Help needed. Virgin 300WM brass measurements?

[pgothro]

I know you really don't want to get the Willis die but if you were able to take that glass back down with the Willis die then you might be able to start all over with that brass and chamber. Just thinking out loud

I want to tag in here on the Willis die. I have used it with my .264WM because of the sticking issue. Being a pre 64 model 70 that has seen some rounds. It cleared up the issue I had with much of the ammo was WW and I added new RP. It had the sticking issue I measured trimmed , re sized, bought bushing dies even trimmed the necks in and out. None worked (the old brass did also). Happened on the Willis die and haven't looked back. Typically fired brass needs it after 3x ( I also havE a 7mm, 300WM and 375HH). I have checked new Norma and Lapua brass that needed it. Try it before discounting it especially if you have a tight chamber.

 

[victor3ranger]

Or he can send me his junk brass I will dispose of it

 

[Short Round]

If you truly want to check the rifle buy some cerrosafe and do a chamber cast, It's not that difficult. Read and understand the directions though. There is a time frame on when to measure it after casting as it will change dimension the longer it cools.

 

[VinceMule]

entoptics has not stated much in particulars in the brand of brass, new or fired in another chamber, and if the chamber is factory or custom.

Worn reamers cut undersize chambers and there are differences in brands of brass in web dimensions.

 

[pdog shooter]

I have had brass sticking issues but with non belted. I figured a small base die would solve the problem. I now believe that once brass has expanded it will quickly go back to that expanded point when fired. That was my experience anyway.

 

[victor3ranger]

I have had brass sticking issues but with non belted. I figured a small base die would solve the problem. I now believe that once brass has expanded it will quickly go back to that expanded point when fired. That was my experience anyway.

I had it happen with 30-06 brass many years ago and a small base die fixed almost all of the problem cases, a few I had to trash

 

[entoptics]

I've got some new Peterson Long on the way. As soon as it arrives next week, I'll haul my Lee hand press to the wheat field, and fire one piece 3 or 4 times in a row. That should give me a good idea of the true chamber diameter at the belt, and regardless of that measurement, if it will still chamber and extract on 4th firing, I'll probably call it good. If not, then I'll send her back to the mother ship.

You are trying to use brass from fat chamber rifle(s) (.513+) in your new rifle that has a standard Sammi Chamber (.512-) No go. Get some new brass and fireform

I'm not sure that's true. Per the SAAMI drawing, brass should be a max of 0.5126, and the chamber should be 0.5136 to 0.5156. Seems that brass that's coming out after firing at .5130 shouldn't stick so tight it requires a mallet to remove if the chamber is really 0.0006 - 0.0026 bigger than that.

entoptics has not stated much in particulars in the brand of brass, new or fired in another chamber, and if the chamber is factory or custom.

Worn reamers cut undersize chambers and there are differences in brands of brass in web dimensions.

As per the first post, the brass is Sig Sauer, fired once in the previous barrel (Shilen Select Match). The problem barrel is a drop in Savage pre-fit carbon fiber from X-caliber.

 

[Tagnbagem]

I've got some new Peterson Long on the way. As soon as it arrives next week, I'll haul my Lee hand press to the wheat field, and fire one piece 3 or 4 times in a row. That should give me a good idea of the true chamber diameter at the belt, and regardless of that measurement, if it will still chamber and extract on 4th firing, I'll probably call it good. If not, then I'll send her back to the mother ship.



I'm not sure that's true. Per the SAAMI drawing, brass should be a max of 0.5126, and the chamber should be 0.5136 to 0.5156. Seems that brass that's coming out after firing at .5130 shouldn't stick so tight it requires a mallet to remove if the chamber is really 0.0006 - 0.0026 bigger than that.



As per the first post, the brass is Sig Sauer, fired once in the previous barrel (Shilen Select Match). The problem barrel is a drop in Savage pre-fit carbon fiber from X-caliber.

I have had this issue in CA Ridgeline 300 wm. Normally shoot Norma brass with no issues. I was able to get some Lapua brass and it shot fine on first firing , short of full size, chambered fine then loaded and shot with lighter loads and it would not eject. Resized with same dies and would not chamber. Norma brass, I have no issues with after many firings. I figured I need to have a Willis die to shoot lapua brass. The lapua brass on this lot has a larger dia. at belt after sizing but have not bought the Willis die as of yet. I have a stock pile of Norma brass. This just my experience.

 

[VinceMule]

entopics, your problem is VERY common when brass is used in different chambers, very common. The brass maintains a memory of the first chamber, you full-length resize the brass, and the brass springs back out. A small base sizer may resize the brass enough fired in the old chamber to where the spring back amount is not enough to hinder use in the X caliber barrel.

Sage advise, "new chamber, use new brass".

Different brands of brass will have different dimensions right in front of the web, production dies will size differently also. Old Blue bag and White Box Winchester is the smallest in the web dimension that I have found.

I would encourage you to buy an inexpensive 0-1 Micrometer that measures to .0001 so you can determine the actual dimension where that new chamber starts to give hard extraction. I may be preaching to the choir here.

Peterson brass is larger in front of the web than Winchester.

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Entoptics, you need .0015 clearance between Brass and chamber at a BARE MINIMUM in order to not have extraction on higher pressure nodes were the barrel will more than likely exhibit the best accuracy.

Also, to complicate things even more, brass ductility will vary between brands, some will be softer while others seem to be indestructible.

It would be an interesting study of the web dimension in front of the web for new brands of brass in various calibers:
NEW BRASS Dimensions only for:

Winchester blue bag = .5091
Remington =
Lapua =
Peterson =
SIG =

Would be nice if fellow members could measure some NEW 300 Win mag brass for us to get a True picture of brass on the market today.

 

[entoptics]

Got my new Peterson Long brass, and got out to shoot the rifle again today.

New Peterson long = 0.510" at the belt.

4X fired Peterson = .511"

1X Fired Peterson = 0.511"

Since I obviously was able to fire one piece 4 times, you can probably figure out that I had no more issues with stuck cases with the new brass.

That said, I still believe this is an undersized chamber. A SAAMI minimum 0.5136" chamber dimension would require believing that the fired brass had >0.002" spring back after 4 firings. I've not seen that sorta elasticity in brass before. I also have 2 other belted mags from the same manufacturer, and I just remeasured several of their many-fired brass at 0.5125" at the belt, which seems more consistent with 0.5136" chamber dimension.

As irritated as I am regarding the out of spec barrel and all the time and money wasted sorting it out, it did shoot pretty good today and I now have 100 pieces of top quality brass that will last at least 4 firings, so I guess I'm gonna skip further time and trouble sending it back, and just keep it.

Sad to say it, as they have good value, accuracy, and lead times, but I will no longer recommend X-caliber barrels to anyone, nor will I be buying another. All three I've had shoot good, but not one of them has actually been a "drop in" prefit.

 

[victor3ranger]

I'm glad to hear that you figured it out. Now go shoot the crap out of it

 

[VinceMule]

entoptics, You need to take a Cerrosafe chamber cast of your chamber, or learn to do so because it teaches volumes.

Your Quote, "I also have 2 other belted mags from the same manufacturer, and I just remeasured several of their many-fired brass at 0.5125" at the belt, which seems more consistent with 0.5136" chamber dimension" may indicate that you are comparing factory rifle chambers to a "custom" chamber, and this would be a mistake.

Chambering techniques can cut actual reamer size or they can cut over size, which is why many factory chambers are larger than custom chambers.

In your first post, you stated this:

2) I've loaded for six very different 300 Win Mag barrels; a 1960s era Winchester 670, 3 x Savage OEM, and a Shilen Match Select. All were fine digesting each other's fired brass, as long as base to shoulder was adjusted as needed by FL sizing to the appropriate BTS for that barrel.

Trying to switch brass from different guns very often leads to problems like you are having, but as soon as you start off with new brass, PROBLEM FIXED! Custom gunsmiths deal with customers all the time on this exact issue you are having, first thing out of their mouths, "Buy some new brass".

This simple issue of trying to use brass fired in different barrels, especially factory barrels, is Madness to deal with. You got lucky on some of the other barrels, believe you me. When I go the route that you went in trying to adopt brass from other chambers fired in a custom barrel, I start off with a small base sizer and PRAY! I have had brass "normalize" and swell back out to what it was originally fired in over a period of 5 years, and I am talking Rem 700 chambers not BAR chambers.

I only go into this because it is one of the first things that custom gun owners learn, and I hope you learn this lesson well or history will repeat itself.

Another lesson learned is that when a company orders a reamer, the reamer makers have a +/-.0005 tolerance on the dimension, you can NEVER forget this fact.

Learning to cast a chamber with cerosafe is a very easy thing to do with minimal investment, just a little time. I can walk you through this in PM's if you have any interest.

In my 300WM, the very best accuracy was always with very hot loads at book max or slightly above, just my luck. For this reason, knowing the exact chamber dimensions vs new brass dimensions, FL sized brass dimensions is critical. Full length sizing always produced the very best accuracy.

Good luck!

 

[Short Round]

Rotometals, a retailer of casting lead also sells their version of chamber casting material. A bit less expensive iirc.

It really isn't hard. Plug barrel ahead of leade, I generally use a cotton patch but have seen cotton balls used. Put your rifle in a muzzle down orientation, perhaps clamped in a bench vise. I recommend constructing a paper funnel to aid in getting your melted alloy in the chamber without making a mess. (spilled alloy just picks off). Pour your metal in and don't over flow to the locking lugs for obvious reasons. Wait the specified time and tap it out with a rod. Wait the specified time and take your measurements and adjust fo the time shrinkage factor as neeeded.


Edit, you can reuse the cerrosafe metal forever.