H4831sc and 6.5 Creedmoor

Intheshop

Banned
There's a BUNCH of 6.5's. With it seems,not enough case difference to amt to much? Heck,mine is a 6.5X54MS and it's chambering is old as dirt.....and still not appreciably different from a 260?

A better discussion to me at least is,the 308 family along with the '06 family..... same cases,different sized holes.
 
Last edited:

Spindrift

Well-Known Member
Lots of interesting info, thanks guys!
The QL results took me by surprise. I wish 3031 was available around here......
Ian, if I could bother you to run calculations with one more powder... Does QL list Vectan tubal-3000? Been shooting it quite a lot recently.
 

fiver

Well-Known Member
those IMR pamphlets ITS shows are full of all kinds of interesting loads.

hey BW look at the 45 colt/44 mag data and see what it shows for 4895.
I think there might be some 4198 data for them too.

whoever the 'engineer' on the project was, he has to have some kind of back story on why they tested some of the loads they show.
 

fiver

Well-Known Member
okay the 260 Rem.
I been mulling this guy over since it's inception.

first Remington jacks it over by repeating the mistake they made with the 6mm rem.
then they jack it over even more by handicapping it in their short action.
straight up following down the path of why there are 2 versions of the 6.5-284.
and even further handicapping it by sending in lower pressure specifications to SAAMI than necessary.
all of this lends itself to just barely matching the 6.5X55 but only with 120gr or lighter bullets.

the boys at Hornady see all of these faults and proceed to back up the cartridge length and case volume to more than match what the 260 truly has with the handicap of the short action and deep seated bullets.
since they are at it they flatten the shoulders some to get just a touch more case volume but not too much so the burn rate of the powder isn't negatively affected.
then they seat the bullet out to the same oal as the 260 has only with another 20grs of weight, tack on the other 3-4K of pressure the 260 dropped on it's way in and there ya go,, the Creedmore is born.

it is what the 260 should have been all along.[ballisticaly]
if only someone would have used the medium action length rifle they been sitting on since buying the importation rights from Charles Daley and pricing themselves out of selling any of those rifles years back.
had Remington only dropped the proper oal with the higher pressure MAP into one of those actions with a synth stainless combination 1/8 twist barrel the shooting world would be a bunch different today.
 
  • Like
Reactions: Ian

Intheshop

Banned
Yeah but... given a choice,I'd take the slower 244 twist over my 80's 6mm V any day of the week. And if there are "early" slow'er twist,shorter throated 260's..... then sign me up for one of those too.

Speaking of 4350.... '68 R700 243 became a one load rig with 43.5g of that powder under an 85g Sierra BTHP. Just wasting time looking for any other load? The slightly larger brother 6mm dotes,as well on FB Sierra 100's with max IMR4350.

Just opinion.... but have been pretty consistent shooting R700's....
Remington,through the 50's and early 60's had hands on shooting engineers steering the ship,as those guys gradually retired,a new breed of engineer shows up. The whole "show" changed when the drafting machine gave way to computers. This is when bean counter "Business major" guys started being run through college in a very much,revolving door fashion. The problem was,that it didn't translate,or transfer of power very well,at all for a company that started "analog".

It gets even more complicated today.... the internet has "seeded" the notion that older 700's are better. I can make a compelling argument against that but won't.

Fiver,not any 4895 or 4198 loads in the above IMR manual for 45 or 44. The 44 mag pressures sure are up there though.... right @40,000.... sheesh!
 

fiver

Well-Known Member
now I'm gonna have to go re-dig through and see where I saw that data at.
it comes to mind it was in the rifle section for those cartridges, and it was for sure IMR data.
 

fiver

Well-Known Member
okay there we go.
now look at the relationship between the powder speeds.
3031/4320/4895 they start showing small variances in pressure and speed even at these outer uses.
you could easily be fooled into thinking 4895 is slower than 4064 or that 3031 is slower than 4320 if you only had say a chronograph to work from.

it'd also be real confusing to sit there and think how the hell am I going slower with 1.5grs more powder and another 2-K in pressure?
burn rate.
the powder is a going real well initially, but it isn't going fast enough long enough to contribute to the acceleration of the bullet after a certain point.

anyway.
this really illustrates the usefulness of powders so slow you'd never think of them as ever being useful.
 

Ian

Notorious member
The angle of the pressure/time slope coming off the peak is where 95% of the "power" is that gives us velocity. If that slope drops off real fast, you have smoke and pressure and noise and recoil, but not much to show for it.