I have been ladder testing IMR 4895 (NOT H4895) in my LMT MWSE 308 semi auto, using Lapua cases, Winchester Large Rifle primers, and Sierra 175g Matchking. Results have been good.
But I see so many on this forum and elsewhere using Varget instead. I see from the powder burn rate tables that Varget burns slower. In addition, the Hodgdon 2012 Annual Manual shows that the peak pressure at max loads is lower with Varget than with IMR 4895 (48,600 CUP versus 57,800 psi), but since one was measured with copper plugs and the other via transducer, I don't know if the actual pressure (measured using the same method) would be different or not.
I also seee an unbelievable difference in maximum powder charges, between the info in the Hodgdon manual and the info in the Sierra manual. The Hodgdon max charges are WAY higher. Since Hodgdon makes the powders and did use the Sierra bullets for the testing, and Sierra does not make the powders, it is tempting to assume that the Hodgdon data is the one to believe.
I am interested in what changes might occur in:
- Accuracy?
- Attainable ACCURATE velocity?
- Cleanliness?
- Gas port pressure higher or lower?
My priorities are:
1. Being easy on the firearm
2. Accuracy
3. Cleanliness
Peak velocity is not a priority, as I want to maximize case life.
How would results using Varget versus IMR 4895 LIKELY differ?
What is an actually good starting point and maximum charge for the Varget in a typical 308 semi auto AR rifle?
I would really have liked to try a Vihtavuori powder, since I have had such great experience with VV powder in my handguns, but I can't get any VV rifle powder locally, and would have to pay the hazardous shipping fee TWICE (once for 1 or 2 pounds to "try" and then again on an 8 lb container if I like it, so I have pretty much given up on that idea.
Jim G
But I see so many on this forum and elsewhere using Varget instead. I see from the powder burn rate tables that Varget burns slower. In addition, the Hodgdon 2012 Annual Manual shows that the peak pressure at max loads is lower with Varget than with IMR 4895 (48,600 CUP versus 57,800 psi), but since one was measured with copper plugs and the other via transducer, I don't know if the actual pressure (measured using the same method) would be different or not.
I also seee an unbelievable difference in maximum powder charges, between the info in the Hodgdon manual and the info in the Sierra manual. The Hodgdon max charges are WAY higher. Since Hodgdon makes the powders and did use the Sierra bullets for the testing, and Sierra does not make the powders, it is tempting to assume that the Hodgdon data is the one to believe.
I am interested in what changes might occur in:
- Accuracy?
- Attainable ACCURATE velocity?
- Cleanliness?
- Gas port pressure higher or lower?
My priorities are:
1. Being easy on the firearm
2. Accuracy
3. Cleanliness
Peak velocity is not a priority, as I want to maximize case life.
How would results using Varget versus IMR 4895 LIKELY differ?
What is an actually good starting point and maximum charge for the Varget in a typical 308 semi auto AR rifle?
I would really have liked to try a Vihtavuori powder, since I have had such great experience with VV powder in my handguns, but I can't get any VV rifle powder locally, and would have to pay the hazardous shipping fee TWICE (once for 1 or 2 pounds to "try" and then again on an 8 lb container if I like it, so I have pretty much given up on that idea.
Jim G