275 Rigby / 7×57/7mm Mauser
- Thread starter RBHarter
- Start date
RBHarter
West Central AR
I won't go into how I figured out that it was case capacity raising Cain with this rifle as an 06' but I'll leave it at I fired an inappropriate number of rounds on a hot day just to empty GI M2 and discover it was shooting 4 groups 18" apart .
Then there was the clean breach end out about 6' and the last 4" clean with a barrel that tapered from .308 to .304 but leaded like .......it was bad . Savage dovetail for the rear sight ........ Fire lapped the choke out out of it shot .310s that that exited at .306 couldn't beat the 1-8.5 twist . I did buy the NOE 230 for it but never did shoot them in it .
My stupid was strong in the 32 Rem which taught me a neat trick for finding the true chamber length ....... I believe there is a variation of that theme at play here .
In hindsight I've probably haggled with neck dia but used or rather T&E with assorted brass brands to find the one that worked .
If I have to ream the chamber to "fix" it , it'll be a 280 Express or 7×64 Brenkke. I do have a 280 Rem reamer . Might be I need to have a .287 size die .
I have a few options heck I can even do a chamber cast and have an actual look at the leade and throat ....... I might even have a junk 308 case I could use for a pound cast .
The first thing I ought to do is get her to settle down and make sure I'm not the 2" problem via over confidence or loss of motor memory.
Then there was the clean breach end out about 6' and the last 4" clean with a barrel that tapered from .308 to .304 but leaded like .......it was bad . Savage dovetail for the rear sight ........ Fire lapped the choke out out of it shot .310s that that exited at .306 couldn't beat the 1-8.5 twist . I did buy the NOE 230 for it but never did shoot them in it .
My stupid was strong in the 32 Rem which taught me a neat trick for finding the true chamber length ....... I believe there is a variation of that theme at play here .
In hindsight I've probably haggled with neck dia but used or rather T&E with assorted brass brands to find the one that worked .
If I have to ream the chamber to "fix" it , it'll be a 280 Express or 7×64 Brenkke. I do have a 280 Rem reamer . Might be I need to have a .287 size die .
I have a few options heck I can even do a chamber cast and have an actual look at the leade and throat ....... I might even have a junk 308 case I could use for a pound cast .
The first thing I ought to do is get her to settle down and make sure I'm not the 2" problem via over confidence or loss of motor memory.
RBHarter
West Central AR
Ok I did the deal with a 25-06' that had a collapsed neck . No sense messing up a good case . Expander out , I formed a 7×57 with a 25-06 neck sticking out of it like a MG blank . Annealed to excess with the deliberate intent of making it readily conform to all of the angles and edges .
My case length isn't an issue chamber gunk maybe but not the length , true length is 2.265 , the book calls 2.235 . The neck/shoulder jct is about .010 short but the shoulder/body is where it should be . The shoulder OD is .006 fat while the neck OD is dead on at .324 . The "blank" neck is .284 .
The form case was fired 2x with 12+ gr of Unique and settled grits topped with a gob of Darrs lube . The collapsed neck pushed out 90% flat the first time and all of the hard cam to close was removed . The necks and shoulders were polished with 0000 steel wool . Primed , loaded , and fired again rifling dents/marks show up with .212 smooth and step from neck to throat .050 long . The 25-06 case is 2.560 now . The neck fold is out and flat even the lube dents are gone . Nothing was sized for the second firing . I'm pretty sure 30k was enough to push stuff to full form . Long long Savage/Weatherby like straight leade requiring long long seating to reach the lands . About the only way to fix that would be to ream it 280 or face a .1 off the barrel , and buy a 7×57 reamer . I suppose a 180 and size the whole bullet.284 .
I might have enough room to just to just turn the barrel down 3 turns and conventionally finish ream the chamber .
I will figure something out I've shot several of these long throats successfully.
Size the .285 to .279 and roll them in paper , maybe .
My case length isn't an issue chamber gunk maybe but not the length , true length is 2.265 , the book calls 2.235 . The neck/shoulder jct is about .010 short but the shoulder/body is where it should be . The shoulder OD is .006 fat while the neck OD is dead on at .324 . The "blank" neck is .284 .
The form case was fired 2x with 12+ gr of Unique and settled grits topped with a gob of Darrs lube . The collapsed neck pushed out 90% flat the first time and all of the hard cam to close was removed . The necks and shoulders were polished with 0000 steel wool . Primed , loaded , and fired again rifling dents/marks show up with .212 smooth and step from neck to throat .050 long . The 25-06 case is 2.560 now . The neck fold is out and flat even the lube dents are gone . Nothing was sized for the second firing . I'm pretty sure 30k was enough to push stuff to full form . Long long Savage/Weatherby like straight leade requiring long long seating to reach the lands . About the only way to fix that would be to ream it 280 or face a .1 off the barrel , and buy a 7×57 reamer . I suppose a 180 and size the whole bullet.284 .
I might have enough room to just to just turn the barrel down 3 turns and conventionally finish ream the chamber .
I will figure something out I've shot several of these long throats successfully.
Size the .285 to .279 and roll them in paper , maybe .
RicinYakima
High Steppes of Eastern Washington
RBHarter
West Central AR
I have a Mason jar full of Sierra 120s and lots of boxed choices . Unfortunately the 154 HPBT I really liked in a couple of other 7mm isn't available anymore.
When I did the 7×6.8SPC I was gifted 7-8 different bullets to try . I have a bunch of those still on hand . As for the limited taper I don't think there's a cure there .
Custom moulds I suppose. The 270-150 might be the ticket here in paper . A shame really I would have really liked to have had the slow fat recipe work . The brass is ready to go for the next volley so I think I'll try a genuine work up, 5 steps at .2 and see where that goes . A weekend reamer isn't all that expensive.
When I did the 7×6.8SPC I was gifted 7-8 different bullets to try . I have a bunch of those still on hand . As for the limited taper I don't think there's a cure there .
Custom moulds I suppose. The 270-150 might be the ticket here in paper . A shame really I would have really liked to have had the slow fat recipe work . The brass is ready to go for the next volley so I think I'll try a genuine work up, 5 steps at .2 and see where that goes . A weekend reamer isn't all that expensive.
RBHarter
West Central AR
Part of that is the taper from not a clean form . It's almost identical to the Clymer reamer except for the taper . This isn't the first place I've seen this
In the Rossi M92's the chambers are 1.305 for the 1.285 case . Whiler the cause is different the same situation exists in the 6.5 Japanese . I have some Cerro cast so I can get a good look at it but I have some expendable brass I can make a 3/4 inch long neck and trim it back until it will chamber with a flared mouth .
I don't care if I have to form and trim every piece to make it work it just irritates that the standard for a 125 yr old cartridge is that sloppy ...... I could fix the reamer ....... I've made more expensive mistakes
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In the Rossi M92's the chambers are 1.305 for the 1.285 case . Whiler the cause is different the same situation exists in the 6.5 Japanese . I have some Cerro cast so I can get a good look at it but I have some expendable brass I can make a 3/4 inch long neck and trim it back until it will chamber with a flared mouth .
I don't care if I have to form and trim every piece to make it work it just irritates that the standard for a 125 yr old cartridge is that sloppy ...... I could fix the reamer ....... I've made more expensive mistakes
.
Missionary
Well-Known Member
I enjoy reading these threads....
How many sincere fellers decide to cast for their favorite hunting rifle without any idea what awaits down in the chamber to destroy their 1st attempts to accurately fire those new cast bullets.
Shooting soft cast with Goex 3F BP is so much more enjoyable. Massive contained explosions sure do sort out alot of issues fast.
But back to this passing fad of "smokeless cast shooting".
How many sincere fellers decide to cast for their favorite hunting rifle without any idea what awaits down in the chamber to destroy their 1st attempts to accurately fire those new cast bullets.
Shooting soft cast with Goex 3F BP is so much more enjoyable. Massive contained explosions sure do sort out alot of issues fast.
But back to this passing fad of "smokeless cast shooting".
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RBHarter
West Central AR
I went out today and shot some of those silly jacketed things in it , old Hornady 120 gr HP . To be fair everything shot high and right so the results high and right are what they are . 45.5 gr of H4831 and a half turn off the lands gave me enough to start with. No clue where the same 45&45.5 4350 loads went . High and right was 8" high and 6" right at 50 yd .
I guess whatever the the deal is in the rifle is action and stock communication. The bullet fit isn't the whole bug here it's a player for sure , I don't think that it's the major cause .
The 45 gr load was about 4" the 45.5 was about 1" . So I think for now I'll set the 168 aside and stick to the NOE 150 Hunter .
I think after all of this while the bullet isn't a great fit I don't think is as at fault
I guess whatever the the deal is in the rifle is action and stock communication. The bullet fit isn't the whole bug here it's a player for sure , I don't think that it's the major cause .
The 45 gr load was about 4" the 45.5 was about 1" . So I think for now I'll set the 168 aside and stick to the NOE 150 Hunter .
I think after all of this while the bullet isn't a great fit I don't think is as at fault
RBHarter
West Central AR
It was bedded tight and solid when I was trying to figure out why it would shoot 2-3 of 5 together and toss the rest over there a foot when it was an 06' .
Donna an I have learned volumes.........applied tomes in any case , together since 1993 .
The mounts weren't parallel by enough that it took a 30x1" piece of rod to get them lined up with the barrel . The new mounts and rings placed the right side of the 1" rod about 1/4' off the left side of the muzzle.
Lots of adventures . This was the one that leaded from the rear barrel dove tail to about 3" behind the muzzle . With humps removed from the roll stamp and dove tail and the muzzle opened from .303 to .305 things improved almost as much as figuring out the case capacity thing .
With the 06' barrel just .3 gr of IMR 4350 it would open groups from 5 over lapping to 1.25" CTC. Literally 25 fps made the difference between meat rifle that'll do and .75 squirrel slayer. Yes there could be some walk but I'm betting against it when a half gr of the very slow almost cannon powders that max out at "you just can't get any more in the case and keep a bullet in it" .
Not disagreeing or discounting the possibilities just relating things as they evolve and progress. It might be useful to the next guy .
I never had a baseline with this set up so I needed to do this anyway.
The jacketed loads smoked cases which I thought was weird also . Loads were well over 35kpsi as the 4350 was clean as was the 4831 .
Donna an I have learned volumes.........applied tomes in any case , together since 1993 .
The mounts weren't parallel by enough that it took a 30x1" piece of rod to get them lined up with the barrel . The new mounts and rings placed the right side of the 1" rod about 1/4' off the left side of the muzzle.
Lots of adventures . This was the one that leaded from the rear barrel dove tail to about 3" behind the muzzle . With humps removed from the roll stamp and dove tail and the muzzle opened from .303 to .305 things improved almost as much as figuring out the case capacity thing .
With the 06' barrel just .3 gr of IMR 4350 it would open groups from 5 over lapping to 1.25" CTC. Literally 25 fps made the difference between meat rifle that'll do and .75 squirrel slayer. Yes there could be some walk but I'm betting against it when a half gr of the very slow almost cannon powders that max out at "you just can't get any more in the case and keep a bullet in it" .
Not disagreeing or discounting the possibilities just relating things as they evolve and progress. It might be useful to the next guy .
I never had a baseline with this set up so I needed to do this anyway.
The jacketed loads smoked cases which I thought was weird also . Loads were well over 35kpsi as the 4350 was clean as was the 4831 .
fiver
Well-Known Member
i don't get too worked up over smoked cases.
everyone makes a deal out of it happening, but whatever.
i've had about everything i've shot dirty up the cases in one way or the other, 9mm's, 45 colts, 30-30's, my deer rifle does it too and manages to shoot 3 shot 1/2" groups in the process.
everyone makes a deal out of it happening, but whatever.
i've had about everything i've shot dirty up the cases in one way or the other, 9mm's, 45 colts, 30-30's, my deer rifle does it too and manages to shoot 3 shot 1/2" groups in the process.