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Discussion Starter #1
The tolerances must be extremely tight in this thing. Even with factory ammo, the bolt can be hard to close, and it is cratering primers even on starting loads.

When I measure my fired brass, the measurments are the same as full sized brass. So is this a good thing, or bad ?
 

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I would say its a good thing as far as accuracy goes, but what do you mean by cratering primers?
 

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Discussion Starter #3
I mean the primer is coming back around the firing pin. If you try to stand one up on the case head, it wobbles around.
 

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I mean the primer is coming back around the firing pin. If you try to stand one up on the case head, it wobbles around.
Now that is worrisome, perhaps and oversized firing pin hole.
 

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Discussion Starter #5
Quickload estimates 83gr of RL22 to be 3033fps with the 180gr Hornady Interlocks. That was the load I was using, which is a bottom end starting load.
 

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Discussion Starter #7
Im going to load up a ladder test, and see what happens at higher pressures. Full power factory loadings are no worse than my low power handloads.
 

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Im going to load up a ladder test, and see what happens at higher pressures. Full power factory loadings are no worse than my low power handloads.
I wouldn't do that, i would measure the firing pin hole and compare it to other senderos, load it up hot enough and you might just get a blown primer.
 

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Sounds like maybe theres a problem with the chamber. No matter what spin you put on the situation, sounds like a problem.
Actually a tight chamber is a good thing in most cases, that part of the situation wouldn't bother me a bit, the primers on the other hand would worry me.
 

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Actually a tight chamber is a good thing in most cases, that part of the situation wouldn't bother me a bit, the primers on the other hand would worry me.
yeah, you guys are much more knoledgable than me, just sounded like a problem given the cratering primers with a starting load, if it were me i would maybe have a smith check it out or send it back in. Also it would have me worried if factory ammo was hard to chamber.
 

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No worries Tang, both of mine do the primer cratering thing as does my .243VLS. It is due to an oversize firing pin hole but I've never had one blow a primer even with 180's going 3274 fps or 200's going 3060 fps. I was concerned at first, but another 300RUM I know does it with factory ammo as well. One of these days I'm going to put an oversize firing pin in them and remedy the problem.

As for the tight chamber, when you full length resize, bump the shoulder back just enough to easly chamber the brass and you should be good to go for several reloadings even if you necksize.

RJ
 

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yeah, you guys are much more knowledgeable than me, just sounded like a problem given the cratering primers with a starting load, if it were me i would maybe have a smith check it out or send it back in. Also it would have me worried if factory ammo was hard to chamber.
You are correct in that factory ammo in a factory rifle should not be hard to chamber, the fact that it is means that the gun probably doesn't close on a go gauge, this is not bothersome because a tight chamber is conductive to better accuracy, so i wouldn't be worried, i would inspect the chamber to make sure there wasn't some fouling or something causing it. back flow in a primer however is a big no no, and it would bother me a lot, and i certainly wouldn't be cooking up hot loads to see what happens, i like my ugly mug just the way it is thanks.
 

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Discussion Starter #13 (Edited)
No worries Tang, both of mine do the primer cratering thing as does my .243VLS. It is due to an oversize firing pin hole but I've never had one blow a primer even with 180's going 3274 fps or 200's going 3060 fps. I was concerned at first, but another 300RUM I know does it with factory ammo as well. One of these days I'm going to put an oversize firing pin in them and remedy the problem.

As for the tight chamber, when you full length resize, bump the shoulder back just enough to easly chamber the brass and you should be good to go for several reloadings even if you necksize.

RJ

Thanks RJ, I was hoping to hear from you. My firing pin hole (best as I can measure), is between .089"-.091". Compared to my brothers VSSF-II, which has a firing pin hole of .065".

I will do what you suggested on the sizing die, and I will also get me a neck sizer.

Where can I get an oversized firing pin ?


Its definetly a headspace issue. Even full size brass is hard to chamber. My nickle plated brass harder still. How can I bump the shoulder back when the size die touches the shell holder anyway ? I might order the Lee dies.

Edit: I tried a piece of fired brass that I got from another guy. It chambers easily. So I went and readjusted my die. The Hornady instructions say to run the die down against the shell holder and tighten the ring down. So I ran it 1/4 turn past that to get any slack out, and tada, the brass chambers.

Now the only problem Im having, is the inside of the Hornady die is rusty and scracthing the crap out of my brass. The dies were bought brand new from Midway last week. I have emailed them about sending them back in.
 

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Elk Whisperer (Super Moderator)
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To polish the dies take a piece of 000 steel wool and wrap it around a drill bit or a piece of dowel would be better and put in your drill and spin it inside the die with the decapping pin out. That should remove the rust.

I've found that some brands of shell holders are thinker than others and sometimes it's necessary to reomove a bit of material from the end of the die to get it to do the job you want. This can be done with a belt sander and 80 or 100 grit paper. yo only need to remove .010" or so. I had to do this to a set of RCBS dies for my 7mag. Didn't affect the dies any, just how far I wanted to bump the shoulder back on some once fired brass I got at a gunshow.

Midway has fining pin kits available with stronger springs. They aren't too tough to install but you need to get the right size drill bit as well to do the job right. A good hardware store will have the right number or letter drill bit to make the new firing pin hole a couple thousandths bigger than the new firing pin.

RJ
 

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tight chambers but also maybe a slow barrel. my latest Kimber 308 has a tight chamber, it its however OK on the receiving end of the bullets..
 

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Are they cratering on factory ammo? A friend had nothing but problems with his 300 RUM CDL and ended up trading it off. There is quite a bit of pressure behind that bullet. As you may know cratering is due to high pressures. Even with an oversized firing pin hole I wouldn't think that it would crater unless you have a large gap between the pin and edge of the hole.

As for the tight chamber, could have been a bad chamber job by Remington. Best first step might be to get some cerrosafe and do a chamber cast to get some exact measurements, or have the smith do it. Then you will know what your dimensions are and you can go from there.

http://www.midwayusa.com/viewproduct/?productnumber=462291

Do you know the twist, and what bullet weights were you using? Where they key holing?
hope this helps.
 

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The tolerances must be extremely tight in this thing. Even with factory ammo, the bolt can be hard to close, and it is cratering primers even on starting loads.

When I measure my fired brass, the measurments are the same as full sized brass. So is this a good thing, or bad ?
Tang,
I would bet my left nut that your firing pin spring is weak. Cratered primers are not always an indication of excessive pressure, it's usually a gun problem. I have swapped out all my Rem700 firing pin springs with David Tubb Chrome Silicon replacements, they are exceptional!
If the chamber was so tight that it was creating excessive pressures, the primer would be riveted beyond recognition. I have a few Rem700's with tight chambers, and they do not show any signs of excessive pressure with starting loads, but do run a grain or two below max book loads.

The minimum chamber is a good thing, your brass will last and it should produce very good accuracy. I always attempt to cut my own chambers to minimum specs, I have succeeded on every occasion with "0.000" spec!

Shoot and enjoy your minimum spec rifle, it will shoot real good, I bet!
 

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Elk Whisperer (Super Moderator)
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Tight chambers do not cause pressure. The only thing tight chambers cause is hard bolt closing on new ammo, unless the mouth of the chamber is so short is crimps the end of the case.

What Tang is experiencing is not "normal" but really nothing to worry about. Of there over 10000 rounds I've put through my 300RUMs NONE have "blown up" NONE. My .243 as I've said does the same thing and it's got over 4000 through it.

Yes there is a problem, but is it serious enough that Tang and I should be running to mommy? No.

RJ
 

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Tight chambers do not cause pressure. The only thing tight chambers cause is hard bolt closing on new ammo, unless the mouth of the chamber is so short is crimps the end of the case.

What Tang is experiencing is not "normal" but really nothing to worry about. Of there over 10000 rounds I've put through my 300RUMs NONE have "blown up" NONE. My .243 as I've said does the same thing and it's got over 4000 through it.

Yes there is a problem, but is it serious enough that Tang and I should be running to mommy? No.

RJ
I think its serious enough that tang shouldnt tolerate it not properly chambering factory ammo, consider it is BRAND NEW lol. id send that ******* in. if not whatd you pay for then? something with a problem, but not serious enough to worry bout? When i buy something brand new, i expect it to function properly, when i buy a new gun, i expect it to properly chamber factory ammunition.
 
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