Huntnful
Well-Known Member
No I don't, just because I need to form them anyways, and then I'll anneal after that. I just used some imperial sizing wax on the necks only.
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7-300 Norma Mag Improved. IT’S ALIVE!!
- Thread starter Huntnful
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No need to anneal…
Those 200 pieces of brass will only be once fired, before that barrel is toasted like the Stay-Puff marshmallow man!
RH300UM
Well-Known Member
I disagreeNo need to anneal…
Those 200 pieces of brass will only be once fired, before that barrel is toasted like the Stay-Puff marshmallow man!
My brass stays more consistent for its life if I anneal (AMP)at the last sizing down stage of the process.
I also am using a hydro forming die to get the case shaped before fire forming
You are right....
But we can place bets...I say, at 550 rounds accuracy starts falling like a rock.
RH300UM
Well-Known Member
No bet
Huntnful
Well-Known Member
It's settled. I have another 1-9 twist brux coming. #6 contour, spiral fluted out to 23" for a 24" finish length.
I also have a 1-8.5 twist benchmark coming at some point that I ordered 4 months ago. #6 contour, spiral fluted out to 25" for a 26" finish length.
Probably put the brux on before season since I know the last one shot so well. And I think a 24" barrel would be just a little nicer for packing around during season.
I also have a 1-8.5 twist benchmark coming at some point that I ordered 4 months ago. #6 contour, spiral fluted out to 25" for a 26" finish length.
Probably put the brux on before season since I know the last one shot so well. And I think a 24" barrel would be just a little nicer for packing around during season.
I had a 300NM with a bit of an oversized chamber. Not horrible but the brass had to be shot once in order to get good SD's and good group sizes (SD 30+ down to 7 and group of 1" down to sub 3/8"). During a demonstration we went thru a wide range of bullet weights and velocities. First thing I noticed was shoulders were not all in the same location- heavy rounds vs light and velocity low and high. Perhaps expected but I found the OD to be in variance also. Enough so that I would actually separate the brass if it was competition based on the fire forming base line load.
Crush fit: are you saying the bolt has a slight load on it? Long or OD?
And great to know- thank you for your process. I have a 7mm barrel that turned into a disaster (tried a 7mm Scorpion- RCC Brass) and can only save it through the round you have shown and documented.
Huntnful
Well-Known Member
Ohhhhhh okay! I understand what you're saying. Case size variances. I haven't seen anything significant like that honestly. I do form everything with the same exact load, in the same exact way. And even then, I don't put a ton of weight on the second firing, because the brass is still forming down near the case head. But second firing still normally shoots quite well.
Yes exactly, the bolt has a load on it when you chamber the virgin brass.
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Elk Hunter 338
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This is RADD!! I love me a fast 7mm!
Elk Hunter 338
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Crush fit>>>AKA resistance when closing the bolt causing the case to set up against neck shoulder junction and push back against bolt, creating a secure round for blowing out shoulder, and case dimensions = consistent shoulder case form all the time, every time! Don't lean on it until after second firing. Its a very good idea to have a 100 or so of the same lot brass for this also. Because we all know lot to lot is a bigger deal then we make it out to be when fire forming consistency.
Now that being said i also have very good luck with the old jammer in the lands and send it method also..
I do this anyways along with slight crush because, well extra insurance!
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WeiserBucks
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Can't wait!
Huntnful
Well-Known Member
Exactly. I have 500 pieces same lot of Lapua 300 Norma Mag brass. Using it for 300 NMI and 7-300 NMI. @Barehandlineman11 sets up a perfect crush fit, and I still jam the lands as well. I can't physically measure the differences between these two 7-300 NMI chambers he's done for me lol. I'm sure the third one will be the same!
to make things clearly understood here, crush fit is slight resistance to closing the bolt.
Not lug-galling resistance, slight crush of the brass.
When necking down i've found leaving a small percentage of the bottom of the neck partially or fully untouched by the smaller bushing does the trick.
Adjustable by the depth of the brass inside the die.
I didn't want a random reader to get the wrong idea.
Not lug-galling resistance, slight crush of the brass.
When necking down i've found leaving a small percentage of the bottom of the neck partially or fully untouched by the smaller bushing does the trick.
Adjustable by the depth of the brass inside the die.
I didn't want a random reader to get the wrong idea.
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RichCoyle
Well-Known Member
I did one that has the same powder capacity. It is a 6.5-.338 RUM using 7RUM brass to get an extra .100" longer neck. It is on a Savage action with a 28" Lilja barrel. I tried one bullet which was a Nosler 140. Velocity is 3,419 feet per second.
