imr4198

[Tomme boy]

do you think this will have enough gas to operate a 556 rifle length gas system with cast? I am hearing yes and no on a jacketed bullet. I have 5lbs of this and only ever tried a couple rounds with it in the 350 legend on a carbine gas.

 

[RicinYakima]

This is the original powder that the 55 grain bullet for the 5.56 AR cartridge was built around. It had enough gas/pressure at the port to make it work, but not destroy the action in the 1950's. FWIW

 

[Ian]

It will operate carbine gas/16.5" barrel 300 BLK 230 cast or 220 jax loaded just barely subsonic with or without the can, and the same in 7.62x39mm AR with carbine gas, FWIW.

 

[Tomme boy]

Well looks like that will get set to the back of the shelf. I might just try loading just a couple to see if it will cycle.

 

[CWLONGSHOT]

I believe it will work just fine. I know I use it, but switch between my bolt and M$R and do not specifically remember.
What I do remember is a friends load with the 230g Lee and is using imr4198 and he shoots a M$R exclusively.

 

[Bret4207]

Based on what I'm reading it looks like it should work fine.

 

[Maven]

It works quite well in my Type 56 SKS with either jacketed or cast bullets.

 

[358156 hp]

It's one of the favored powders in 458 SOCOM. It should cycle your .350 without any fuss. It's designed around small capacity cases like your .350, I don't understand your reluctance to try it.

 

[Ian]

If it makes 8,000 PSI at the gas port it will cycle and lock back a normal 5.56 carbine buffer and full-auto BCG in stock form with no polishing the hammer face, buffer tube, or using special springs. Run it in Quickload and see what you have.

 

[glassparman]

I've used that powder in an M1 carbine and it cycles good. I have only used it with normal loads and non cast bullets.

 

[Tomme boy]

this is with a 556 chambering

 

[Ian]

this is with a 556 chambering

Wasn't sure based on your first post if it was 5.56 or 350 Legend. Reference Ric's post #2.....those were ALL "rifle length" gas systems.

 

[fiver]

i know it works in the X39 and does fine with cast loads in bigger cases.
the only time i tried it in a 223 was in a bolt gun.
soo [shrug[ nuthin here useful for ya.

 

[RBHarter]

It landed in an awkward place with 6.8 SPC and a 16" Carbine gas . In the 20" rifle it's great . The gas pressure was high enough to run the action but to high to release the brass and not high enough to overcome the brass grip ....... If that makes any sense at all .

 

[358156 hp]

Wasn't sure based on your first post if it was 5.56 or 350 Legend. Reference Ric's post #2.....those were ALL "rifle length" gas systems.

I thought we were talking about the .350. Rics post is spot on.

 

[Tomme boy]

Well I tried to load some of these up using the 65gr mp bullet. This powder does not meter at all in the lee auto drum. It would give a 1-2 gr spread. Then it would not drop anything.

So, I got out the rl10x and it started to lock back the bolt at 20.5gr. I forgot to grab my chrono so no speeds. I was just happy as i really like this powder. Problem is I will have to start looking for more. Dont have a lot of it like other powders. I only use it for a bolt action 223 that i hardly ever shoot.

 

[Ian]

Watch that 10x, it runs away from you when you get near the top.

The Lee drum is non-serviceable in my opinion, had two of the damned things and neither one worked. The disk measure is pretty good though, I use them for just about everything and the only thing that I don't use them for is the big flake powders like Red Dot and Clays because I've had bridging issues.

 

[Outpost75]

In the original M16 and Colt SP1 22 grains of old IMR4198 with the 55-grain M193 FMJ approximates ball ammo producing normal full-auto cyclic rate and velocity for 3200 fps from 20-inch barrel. Slightly exceeds SAAMI MAP in a .223 Remington chamber, but is not "dangerous."

 

[Matt_G]

In the original M16 and Colt SP1 22 grains of old IMR4198 with the 55-grain M193 FMJ approximates ball ammo producing normal full-auto cyclic rate and velocity for 3200 fps from 20-inch barrel. Slightly exceeds SAAMI MAP in a .223 Remington chamber, but is not "dangerous."

Do you happen to have the approx. time frame that IMR 4198 changed and the characteristics of said change?

 

[fiver]

i had an SP-1 in the very early 90's it was at least 10 y.o. by the time i got it, so probably in the
mid-late 70's