.270-300jls ai

[remingtonman_25_06]

Apples to apples, if your cartridge is outdoing another by 200-250fps with less case capacity, something just dont make sense. There is no such thing as "efficient" when your talking over bore rounds, and your 270-300 WIn mag improved is still definately over bore as is the 270-300 WBY in comparison. Dont think anybody in there right mind would consider either of them efficient rounds...

Velocity is usually a direct corralation to pressure. You could have a slightly fast barrel which could account for an extra 100-150fps at most, but to be getting 3700fps w/140's looks to be a bit ridiculous the more I look and think about it...

Like I said in my first post, I think you've got an exception rather then the norm. I'm not calling you out, but you gotta understand why a couple of us are questioning the velocity when its got what, 12-14g less H2O capacity then the 270-300 WBY, and its outdoing it by 250fps.

What kinda cronograph are you using by the way?

 

[CZ]

Apples to apples, if your cartridge is outdoing another by 200-250fps with less case capacity, something just dont make sense. There is no such thing as "efficient" when your talking over bore rounds, and your 270-300 WIn mag improved is still definately over bore as is the 270-300 WBY in comparison. Dont think anybody in there right mind would consider either of them efficient rounds...

Velocity is usually a direct corralation to pressure. You could have a slightly fast barrel which could account for an extra 100-150fps at most, but to be getting 3700fps w/140's looks to be a bit ridiculous the more I look and think about it...

Like I said in my first post, I think you've got an exception rather then the norm. I'm not calling you out, but you gotta understand why a couple of us are questioning the velocity when its got what, 12-14g less H2O capacity then the 270-300 WBY, and its outdoing it by 250fps.

What kinda cronograph are you using by the way?

We are using a CED M2 and a chrony Beta, my friend I dont think
there is a problem of measurement of the velocity, and "efficient" sorry for
missing and "f" hihi for sure it is, for the amount of powder we get
a "questionable" velocity, maybe like I said its the Cal, the barrel, the
capacity or all combined but its working, maybe someone here on the past had one or maybe in the future will have it and can compare "apples with apples". And to call me out first you have to test it to have a valid
comment.

 

[bullet]

It is an impossibility for a 270/300 to out do a 270/300Wby by 250fps. I think you need to chronograph again and post pictures of the chronograph and then use another one to compare it to and post pictures of that chronograph reading. Something is not right, but it can be figured out.

 

[CZ]

It is an impossibility for a 270/300 to out do a 270/300Wby by 250fps. I think you need to chronograph again and post pictures of the chronograph and then use another one to compare it to and post pictures of that chronograph reading. Something is not right, but it can be figured out.

 

[CZ]

It is an impossibility for a 270/300 to out do a 270/300Wby by 250fps. I think you need to chronograph again and post pictures of the chronograph and then use another one to compare it to and post pictures of that chronograph reading. Something is not right, but it can be figured out.

A lil time and I will post pictures and info regarding the round, If you consider a .308 "almost" equals a .3006 (more comments), why shouldnt this round be questionable? that .270-300wby its largely overbore as
a .264 Mag is, and its not too "efficient" burning those doses of slow
burning powder, Im not doing anything new it has done on the past but
with these "new" powders its another game, a 7mmSTW was questionable
on the past??????? a 280 ai had decades and now a lot of people using it?? is it a good round??? and we can continue.......

 

[bullet]

It is an impossibility for a 270/300 to out do a 270/300Wby by 250fps. I think you need to chronograph again and post pictures of the chronograph and then use another one to compare it to and post pictures of that chronograph reading. Something is not right, but it can be figured out.

A lil time and I will post pictures and info regarding the round, If you consider a .308 "almost" equals a .3006 (more comments), why shouldnt this round be questionable? that .270-300wby its largely overbore as
a .264 Mag is, and its not too "efficient" burning those doses of slow
burning powder, Im not doing anything new it has done on the past but
with these "new" powders its another game, a 7mmSTW was questionable
on the past??????? a 280 ai had decades and now a lot of people using it?? is it a good round??? and we can continue.......

I agree that you should get pretty close but not the same or more than the 270/300Wby and certainly not 250fps. I worked with a 270/300Wby that Foster a friend of mine had built and he ask me to help with the load development. I know the pressures it can take in a Mark V receiver and we were pushing some very fast velocities and because of my experience with the 270/300Wby I can not see how it is possible to be 250fps over the velocity of the 270/300Wby especially at the velocities we were pushing. I just think you need to compare chronograph readings with at least another chrony to make sure, that is all I am saying. I had a chrony that read 200-300fps faster than my other chrony and a friends. So just check it out and make sure. I also work with my own custom 257/300Wby and my custom 7mmSTW, sorry but I just can't see what you claim in velocity no matter what powder you use.

 

[CZ]

It is an impossibility for a 270/300 to out do a 270/300Wby by 250fps. I think you need to chronograph again and post pictures of the chronograph and then use another one to compare it to and post pictures of that chronograph reading. Something is not right, but it can be figured out.

A lil time and I will post pictures and info regarding the round, If you consider a .308 "almost" equals a .3006 (more comments), why shouldnt this round be questionable? that .270-300wby its largely overbore as
a .264 Mag is, and its not too "efficient" burning those doses of slow
burning powder, Im not doing anything new it has done on the past but
with these "new" powders its another game, a 7mmSTW was questionable
on the past??????? a 280 ai had decades and now a lot of people using it?? is it a good round??? and we can continue.......

I agree that you should get pretty close but not the same or more than the 270/300Wby and certainly not 250fps. I worked with a 270/300Wby that Foster a friend of mine had built and he ask me to help with the load development. I know the pressures it can take in a Mark V receiver and we were pushing some very fast velocities and because of my experience with the 270/300Wby I can not see how it is possible to be 250fps over the velocity of the 270/300Wby especially at the velocities we were pushing. I just think you need to compare chronograph readings with at least another chrony to make sure, that is all I am saying. I had a chrony that read 200-300fps faster than my other chrony and a friends. So just check it out and make sure. I also work with my own custom 257/300Wby and my custom 7mmSTW, sorry but I just can't see what you claim in velocity no matter what powder you use.

that are my readings by now, for sure I will continue with the tests, and
what you are saying you got 3450 fps with ur .270-300Bee, a lil slow dont you think? My readings now are 140gr AccuBond@80gr RL22 fed 215 mag @ 3690fps, Ive got with the 7mmSTW last tested 140Accubond@82gr
RL22 fed 215 @ 3580fps, all are barrels tested are poly form PACNOR in the 7mmSTW and Broughton in the .270-.300jls ai 28" long.
Its nice to have a good debate here in the forum.
have a nice day and enjoy ur guns.

 

[bullet]

It is an impossibility for a 270/300 to out do a 270/300Wby by 250fps. I think you need to chronograph again and post pictures of the chronograph and then use another one to compare it to and post pictures of that chronograph reading. Something is not right, but it can be figured out.

A lil time and I will post pictures and info regarding the round, If you consider a .308 "almost" equals a .3006 (more comments), why shouldnt this round be questionable? that .270-300wby its largely overbore as
a .264 Mag is, and its not too "efficient" burning those doses of slow
burning powder, Im not doing anything new it has done on the past but
with these "new" powders its another game, a 7mmSTW was questionable
on the past??????? a 280 ai had decades and now a lot of people using it?? is it a good round??? and we can continue.......

I agree that you should get pretty close but not the same or more than the 270/300Wby and certainly not 250fps. I worked with a 270/300Wby that Foster a friend of mine had built and he ask me to help with the load development. I know the pressures it can take in a Mark V receiver and we were pushing some very fast velocities and because of my experience with the 270/300Wby I can not see how it is possible to be 250fps over the velocity of the 270/300Wby especially at the velocities we were pushing. I just think you need to compare chronograph readings with at least another chrony to make sure, that is all I am saying. I had a chrony that read 200-300fps faster than my other chrony and a friends. So just check it out and make sure. I also work with my own custom 257/300Wby and my custom 7mmSTW, sorry but I just can't see what you claim in velocity no matter what powder you use.

that are my readings by now, for sure I will continue with the tests, and
what you are saying you got 3450 fps with ur .270-300Bee, a lil slow dont you think? My readings now are 140gr AccuBond@80gr RL22 fed 215 mag @ 3690fps, Ive got with the 7mmSTW last tested 140Accubond@82gr
RL22 fed 215 @ 3580fps, all are barrels tested are poly form PACNOR in the 7mmSTW and Broughton in the .270-.300jls ai 28" long.
Its nice to have a good debate here in the forum.
have a nice day and enjoy ur guns.

I did not post any velocities, you must be thinking of some one else and their post. I looked back at my notes and we drove a 130gr bullet using IMR7828 over 3800fps out of our 270-300Wby. A 140 over 3500fps and a 150 over 3350fps. We were more interesting in the 130gr bullets so did not exhaust our resources on the 140 or 150gr bullets.

 

[SJB358]

CZ, it will be pretty neat when you have your final load development. Either way, if you are happy with your loads and feel safe with them, and they aren't going to hurt you, I say rock on. Can't wait to see some targets. Sounds like an impressive round. Scotty

 

[remingtonman_25_06]

Sure a 308 can "almost" reach 30-06 velocities, but you dont see anyone claiming a 308 to get 250fps over a 30-06 do you?

The 270-300 Win Improved should be able to "almost" reach 270-300 WBY velocities, not beating them by 250fps...

Its the same difference, the one with the MOST capacity will win in the end reguardless. Theres no way something with 14g less capacity is going to outdo something by 250fps without being ridiculously over pressure. This is common sense in the shooting world, you dont have to own one or test one to know that.

Like I said in the beginning, you could very well be getting those velocities, but I think its an exception rather then the norm.

Anyways, I"ll be looking forward to see actual pics of the cartridge, rifle, groups, and velocities on the cronograph.

 

[FOTIS]

TINSTAAFL!


My favorite saying.


There is no such thing as a free lunch! :lol:

 

[bullet]

CZ, if you are using that much of the powder you mention, and you have got to be cramming it in the case, you could be setting yourself for being hurt. That rifle can't take what you are saying it is being fed. I hope I am wrong but I don't think so. A very close friend of mine who knows more than I do is very concerned about your load. Hope you are taking all that we are saying to you into account.

 

[30-338]

I know someone mention the 270 Allen Mag off the RUM case as an example but there is a history of other cases used for the 270. Kirby Allen also did a 270 Allen Express on the 300 Dakota case that one used 169.5gr wildcat bullet @ 3200fps. Next up was the 277 Allen Mag was a 270 on the 338 Laupa mag case that one use a 195gr Wildcatt bullet @ 3200fps.

I think most of those used a 1/8 twist 30" long Lilja barrel and with 140gr AccuBond those rifles 3650 to 3800fps was normal.

I mention that I looked at doing the 270 on the standard 338 mag case but I also looked at Kirby's 270 line up and I also looked at AI the standard 270Wby case. The Allen mags that shot the 140gr AccuBond they held up real good at that higher velocity and some shot the 130gr BT and you have to also figure they use 1/8 twist barrel vs a 1/10 that I was going to use.

I'd spend alittle time researching build a wildcat 270 and I think CZ did also. I think he build a good case and I'm surprised haven't seen more wildcats since Berger came out with his 270 bullets.

 

[CZ]

CZ, if you are using that much of the powder you mention, and you have got to be cramming it in the case, you could be setting yourself for being hurt. That rifle can't take what you are saying it is being fed. I hope I am wrong but I don't think so. A very close friend of mine who knows more than I do is very concerned about your load. Hope you are taking all that we are saying to you into account.

for sure I will take care, but Im serious about load development, I have my 2 Chronos handy always, and Ive worked with some wildcats on the past, 7mm STW on the 90" when it was a wildcat, 6mm mach iv (100gr
at 3900 fps, 6mm bullet in a 7mag case), .280ai when Nosler didnt take
care of it, and some more, I have a lil experience working with this toys.
The most intersting part of this is that maybe one or two will make one in the future,hihi.