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Joined: Jul 2001
Posts: 60,052
Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,052 |
Your photos were interesting.
Perhaps even more interesting is that the bullet base sticking down into the case doesn't make much difference in case capacity. At least not enough to make any substantial difference in muzzle velocity.
According to my calculations, seating a .257's bullet out an extra .27" (as in your photo) results in an increase in powder capacity of 6.8%. This means a potential increase in muzzle velocity, at the same pressure, of 1.7%, or about 50 fps in a typical 120-grain load. This is according to the 1/4 rule, which states that any increase in powder capacity results in 1/4 that much increase in muzzle velocity, at the same pressure. Which is aout as much as we gain or lose between 22" and 24" barrels. It's there, but not much.
Not that adding powder room and barrel length can't gain something. I once owned a Ruger No. 1B in .257 with a throat so long that only 115-120 grain bullets could be seated anywhere near it. In that rifle 3100 fps was possible with a 115, but it also had a 26" barrel. And 3100 with a 115 is pretty much crusing speed for a .25-06.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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Joined: Apr 2003
Posts: 122
Campfire Member
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Campfire Member
Joined: Apr 2003
Posts: 122 |
This is a "classic" cartridge......right?
Then spend the extra bucks and build it on a "classic" action, IMO. Find a Czech VZ-24 or a FN-98 action.
Ol' John..(still at play in the fields of the bewildered and loving it.)
Near the Llano River in Castell, Texas
Mark Twain was right..."There is no such thing as too much good whiskey!"
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Joined: Jul 2001
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Campfire Kahuna
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Campfire Kahuna
Joined: Jul 2001
Posts: 60,052 |
Or a Mexica Mauser, "short" Montana 1999, or one of those new classics, the Model 20 NULA. All of which have at least 3" magazines and won't get you anything more out of the round, but will make some people feel better.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.”
John Steinbeck
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Joined: Mar 2003
Posts: 6,935
Campfire Tracker
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Campfire Tracker
Joined: Mar 2003
Posts: 6,935 |
The 7X57 (parent of the .257R) was built on an intermediate length action by the Mauser factory for its commercial models. I have one in the safe that I keep telling myself I am going to use as the donor for a .257...jim
LCDR Jim Dodd, USN (Ret.)
"If you're too busy to hunt, you're too busy."
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Joined: Dec 2002
Posts: 32,122
Campfire 'Bwana
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Campfire 'Bwana
Joined: Dec 2002
Posts: 32,122 |
I just bought a Peruvian 1935 in either 30-06 or 7.65x53, the seller wasn't sure, built by FN. Is that an intermediate length action like the FN 24/30?
Jeff
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Campfire 'Bwana
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Campfire 'Bwana
Joined: Dec 2002
Posts: 32,122 |
I'm currently putting together a matched pair of rifles in 257 and 7x57 on 1942 vintage Swedish 38s for a Norwegian bachelor farmer friend. They're getting the Dayton-Traister cock-on-opening kits, Timney or Bold triggers, and A&B 21" barrels from MidwayUSA. He likes the Swedish Mausers and buys nearly every sporterized 1 that he comes across for less than $200. Seems like every time that I stop by his place, I leave with a couple of them in the truck and a wish list for how he wants them worked on. When the current rifles are done, he'll have Sweds in 22-250, 6mm Rem, 250-3000, 257 Bob, 6.5x55 (x11), 7x57, 300 Savage, 8x57 (x6), and 35 Remington.
Jeff
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Campfire Tracker
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Campfire Tracker
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I just bought a Peruvian 1935 in either 30-06 or 7.65x53, the seller wasn't sure, built by FN. Is that an intermediate length action like the FN 24/30?
Jeff The 1935 Peruvian is standard length M98. The 1909 is intermediate.
Old Corps
Semper Fi
Get off my lawn.
FJB
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Joined: Sep 2009
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Campfire Tracker
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Campfire Tracker
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There is no reason to put a 257 in a 30-06 action. Just build a 25-06 and be done with it. Or buy a Vanguard in 257 WB....you can always download it.
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Joined: Jun 2002
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Campfire Outfitter
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Campfire Outfitter
Joined: Jun 2002
Posts: 11,944 |
Your photos were interesting.
Perhaps even more interesting is that the bullet base sticking down into the case doesn't make much difference in case capacity. At least not enough to make any substantial difference in muzzle velocity.
According to my calculations, seating a .257's bullet out an extra .27" (as in your photo) results in an increase in powder capacity of 6.8%. This means a potential increase in muzzle velocity, at the same pressure, of 1.7%, or about 50 fps in a typical 120-grain load. This is according to the 1/4 rule, which states that any increase in powder capacity results in 1/4 that much increase in muzzle velocity, at the same pressure. Which is about as much as we gain or lose between 22" and 24" barrels. It's there, but not much.
Not that adding powder room and barrel length can't gain something. I once owned a Ruger No. 1B in .257 with a throat so long that only 115-120 grain bullets could be seated anywhere near it. In that rifle 3100 fps was possible with a 115, but it also had a 26" barrel. And 3100 with a 115 is pretty much cruising speed for a .25-06. I agree ...... Way back when, I read the article about the 257 by Ken Waters and how he expounded on the virtues of a 3" 257Roberts. I formed my opinions based on that and not on any personal experience, so it was only natural that I used the long action I had on hand and requested it have a 3" OAL when chambered. I personally don't like to have a bullet sit down too far into the case and the couple extra ounces that a long action weighs is worth it for me to over come this. If I wanted a lighter lightweight 25 cal, I'd probably go to a short action 700 ADL with a 21" bbl (MR contour) in a McMillan Edge chambered for 250AI. These debates are pretty much "chicken or egg" debates. Both sides are right.  .
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Joined: Jun 2002
Posts: 11,944
Campfire Outfitter
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Campfire Outfitter
Joined: Jun 2002
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There is no reason to put a 257 in a 30-06 action. Just build a 25-06 and be done with it. Or buy a Vanguard in 257 WB....you can always download it. I built a 257Roberts because I wanted a 257Roberts , not a 25/06. I don't need (or want) that much velocity. The long action is perfect for my needs as is the short action for others. For the average deer hunter, the 257 is a well rounded and efficient cartridge as is, plus it is a lot of fun to shoot without burning much powder or enduring much blast. Were I live, 3100fps with a hundred grain Hornady is lots. Most 257Roberts owners recognize these virtues and and will pass over the faster 25s because of them. .
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Campfire Tracker
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Campfire Tracker
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I like to seat the heavy 120 gr. bullets .257 deep in my case and get more powder space and I get quite a bit of velocity advantage and I will argue that all day with anyone, but it's not necessary, it suits me and thats the bottom line...My 257s, 7x57s are all set up like that. It usually takes a long action to do this..With a pre 64 M-70 you can just substitute a 30-06 box as it already has the long throat and some Mauser also. This works great with some cases and not so much with others but any cartridge on the 7x57 case improves well according to my chronograph, also the 250-3000...those two case also gain more advantage in velocity than any of the Ackely IMP. according to Ackley..
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Joined: Mar 2001
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Campfire Tracker
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Campfire Tracker
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I like to seat the heavy 120 gr. bullets .257 deep in my case and get more powder space and I get quite a bit of velocity advantage and I will argue that all day with anyone, but it's not necessary, it suits me and thats the bottom line...My 257s, 7x57s are all set up like that. It usually takes a long action to do this..With a pre 64 M-70 you can just substitute a 30-06 box as it already has the long throat and some Mauser also. This works great with some cases and not so much with others but any cartridge on the 7x57 case improves well according to my chronograph, also the 250-3000...those two case also gain more advantage in velocity than any of the Ackely IMP. according to Ackley..
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Campfire Tracker
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Campfire Tracker
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Ray,
How can you "seat the heavy 120 gr. bullets deep in my case and get more powder space" ?
Old Corps
Semper Fi
Get off my lawn.
FJB
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Joined: Jan 2006
Posts: 21,810
Campfire Ranger
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Campfire Ranger
Joined: Jan 2006
Posts: 21,810 |
Short action! If you want to shoot longer cartridges, use a 25-06 in a long action.
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Joined: Jun 2009
Posts: 1,948
Campfire Regular
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Campfire Regular
Joined: Jun 2009
Posts: 1,948 |
I like to seat the heavy 120 gr. bullets .257 deep in my case and get more powder space I think Ray is saying that he seats the bullets no deeper than the neck / shoulder junction, leaving everything else for powder. If I am misunderstanding him I'm sure he will correct me.
" He who refuses to do the arithmetic is doomed to talk nonsense" John McCarthy
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Joined: Sep 2009
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Campfire Tracker
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Campfire Tracker
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I understand if you want a 257 BOB rather than a hotter 25. If so there is no reason for a long action. Find a minty Remington 722 and you'll have one of the most accurate rifles ever to leave a factory. In fact ANY 722 or 721 is a far better rifle than than its successor. Little things like cut rifling, a real blue job and an adjustable trigger that really adjusts and an action as smooth as greased kitty litter, keep me buying them. 721 AC 300 H&H, kills whatever it is shot at since 1952! ![[Linked Image]](http://i191.photobucket.com/albums/z231/leadloader/DSCN2022.jpg)
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Campfire Member
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Campfire Member
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Granted my .257 is an Ackley Improved, but I built it on a long action, just so I could seat the bullets out where I could take full advantage of the powder capacity in the short case. Yes, I basically have a .25/06, same ballistics but with less powder, and I have something that is unique, and that is more important with that paticular rifle.
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Joined: Mar 2003
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Campfire Tracker
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Campfire Tracker
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I just bought a Peruvian 1935 in either 30-06 or 7.65x53, the seller wasn't sure, built by FN. Is that an intermediate length action like the FN 24/30?
Jeff Jeff, Measure the length between the guard screws and see if you get standard length or shorter...jim
LCDR Jim Dodd, USN (Ret.)
"If you're too busy to hunt, you're too busy."
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Joined: Jun 2009
Posts: 148
Campfire Member
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Campfire Member
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Posts: 148 |
If I remember the last run of the 700 classic in 257 Robts was on a long action.
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Campfire Tracker
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Campfire Tracker
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Craigster,
????????? I seat a 7mm bullet .284 in the case that is one 7mm caliber into the case, about half way down the neck..that requires a long magazine box, and a long throat in your chamber.
On a 257 Robts I will seat the bullets .257 deep into the case and again that equates to one caliber deep..
It is basically the same as improving the caliber without blowing the shoulder out and without having to rechamber some guns..
BTW a Short action Mod. 722 Remington in .257 Roberts can be lengthened by substituteing a Rem 721 30-06 or 270 magazine box..thats a pretty simple, inexpensive fix..Also applies to the pre 64 Mod. 70 Winchesters..
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