr Hunter and 65gr Magpro.
These get me into the 2950 accuracy node and give repeatable cold bore hits.
We use this rifle as our 500 yd steel ringer. 12" x 12" steel with a 4" dot.

Enjoy and be safe.

 

[youngtrout]

Camper. What bullet are you using with those loads.

Not pressing it too hard either Still staying within published loads Hodgton lists an extra 1.5 grains as max. My best group hit about 1 grain or so from max. Over that velocity started to level out and accuracy open again. Figured I found my sweet spot with h4831. Still need to give h4350 a go. Hodgton powders are the easiest for me to get

I topped out at around 2900. About the velocities posted for a 24 inch barrel. I'm running a 26 Still only 50 rounds through and still copper fowling pretty good. We will see what another 50-100 will do

Side note, breaking in another 260. Shilen select bull. Can't believe this barrel. 20 or so rounds and almost zero copper. I even changed cleaning a bit because I thought something was up! It's shaping up as a hammer to. For sure the most accurate rifle I've owned. First F Class shoot it two weeks with it. Super excited. Sorry for the tangent

 

[4bycamper]

Sorry, I should have said...

Been using 160 Nosler AB's mostly, just like I was reading. Man they shoot good!
Also found Hornaday's 162 SST will hit in almost the same spot (+ or - 2".)

Why is your barrel copper fowling? Factory barrel or custom?
Maybe hot lap it to see if that will help. You can but polishing compound on a couple bullets or buy Tubb's hot lap. If that doesn't work, you might have a tomato stake.

Side note.
Good to hear you've got a shooter. Good barrel = no copper. IMO.

No copper from my 7 saum either. posted a pix of it in "Browning A Bolt. Rifles, Bullets, Barrels..."

 

[MontanaRifleman]

Maybe hot lap it to see if that will help.

What is hot lapping?

 

[4bycamper]

What is hot lapping?

Well, lets see...

If hand lapping is using your cleaning rod and a polishing patch to smooth out a rough barrel, hot lapping is coating a bullet, firing, cleaning and repeat for a few rounds. For a better explanation see Mr Tubbs website where he sells a hot lapping kit.

A good quality custom barrel almost never needs to be hot lapped. Many are hand lapped at the factory.
I have used hot lapping as a last ditch effort to fix a bad situation. If it didn't work then I would own another tomato stake. MHO Others may have more patience than me. I hate throwing good $$ after bad.

 

[MontanaRifleman]

I've heard the term used in another context. I've never tried Tubbs bullet treatment. Seems to me it would be harsh on the throat.

 

[J E Custom]

One of the things that the people that first reloaded the Short mags found was that they seemed to move the shoulder of the cases more that most rounds. As a result the shoulder must be moved back a few thousands before they would chamber in the gun that they were fired in. I am sure that with a load that is not full tilt would move the shoulder less and would not need to be moved back, but high pressure loads do move the shoulder.

Because of this I have always full sized my 300 WSM's, 270 WSM, and 7 mm SAUM.

Not to be argumentative because everyone has there preferred method of sizing for there needs.

I don't shoot hot loads any more and if I want more velocity out of a bullet I simply go to a bigger
case and/or longer barrel.

The concept of the 40o +or minus shoulder was for more case capacity and the up side was less
case stretch.

The old case designs like the 300 H&H with a very long 8.5 shoulder angle was notorious for case
stretch (Sometimes up to .030 thousandths after a couple of firings.

I have yet to have to trim any of my short mags. and I only neck size as needed. I rarely move
(Bump) shoulders on any cases.

I do however run little or no head space and like I said, I back off MAX loads.

Full length sizing Every time is very consistent but it is hard on brass and Does effect accuracy to
a small degree. The rules are different when reloading to squeeze every thousandth of accuracy out\of a weapon in my opinion.


J E CUSTOM