I've had several people Pm me about the rimless 357Max AR15s I've made so I figured I could add some more info about it. Don't know if removing the rim counts as a wildcatting or not but overall it is a little more detailed so here goes.
5 years back or so I was wanting a better performing/with mild recoil and cheaper alternative to what was available to chamber an ar15 barrel in. The cartridge needed to be a straightwalled case and be less than 1.8" in length for hunting regs. I had previously made a DI (gas operated) 9mm luger ar15 upper and had looked at a 357mag rimless, then thought what about a 357Max rimless. Searching the web I could find lots of other guys who said it couldn't be done and others that had made up dummy rounds but couldn't find anyone who had gone ahead and chambered an upper in it. I've always been told that anything you can think of with wildcatting has already been done and that seems to be the case. So here is what I did to make it work, hopefully it will help others.
The reamer needs to cut a shoulder for the case to headspace on since it no longer has a rim. Looking at 357Max chamber drawings and reamer prints I came up with an initial chamber drawing. I had never made a reamer before, but have three lathes and a bench mill. From the drawing a piece of O1 drill rod was turned around .0015" over final diameter and then polished down to size. 6 Flutes were then laid out .005" below centerline of the reamer blank and then milled out. The blank was heated bright red while being held in a long extension spinning slowly in a drill press. Then dunked in oil while still spinning until cool enough to touch. The reamer is then held between centers and using a boring bar as a guide the flutes are carefully stoned with a diamond hone on a stick. My first reamer wouldn't cut as it was still too soft, so I made another one which worked well.
Not knowing if I'd be able to get it to feed well or not I used a cheap $35 timberwolf blank as a test barrel. Once it was rough turned and an extension installed the feed ramps were modified until they would feed the cylindrical rounds. Which brought me into the next issue. All ar15 mags have bullet feed guides in them to push the shoulder of the cartridge towards the center of the mag as they are pushed forward. The feed guides prevent the straight 357 rounds from double stacking. USGI type mags have them pressed into the metal and they cannot be easily removed. Pmags on the other hand have the feed guides molded in and can be removed with a dremmel and a sanding drum.
Using Quickload as a guide, loads were worked up from reloading manuals until they were at max for standard 357Max loads with 2400 powder, then loads for TC before working up to what QL said would be maximum loads if allowing 223/5.56 pressures of 60k psi. I never shot that barrel for accuracy, just load development and to see if it would cycle the action. Since it did a .358" 1:14" GMB barrel blank was ordered and another reamer was made since the pilot from the first one would be too small. Not to bore you with all of the details, the barrel and second reamer worked out just fine. I continued to work up loads from reloading books using QL as a guide. So far I have loaded 140, 158, 180, 200, 205, and 220gr bullets using bluedot, 2400, and W296. I plan on using other powders and bullets as time allows. My son and I have both harvested deer with our 357AR rifles and have been very pleased with them. The recoil is clearly more than an ar15, but less than my marlin 30-30.
Still exciting if it comes to pass! But I think it may end up being one of those "be careful what you wish for" type things if all the changes I've seen so far take place. It almost looks like they're trying to lock you into their proprietary bullets, die sets and perhaps cases v/s easy to get off the shelf stuff.
https://www.outdoorhub.com/news/2019/01/21/shot-2019-winchester-new-350-legend/ 1.71" case length, It'll still work in an ar15 magazine. With a spire pointed bullet or similar like a 180gr SSP or 180GR HCFN the COL is aleady maxed out for an ar15 magazine so the .11" longer case won't gain you anything, but in lighter bullets or xtp types it could if they feed well at the longer COL.
Ha, I wish. It's based off of the 357Max with the bullets seated out further to max out the useable COL of the ar15 magazines. All they did was lengthen the case .11" to cover the bullets up more. With a 180gr SSP or 180gr HCFN you're looking at 2130-2150fps out of a 16" barrel for what we use as a deer hunting load. On Winchesters site they show a 180 bullet at 2100fps https://winchester.com/Products/Ammunition/Rifle/Super-X/X3501
I think winchester's claim probably was limited to SW cartridges with max 1.8" brass length. My comment was made because i was thinking ohio SW cartridges which don't have a max brass length restriction.
Hornady sells a couple 444m 265g loadings and claims over 2,300 fps for them.
There is a pic of a 350L bolt gun on the winchester site. I would think the 350L would be an easy conversion on a savage or ruger 223 bolt action. A bolt gun would let a handloader max out the 350L. I wonder what pressure winchester plans to load the 350L?
Woodbury Outdoors has info on the win 350L rifles. MSRPs from 550 to 800 bucks. They look like RARRs, box mag too. Said most models will be available later this year.
Hi, sorry if I ask wrong question here, but I take chance. To day its possible to bye Starline Straight Walled Unfinished .223 Remington Brass, and other.
Is there any reamer on the market that I can bye to make barrel for a 357 maximum bolt action, and use the unfinished. 223 straight wall brass? If I get a 357 blank barrel and 357 max die sett, I like to make a 357 maxrimless out of a ruger American 223.
Anyone have any idea if this will work?
The problem are probably to get a chamber reamer ?
Best regard Kai
Hi Kai, Manson Reamers has the reamer on file and lists international sales. Is there a reamer company in Europe that you have used before? The print is likely listed earlier in this thread if not I can add it. If Starline doesn't directly export brass perhaps they know of a distributor that does. If not the cases can be make from 223 Remington or 5.56x45 cases, but the starline cases is much less work. The Ruger American rifle is available now in 350 Legend which is a very similar cartridge and might be a cheaper option. I don't have a Ruger American rifle, but it looks like they make it with two different style of magazines. One is a flush fitting plastic rotary magazine and the other similar to a 5 to 10 round M16/AR15 magazine. The M16/AR15 style can be changed to a 350 Legend magzine, but you would have to try some dummy rounds in the rotary style magazine to see if they will work.
cpj, Since Starline came out with their 223 basic cases I've just been using them. You can use the starline cases by trimming with a forster trimmer with a .356" reamer in place. The reamer will only remove a bit of case metal towards where the base of the bullet would be if using a heavier/longer bullet. Still best to full diameter expand them first as the starline cases are slightly undersized and will shrink in length the first time you shoot them. Full length expanding will mitigate how much the case shrinks, but it is a good idea for the initial trim if you don't expand them to trim to max case length or the max length of what will chamber easily chamber in your barrel.
For expanding 223/5.56 if you have a progressive press you can set it up to do the initial and full length expanding and then resize an annealed case in one trip through the press. The more steps you use to expand the cases the fewer losses you will have. You can do it in 2, but 3 steps works better. I'd usually have my 6x45 die in the first station set high so it is only expanding the case mouth, then a "skinny expanded that is about 1.5" long and tapers from .225" up to .355" which will expand up just the neck area. Then an 2.90"-.355" expander and followed by a full length expander that has a small radius on the bottom but the rest is .355". Set the full length expander so that it just starting to bulge the cases about 3/4"-5/8" from the rim. Then resize.
All of the expanders have a tapered working area of about 1.4"-1.5" long with a 3/4" length of 5/8"-18tpi threads with either a hexed head or knurled head to make them easier to screw in. 5/8"-18tpi is the same thread pitch on Lyman M dies as well as Lee powder through die sets as well as others I'm sure.
If not using a 6mm die set first I'll use a skinny expander that is .2"-.357" followed by the full length expander which has a small radius from .3" up to .355 over .3" and is .355" for the rest of the length followed by a standard 357 sizer die.
I've only ever used a standard 38/357mag-max carbide die set and a Lyman 357 taper crimp die. The carbide die isn't ideal as it removes the case taper, but it doesn't seem to be an issue. The 357AR chamber has about .007" less case taper than a 350L chamber. I've never tried it but likely a 350L die set would work to size 357AR cases but may require the die to be trimmed slightly if the bases aren't getting sized down enough. Or you could just add taper to a steel 357 die set. Never opened up a steel 357 die set as we've had no issues with the carbide die.
If you're making your own barrel and reamer, make up some dummy rounds using the bullets you want to use and see what the longest COL that will still feed well and keep the case mouth solidly on the driving band surface and away from the ogive. A .357" or .358" using the legend case with a 1.65" case length might be something to look at. What action are you going to use?
Pic of a few .357"expanders. The two with hardware store bolts on them were the first two (didn't have any 5/8" drill rod so press/pin into the bolts to try them out. Worked fine so never made new ones just like them. Far right is one made based off of a cerrosafe casting of the ID of a sized 357AR case. Top 9/16" is .358" then tapers down to .310" over the next 5/8" with a small radius at the bottom.
Very nice, thanks! Action will be a Savage Axis. Its currently wearing a .223 barrel from Handi rifle, which I know will make some here cringe. Hey, it was free and I was bored. Cut the lug from the bottom, (that SUCKS, the welds make hard spots in the barrel) threaded and installed. There is enough free bore to seat 500 grain .223 bullets without touching the rifling. Yes, I exaggerate. But theres too much, and Ive yet to get it to shoot to my liking. I digress. I'm bored and need a project, and the Axis is easy to mess with. Really liked the idea of the 350 Legend, but as mentioned there is too many variables.
Ive made similar expanders for a project I was involved with. Cut a .308 Winchester case to 1.8', expanded to fit a .429 bullet. Good fun, sends 250 grain bullets in the 2300-is FPS range. Big balls of fire, nasty recoil and muzzle blast from a 16.25' long barrel.
A couple expanders were tried, and the steeper angled ones worked better than the more gentle slope. We theorize the long taper put more friction on the case.
Sounds like we've done some overlapping wildcats then. I've also done a 44x1.8" based off of 308/30-06 sized case heads in first a 1891 Mauser, then an AR10, and finally a AR15 with the 800 series bolt/extension for a 22-250. Launches the 265 Interlock at 2300fps out of the 16" barrel. Did a couple with a 1.6" case lenth and 450BM bolt/extension. The case capacity is the same as the 445SM so you can use load data for that. Also have a .375FUW posted here based off of 6.8spc cases and a .40 bases off of .473" case heads. Nice to have access to lathes and mills as just trying things out becomes much cheaper and quicker.
Much appreciated! Ill certainly dig into that a bit more. If I end up going through with this, Ill end up making my own reamer. Why? Because I have lathe, mill, and head full of bad ideas. I am smart enough to not do anything to blow myself to bits, so the worst that can happen is I ruin a perfectly good barrel and a bit of drill rod. No worries, right?:tango_face_grin:
You can make quite a few chamber reamers with a $10-$20 stick of O1 drill rod even if you mess up occasionally. I still occasionally buy a chamber reamer, but usually make several every year. 1st one is a 44x1.8" reamer I made for the AR15 with a shorter freebore than the one I used on the mauser/AR10 since the shorter mags limit COL. 2nd one is a 357AR reamer from 8 years ago or so. Last one is a 375FUW reamer.
Those look real nice. Have you ever made a D bit style reamer? Easy to make, and worked great for a 22 LR project I did. Appears the pics are sideways. Hmmm. Anyway, the odd looking pistol is one I built. I made my own action to keep it legal, since we can’t pistols from rifles but we can make our pistols from scratch. Bolt is from a Springfield something or another 22, trigger is from a Mauser. Barrel is from a 10-22. It had a no name random surplus barrel on at first, that shot circles around the Ruger barrel. But it was 18” long and not handy on a pistol. I was afraid to cut it because it shot so good. So I took it off and used the Ruger. Just more practice, anyway. Keeps me off the streets. attach]242578[/attach]
Very nice! Don't blame you for not cutting down the accurate barrel. I've made D reamers but usually make chamber reamers with 3 to 6 flutes as the fluting part goes fast with the indexer and power feed. For me it's getting the reamer blank turned down and polished to the correct diameter that takes me the most time. .005" below centerline and feed in and index until you get the flute width you want, drop down another .002" for .007" total below center line and take a final pass over each flute. Takes me longer to set up the mill level and with the offset wanted than to cut the flutes. Keep looking at the tool post grinders which probably wouldn't save me any time, but would make them easier to make.
I stuck the barrel on there at the full length, just because I was trying stuff. I try and not do work thats not required before testing my dumb ideas. No sense cutting/profiling etc a barrel if its not going to work. Well, of course it worked. The ruger barrel doesnt shoot bad, but the other shot so good as to make me question if the groups were a fluke. Which, they were not. Its just obnoxious to have a pistol with an 18' barrel.
I need an indexer of some sort, for sure. Cutting a basically straight profile shouldnt be terrible. I have a friend with a nice CNC lathe, I may see what he would charge to whip one out.
So the lead angle on the throat is one degree, 30 seconds? Im attempting to decipher the drawing. Being self taught I do things my way, which is typically backwards from the real world. :tango_face_grin:
Yep, generally they're 1-3 degrees. Taking the height of the rifling and using whatever angle you want to use, you can plug that into a right angle calculator and get how long of an area the leade needs to be on the reamer blank. Then just offset the tailstock until when a test indicator is run over the leade area the depth matches the rifling height and extend it so the cutting edges go slightly under land diameter.
Between centers is easier for me to do most angles on a reamer since the angles are so shallow. Make perfectly straight test bar to get you in the ballpark for centering the tailstock, but adjust until it cuts straight. For body taper you know the taper and length, for the leade you know the taper and angle using the right triangle calculator will get you the length. Then it's just adjusting the tailstock until a test indicator reads the correct offset between the start and stop. Even then it's easier to cut straight areas first like a rim cutter, freebore and the pilot. Floating pilots are best cut last as the small dia will flex. Here's a couple pics of a 357Max reamer that the pilot area was cut to just under bore dia until everything else was turned before turning down to 1/4" for the pilot stem. Pic with the test indicator is setting up the leade cut between the two arrows. Next is the cut leade, pic with pilot dia turned. Last is the reamer after hardening but before polish and sharpening.
Usually make the reamers on the little 9x20 lathe as its easier to setup. Pic of finished reamer and test fire on rough octagon cut barrel before it was given any taper.
If you really want to convert 223 brass, the 357 Max AR is worth consideration. Note that the case conversion effort is substantial and getting good results (brass suitable for top accuracy) can be tricky. Also note that you need to be ready to work through feeding challenges.
I have the barrel and most of the parts. I need a few more pieces to get it running. What kind of follower do I need in the mag?? I belt sanded 2 of my followers smooth to see if that works. If not, I can use them in the 450 BM.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Graybeard Outdoors
2.7M posts
63.7K members
Since 1987
A forum community dedicated to the great outdoors and hunting enthusiasts. Come join the discussion about hunting, fishing, survival, archery gunsmithing, optics, reviews, accessories, classifieds, and more!