When is 25X30 not 750?
Feb 2, 2009 18:41:32 GMT -5
Post by rbinar on Feb 2, 2009 18:41:32 GMT -5
8-)I recommended loads for 55 65 and 70 grains with an 4198 duplex. Today the 55 grain load will be introduced.
In deciding the proportions I used something I don't normally suggest: a guess, but it was an educated guess with several protective precautions taken. The most important was I used my safety rest. I've mentioned this device before but all it does is allow the trigger to be pulled at a distance from the rifle.
After the first two shots were taken the sabots were found in tack and two holes in the target were round. Only then did I fire a shot from the shoulder.
The load is 25 grains of Xmr-5744 under 30 grains of H4198. The weather was a cool 52 degrees and all shots (20) fired with no sign of high pressure except for a few lost sabot pedals. There was no attempt to make accuracy an issue but three of the shots did work into about 1 1/4" most of the shots were for reliability and sabot integrity tests.
I had a hard time getting a speed on the timer with the sun low and clouds at just the wrong times. The one shot that gave a speed was fast (over 2450fps) but more will have to be done to get an average speed. Sabot seemed to hang with the bullet and one was timed 40 feet from the muzzle at 147.5fps. The condition of the sabots indicate speed as well with widened (not severely) bases.
In warmer weather it might be necessary to lighten up on the booster a few grains. If this load is tried with N110 as a booster it's qualities might require a 20/40 load but it can't be said at present.
Using the Harvester short black sabot the barrel fit was fairly loose. However the chance of misfire or temperature effect is NONE. There was zero muzzle flash all powder burned about as cleanly as I've seen in 50 caliber and ignition is very immediate.
So when does 25 X 30 equal 2450. When you're at the shooting range of course.
In deciding the proportions I used something I don't normally suggest: a guess, but it was an educated guess with several protective precautions taken. The most important was I used my safety rest. I've mentioned this device before but all it does is allow the trigger to be pulled at a distance from the rifle.
After the first two shots were taken the sabots were found in tack and two holes in the target were round. Only then did I fire a shot from the shoulder.
The load is 25 grains of Xmr-5744 under 30 grains of H4198. The weather was a cool 52 degrees and all shots (20) fired with no sign of high pressure except for a few lost sabot pedals. There was no attempt to make accuracy an issue but three of the shots did work into about 1 1/4" most of the shots were for reliability and sabot integrity tests.
I had a hard time getting a speed on the timer with the sun low and clouds at just the wrong times. The one shot that gave a speed was fast (over 2450fps) but more will have to be done to get an average speed. Sabot seemed to hang with the bullet and one was timed 40 feet from the muzzle at 147.5fps. The condition of the sabots indicate speed as well with widened (not severely) bases.
In warmer weather it might be necessary to lighten up on the booster a few grains. If this load is tried with N110 as a booster it's qualities might require a 20/40 load but it can't be said at present.
Using the Harvester short black sabot the barrel fit was fairly loose. However the chance of misfire or temperature effect is NONE. There was zero muzzle flash all powder burned about as cleanly as I've seen in 50 caliber and ignition is very immediate.
So when does 25 X 30 equal 2450. When you're at the shooting range of course.
. Perhaps I should have just said it's the 250 grain Xtp
