First attempt reloading 300wsm

sammer

Member
Rating - 100%
9   0   0
Location
East Kootenays
I've been reloading for my 308 for a while and have built a pretty consistent load.

Just reloaded my first rounds for my, new to me, Win mod70 300wsm.
Yesterday was a bit of a gusty head wind at the range but wasn't really my best day of shooting.

Shooting new Winchester brass with H4350 and 178 ELD-x. CCI250 primers
Was mostly looking for pressure signs and trying to see if the ELDX would shoot ok.
Let barrel cool between groups. Didn't bring the magnetospeed.

Found it weird that groups were rising as the load increased, as expected, until I got to 62.5grns then dropped back to point of aim.
Orange dots are 1" target, was at 100yrds.
Still trying to figure out how to post an image, but should be able to open the link.
The vertical stringing was probably me trying not to flinch but hey.

Thinking that somewhere between 63.5 and 64 should be my next attempt in 0.2grn increments.

Thoughts?

https://www.flickr.com/photos/195929725@N06/52165521333


Sam
 
My two cents...I don't reload 300wsm but I do reload for 300 Winmag and 300 Weatherby. To me, your 62.5 load +- looks the most promising but you may not get the velocity you want, have you considered tweaking your COAL as I find that can make a difference. Also, different powders make a big difference in my loads, but these days hard to find a variety to test.
 
Thanks guys.

I'll load up 5 more at 62.5 and see how they chrono.

I was more concerned how that load dropped more than an inch from the load previous. My point of aim didn't change thru these strings. Crosshairs on the center of the dot every time.

Don't have a lot of powder to burn, and still want to try the 165tsx, 168ttsx, and the 175lrx before I settle on a hunting load for the fall.

Sam
 
You have a few nodes there you could try for sure. 61, 62 1/2

Personally I think you are dealing with barrel harmonics with the different loads, is why you have them group in different areas.

In my PRC I was getting great groups with N568, and went to H1000 and getting the same tight groups, but also increased velocity at the same time. Everything stayed the same, as primer, case, bullet. Had to adjust seating depth a little less with the H1000.
 
I found the 178 ELDX picky to load for. You might find the Barnes bullets settle in a little more consistent. I used to load alot of H4350 in the 300WSM with 200+gr bullets.

RL17 7828SSC H1000 were better for me in the 165/180 range if you happen to have any on hand.
 
Thanks guys.

Will try the Barnes when i get a chance.
Would be good to find a load with the 175LRX as my 308 didn't like them much. It liked the ELDx though!

Unfortunately I'm stuck with Varget and H4350 for the moment, so gotta work with that.
Varget is probably a bit fast for the WSM.

Will post back once I find some time to get back to the bench.

Sam
 
Higher loads shooting lower happens, just not all the time. Close range zero's are more about timing a whipping barrels exit time than anything. Same with close range groups for that matter
 
I'VE loaded the 300wsm for 10 plus years. It's always my goto.
Bought a Tikka t3 Wideland Roughtec and took it out this AM with 5 different bullets with similar powder charges per bullet weight using HV100 and Superformance to get an idea of what the gun might like. Three of the groups were 1.2 to 1.4 inches. 190 Accubond LR were .9 and Sierra Gamechangers were .31. It's all about consistency and harmonics..searching for a node. Now I'll take the ones that shot well and increase by .2grains until pressures start to show. I'll take the most accurate and play with seating depth, the longest being -.020 short of magazine length. Everybody uses a process that works for them and with the price of components, shortening the process keeps the cost down.
 
Blew up 3 200 ELDX two years ago on a moose..8" of penetration at 75yds. Finally shot him in the head. They shot great but blew up like varmint bullets. All 3 had full jacket separation...yikes.
 
I'll second or third the comment about the Barnes bullets. They shot great and tuned very easy in my 300wsm, I struggled to get bergers to shoot less than 1" @ 100, and hornadys were all over the place..

My tip, start the barnes 75 to 100 thou off the lands. Should be near the top cannelure (depending on bullet weight).
 
Loaded up 10 at 62.5. Slight crimp on 5, no crimp on the other 5, just to see if it makes much of a difference in speed.

Hope to get to the range with the magnetospeed in the morning and will post results.

Thanks all!

Sam
 
Got out to the range this morning and shot the 62.5 loads.
The 5 un-crimped loads averaged 2900fps and shot a .69" group.
The 4 crimped loads (1 misfired!!!) shot a 1.2' group and and average speed was a little lower at 2880fps?

I had 2 misfires today out of 18 loads. Primers had a pretty good dent and I tried them each twice after waiting a minute or 2 to open the bolt.
Will pull them apart and gently press the primers out to inspect. Not a good result though considering this may be my hunting round. CCI-250's

I also took 20 9mm that I loaded last night with 4grns of titegroup. They cycled both my guns and grouped good as can be expected for my ability.
I definitely need to spend more time shooting these guns. 8" at 7-8yrds could use some improvement for sure!

Sam
 
Just two comments. Don't crimp unless you need to. Do you wet tumble?

No wet tumbler. They were new Winchester brass but had a bit of corrosion so did get a vibratory cleaning with corn cob before they got primed.
Wondering if the primer hole had some media stuck in them. Will have a look at what comes out.

Sam
 
It's rare these days to get a bad primer. Having several at once points to a systemic problem. Water contamination if not dried properly. It takes a lot of anything else to contaminate a primer to the point of failed ignition.

Next up is not seated deep enough but in a rifle the first strike usually will seat it deeper so the second strike will fire it. But I did do this myself recently with a brand new rifle, 30-06 and CCI primers. Had three refuse to fire no matter how many times they were hit. Broke the rounds down and realized my Frankford Arsenal priming tool was set too shallow. Reseat the "defective" primers, recharged the cases and put the pulled bullets back in.

Voila - all three went off.

So the combination of new components I hadn't used before and not paying attention to primer seating and I had a problem which I hadn't had in years.

Lastly, a really bad obstruction or mechanical problem with the firing pin and spring but this would have to be extreme to cause an actual ignition failure.
 
I pulled the bullets and pushed out the primers
Flash holes were clean.
Looking closer at the primers and comparing them to the ones that did fire they look like lighter strikes.
Will measure to see how much, if any, the shoulders are back.
It was all new winchester brass, but i ran the all thru the full length die.
Maybe a head space issue.
Took the bolt apart and check the pin, springs and bore. All looked ok.
Will check pin protrusion next time i get a minute

Other than 22lr I've never had a misfire. Bit of a mystery for sure.

Sam
 
I found the 178 ELDX picky to load for. You might find the Barnes bullets settle in a little more consistent. I used to load alot of H4350 in the 300WSM with 200+gr bullets.

RL17 7828SSC H1000 were better for me in the 165/180 range if you happen to have any on hand.

Funny as RL17 is almost the identical burn rate as H4350 BUT IMR7828 and H1000 are a lot slower ! RJ
 
Back
Top Bottom