Looking at IMR 7977 in latest QuickLoad update

[ksubuck]

Just got the newest update in the mail today. Loaded it on the computer and adjusted my powder list to include the Enduron powders. Ran a few simulations with various magnum cartridges and am confused.

I thought that IMR 7977 was the slowest of the Enduron powders, between H1000 and IMR 7828. Numerous different cartridge/bullet combinations predicts that IMR 7977 produces less velocity than IMR 4955, IMR 4451, and sometimes IMR 4166, and often has much less complete burn. 7977 doesn't come close to H1000 or I7828. It also often falls below H4831 and occasionally H4350. Predictions usually run 150 to 200 fps slower than comparable published burn rate powders.

I was starting to wonder if there was an error in the new Quickload numbers. Since I had done some load work using 7977 in a 7 rem mag, I adjusted a model to match my chronograph numbers to see where things settled out. I found that I had to adjust the Ba about 6% to match my numbers. It did predict my accuracy nodes dead on and also matched where I noted early pressure signs.

Maybe 7977 isn't what the manufacturer claims? Wonder what a 32 inch barrel would do?

Educate me, please.

 

[Bbear]

I'm currently running 7977 in two of my 25-06's pushing the 110 AB. Both are with 22" barrels. Velocities in both are in the 3175-3250 range and accuracy is superb. Taking them out to 400 yards, drops are consistent and groups hold their .5 or so groups out to that range.
No pressure signs, accurate and fast enough to do what I want.

 

[ksubuck]

Get much smoke with that load and a short barrel? My 7 rem mag load is a 140 AccuBond over 7977 running 3085fps. A little slow, excellent accuracy, smokes like a campfire using wet wood...

 

[MrMinks2]

I'm currently running 7977 in two of my 25-06's pushing the 110 AB. Both are with 22" barrels. Velocities in both are in the 3175-3250 range and accuracy is superb. Taking them out to 400 yards, drops are consistent and groups hold their .5 or so groups out to that range.
No pressure signs, accurate and fast enough to do what I want.

Bbear: I'm looking at the same combination. I haven't worked up any loads yet but I'm thinking of starting out at 58 grains. Where did you find your best results?

Regards

 

[gerry]

So far it delivers with 150-160 gr bullets in the 270 Win and gets the speed Hodgdon shows in their data. I used in in 7mm Rem Mag with 154 gr Hornady bullets but didn't end up running it over a chronograph, shot well though.

 

[Bbear]

I'm currently running 7977 in two of my 25-06's pushing the 110 AB. Both are with 22" barrels. Velocities in both are in the 3175-3250 range and accuracy is superb. Taking them out to 400 yards, drops are consistent and groups hold their .5 or so groups out to that range.
No pressure signs, accurate and fast enough to do what I want.

Bbear: I'm looking at the same combination. I haven't worked up any loads yet but I'm thinking of starting out at 58 grains. Where did you find your best results?

Regards

I started at 56 grains and worked up to 61. Started getting some swipes at 61 and the groups opened up.
One rifle likes 58.5 and one likes 59. Using BR2 primers and Hornady brass.

 

[kraky1]

Quickload doesn't always get things right. I have some 7977 loaded up in various calibers but haven't been to the range yet.
My version of quick load is not new enough to have it. almost every time somebody posted results with it on the internet I went to quick load and found it really really matched up well to reloader 25 in quick load. Hogdons data seems to mirror re25 for casts on quickload too.

 

[ksubuck]

I noticed that 3 of the Enduron powders have no value for regressivity (a0). Having no idea what that is, I wonder if that has something to do with the odd predictions.

Anyone know anything about regressivity?