Reloading 300WM

Walks with loud stick, thanks. I'd agree that these groups show that I was not shooting well, and are basically meaningless.
I was having a hard time getting the gun to stay on target, and wasn't recoiling straight back (usually it does). I was using a different bench, and suspect that may have been part of it. Along with my lack of technique.

I will weigh and sort my brass.

Are you shooting a match chamber?

I didn't see any pressure signs that would stop me from using the higher loads. Only that the groups went from horizontal spread (which is definitely my technique) to vertical.

Thanks again.
 
Test 73.5, 73.6, 73.7, 73.8gr - calm day.. use flags.

Also check the fired brass for enough neck clearance. Bullet should drop freely into the fired case. I prefer 12 to 13 thou necks. Turn if needed with an eye to the base of the neck and remove any thickening. If you have fired the brass more then 4 times, consider annealing properly.

All your loads and brass over 74gr are showing pressure related issues.

Jerry
 
Thanks Jerry. I have tested the 73.6 gr loads, and around them. They shoot well. Albeit not as much velocity as expected.

The first ladder I did has all the pressure signs. I messed up on the break in of the barrel and gummed things up pretty bad. First round would be okay, but then the next shot would have pressure signs (of the same load). Those sort of problems. I now know for certain that my max load is 74 gr.

I will finally admit, d:h: that everyone's right, and I need to try a different combination if I want to get more speed out of this rifle. Or get the throat cut longer, if I am dead set on launching these 210 vlds faster. I'll order up some 175 SMKs and see how they shoot, for a benchmark. If I can't get those to shoot, I am going to start golfing. Laugh2 more likely to only switch back to sporting clays, golf a silly sport. ...Chasing around those little balls, trying to knock them into gofer holes... (the late Robin William's words, not my own).
 
You do realise that the SAAMI max velocity for a 300WM/210gr combo is UNDER 2900fps for a 24" barrel?

Your listed speeds at 73.6gr is right on max velocity with best accuracy.... this IS the node for this barrel and combo.

I ran this bullet at 2500+ fps and it shot great at 1000yds ... you are running a whole lot faster. 1000yds will be pretty straight forward.

Lengthening the throat will allow you to add a bit more powder but the end result will not change... you will just add more fuel to get to the same harmonic so the bullet will be traveling the same speed. Barrel wants what barrel wants.

You might pick up a few FPS using a slower powder... maybe... but it will not be mind blowing.

I think you might want to send some out there and see how it flies. I bet the need for more speed dissappears as you hammer any reasonable sized gong at 1000yds with boring regularity. More then likely you will spend more of your time around 1300 to 1400yds cause anything closer will be pretty boring.

Jerry
 
Thanks again, Jerry. Plan is to do just that on Saturday.

Interestingly, I was (am) out at my reloading bench sorting brass by weight (yes, I listened finally), and decided to chamber a few once fired brass. I had been having a few rounds out of each box that had a stiff(er) bolt on closing.

Now my brass prep I have been over before, but basically, trim, chamfered (in/out) mouth, deburr flash hole (from the inside), and neck size.

I found this:
20190516_211623.jpg

The empty spots are the number of brass that i can't close the bolt on. The primed ones are new brass, unfired. Some of the unfired also would not chamber.

Out of the last 100 brass, 12/50 and 7/50 don't or are very hard to close the bolt on (black boxes). Out of the 10 rounds from the blue box 2 wouldn't allow the bolt to close. The blue box is a different lot.

I think I will add this check on to new brass going forward.

Now, I assume this is "normal" using a match chamber, and prvi brass? I tried body sizing the ones that the bikt won't close on, no difference. I don't have one of Larry Willy's dies to try, or a die to bump the shoulders, I assume if I had both of those items, I could get all the brass to chamber. Maybe?
 

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Check the crown with a 10X magnifier. Weigh the brass.
Check with a light the last 5 inches of the muzzle.
300 wm should shoot better than it is.
 
TrevorJ said:
Thanks again, Jerry. Plan is to do just that on Saturday.

Interestingly, I was (am) out at my reloading bench sorting brass by weight (yes, I listened finally), and decided to chamber a few once fired brass. I had been having a few rounds out of each box that had a stiff(er) bolt on closing.

Now my brass prep I have been over before, but basically, trim, chamfered (in/out) mouth, deburr flash hole (from the inside), and neck size.

I found this:
View attachment 274246

The empty spots are the number of brass that i can't close the bolt on. The primed ones are new brass, unfired. Some of the unfired also would not chamber.

Out of the last 100 brass, 12/50 and 7/50 don't or are very hard to close the bolt on (black boxes). Out of the 10 rounds from the blue box 2 wouldn't allow the bolt to close. The blue box is a different lot.

I think I will add this check on to new brass going forward.

Now, I assume this is "normal" using a match chamber, and prvi brass? I tried body sizing the ones that the bikt won't close on, no difference. I don't have one of Larry Willy's dies to try, or a die to bump the shoulders, I assume if I had both of those items, I could get all the brass to chamber. Maybe?
Click to expand...

Redding comp shell holder set.
 
TrevorJ said:
Thanks again, Jerry. Plan is to do just that on Saturday.

Interestingly, I was (am) out at my reloading bench sorting brass by weight (yes, I listened finally), and decided to chamber a few once fired brass. I had been having a few rounds out of each box that had a stiff(er) bolt on closing.

Now my brass prep I have been over before, but basically, trim, chamfered (in/out) mouth, deburr flash hole (from the inside), and neck size.

I found this:
View attachment 274246

The empty spots are the number of brass that i can't close the bolt on. The primed ones are new brass, unfired. Some of the unfired also would not chamber.

Out of the last 100 brass, 12/50 and 7/50 don't or are very hard to close the bolt on (black boxes). Out of the 10 rounds from the blue box 2 wouldn't allow the bolt to close. The blue box is a different lot.

I think I will add this check on to new brass going forward.

Now, I assume this is "normal" using a match chamber, and prvi brass? I tried body sizing the ones that the bikt won't close on, no difference. I don't have one of Larry Willy's dies to try, or a die to bump the shoulders, I assume if I had both of those items, I could get all the brass to chamber. Maybe?
Click to expand...

have a look at the brass just infront of the belt. If there is a bulge on the first firing, you are running very hot pressures vs the chamber dimensions. Bumping the shoulder 3 thou under chamber will work but if the case is bulged infront of the belt, you are going to be fighting that going forward.

Why many do not want to run a belted case in precision shooting.

If this is a true match chamber that suits the brass, there will be very little gap between the belted section and the case body area. This can force some to turn the belts to a precise fit... this would be a good thing.

If there is a significant gap, then the brass will swell in this area, be hard to properly size and brass simply will not chamber after several firings. When I was shooting belted rds, I would toss the cases when this bulged occured... it typically happened around 6 firings.

If bulges are forming on the first firing, back down your loads ALOT.. like 2 or 4 grs and work up. PRVI is durable stuff so if you are yielding the brass, things are very toasty.

Jerry
 
Measured in front of the belt this evening on a few of the brass that don't chamber, they all measure the same, or less (in the case of the unfired brass) then the brass that chambers.

I have run into problems on brass with many firings on my last barrel from the swell you described. Some say a Larry Willis die will help extend the life beyond 6 firings. I took your advice, and others, to turf them and buy some new stuff at the time.

In hindsight, 300wm was not the best cartridge for this endeavor. I bought it on the recommendation of a former co-worker. Said it was the best round going for this sort of thing. He's in jail last time I checked, so maybe his recommendations aren't the best...

I have learned lots, and look forward to trying it at some longer ranges. I'll be at Aimens practice tomorrow trying my reloads out to 500m.

Thanks for all the responses.
 
A quick and dirty way to diagnose chambering problems is to colour the case with a black marker, and try to chamber it. The tight spot will rub off the ink and the truth will come shining through.
 
The only ways a belted case can be hard to chamber is not moving the shoulder back enough for the headspace

A bulge in front of the belt.... or the case head not being square anymore (bolt face is not true to chamber).... then it could be a bit of dirt/fouling in the belt groove that needs to get swabbed out.

This is a long shot but if the case neck diameter with a bullet is wider then the chamber, it is going to be VERY hard to chamber and you will get pressure spikes on loads that should be moderate in pressure. To check, see if the bullet will fall freely into a fired case. If not, consider neck turning to increase the clearance around the loaded rd.

I believe you are not trying to jam the bullet so long OAL is not likely a culprit.

Good luck and hopefully, you can find a stable and consistent load for what you want to do.

Jerry
 
Buy or borrow a lead sled for load development. I used to sight in rifles for people and 300wm was brutal from the bench. 300ultra was the hardest on me to date, from the bench. I bought a gun rest with a back strap and load it down with 2 25lb bags of shot. Easy peasy now even with .338 lm with no brake.
I start with the least amount of powder and work my way up. Powder goes farther that way. Finding the nodes and tweaking the oal till I'm happy is my method. I've had great success with the ladder test method at 100 yards.
 
Have been doing more reloading, and shooting with this 300WM.
I suspect that I had set the headspace to be very tight, and the few cases that have a belt closer to the .220 vs .210 the bolt wouldn't close. Most of my brass is around .210/.212.
Coloring the case didn't show any rub marks, which got me looking at the belts (specifically a bulge in front of the belt, as many suggested).
I took the barrel off (for other reasons), and while it was off I dropped many pieces of new and fired brass into the chamber, and they all hit the belt (sort of like the plunk test for pistol rounds) best I can tell.
I should have verified my headspace before I spun the barrel off, but I'll likely set the headspace to .215. I've read that some come from the factory spaced at .220.

Current load is 73.6gr of H1000, 3.6065" coal, which I think is touching the lands, CCI 250, PPU brass. I have started to notice a small amount of cratering on the primers, and think I will back off a whole grain to 72.6gr.
Loaded some 175gr SMK's up a couple weeks back. They all shot well, start to get pressure (cratering from the firing pin) at 80 gr of H1000.
 
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