You get a .358 Winchester loads With just 47 grains of 742, that sends a 220-grain Speer down range 2800 fps (should have been around 2200), a bolt that won't open and a brass flow into the ejector hole (Clogging the ejector)!

When we put a go-gauge on it a few minutes ago, bolt closed with no resistance on the no-go, but would not close with one thickness of electrical tape wrapped around the head (smith said this is more common than you would think). He also put my reloads into a case gauge, and the rims were below flush enough to break a fingernail. So one problem compounded the other. He then proceeded to shoot a factory round (200-grain Silvertip). It shot, no pressure signs on the brass.

It's just a good thing I started low. If I had started at max (52 grains 748), I might have established a new velocity record for the .358 Winchester. Of course, I might not be here to receive the accolades,

Barrel maker has already asked for it back, on their nickel. Gee, I wonder why?

???? Not trying to start anything but I always set the sizer to my chamber. If I don't feel any resistance at all to a sized case I start exploring. Wouldn't that have precluded your problem?

You are absolutely correct. I had a brain fart and followed the RCBS directions of screw it down til it touches the holder and then turn it 1/4 turn further in ensure full-length sizing.

I have a one other rifle that if I full length size as per the directions, headspace is excessive. But, even on that one, it took a session or two to figure out what was wrong.

Be careful with your assumptions.
I know no reason for your load to do what you claim.
The combination if the conditions you mention does not sound like a recipe for high pressure.
If you are checking the headspace after the fact your over load may have caused the excess headspace.

quote:

Originally posted by GAHUNTER:
You get a .358 Winchester loads With just 47 grains of 742, that sends a 220-grain Speer down range 2800 fps (should have been around 2200), a bolt that won't open and a brass flow into the ejector hole (Clogging the ejector)!

When we put a go-gauge on it a few minutes ago, bolt closed with no resistance on the no-go, but would not close with one thickness of electrical tape wrapped around the head (smith said this is more common than you would think). He also put my reloads into a case gauge, and the rims were below flush enough to break a fingernail. So one problem compounded the other. He then proceeded to shoot a factory round (200-grain Silvertip). It shot, no pressure signs on the brass.

It's just a good thing I started low. If I had started at max (52 grains 748), I might have established a new velocity record for the .358 Winchester. Of course, I might not be here to receive the accolades,

Barrel maker has already asked for it back, on their nickel. Gee, I wonder why?

Had a gunsmith tell me the 742 kept him in business.

Fit your brass to your chamber. But; if you are asking if that slight amount of excessive headspace will kill you; most definitely not. The pressure won't be increased and your brass will not fail, as long as your load was ok to begin with. Excessive headspace will not increase pressure like yours. It is a misconception that excessive headspace is actually dangerous. It will make your brass fail early but brass separation won't hurt you. You do have some issues but I do not know what they are.

richj,742 powder not rem742

Well, I am sure that my load density was correct (unless someone replaced my powder with 760, that looks the same). I came home, pulled bullets and re-weighed every load on two different scales. All were spot on.

Only other thing it could be is that there is a problem with my new barrel. That's why the barrel maker wants it back for testing. For brass to flow like that, with that kind of velocity something went badly wrong!

I'm going to send it to them next week. We know for a fact that there is excessive headspace, What I don't know is if the barrel itself is in spec.

If you have a soft lead sinker or .38/.357 bullet mash it a little over size and then drive it into the muzzle with a wood dowel about an inch.
Then knock it back out and measure it.
It should be .358.

quote:

Originally posted by GAHUNTER:
Well, I am sure that my load density was correct (unless someone replaced my powder with 760, that looks the same). I came home, pulled bullets and re-weighed every load on two different scales. All were spot on.

Only other thing it could be is that there is a problem with my new barrel. That's why the barrel maker wants it back for testing. For brass to flow like that, with that kind of velocity something went badly wrong!

I'm going to send it to them next week. We know for a fact that there is excessive headspace, What I don't know is if the barrel itself is in spec.

quote:

Originally posted by SR4759:
If you have a soft lead sinker or .38/.357 bullet mash it a little over size and then drive it into the muzzle with a wood dowel about an inch.
Then knock it back out and measure it.
It should be .358.

Yes, I've thought about slugging the barrel, but didn't have any proper lead slugs. Never thought about .357 lead bullets. I happen to have some loaded .38 special wadcutters that I can pull.

I've never relished the thought of pounding a lead slug through my crown, no matter how many times folks tell me it won't hunt it.

Okay, I just slugged my muzzle -- .356, all the way around. Considerable amount of lead shavings when I drove it in.

Surely, .002" is not enough to cause this kind of pressure spike?

Now I'm going to slug my .35 Whelen for comparison.

The Whelen is .357, with a spike in one spot at .358 (But it settled back to .357. I re-slugged the .358 Win., -- still .356.

Ok, I assume you mean W748 instead of 742, right? If it was 760, that is much slower than 748. Your load of 47 grains of W748 and a 220 grain bullet should be fine. Either a hot lot of powder, or the .356 barrel might do it.

quote:

Originally posted by dpcd:
Ok, I assume you mean W748 instead of 742, right? If it was 760, that is much slower than 748. Your load of 47 grains of W748 and a 220 grain bullet should be fine. Either a hot lot of powder, or the .356 barrel might do it.

I just realized I wrote 742 instead of 748. Yes, I meant W748. I am absolutely sure that I didn't overload the round. In fact, something I didn't mention: thought my chrono was wrong on the first shot, so I shot another round, which was chroned hotter than the first. Then I went to a starting load of Varget, and that's when my brass flowed and dumb ass me realized something is very, very wrong!

Like I said, the barrel company wants it back, so I'm going to oblige them.

None of this adds up.

1. Excessive headpsace doesn't cause more pressure; in fact, the larger chamber tends to yield less pressure. It can seem like a lot of pressure if the headspace is excessive enough to allow a case head separation.

2. Your story is inconsistent, but apparently the first load you mention with WW-748 (originally misidentified as "742") was not the culprit which caused the stuck bolt, but rather a load with Varget. Is this correct?

3. Just because one end of the barrel measures .356" or so (which is not small enough to cause an extraordinary excursion in pressure) doesn't mean that all of the barrel is .356", which may be the reason the barrel maker "wants it back". A little better clue as to why the maker is concerned about the barrel might shed some light on the subject.

4. You seem to be telling us that an overly generous headspace condition existed prior to the firing of overloads, meaning that the overloads did not cause the excessive headspace. Since this was a brand new barrel it is then obvious that whoever chambered and installed the barrel caused the excessive headspace and should be held accountable for that problem.

I agree -- it doesn't add up. That's why this is so frustrating.

BTW, I slugged the barrel all the way through, and it's .356 all the way.

I had that happen with a 270 using bulk powder. Brass flow - the case looked like a belted magnum! Had to use a block of wood to open the action.

Turned out that the powder wasn't what was advertized! Maybe you got the wrong powder or somehow contaminated it with something else.

Just a suggestion.

I just opened a new pound of W748 today and loaded up a few starting loads with 220-grain Speers. I also loaded a few starting loads with H335. This time I was very careful not to set the shoulder back too far. I bought a Wilson case gauge off off ebay and sized to the max case dimensions instead of the minimum. Bolt just barely turns down when case is inserted.

I also have a box of factory loads. That I plan on shooting to make fire-formed brass.

If I get high pressure signs or extreme velocities during this session, the barreled action goes back.

I may be on the way to solving this problem. On the last bunch of reloads, I sized my brass to the max, and reduced starting loads to 2 grains below Speer's book starting load. Then I started working up.

On the first few shots, I got a "shine" on my case face, like it was about to flow. But the more I fired, the less this "shine" showed up. I was able to work up all the way to 50 grains of w748, and the shiny spot had disappeared and no sticky bolt!

Do you think maybe I had a "imperfections" in the chamber from the reaming process that got worked out the more I fired it?

BTW, With 49 grains of 748, I shot a .335 (one hole) group at 2380 fps. I only fired one 50 grain load, but it chronoed right at 2400 fps with no pressure signs.

Well, I do still have a problem. I just took my brass from day-before-yesterday's range session to the reloading bench. First thing I notice is a pronounced bulge in front of the web on all cases, regardless of the amount of powder fired through them. The bulge measured .009 to .011, depending on the case.

When I resized a fired case, I backed the sizer die way off and then checked the case in my case gauge. The rim stuck up a few thousandths above the max, but when I tried it in my rifle, it chambered and the bolt closed with very little difficulty.

Then I measured case stretch. With just one firing, my cases were .012" over maximum, which means I had a case stretch of .014" per firing.

I've already mentioned that I had some signs of my brass trying to "flow" (shiny spots on the rim face). These spots showed up regardless of the powder amount. (I thought they had disappeared with heavier loads, but inspection at the bench showed that the shiny spots were still there.)

Ladies and Gentleman, I have a grossly oversized chamber!

Agree or disagree?

Oversized chambers will not increase pressure; they reduce it. Post pics. Sounds like your chamber is OS; who did the chamber job and what make reamer did they use. And there is always the possibility that you have some soft brass; I had some WW 308 brass a few years ago that opened up primer pockets with any load, even lighter ones.

The barrel and action are on the way back to E. R. Shaw. As soon as I told them that it closed on a no go gauge, they said get it back them. They agree that all signs point to an oversized chamber.

The most disconcerting thing was case stretch from an unfired .358 Winchester case to a resized case of .022 inches (2.005 to 2.027). Also, when I was putting brass together to send with the barrel, I noticed that on one case the base of the "bulge" would actually catch my fingernail, indicating a case rupture.

Like I said above, I don't think my "pressure" signs were really pressure signs at all, since the signs did not increase with progressively heavier loads.

Glad you got that sorted.

I used to own a Mod 70 rebarrelled to 358 Win.

I was using Sierra 225 gr GK bullets & they were lethal on red deer.

But using IMR 3031, I struggled to get 2400 fps out of a 20 inch barrel.

Pressure was low with the fast powder and I got 10+ reloads and rarely trimmed.

The point I am trying to make is that you are unlikely to get high pressure from the slower Varget.

Okay, the problem is solved! I got the replacement, reamed barrel back from E.R. Shaw (free of charge) last week, and it matched up perfectly with the bedding in my stock. With this new barrel, the bolt will not close on a no-go gauge. At the range today, I shot twenty rounds, (break-in cleaning between shots), with a variety of loads. There were no issues with my brass or signs of excessive pressure. After Zeroing, all my bullets (220-grain Speers), regardless of powder or charge, landed within an inch of each other at 100 yards.

I worked my way up to 51 grains of 748 (2420 fps), and 47 grains of Ramshot TAC (2375 fps). My best group was with 50 grains of 748 (3/4-inch), at 2370 fps. I came home and loaded up 10 for opening day of deer season this coming Saturday.

I don't know for sure what was going on with that other barrel, but whatever it was, it was bad!

GA Glad to hear things have worked out. You are going to be very happy with your 358 when you start hunting with it. It is quite a little stopper.