7383 load data

[twocool4u]

Does anyone have load data for 7383 in a 30-06 with a 200 grain cast boolit? I have looked high and low for this loading and have not found anything.

[Nobade]

Many lots of that powder are different, you'll have to work up your own. But try about 80% of the available space (measuring to the base of the bullet once it's seated) should get you in the ballpark. It is possible to overload a 30-06 with that powder, so be careful.

[twocool4u]

Thanks Nobade.

They say this powder is very fickle, so I was hoping for something a little more definite, but thanks just the same.

I will check around some more and load a few up before long.

[Nobade]

The only thing I'd add is that if you get to the point where it is burning clean and not leaving any unburnt powder in the barrel you are loading it too hot. It seems to work best around 35KSI, and can get dangerous if pushed too hard.

[wiljen]

I have been loading 54gr of my lot behind a 150gr FMJ for practice ammo for the garands (W adjustable gas plugs) and it does quite nicely. I would differ from what Nobade says on one count. When you reach the point it burns clean, quit that is as good as it gets, but you dont necessarily have an over-pressure situation at that point. You will if you continue beyond it.

7383 reacts badly to compression so at most you want a case full with minimal compression. The more it is compressed (beyond mild compression say 2%) the more fickle it gets and the more likely you are to have pressure excursions.

Linstrum wrote a good article on 7383 characteristics that is on here somewhere if you search. Jim and I have both been experimenting and using it a great deal. 7383 is a very useful powder for full power loads in most mid-sized cases. It does not do well in greatly reduced loads and I would not try it at below 80% fill nor does it do well with compression. Used within those parameters, it makes an extremely accurate load in most mid sized /mid bore rifle cases.

For cast loads in the 30-06, you may find that the sweet spot for 7383 is well beyond the point at which accuracy falls off with a cast boolit. I'm gonna suggest you save the 7383 for the jacketed stuff and get some IMR 4831 or IMR 7828 for the cast loads. I've had good accuracy out of IMR 4831 with cast boolits in hunting loads.

Fast powders like 10gr of unique will also work for your cast stuff.

[45 2.1]

I load this powder in the 7.5x55 jacketed loads for military duplication. It is a triple based powder and has some strange use requirements. Actual compression is a bad thing here, BUT densifying the charge by the use of a drop tube to get less air space does wonders for accuracy, that is provided the load is safe for the cartridge. I'm trying this in the 308 semi-autos right now............. lots of potential, but it is slow burning enough that i'm going to have to use filler to clean up the residue.

[wiljen]

I hadnt tried a drop tube with it but can see how it would be handy as 54gr typically fills a 30-06 case to the top of the neck and settles to the base of the neck on gentle tapping. I might give that a shot too, thanks for the idea.

[Jim]

I've been burning this stuff since '02 and I can sure tell you it's a weird powder. My experience has been it can be used for cast, but it's not user friendly. I've had to back off the case density and kick it with a coupla' grains of B/E to get it to do like I want. That requires a compressible filler and I've recently found that kapok seems to work better than dacron.
It does seem to work well for me using factories. Most of the time, a case density of about 98 to 100% seems to bring out the sweet spot. Kinda' like 820, it likes pressure, but has a very fine line where it breaks from the sweet spot to high pressures.
CAUTION: This stuff WILL wreck a rifle! Proceed slowly and watch for pressure signs. Don't let it fool you into thinking you can increase the load significantly. If you need help or have questions, ask somebody that has experience with it!
Shoot safely!

[twocool4u]

My line of reasoning was this, people seem to be using 7383 in the '06 under jacketed bullets of about 150 grains.

I figure a cast boolit of that weight would be going way to fast with the pressure the powder likes to burn at. That is why I asked about the 200 gr. boolit, to get the pressure up to the sweet spot, but keep the velocity down to something a gas-checked water dropped wheel weight could stand.

Is this idea logical or am I just wasting time?

[wiljen]

Only way to know for sure is to try. My suspicion is that is wont be enough extra weight to do what you are hoping for, but again, I've been wrong before.

[Maven]

tc4u, I've used IMR 7383 in my '06 with jacketed bullets as light as 130 grs. with no problems at all and excellent accuracy. However, until you can determine the burning rate of your lot of it (You'll need a chronograph for this.), use starting loading data for either IMR 4064 or H 380 and bullets which weigh about the same as the ones you wish to use. You'll know what to do if the velocity isn't what you expected. In any event, as others have mentioned, be cautious about using so much powder as to require compression.

[WineMan]

I was looking for a reduced range load for my M1 to use on a 50-100 yard practice range that I could do single load and rapid fire. My best bet was trying to make a BobS load using a slow powder in a 40 grain quantity with cast. I got some IMR 7383 but did not do my homework before buying it. Wow, there is plenty of BE CAREFUL out there and I thought I may have gotten some expensive lawn fertilizer.

I just went through an exercise using the current GI Brass IMR 7383. Jeff Bartlet said to use H4831 data reduced by 15%. I used another method and filled cases to the brim and got an average fill volume. I took 75% of this which in a HXP 30-06 case comes to 42 grains. I backed off from there to start at 34 grains and back up to 42 in two grain increments. This was under a 311299 at 0.309", Hornaday gas check, Speed Green pan lube, and a CCI 200 LR. The temp was 65 F and they were shot in an M1, single loaded at 50 yd. off an MTM bench rest.

The rifle would eject but not hold the bolt back until I got to about 1,750 fps.

Here is a table of the results:

Charge Low High Ave Spread SD #shots
34 grains 1487 1553 1519 65.29 20.07 8
36 grains 1603 1647 1627 44.08 16.03 8 one error so only 7 recorded
38 grains 1648 1772 1697 74.60 26.03 8
40 grains 1687 1777 1736 89.90 33.58 6
42 grains 1791 1820 1806 29.31 13.15 5 this was the most consistent and was more like M2 Ball. Needed 14 clicks up 50 yd

I did not see significant unburned powder and the accuracy at 50 yards was decent although I was only doing function and velocity measurements. Most shots were in a two inch circle. I also did not see if the rifle would function with a full clip. Cleaning did not seem to be any worse than with HXP Ball M2 ammo. The reports of the smell are true. I could still smell it on my clothes later in the evening. I may play with a grain or two more than 42 but at this point I am pretty close to my goal.

Wineman

[TCLouis]

I thought someone was working on a compilation of load data for this powder that was going to be posted on Cast Pics site.

[wiljen]

I are but have been a bit sidetracked. I will have something up soon. In the meantime -was there a particular load you have need of?

[TCLouis]

Can't wait to see some data posted for several different cartridges so I can do some load development in those of interest to me. Weather should continue to keep folks inside so I can for a while.enjoy range days.

Hope to get some coated and some real boolit loads put up for plinking and huntin.