Home Forums Hunting & Shooting Ask The Gunwriters 444 BOLT GUN LOADS

New member here, checking in with a question. I have a custom Mauser in 444 Marlin that I'm trying to work up some loads for. Question is, are the pressures listed in the manuals (app. 42K max) for the brass or because of the strength of the normal rifles this round is chambered in? Seems that some of the wildcats based on 444 brass generate a bit more pressure than the parent round, so I'm thinking that maybe a slight increase could be had in the bolt action. Thanks in advance. Gary.

Well, I'm not a gunwriter but I'll give my $.02.

The SAAMI pressure specification for the 444 Marlin is, like all these specs, based on the firearms the round is most likely used in. Hence, the 42,000 psi or 44,000 CUP 444 Marlin pressure figure is limited due to the Marlin 336 action the Marlin 444 rifle is based on. Unlike the 45-70 which has a history of being chambered in the Ruger #1/#3, the 444 Marlin has not been readily available in rifles with stronger actions than the Marlin lever action. So, while the 444 Marlin can probably be loaded to 50,000 CUP in your bolt action there is little if any load data that would allow you to reach such pressures without using some kind of pressure testing equipment. Watching for classic signs of excessive pressure is probably unreliable for such an endeavor. Quickload software might be some help in estimating a 50,000 CUP load, but it cannot predict actual pressures.

I too have a .444 on a Mauser -- except that mine uses blown-out and shortened .30-06 brass headspaced on the mouth of the case.

Articles and releases that announced the then-new .444 Marlin also revealed that the factory was making the .444 Marlin cases from lots the rest of which were on their way to becoming .30-06 cases. At some point along the line, some of the cases being formed were diverted to become .444 Marlin cases, while the rest went on to become .30-06s.

So the only differences were that
(a) the .30-06 cases had more brass removed from the head (forming a rimless case), were trimmed longer, and necked-down, while
(b) the trimming of the .444 cases left more brass in the head (forming a rimmed case), trimmed those cases shorter, and left them straight,not necked.

From this, I assume that a .444 Marlin on an action strong enough to take .30-06 forces and pressures can be loaded to the same maximum pressures as the .30-06, .270, .243, .308, etc.

Garyl, I also have a 444 on a P14 actoin. What are you using for bullets? I am looking for some heavy jacketed bullets but my source has dried up. I was using 300gr flat nose. Smokey

Thanks for the input and information. I found some data over at Beartooth bullets that hotrods the 444 a bit. but since mine don't shoot cast bullets worth a hoot, I think I'll stick with the published loads. Don't really need more for anything I hunt anyway. A 300 grain bullet at 2200 fps. should be plenty for these N.C. whitetails.
Smokey; I've settled on the 300 grain XTP from Hornady as the best bullet for my rifle. It gives darn good accuracy, and seems to hold together at the velocity I'm getting, so I guess that's my load.
Now , a question for Mr. Howell, please. Sir, the 444 you have based on a regular (not rimmed) 30-06 case sounds very interesting. My question is this: will this round work in a normal 444 Marlin chamber? If so, I may be fitting a new bolt to my Mauser to get away from the feeding problems associated with rimmed cases in a bolt action.
Once again, thanks to all for the input.

Probably not.

My rimless .444 case headspaces on the mouth of the case -- the mouth of the case bears hard against a ledge at the mouth of the chamber. A good gunsmith can set your barrel back a thread and reream the chamber -- using a special .444 Rimless reamer -- to produce this headspacing ledge, which your present chamber most likely doesn't have.

I'll be happy to sell my .444 Rimless rifle -- sporterized military Mauser action, 24-inch (I think) McGowen barrel, synthetic stock.

Smokey;
is your P-14 a single shot or a repeater? What did you do to the bolt and magazine to get it to feed properly?