338 Lapua and IMR 7977

[DTF370]

Hey guys, does anybody have any IMR 7977- 338LM data? I’ve been working on trying to get my 338 to shoot better. I have H1000 which I have tried with no luck. I picked up some IMR 7977 to try some different bullet/powder combo’s but I’m not finding much data. I’m hoping to try 250gr berger EH, 285eld-m, and 285 BTHP. Any help and/or guidance would be much appreciated.

Thank you.

 

[Steel head]

7977 uses almost exactly the same data as H1000 with very similar speeds.

 

[Fixr]

I tried 7977 and H1000 without much luck, finally settled on Retumbo with the 285gr ELD-Ms. Some 7977 load data here https://www.snipershide.com/shooting/threads/new-338-lm-loads.6955101/

 

[DTF370]

I tried 7977 and H1000 without much luck, finally settled on Retumbo with the 285gr ELD-Ms. Some 7977 load data here https://www.snipershide.com/shooting/threads/new-338-lm-loads.6955101/

I believe this is going to be my experience as well. Unfortunately Retumbo seems to be a ghost that nobody has seen.

 

[jambau]

Hey guys, does anybody have any IMR 7977- 338LM data? I’ve been working on trying to get my 338 to shoot better. I have H1000 which I have tried with no luck. I picked up some IMR 7977 to try some different bullet/powder combo’s but I’m not finding much data. I’m hoping to try 250gr berger EH, 285eld-m, and 285 BTHP. Any help and/or guidance would be much appreciated.

Thank you.

I'm loading the 285 ELDM's with 98.0 grains of RL33. Super happy with this combo. The ELDM's dont seem to be too sensitive to seating depth.

 

[DTF370]

I had no luck with my factory RPR barrel. Just couldn’t get under 0.8 moa. I tried H1000, IMR7977, and 4891 with 4 different bullet combos. Ordered a LRI barrel after giving up. I’ll be going to 338 LM AI and shoot 300gr Berger’s.

 

[jambau]

That's suprising. I have 4 shooting buddies that run RPR's. Two are 338 LM. They're all having good results. Good luck with the new set up. Let me know if you want to sell the barrel. One of the guys may want it.

 

[DTF370]

That's suprising. I have 4 shooting buddies that run RPR's. Two are 338 LM. They're all having good results. Good luck with the new set up. Let me know if you want to sell the barrel. One of the guys may want it.

Thank you. Yes every RPR I’ve tinkered with have all been hammers. I would be willing to sell the take off barrel once I get setup.

 

[jambau]

I got a buddy in FL that's about due for a barrel change. He's not a precision guy and only shoots to 600. I'll check with him and PM you if you dont mind.

 

[supraguy88t]

I myself have been shooting Sierra 300gr with H1000. With H1000 being harder to find recently I am going to try the 7977 with both the 300Gr and some 250Gr Bergers. here is the Data I found of Hodgdon's site

Case: Norma
Twist: 1:9.000"
Primer: Federal 215M, Large Rifle Magnum Match
Barrel Length: 24.000"
Trim Length: 2.714"
BULLET WEIGHT250 GR. HDY SP

Manufacturer IMR
Powder IMR 7977
Bullet Diam. 0.338"
C.O.L. 3.550"

Starting Loads
89.2 Grs.
2,691 Vel. (ft/s)
49,200 PSI Pressure

Maximum Loads
97.0 Grs.
2,927 Vel. (ft/s)
61,300 PSI Pressure

 

[DTF370]

I myself have been shooting Sierra 300gr with H1000. With H1000 being harder to find recently I am going to try the 7977 with both the 300Gr and some 250Gr Bergers. here is the Data I found of Hodgdon's site

Case: Norma
Twist: 1:9.000"
Primer: Federal 215M, Large Rifle Magnum Match
Barrel Length: 24.000"
Trim Length: 2.714"
BULLET WEIGHT250 GR. HDY SP

Manufacturer IMR
Powder IMR 7977
Bullet Diam. 0.338"
C.O.L. 3.550"

Starting Loads
89.2 Grs.
2,691 Vel. (ft/s)
49,200 PSI Pressure

Maximum Loads
97.0 Grs.
2,927 Vel. (ft/s)
61,300 PSI Pressure

I did see Hodgdon’s data, but unfortunately they only list the hornady SP bullet. I love Hodgdon, but I think 97gr is dangerous in most 250 class bullets. For example, berger lists 90gr of H1000 as the max charge. H1000 is supposed to be extremely close to IMR 7977. I tried 250gr Berger’s and 7977 in a pressure test. I hit Hard bolt lift around 93gr. With 285 ELD’s I hit hard lift at 91 grain.

 

[Steel head]

I did see Hodgdon’s data, but unfortunately they only list the hornady SP bullet. I love Hodgdon, but I think 97gr is dangerous in most 250 class bullets. For example, berger lists 90gr of H1000 as the max charge. H1000 is supposed to be extremely close to IMR 7977. I tried 250gr Berger’s and 7977 in a pressure test. I hit Harold bolt lift around 93gr. With 285 ELD’s I hit hard lift at 91 grain.

Lol
I saw a guy shooting 91-92 grains of H1000 and 300 Berger’s yesterday.

 

[DTF370]

Lol
I saw a guy shooting 91-92 grains of H1000 and 300 Berger’s yesterday.

More what I was meaning is I think 97 grains of 7977 with 250 grain bullets may be dangerous in bullets other than the 250gr hornady soft point. It seemed to me Hodgdon was more aggressive with the max load when comparing to other loads and in my case is sure was. YMMV

 

[Steel head]

More what I was meaning is I think 97 grains of 7977 with 250 grain bullets may be dangerous in bullets other than the 250gr hornady soft point. It seemed to me Hodgdon was more aggressive with the max load when comparing to other loads and in my case is sure was. YMMV

I agree 97 seems a bit high for 250’s
The pressure signs WERE showing on the 92 grains load.