I am switching from 257 brass to 7mm rem mag brass in my 257 bee. Its shorter on the neck, do I have to worry about carbon build up in the short neck area using the 7rem brass?
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Switching from 257 bee to 7mm rem mag brass
- Thread starter Dmagna
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LBEdgin
Well-Known Member
I been doing it for 10+ years with no problem at all, other than it will be shorter. Yes there is built-up but I found the brass life will run out first as I sure you know the 257 wby in hard on brass.
Winchester brass is the best unless you want to foot the bill for AGD. I formed perfect brass in the Forster 257 Weatherby FL sizer on the first pass. I used a pistol brush to clean the excess carbon out of the neck, then had a reamer ground with a shorter neck for the Winchester brass.
I believe that the Winchester brass forms .050 shorter than Weathbery brass in the neck, and is much tougher than Nosler brass, Rem, and federal brass.
I had my reamer ground with zero freebore with the shorter neck, 100s at 3850 with R#22, fed 215's shoots sub 3/8" groups, 110 and 115s at 3600.
Primers crater, I ignore that issue, never had one pop as the small rifle primers do. There are plenty of guys who can fix an oversized firing pinhole if the cratering annoys you.
You can watch the bullet impact the deer, water vapor flies off the deer hide, the bullet impact the backstop behind the deer with a 25", #5 contour on a rem 700 with Boyd's stock, and Gentry muzzle break. This is the perfect setup for a person who is recoil-sensitive.
My nephew has an X caliber 9T off this reamer where he has killed a dozen or more deer with the 110g Accubond and 115g Bergers at 3590 fps, 25" barrel, he loves the rifle like no other due to his seeing the hits.
I believe that the Winchester brass forms .050 shorter than Weathbery brass in the neck, and is much tougher than Nosler brass, Rem, and federal brass.
I had my reamer ground with zero freebore with the shorter neck, 100s at 3850 with R#22, fed 215's shoots sub 3/8" groups, 110 and 115s at 3600.
Primers crater, I ignore that issue, never had one pop as the small rifle primers do. There are plenty of guys who can fix an oversized firing pinhole if the cratering annoys you.
You can watch the bullet impact the deer, water vapor flies off the deer hide, the bullet impact the backstop behind the deer with a 25", #5 contour on a rem 700 with Boyd's stock, and Gentry muzzle break. This is the perfect setup for a person who is recoil-sensitive.
My nephew has an X caliber 9T off this reamer where he has killed a dozen or more deer with the 110g Accubond and 115g Bergers at 3590 fps, 25" barrel, he loves the rifle like no other due to his seeing the hits.
Why would anyone do this?
Brass at a reasonable cost is the main reason, for a rock chuck rifle, or coyote rifle. The 257 Weatherby at the speeds I speak of is rough on brass primer pockets. 85-87g bullets run 4130 fps with R#19 or IMR 4831, amazing accuracy. A friend has a 30" 12T where he shoots the 100g Sierra at 4000 fps.
As you have a reamer ground for shorter freebore, may as well make the neck the appropriate length and dia to accommodate the Necked down Winchester brass. Plus the increase in accuracy due to less freebore, and the increase in velocity. My first reamer was off of std Weatherby case spec, with .030 freebore.
I am on my third reamer for short freebore. Friends keep wanting to borrow the reamer for their barrel, and one gunsmith ruined a reamer.
The extreme speed with little recoil makes a guy love this caliber, probably why the 257 Weatherby was Roy Weatherby's favorite cartridge.
Today, a 25 PRC would equal the 257 Weatherby in ballistics and they are almost identical in capacities as the 7 mag/264 Win.
As you have a reamer ground for shorter freebore, may as well make the neck the appropriate length and dia to accommodate the Necked down Winchester brass. Plus the increase in accuracy due to less freebore, and the increase in velocity. My first reamer was off of std Weatherby case spec, with .030 freebore.
I am on my third reamer for short freebore. Friends keep wanting to borrow the reamer for their barrel, and one gunsmith ruined a reamer.
The extreme speed with little recoil makes a guy love this caliber, probably why the 257 Weatherby was Roy Weatherby's favorite cartridge.
Today, a 25 PRC would equal the 257 Weatherby in ballistics and they are almost identical in capacities as the 7 mag/264 Win.
Because I want to run ADG brass.
Do you have a SAAMI chamber?
For brass yes. Except it's a 1-7 twist long throat made for monos
Seems like the short neck of 7 mag brass is defeating some of the advantages (whether perceived or real) with the long neck and Venturi shoulder.
Mike, I could be wrong, but I think that he is forming the AGD 7 Mag brass into 257 Weatherby, ending up with a .050 shorter neck.
The Venturi Sholder impedes brass flow into the neck, but for me, the brass does not last 4-5 firings(Winchester). I don't know how many firings you could do with Win brass or AGD in a std .300 Free Bore Weatherby chamber. My short freebore is running 200 fps faster than weatherby chambers meaning that there is a LOT of gas blow by before the bullet obturates in the lands.
The Venturi radius forms on the Winchester brass perfectly when run through a regular Weatherby die...hard to believe how easy it is.
Federal, Nosler, and Rem brass are not worth a darn for forming into 257, 7mm, or 270 Weatherby, way too SOFT!
All of this brass forming is a waste of time for a guy that only fires 3-5 rounds of year, of course.
The Venturi Sholder impedes brass flow into the neck, but for me, the brass does not last 4-5 firings(Winchester). I don't know how many firings you could do with Win brass or AGD in a std .300 Free Bore Weatherby chamber. My short freebore is running 200 fps faster than weatherby chambers meaning that there is a LOT of gas blow by before the bullet obturates in the lands.
The Venturi radius forms on the Winchester brass perfectly when run through a regular Weatherby die...hard to believe how easy it is.
Federal, Nosler, and Rem brass are not worth a darn for forming into 257, 7mm, or 270 Weatherby, way too SOFT!
All of this brass forming is a waste of time for a guy that only fires 3-5 rounds of year, of course.
That's odd that you say Weatherby brass is soft. I'm pushing mine what I consider extremely hard with 115 Bergers at 3600fps in a 25" barrel and I get 6-8 firings on my brass.
The freebore would have to be huge on a case that is .050" shorter than factory Wby brass because the .257 already has .375" of freebore on a SAAMI reamer.
Also I can't imagine how bad carbon ring buildup and/or flame cutting has to with that much shorter neck.
I guess I just don't see the benefit.
Mike, I never said the Weatherby brass was soft, you miss read.
When I had my custom reamer ground with the short neck, I made an adjustment on the freebore dimension. The Freebore dimension starts at the end of the neck.
The carbon build up on the shorter neck with Chamber is no different than the Weatherby brass in a normal chamber.
Two benefits:
A. shorter freebore-benefits are many
B. Brass availability-Winchester brass is plentiful, AGD maybe a game changer in terms of getting tough brass. Compare costs of 100 Weatherby cases vs 100 Winchester cases.
The benefits of the Short Neck and the minimal freebore are based around a Custom designed chamber. Guys that shoot the short neck brass in their standard weatherby chamber will have to remove the carbon in the neck simply by using a bronze bristle brush, ten or so twists with bore solvent on the brush. Seat he bullets to the same COAL as you would if the neck was longer.
The simple fact of .375 freebore in a standard Weatherby chamber does not leade to any apreciable barrel life, I have shot out a few Mark 5's. The shorter freebore lends to much longer barrel life in that factor alone, short neck or not.
I shot the 115's around 3350 in my Mark 5's, Mike I would love to know your load you are getting with that speed, it is incredible to say the least!
In the short freebore chamber in the 9T X caliber barrel, the 115g Berger is 3590 fps, groups are sub 3/8", same for the 110g Nosler accubond. R#22 with fed 215's is the powder used, with the 100g bullets at 3850 shooting groups in the high 2's, and the 85-87g bullets with R#19 at 4130 fps.
I used the 257 Weatherby like most would use a 22/250, Ruck Chucks, jack rabbits, and calling in coyotes on longer shot stands in Nv.
When I had my custom reamer ground with the short neck, I made an adjustment on the freebore dimension. The Freebore dimension starts at the end of the neck.
The carbon build up on the shorter neck with Chamber is no different than the Weatherby brass in a normal chamber.
Two benefits:
A. shorter freebore-benefits are many
B. Brass availability-Winchester brass is plentiful, AGD maybe a game changer in terms of getting tough brass. Compare costs of 100 Weatherby cases vs 100 Winchester cases.
The benefits of the Short Neck and the minimal freebore are based around a Custom designed chamber. Guys that shoot the short neck brass in their standard weatherby chamber will have to remove the carbon in the neck simply by using a bronze bristle brush, ten or so twists with bore solvent on the brush. Seat he bullets to the same COAL as you would if the neck was longer.
The simple fact of .375 freebore in a standard Weatherby chamber does not leade to any apreciable barrel life, I have shot out a few Mark 5's. The shorter freebore lends to much longer barrel life in that factor alone, short neck or not.
I shot the 115's around 3350 in my Mark 5's, Mike I would love to know your load you are getting with that speed, it is incredible to say the least!
In the short freebore chamber in the 9T X caliber barrel, the 115g Berger is 3590 fps, groups are sub 3/8", same for the 110g Nosler accubond. R#22 with fed 215's is the powder used, with the 100g bullets at 3850 shooting groups in the high 2's, and the 85-87g bullets with R#19 at 4130 fps.
I used the 257 Weatherby like most would use a 22/250, Ruck Chucks, jack rabbits, and calling in coyotes on longer shot stands in Nv.
Clay Target Guy
Well-Known Member
I have used 7mm mag brass as well as 264 Winchester Mag brass. Both give my 257 WBY good results.
Glad it can't read what is on the headstamp of the brass, it would not know what it was.
Glad it can't read what is on the headstamp of the brass, it would not know what it was.
Morning. I should have clarified I wasn't talking about your gun, I was speaking of a SAAMI chambered gun using 7mm brass. If the case/neck length is .050" shorter than 257 Wby brass is why I was mentioning my concerns above.
My load listed is with RL25 powder and a case full of it, certainly well over a published data so I'd prefer not to post details.
