7500ftlbs is to 460, as x ftlbs is to 50BMG

26 May 2003, 05:15

I'm not after loads. This is more of an Overkill type question [Big Grin]

.

I've always been lead to beleive that 13000ftlbs is reasonable for a 50(published ammo/military specs etc.)

But for a calibre with such varying barrel lengths this must also vary a lot.

Anyone know what 'safe maximum KE' matches up with what barrel length?

30, 36, 45 etc.

Karl.

[ 05-25-2003, 20:22: Message edited by: Karl ]

26 May 2003, 05:40

Robgunbuilder

Most match .50BMG's run in the 12,000 ft lb range and barrel lengths are ususally 32-34 inches. The .50 BMG M2 uses a 45 inch barrel if memory serves me right.-Rob

27 May 2003, 07:27

<Axel>

Karl, I hope this helps. I received this information from a friend.
50BMG

647 grain BT
Barrel lengths
28" ~ 2775 fps / 11100 ftlb
32" ~ 2860 fps / 11780 ftlb
36" ~ 2930 fps / 12370 ftlb
42" ~ 3020 fps / 13150 ftlb

750 grain AMAX
Barrel lengths
28" ~ 2590 fps / 11160 ftlb
32" ~ 2670 fps / 11850 ftlb
36" ~ 2735 fps / 12450 ftlb
42" ~ 2820 fps / 13250 ftlb

800 grain Barnes
28" ~ 2510 fps / 11200 ftlb
32" ~ 2590 fps / 11900 ftlb
36" ~ 2650 fps / 12470 ftlb
42" ~ 2750 fps / 13400 ftlb

This data was gathered from an actual rifle, which barrels were swapped on. I was told best accurace was found with the longest barrel.

Axel

27 May 2003, 07:31

Nickudu

A most excellent post, AXEL.

28 May 2003, 04:55

Karl

Still no estimates of max loads [Frown]

Some buddy who know?
I don't want to have to resort to tackling Ed's formula yet [Big Grin]

28 May 2003, 05:00

<Axel>

Karl, the data I gave was considered to be a safe maximum load. Safe from a pressure perspective and maximum from an accuracy perspective. The powder charges for the above loads were around 225 to 232 grains depending upon bullet type.

I have heard of 50 BMG rifles being loaded to around 90 ksi for hot rodding loads, but these are NOT accurate and may be DANGEROUS! If you want more power than a 50 BMG provides with accurate and safe loads why not go up to a 14.5mm, it will provide a substantial increase in KE!

Axel

[ 05-27-2003, 20:02: Message edited by: Axel ]

28 May 2003, 05:49

Karl

quote:
Originally posted by Axel:
Karl, the data I gave was considered to be a safe maximum load. Safe from a pressure perspective and maximum from an accuracy perspective. The powder charges for the above loads were around 225 to 232 grains depending upon bullet type.

I have heard of 50 BMG rifles being loaded to around 90 ksi for hot rodding loads, but these are NOT accurate and may be DANGEROUS! If you want more power than a 50 BMG provides with accurate and safe loads why not go up to a 14.5mm, it will provide a substantial increase in KE!

Axel

Axel,
I never said I wanted more power than anything.

I'm interested in what loads people consider velocity/energy maximums having seen the calibre published with such a wild variety in and out of the military(12000-14500ftlbs) not always stating barrel length.

The same question about the following
416 rem, 416 weatherby, 500 A-aquare and 585 nyati

Would be answered
5700ftlbs(25")
6800ftlbs(28")
9000ftlbs(26")
10700ftlbs(25")
Respectively.

Its not an ambiguous question and it doesn't involve accuracy.

Karl.

28 May 2003, 06:11

<Axel>

Karl, I have provided you with what a good friend of mine considers to be the maximum loads in his 50 BMG. He unfortunately, considers accuracy as a prime consideration in the role of his loads. He told me that his loads should have pressures around 62,000 psi. He also says you can run a 50 BMG considerably hotter than that without sticking bolts and blown primers. He says he doesn't because he has experienced accuracy reductions.
FWIW, I was not trying to start anything, just trying to better understand what you were asking
for.

Axel