Double Crimping?

[Matt304]

I have a problem here and I'm not exactly sure the best way to handle it.

I am loading a 444 Marlin in a single-shot handgun. For my light loads I am using 55.5gr of IMR4350. I am using a standard roll crimp into the cannelure.

After I fire them, there are usually 3-5 visable unburned pellets sitting inside the barrel. So I have a good feeling that a lot more of that powder is just getting thrown out of the barrel.

I do have a Lee factory crimp die. Is it possible to double crimp a case with powder burning issues like this? By "double-crimp", I mean apply a standard roll crimp, and then apply a Lee factory crimp below it. Would this serve a purpose, or would this increase pressures too much?

 

[rcmodel]

I think I already answered the same question for you a couple of days ago.
(If it wasn't you, I apologize!)

I will try again!
No, there is no practical way to double crimp a round.

Your problem is with your choice of powder.

IMR-4350 is a pretty slow burning rifle powder, at it's best in bottle-neck rifle cases, and rifle length barrels.

It is not a suitable powder for the .444 Marlin with any practial bullet weight.
Especially in a pistol length barrel.

Try a faster powder like IMR-4198, H-4198, or RL-7 and your velocity will go up, and your unburned powder problem will go away.


rcmodel

 

[birdbustr]

The Lee FCD may delay the bullet leaving by enough time to cause a more complete burn, but I doubt it. More likely the cause is that you need to find a faster burning powder or a hotter primer. In fact, the 4350 isn't a recommended powder for the 444 Marlin according to the IMR reloading website. Try a different powder.
240 GR. REM SP 240 IMR 4895 .430" 2.570" 56.0C 2200 38,600 CUP
240 GR. REM SP 240 IMR 3031 .430" 2.570" 54.5C 2175 35,900 CUP
240 GR. REM SP 240 IMR 4198 .430" 2.570" 47.0 2335 44,000 CUP
240 GR. REM SP 240 SR 4759 .430" 2.570" 33.0 2055 43,600 CUP

 

[Matt304]

Sorry I didn't mention, yes I am using the 240gr jacketed bullets.

RCmodel, I asked before about double crimping with a factory die twice. I assumed that it is possible to crimp twice with one roll crimp and a second factory die crimp.

Lee's loading data they provided specifically states 55.0gr of IMR4350 for the 240gr in the 444. I will discontinue using it after these loaded ones are fired.

52gr of RL-7 works much better for hotter loads, but I was trying for some mild loads with the 4350 they recommended. Any recommendations for lighter load powders?

 

[rcmodel]

They have three different type FCD's, and the case design determines which type you get.

For straight-wall revolver calibers, it is a roll-crimp.
For auto-pistols it is a Carbide taper crimp.

Although there is some over-lap between the two types.
(IE: you can get either a roll, or taper crimp die for some revolver calibers)

For most rifle calibers, including the .444 Marlin, it is a collet crimp type that would crimp in the exact same place the seating die roll-crimp was placed.

Hornady #6 says:
A starting load of 29.1 grains of IMR-4198 & a 240 XTP or FMJ will give you about 1,700 FPS in a 15" T/C pistol barrel.

A starting load of 37.0 grains of RL-7 should do about the same.

As you can see, IMR-4198 is quite a bit faster burning then RL-7, as it uses about 8 grains less powder to get the same velocity.
In my opinion, it would be a much better powder for reduced loads in a pistol length barrel.

RL-7 would probably get the nod for full-power loads with the same bullet weight, as it will give about 100 FPS more velocity before max. pressure is reached.


rcmodel

 

[Matt304]

Thanks for that info. I was a little confused about the FCD since I haven't actually used it yet. I thought that you could simply place crimp rings wherever you positioned it on the case. This is why I thought it was possible to do two crimps in different places.

I looked at the page of data they sent with the Lee dies, and I just used it to get me started a little anxiously. I should have bought a manual or something with more coverage on the 444. The page they provided shows 51gr RL-7 as the max, and minimum loads for the 240gr bullet. I still don't quite understand what they are doing, as a few of the loads they list show the same starting and max loads. So I just assumed I should not go under what they had listed. Now I know that I can do some light loads with the RL-7 like you say.

4198 was at the top of my list actually, but when I got to the store and they didn't have it, I bought the next two on my list that appeared useful for max and minimum loads. They say that 4198 actually gets 99fps more at their listed max than the RL-7, with the 240grs. I'm finding that I am running out of case capacity even with the RL-7 before meeting the levels I desire to reach. I finished loading the rest with 52.5gr of RL-7 and cases extract very easily, but I'm not sure how much powder compression is possible without getting into dangerous areas. Just dumping that much in loosely appears to be about right at the base of the bullet. So maybe the 4198 is the better candidate for fast loads in this cartridge.

 

[rcmodel]

A compressed load in itself is not at all dangerous, as long as the charge weight is a recommended load.

The only reason Lee recommends some of those powders they list with the dies, is so you can use the powder dipper they also give you, with no chance of blowing yourself up!

They are very often, in no way, related to the "best" powders for the caliber.


rcmodel