dellet
Gold $$ Contributor
I’m curious what the estimated pressure was with Quickload.
For a primer pocket to get loose in only a few firings, it’s not a 65,000 psi load. It likely higher. Measuring base expansion would be helpful.
My experience with 296 lilgun in small cartridges, with low density is exactly what you’re getting. High ES/SD numbers and flyers. With 296 groups really tighten up around 95%. Doesn’t sound like you’ll get there.
With the other powders mentioned before. 1680, N120, Shooters World, LT 30, 4198. You might drop 100 fps. But the pay off will likely be cutting your group size at least in half.
17.5 twist really isn’t a problem. You’re not using a boat tail. Unless it’s very long for length, it will be stable. JBM will not work very well for flat base bullets. You need to use a full on drag calculator, entering the complete bullet dimensions. Greenhill might even be more accurate.
At 25-2700 fps, varmint bullets won’t come apart with any drama. But they will have double caliber expansion down to around 2000fps or less. I think you said you were hoping for an 11 year old to shoot this? Unless you have them shooting past 300 yards, 2600 fps will be more than adequate.
A sub MOA load at even 2500 fps will be more than enough.
Can you give a cartridge base or ogive length on your current bullet?
For a primer pocket to get loose in only a few firings, it’s not a 65,000 psi load. It likely higher. Measuring base expansion would be helpful.
My experience with 296 lilgun in small cartridges, with low density is exactly what you’re getting. High ES/SD numbers and flyers. With 296 groups really tighten up around 95%. Doesn’t sound like you’ll get there.
With the other powders mentioned before. 1680, N120, Shooters World, LT 30, 4198. You might drop 100 fps. But the pay off will likely be cutting your group size at least in half.
17.5 twist really isn’t a problem. You’re not using a boat tail. Unless it’s very long for length, it will be stable. JBM will not work very well for flat base bullets. You need to use a full on drag calculator, entering the complete bullet dimensions. Greenhill might even be more accurate.
At 25-2700 fps, varmint bullets won’t come apart with any drama. But they will have double caliber expansion down to around 2000fps or less. I think you said you were hoping for an 11 year old to shoot this? Unless you have them shooting past 300 yards, 2600 fps will be more than adequate.
A sub MOA load at even 2500 fps will be more than enough.
Can you give a cartridge base or ogive length on your current bullet?
