A tale of 2 bullets...XTP and A-Frame in 41 magnum

[Ridgerunner665]

I did some individual groups with the loads...
no difference in accuracy between the 2 bullets that I can see.

I shot both on steel out to 200 yards, and paper at 50 and 100.

I think from a solid rest the rifle will do at least 1 inch at 50 yards...I forgot to take my Bulls Bag today so I was shooting from sitting, on the ground, same way shoot when hunting.

[JEBar]

that'll do and do very nicely ..

[Ridgerunner665]

The ballistician from Swift called me back today... he hasn't shot 4100 in the 41 mag yet, but max he recommends with 296/110 is 20 grains.

Given that 4100 is slightly faster burning than 110, 20.3 grains of 4100 is likely a little over the limit.

19.5 grains of 4100 should be OK... I'm gonna try 296 when I get back home since I have a pound of it already.

[Ridgerunner665]

Something is not adding up...

Swift says they maxed out with various powders (110, MP-300, Lil Gun) at around 1,430 fps from a 10 inch barrel.

Everywhere else you look that has pressure numbers with the load data is maxed out at 1,600+ fps from 10 inch barrels with various jacketed 210 grain bullets.

I've went over data from Lyman, Speer, Sierra, Lee, and Hodgden... every one hits 1,600+ fps with 210 grain jacketed bullets, from a 10 inch barrel.

The Swift bullet is longer than the XTP, by .053", but that isn't enough to slow it down to that degree.

I'm not sure what the length of the Nosler bullet is, but I expect it's pretty close to the XTP.

I'm inclined to believe my load of 20.3 grains of 4100 at 1,705 fps from the 16.5 inch barrel is safe and then some.

Because I know from experience that 20 fps per inch is an accurate estimate for velocity per inch for barrels between 4 and 20 inches long with both the 41 and 44 mag.

Using that, my load would be 1,575 fps from a 10 inch barrel....66 fps below Accurate Powders data for a max load of 21.1 grains of 4100 with the Nosler bullet... that also applies within a few fps for Hodgden, Lyman, Lee, etc...I can see a .053" longer bullet costing 66 fps, the numbers fit.

Use that info however you want, I believe my load is safe...

[Mags]

.

... from experience that 20 fps per inch is an accurate estimate for velocity per inch for barrels between 4 and 20 inches long with both the 41 and 44 mag.

Using that, my load would be 1,575 fps from a 10 inch barrel....66 fps below Accurate Powders data for a max load of 21.1 grains of 4100 with the Nosler bullet... that also applies within a few fps for Hodgden, Lyman, Lee, etc...I can see a .053" longer bullet costing 66 fps, the numbers fit.

Use that info however you want, I believe my load is safe...

[JEBar]

I'm not sure what the length of the Nosler bullet is, but I expect it's pretty close to the XTP.

Nosler uses a 10" Douglas barrel for its test

[Ridgerunner665]

I'm not sure what the length of the Nosler bullet is, but I expect it's pretty close to the XTP.

Nosler uses a 10" Douglas barrel for its test

I meant the length of their 210 grain bullet.

[Ridgerunner665]

To explain all this about bullet length a little bit, and why it matters...

The Swift bullet seats deeper into the case than the XTP, that means the usable case capacity is less for the Swift bullet... that means less powder for equal pressure (compared to the shorter bullet), which always means a little less velocity...its just like the say with cars, there is no replacement for displacement.

The bearing surface (the area that contacts the barrel) is pretty dang near identical between them.... the reason for that is because the XTP is full diameter in front of the cannelure and the Swift isn't... The Swift is only full diameter behind the cannelure.

I ran into this same dilemma with the Cutting Edge 190 grain HG Solid in the 10mm... try as I might, I just couldn't get it going 1,300 fps, not even from a 7 inch barrel.... not enough room left in the case to get enough of the right powder in there to do it....1,285 was all the 190 could do, the 200 grain XTP and Nosler would both exceed 1,300 fps.

The CEB 190 HG Solid is much longer than the 200 grain cup and core bullets, and the 10mm case is pretty "capacity challenged" (short).

[JEBar]

I meant the length of their 210 grain bullet.

my ooops .... in the picture below taken from Nosler list the OAL at 0.687"

[Ridgerunner665]

Thanks man.... Nosler didn't used to have the length online...or if they did I don't remember it...I should have at least looked though