retumbo powder......pressure signs

[YOTES2CALL]

I am loading for my 7mm RM. Using 73 grains of Retumbo and a 168 berger vld. Not even the max load and I am having pressure signs on my cases and primers. The headstamp is getting marked up from the bolt face...

Anyone else seeing this when using Retumbo ? /ubbthreads/images/graemlins/confused.gif

 

[Jim Oliver]

Haven't used it at all in the 7RUM--a little in the 300 RUM.

Haven't noticed what you are seeing. What is your velocity?

Jim

 

[YOTES2CALL]

3143 avg. on 5 shot string with 21 fps from high to low

 

[kraky]

Not sure where you are getting your data....here is hodgdons' website. Looks like you are right at max to me.

http://data.hodgdon.com/main_menu.asp

Also I've had good luck running retumbo in my 300 wby. All my loads have been perfectly "called" or guessed by my quickload program so I think it has the burn rate pretty well "nailed" on retumbo.

I ran you load past quickload and it guesses you will do 3127 fps at 66,000 psi......

I'd say you've hit the max....good job on watching signs!!

 

[270bdl]

I've had good luck with it too in my 7mm saum with 175's.

 

[Joel Russo]

I was shooting 93 gr of Retumbo with the 168 Berger in my 7 RUM, 215's with a 32.5" bbl. Killer accuracy, killer velocity, 3580 fps, and also killer on the cases. Only get one or two reloads before the primer pocket opend up. Every once in a while I would blow them up on the way down range.
One day I walked it down to 85.0 gr in one grain increments to see where accuracy and velocity fell off. I ended up with 85.0 gr at 3300fps with the same killer accuracy, and an ES of 15 fps. Cases now survive about five or six reloads. You may have a tight barrel. Try doing what I did, you may find that comfortable load on the bottom.

 

[YOTES2CALL]

Thanks guys....

Joel, i will try that....

Thanks Kraky for running that...

Yotes

 

[toddconley]

I am interested in that quick load program Where do I get that? How much is it?
Thanks,
T

 

[284STW]

Your shooting a 7mm Rem Mag and not a Rum correct? That velocity seems pretty high for a 168 in a Rem Mag. Somteimes you can reach max velocity or pressure before book. That being said, the Hodgdon manual shows 73.5 for a 162 and 68 for a 175. If it's a Rum it should be wanting more like 95 grains or so...

 

[kraky]

Here's where you get it....

http://www.neconos.com/

It also comes with a great ballistic calculator. I used to think it was only slightly better than crossreferencing loading manuals. BUT...they keep upgrading the burn rates and have added tons of cartridges....to the point I think they are more accurate than alot of manuals.....escpecially the way all the bullet and powder people are taming down the charge wts because of "Lawyerism"!!
I now find it worth every penny and use it quite a bit.

 

[YOTES2CALL]

correct, I am shooting a Rem mag. at 5125 ft. elevation

Thanks guys... loaded some at 71 down to 68 that I am gonna go try out.... I'll let ya know the results.

think I will toss the cases with the slight pressure marks.

 

[kraky]

I wouldn't toss em just because of the marks. I've seen factory weatherby that got the marks with factory loads and the cases lasted another 3-4 loadings. I'd resize them and see how easy the next batch of primers seats.

 

[YOTES2CALL]

I'll try that..... thanks guys.... Yet to shoot the new loads.... Wind is crazy around here lately !!!

 

[YOTES2CALL]

Hodgdon Powder Company
Cartridge Load Recipe Report - 1/26/2007 7mm Remington Magnum
Load Type: Rifle Powder: Retumbo

Cartridge Information
Case: Winchester Barrel Length: 24"
Twist: 1:9.5" Trim Length: 2.490"
Primer: WINCHESTER LR

7mm Remington Magnum
Cartridge Load Data Starting Loads

--------------------------------------------------------------------------------
Maximum Loads

--------------------------------------------------------------------------------

Bullet Weight (Gr.) Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
140 GR. NOS PART Retumbo .284" 3.250" 71.0 2955 46,100 CUP 75.0C 3107 49,400 CUP
150 GR. NOS PART Retumbo .284" 3.270" 68.0 2818 43,300 CUP 72.5C 2998 50,300 CUP
160 GR. NOS PART Retumbo .284" 3.290" 65.0 2756 43,200 CUP 69.5C 2915 49,900 CUP
162 GR. HDY SPBT Retumbo .284" 3.290" 69.0 2787 43,900 CUP 73.5C 2963 50,500 CUP
170 GR. SIE RN Retumbo .284" 3.270" 71.0 2752 44,200 CUP 75.0C 2899 50,700 CUP
175 GR. NOS PART Retumbo .284" 3.290" 64.0 2650 45,400 CUP 68.0 2800 51,200 CUP