Imr4227

[Kraschenbirn]

Is IMR4227 terribly position sensitive? I've burned an awful lot of it in handgun cases and .22 Hornets but never in a bottleneck case...like a 30-30 or 8x57...so I really don't have a clue.

Bill

[2muchstuf]

4227 has been a great " never fail to cycle" powder for my M1 carbine. Never used it in anything else though. I would think that you would be better off with something like 3031 or 748.
Just my 2 cents.

[35remington]

It can be.

Good cast bullet powder.

[longbow]

I've used quite a bit of IMR 4227 in .44 mag, .308 win and .303 British all with cast boolits and find it to be pretty good. I'm not shooting matches mind you but my guns seem to like it.

I find 18 to 22 grs works well in both the .308 and .303 for boolits up to 215 gr. 22 grs. under a gas checked Lyman 31141 performed very well in my .308. You'd want a little less in the .30-30 due to smaller volume.

Check the Lyman Cast Bullet Handbook - IMR 4227 is pretty common for cast loads.

[Bass Ackward]

For a lot of years, 4227 was considered " THE " cast boolit powder. But any powder can and will show position sensitivity. Just depends on how low that goes in your case design.

That's why fillers in rifles are popular.

[sundog]

Bill, I buy 4227 eight pounds at a time and usually have an unopened eight ponder as back up. That tell you anything?

[DonH]

Regarding bottleneck cases, I guess it depends on how big a case you are talking about. As for .30-30 size cases, I will refer to my single rifle shooting. In ASSRA and other schuetzen-type shooting venues, 4227 has been one of the "go to" powders with lead bullets and nearly always "reduced load" status.
In this type of shooting the bullet is nearly always seated into the rifling, rather than in the case, and the case then chambered behind it. This of course leaves much more powder space than with normal fixed ammunition. While a wad is used at the case mouthby some to keep from spilling powder into the action, many do not use a was at all. Some use a wad seater which places the wad down the neck about where the base of the bullet would be if seated into the case. Whichever method is used re: wad, the result is at least the same reduced capacity situtation as fixed ammunition, or worse.
The point of all the preceeding is that if 4227 was very position-sensitive in cases like .30-30, .32-40, .38-55, etc, these guys would know it. AND when using the powder in reduced-load capacity in old single shot rifles, where unpredictable pressure excursions could wreck a very valuable rifle, if THAT WAS a problem 4227 would not have the following it has had. The new trend toward smaller cases with near 100% loading density is seeing 4227 lose ground to other powders in SS benchrest shooting. Accuracy-wise, 4227 IS losing out to the newer case/powder combinations but the shooters who can take advantage of the gains are those at the very top level. A trade-off is that when one goes to the smaller case, faster powder, 100% density set-up, higher pressures are a way of life - to the point where these loads are not safe in most older actions.
To establish what level of accuracy I refer to, the 25 or center ring on the 200 yd target is 1 1/2 inches. 5 shot groups have been fired at 200yds measuring less than 3/4 inch.

Probably none of the preceeding is relative to the type of shooting intended in the original post. My intent was to show 4227 in a setting where it is widely used in the manner in question.

[joeb33050]

POWDER POSITION SENSITIVITY TESTING

Does the position of the powder in the cartridge case affect muzzle velocity, (MV); does powder position affect the standard deviation, (STDEV) of MV; and does that position affect accuracy?
Powder is moved to the FRONT of the cartridge case by holding the rifle at ~ a 45 degree angle and slapping the side three times, then putting it carefully on the rest.
Powder is positioned LEVEL in the case by putting the rifle on the rest and slapping the side ten times.
Powder is positioned to the REAR of the case by pushing a wad down on the powder.
I recommend cotton but use Dacron wads. Use as small a wad as works. I use a teased wad about dime to penny size, and push it on top of the powder with a pencil.
These loads, 15 of each last time out, are shot at 100 yards over my PACT chronograph.
I'll record all results on an EXCEL workbook called "POWDER POSITION SENSITIVITY" and a WORD summary, this is it, called " POWDER POSITION SENSITIVITY TESTING". (See the EXCEL workbook for all the information about the loads and results.)
These two files will be on http://sports.groups.yahoo.com/group/CB-BOOK/
in FILES,in ERRATA


3/12/08, 30/30, 14.5 IMR4227, WLP
Level Front Rear
1347 1353 1435

3/12/08, 30/30, 14.5 IMR4227, 2-1/2
Level Front Rear
1357 1357 1434

joe b.

[Kraschenbirn]

Thanks for the info, guys. Now, at least, I've got some idea what to expect. As I said, for the last 40 or so years, 4227 has been my flat-out favorite for CB in .357, .41, and .44 mags as well as for JBs in the Hornet but I'm just really getting started shooting cast in my rifles and will take all the help I can get.

Bill

[35remington]

You'd think, in a little case like the .25-20, that IMR 4227 would be less position sensitive since the charge isn't that far from the primer.

Apparently, though, it's all relative. A 6-6.5 grain charge occupies the same amount of space, percentagewise, as a larger charge in a bigger case.

Point of all this is that even the little .25-20 shows large swings in velocity - on the order of 125 fps or more - from extremes in powder position.

Yeah, I use dacron. 4227 does well in the .25-20 with it.