http://www.midwayusa.com/product/418623/hornady-gas-checks-416-caliber-box-of-1000?cm_vc=ProductFinding

Should work alright . . .

Or you can get one of these:

http://www.corbins.com/gascheck.htm

RJ

Thanks, RJ. that'll work, but a couple of 'problems'. One, $42 + S&H PLUS a $10 surcharge for living in Alaska is a bit steep (and insulting) WHEN I can get them for $40 on Ebay. Plus I found a guy that has an "attitude" about gas check prices, and decided to make his own gas checks and start selling them on Ebay. The price: $20 per thousand for his .22 caliber ones. Also, I don't do business with MidwayUSA anymore. They're ripping off Alaskans on shipping. $10 ON TOP of shipping charges "just because".

I was wrong about the weight of the gas checks. I weighed 10 of the .44 caliber ones I have, and the average weight was 7.4 grains. That makes the final weight with gas check right about 297 grains. I can 'live' with that. I made one of the .44 cal GC work by putting it through the .424, and .411 sizers first. Final OD after springback is 0.407". It would do in a pinch, but I'm going to try to get the guy I mentioned to make me some .40 cal ones.

Paul

QuickLOAD says:

If I launch that bullet at 1947 f/s, it will have 2500 ft-lbs of energy at the muzzle at a chamber pressure of only 25,000 PSI.

It will carry 1000 ft-lbs, be 10" low, and have an impact velocity of 1185 f/s at 275 yds.

At 150 yd, it will have 1523 ft-lbs of energy, be 4.3" low, and have an impact velocity of 1520 f/s. (Yup, the ft-lbs and f/s figures are correct and almost identical. 150 yd, 1500 ft-lb, 1500 f/s. Has a certain 'symmetry' to it. At least on paper. )

Paul

Did some more paper-whipping ('cause I can do that at night when I'm finished working on The Chair), and have come up with the following two loads based on actual SHOOTING:

42.9 grains of Accurate 2495: for MV of 1950 but max pressure of only 17,784 PSI, and
41.0 grains of IMR-3031: for MV of 1950 and max pressure of 19,128 PSI.

Other than the fact that the best burn rates are only about 88% for 3031 and 94% for 2495, (even in a 27 & 5/8ths inch barrel), those loads should 'do' just fine.

Paul

So, I was supposed to go out and "work on The Chair", but I decided that since I had  the cartridges loaded and ready to go, and it wasn't raining, and I had the new MagnetoSpeed display, that I would go ahead and test the new loads. Five shots wouldn't take long to 'rip off'.

The results were not what was expected. You may recall from earlier in this thread that I had to adjust some of the burn characteristics of the powders I was using in order to get the measured muzzle velocities (MV) to match the QuickLOAD-predicted (QL) MVs. Doing so got me "on" WITH IMR-3031. I figured (assumed) that since Accurate 2495 always yielded the same output as I3031 in QL, that a similar adjustment would yield a similar output. Didn't work out that way. The predicted MV was 1950 f/s. The average chronographed MV was 1692 f/s with a standard deviation of 28 f/s. In order of firing, the individual values were:

1734
1681
1708
1678
1663

The last one almost 300 f/s slower than predicted. SO... I'm going to have to adjust the burn characteristics of 2495 to yield these values. While that's a little annoying, 'fine tuning' is basically a trial and error process. While this was "trial" and "error", I now know more than I did before I shot. That's the important part. ALSO important is being able to MAKE the adjustments.

More when there is more.

Paul

PS - THAT'S INTERESTING. When I went to make the adjustments to the Ratio of Specific Heat, I went back to the unadjusted form of 2495. Plugging in the QL-standard values and the charge of 42.9 grains, the QL-predicted MV was 1694 f/s. That is 2 f/s different than the actual measured values! Therefore, 2495 doesn't need any "adjustment" to have the predicted values match the observed ones. I LIKE that. I wonder if this is a function of I3031 being an "old" - pre-WWII - powder, and Acc-2495 being a "new" - 21st century - powder? In the grand scheme of things it doesn't matter, but it is something to think about.

Paul

PPS - There's more to the story than the simple explanation above. First, the discussion about adjusting Ratio of Specific Heat (RSH) is in another thread, http://www.thehunterslife.com/forums/showthread.php?t=18269, not this one. Second, I DID use Acc-2495 in the initial loads, and QL gave poor estimates without "adjustment". SO, what appears to be true is that the response to adjusting the RSH is not linear. That's not particularly surprising since most other elements of powder burning characteristics aren't linear, but it does make finding the right adjustment more difficult.

Paul

On  rereadng this , I FINALLY caught your statement about using 1018 cold rolled to make a reamer.
That is low carbon, mild steel and is almost impossible to harden.
I have some O-1 in the shop, I shall send you a piece tomorrow, IF I can get the shop door open.
We have just had anoher storm, another 2.7" of rain, the squishy places are turning soupy and the mold is starting to mildew!, Oh well, by August we will be wishing for some of this back.

This is what I was working off of:

QuoteHEAT TREATING
1018 will respond to any carburizing method and subsequent heat treatments. Case hardening results in a hard case and relatively soft core. Carburize at 1650°-1700°, oil or water quench and temper at 300°. For a hard case and tough core, the following heat treatment is suggested: Carburize at 1650°-1700°F for approximately 8 hours, cool in oven and reheat to 1400°-1450°F. Quench in water and draw at 300°-350°. Carburizing depth typically .060-.070".

From: http://www.speedymetals.com/information/Material26.html

Paul

Here are the cases after firing and before resizing the above-mentioned 5 shots with the bullet from the new Accurate Mold.



Paul