308 necked up to 44 cal?

[am44mag]

Here's an idea I've been pondering. What if someone took a 308 and necked it up to 44 cal for use in an AR-10? I think that would be a pretty sweet little set up. It would be a great round to cast for, the brass is cheap as dirt, and it would be a good deer rifle too.

I'm not sure how to make that a reality though. I know you would need to order a custom reamer and possibly custom dies. I'm not sure how you would go about actually designing the cartridge and developing load data though. Any ideas what kind of velocity you could expect out of this with 240gr and 310gr bullets?

[am44mag]

You could also probably just trim some 444 marlin brass down to 308 length as well. That would probably be the easiest way to make the brass. You would just have a rim then. You might be able to use 444 dies to convert 308 brass.

[nekshot]

I think some one did this and I think it was a gunsmith in NY state, but I draw a blank for more info.

[Moleman-]

Not as hard as you think. For the past two seasons I've hunted with an AR10 in 44x1.8". The only reason it has a 1.8" and not 308 length is because in my DNR zone we're limited to straight walled cases no longer than 1.8". Running the pressure at 308 levels it's not hard to meet or beat book loads for a 444 Marlin with a similar length barrel. With a full length case you could likely drop the pressure back or blow the doors off of the 444 marlin with a rimless "444 magnum" version. Mine is pleasant shooting and is easy to shoot 200rnds at a sitting without being sore and bruised the next day. Don't know if that would hold true for the longest version that'd fit in the magazine and still feed well. Make some dummy rounds, make a chamber reamer based off of your dummy rounds, make your barrel, mod mags, assemble, tweak, enjoy. http://castboolits.gunloads.com/showthread.php?333694-AR10-LR308-type-build-in-44BGM-(44x1-8-quot-) I load with 444 marlin dies and a Lyman taper crimp die since you shouldn't use a roll crimp on them.

[NoAngel]

Skip the 44 and go straight to 45.
Then you end up with a rimless .460 S&W known as the 45 Raptor.
No custom dies needed.

[GhostHawk]

Its called the .45acp. :kidding:

[Nobade]

411 Davis Hawg. Straight taper, headspace on the mouth, use 405 win bullets or 41mag pistol bullets.

[am44mag]

After looking into the 45 Raptor, it's easy to see that niche is pretty well filled in. There might be a little room for something in an AR-15 though. The 50 Beowulf necked down might be an interesting round. I think you'd still get pretty close to 444 Marlin ballistics.

[country gent]

Shortened down some it would be the 44 auto mag round. Full length would be an interesting round. It wouldn't be to hard to make the cases. a custom reamer would have to be ground, Dave Manson is good here at Manson Reamers. My Last wildcat reamer was $180.00 from him. Dies would be special but not a big deal, possibly a standard die could be modified. Necking up the necks will get thinner so that's a plus there. Also allow for a little trim so case mouths can be squared up after sizing.

As to case forming it can probably be done a couple ways fairly easily. With unprimed brass Anneal neck and shoulder area. A set of tapered expanders can be made to size up the neck shoulder area to a little over what you want then sized back down in the sizer die. This will be several steps to get from 308-429 . But the final expander with the correct taper to match the case should make a case when sized is a finished case. Next is to take your annealed cases prime and charge with 10-12 grns of unique, fill with a wad ( 1/4 sheet toilet paper, cream of wheat, grx, dacron. ). Load this iinto the rifle and fire. pressure will fire form a case quickly and easily.

Once a few cases are in hand. seat a spent primer or leave the spent primers in place. Check water capacity of the cases to get an Idea of volumne. Look for cartridges of the same or close to caliber of the same capacity and reduce data to start and work up from there. With the water capacity and boolit weight there are programs that suggest powder charge and pressure.

Once cases are on hand one can be measured to make the reamer. I usually make a drawing and send a dummy round. With the fired formed or sized up brass necks loaded round dia is known for the round as it is formed and reamer can be ground for it with clearance. On this round I would probably specify 1.990 - 1.995 case length so a small amount can be trimmed to square and true the case mouths after forming. Sizing up cases will get thinner and shorter. The other issue is case taper for ease of extraction.

It is a doable project and will be interesting ( Its fun to shoot a cartridge you named), but it wont be cheap unless you can do the work yourself.

[stubshaft]

If it is to be a rimmed cartridge use the old Winchester .307 brass blown out.

[Texas by God]

The full length 308 case necked up to .429"would be the ultimate AR-10 power to weight ratio cartridge. Big slap Factor.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[clodhopper]

I have been thinking 44X1.8 for quite a while.
Easy making swaged bullets from40 S&W cases.
After looking for a barrel maker to make a barrel at reasonable cost and not being able to find one,
I submitted and ordered a 45 raptor barrel.

Still short a few parts, but the barrel arrived today. Also have to make a feed ramp to fit in the magazine.

[lrdg]

Would it be easier to trim a 30.06?

[adcoch1]

I've made a few dummy rounds from 306 and 30-06 brass, the 30-06 gives you an easier time since you trim off most of the shoulder before expanding. Takes less steps to get there, but 308 brass definitely works too. I'd love to have a bolt gun in 44x1.8", but an ar 10 would be cool too.

[Moleman-]

Would it be easier to trim a 30.06?

Yes it is. I've used 30-06, 270, 308, a couple of the mausers, and others. Raptor brass run through a 444 die is the easiest but then you're throwing a lot of money at it as raptor brass isn't cheap. I'd love to do as long of a version that would still feed in my rifle, but the DNR zone I deer hunt in limits us to 1.8" long straight walled cartridges.