IMR 4227 postition sensitive?

[blixen]

I’ve given up ever seeing again one of my favorite powders—IMR SR 4759. But I can find IMR4227 and H4227, which are in the ballpark in burn rates.


Can anyone tell me how 4227 would compare to 4759? Is it position sensitive? Any problems in reduced loads?

Or any other tips/warnings about 4227 for 30-30 and .300 Savage loadings And in military cartridges like 7.7 Arisaka, ’06, Argentine, where I had great success with 4759 at about 20 grains.

I'm also desperate to find a substitute for my old fav Alliant 2400--which I used at around 16 grains in military cartridges.

Thanks.

[Larry Gibson]

In the lower load density with lower end psi's using light weight for cartridge cast bullets they are. However a Dacron filler cures that quite well. With heavier cast bullets and top end loads for such H and IMR 4227 isn't quite as position sensitive and doesn't require a filler.

Larry Gibson

[1johnlb]

In my experience imr4227 is position sensitive and gets worse in colder weather. But I use the Ed Harris load below lyman start loads. Using dacron took care of it for me. From what I understand, from reading, the lyman loads don't exhibit the position problems.

I don't have enough experience with 4759 to compare the 2. But I picked up 4227 to fill the gap from the lack of 2400, now I have some 2400 and still using the 4227. 4227 is a excellent reduced load powder just beware of the possible chance of see in colder weather.

[blixen]

Thanks! I'll get some.
How do you measure the amount of Dacron? Just stuff enough in to fill the void I suppose.

[Mr Peabody]

I don't use more than 1 gr of Dacron in my cases. You can weigh some and see that 1gr is a lot more than you might think. If you fire a round off and have a little bit of black residue on the outside of your case neck, use less. I usually use a piece of small diameter dowel or a pencil to push it in. I like to leave it expanded and fluffy in the case, not tamped down to where you have a solid pill of material.

[1johnlb]

How do you measure the amount of Dacron?

I use 0.5 to 0.7 grs measured on powder scales. Here's a good read on it and be sure not to pack it.

http://castboolits.gunloads.com/showthread.php?109280-The-proper-use-of-fillers