IMR 7977 Load Data vs H1000

[dwm]

So I loaded some 270WIN with IMR 7977 based on a conservative H1000 charge and took them out and shot them.

Let's just say I don't appreciate primers falling out when the case is extracted.

Now I have to pull the bullets out of the rest of them and start over.

The IMR 7977 that I have is no where near as slow as H1000. It is much faster.

I think using IMR 7828 load data would be closer to IMR 7977 than using H1000. (and the error would be on the conservative - safe side)

I can tell you I am going to back this load down at least 2 grains maybe more before I try IMR 7977 again.

This is what the Hodgdon's web site says for a .277 cal 160 Nosler Partition:

Manufacturer Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
Hd H1000 .277" 3.340" 55.0 2,614 44,200 CUP 59.0C 2,765 50,900 CUP
IMR 7977 .277" 3.340" 56.4 2,662 50,700 PSI 60.0C 2,843 59,800 PSI

By looking at this one would get the impression IMR 7977 is slightly slower than H1000. (IMR 7977 goes from 56.4 to 60C, H1000 goes from 55 to 59C)

Has anyone else had a similar experience with IMR 7977?

Use IMR 7977 with caution!

Thanks,

Doug

 

[RockyMtnMT]

So I loaded some 270WIN with IMR 7977 based on a conservative H1000 charge and took them out and shot them.

Let's just say I don't appreciate primers falling out when the case is extracted.

Now I have to pull the bullets out of the rest of them and start over.

The IMR 7977 that I have is no where near as slow as H1000. It is much faster.

I think using IMR 7828 load data would be closer to IMR 7977 than using H1000. (and the error would be on the conservative - safe side)

I can tell you I am going to back this load down at least 2 grains maybe more before I try IMR 7977 again.

This is what the Hodgdon's web site says for a .277 cal 160 Nosler Partition:

Manufacturer Powder Bullet Diam. C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
Hd H1000 .277" 3.340" 55.0 2,614 44,200 CUP 59.0C 2,765 50,900 CUP
IMR 7977 .277" 3.340" 56.4 2,662 50,700 PSI 60.0C 2,843 59,800 PSI

By looking at this one would get the impression IMR 7977 is slightly slower than H1000. (IMR 7977 goes from 56.4 to 60C, H1000 goes from 55 to 59C)

Has anyone else had a similar experience with IMR 7977?

Use IMR 7977 with caution!

Thanks,

Doug

What did you load? We have used it quite a bit and like it.

Steve

 

[dwm]

Sorry I did not mean to imply there is something wrong with IMR 7977. I am only saying be careful determining a starting load for it and don't base your starting load on H1000.

I loaded 58.5 grains IMR 7977 under a 165 Matrix in both Hornady and Norma cases. I am jumping them 0.015" at a COAL 3.435".

According to QL, based on H1000, that should be 55Kpsi, and a conservative H1000 load. QL has been very accurate in predicting H1000 loads.

The IMR 7977 load I used, based on H1000 load data produced excessive pressure.

 

[Bbear]

I ran 7977 in two of my 25-06's with the 110 AB. Hodgden showed I-7977 for 100 and 117 gr pills with max figures of 61c and 59c respectively.

I ran the two rifles with loads to 59c and stopped. No pressure signs and got uniform groups near .5" with the load.