Building a 45 Super/SMC conversion

[Magnumite]

I have been sitting the idea of a 45 Super/SMC pistol for awhile. This cartridge is externally a 45 ACP but operates at higher pressures. Ballistics with some commercial specialty ammo companies are in the vicinity of:
> 185 grain @ 1425 fps for 835 ft-pounds of energy;
> and 230 grain @ 1225 fps for 750 ft-pounds of energy.
This is young 44 Magnum territory. With a 6” barrel it is deer legal in Maryland. Which is how I am building this one.

It is a Springfield Armory Mil-Spec which I an redoing, kerping the Mil-Spec retro flavor and fitting a 6” 45 Super/SMC top end. The pistol will be a 45 ACP/45 Super convertible.

Well, here’s a start. There will be complete slide and recoil assemblies for each top, slide stop, and a mainspring specific to each caliber. This being a keeper is why I used a Springer Mil-Spec as the base pistol. Keeping with the contemporary features while maintaining a retro flavor of 6” long slide, chambering, and Derr grip safety I chose to use an Extreme Engineering Wide (semi wide) bobbed, serrated hammer. Most, if not all, of the internals will be upgraded as shown. Parts displayed will be used in completion of this build.

The ballistics and lot tag in the upper left corner is from Federal rimfire ammo photo bombing my pic.

Slide-frame fit clearances (on upper left slip of paper) obtained were largely dictated by the dimensions of the base frame. I’ll use a BoMar pattern Colt take-off rear sight and a Novak front post or semi post front sight. The present reverse plug is a top hat type supported part from TMC…for 6” long slide. This is a part I am not too fond out of all their other very nice products. The spring bore in the plug only accepts smaller diameter springs or small gauge spring wire. I now have it where it just accepts the long slide specific Wolf recoil spring but if the plug fails I have lots to do on a new plug. Same thing occured on the 5” 9mm I built. So I’ll be ordering and EGW cutter and reverse plug. Their plug, however, is compatible with the much more common 5” slide recoil springs.

 

[lazarus]

Very nice! My biggest issue has been sourcing cases as no one has 45 super or 45 SMC cases right now.

My Glock 21L I am planning to setup for 45 super/SMC at some point, I grabbed 4 boxes of Underwood, 2 of hardcast 250gr and 2 of JHP 230gr that I can use for reloading once I've shot it. I still need a higher spring rate guide rod for it to safely shoot 45s/smc. But like you said, 44 Magnum territory for power. Especially out of the 6.61" threaded barrel in my 21L.

It makes a NICE bear gun.

 

[ohen cepel]

Mech Tech makes Glock/1911 rifle uppers in 45 Super also if that interests you any.

 

[John from MD]

Very nice! My biggest issue has been sourcing cases as no one has 45 super or 45 SMC cases right now.

My Glock 21L I am planning to setup for 45 super/SMC at some point, I grabbed 4 boxes of Underwood, 2 of hardcast 250gr and 2 of JHP 230gr that I can use for reloading once I've shot it. I still need a higher spring rate guide rod for it to safely shoot 45s/smc. But like you said, 44 Magnum territory for power. Especially out of the 6.61" threaded barrel in my 21L.

It makes a NICE bear gun.

This will fix your case supply problem.

.45 super from .308 brass ?? - AR15.COM

Firearm Discussion and Resources from AR-15, AK-47, Handguns and more! Buy, Sell, and Trade your Firearms and Gear.

www.ar15.com

 

[lazarus]

This will fix your case supply problem.

.45 super from .308 brass ?? - AR15.COM

Firearm Discussion and Resources from AR-15, AK-47, Handguns and more! Buy, Sell, and Trade your Firearms and Gear.

www.ar15.com

I appreciate passing it along. I'd seen you can make 45 super from .308 brass. I haven't wanted to go to that if I didn't absolutely have to. I probably won't be trying to shoot any for a few more months, but if none is available by then, I might convert some brass.

 

[Magnumite]

More of the project…

Trigger is a Remington R1 part. I drilled and tapped for over travel screw. It was too short for the trigger shoe cut out and trigger track, even with a dimpled bow, so I drilled the top of the shoe and tapped in a short steel rod. Filed it for reduced vertical play. Then I dimpled the left and right sides, top and bottom, to reduce lateral play.

The Derr grip safety is intended for a bobbed hanmer. And I do mean a BOBBED hammer. The bobbed EE wide spur hammer was way too long. So not wanting to alter the EE hammer I resorted to the parts box. I found an old GI hammer I bobbed way back. I bobbed it more…bobbed it some more. More. Nicely done. I also retrieved a tool steel sear and a take off long disconnector. Did the trigger work. Dry I have a crisp 3 pound 10 ounce pull.

Mainspring housing for the heavier 45S conversion is a checkered Remington R1 part. Great fit…even as a drop in part. Will do the tightening, blending, etc. later. The stippled original housing will retain the mainspring for the 45 ACP application.

The thumb safety is the stock Springer Mil-Spec tear drop part reconfigured to USGI.

Anyway, pics attached. Getting close to range shakedown. And loaded 45 Super power ammo.

 

[Magnumite]

Couple more pics

 

[alucard0822]

Nice, I do love the caliber. I built a 460 Rowland several years ago, but shot 45 super through my USP and a G30 with barrel/spring for it. I do like the SMC brass/small primer, but load it to slightly softer 45 super specs, if I need more than that I have the 460 Rowland. Also, the comp in my 460 Rowland is kind of what makes it awesome as it self-adjusts to a degree, the more gas, the more recoil is reduced and the more force holding the slide in battery, I can use the same 20# spring with 45ACP, super and 460 loads from a 230gr@750FPS up to 1400fps, and it functions fine.

 

[Magnumite]

Ready to test fire…

 

[Magnumite]

Nice, I do love the caliber. I built a 460 Rowland several years ago, but shot 45 super through my USP and a G30 with barrel/spring for it. I do like the SMC brass/small primer, but load it to slightly softer 45 super specs, if I need more than that I have the 460 Rowland. Also, the comp in my 460 Rowland is kind of what makes it awesome, the more gas, the more recoil is reduced and the more force holding the slide in battery, I can use the same 20# spring with 45ACP, super and 460 loads from a 230gr@750FPS up to 1400fps, and it functions fine.

Thank you. Nice setup you had going there.

I understand the comp is what keeps the pistol alive as well.

I do have a comped barrel, 5 port IIRC. I used it for some upper end loads back when I was playing with an open gun. The comp works. I’ve been tempted to get it rewelded and I’d chamber it for 460 Rowland. My only hang up on the project is if I need that much power I have 3 revolvers that fill the bill.

Did you use the same bullets in the whole series of chamberings?

 

[alucard0822]

Thank you. Nice setup you had going there.

I understand the comp is what keeps the pistol alive as well.

I do have a comped barrel, 5 port IIRC. I used it for some upper end loads back when I was playing with an open gun. The comp works. I’ve been tempted to get it rewelded and I’d chamber it for 460 Rowland. My only hang up on the project is if I need that much power I have 3 revolvers that fill the bill.

Did you use the same bullets in the whole series of chamberings?

The comp isn't a necessity in 45 super, the USP especially handles it well, pretty much the same power as 10mm, so it's got plenty but still useable. The 460 is a beast, a big jump in power, not sure it would function without the comp, being that was designed for the caliber. I do have magnum revolvers too, but getting the same power out of a mag fed 1911 as my 44 wheelgun is cool, although the 1911 is much easier to shoot at that power level. I do load with the same bullets, but some loads are more fun than others. Probably my favorite 460 load is a 185gr XTP/HAP with 13.5gr of power pistol, it's 1500+ FPS and the fireball is stupid huge, but super accurate out at 100 yards or further. I use the same bullet for both this load AND my 45ACP match loads for 3 gun heavy, probably the lightest 45 load I do. Of course I use 230gr RN plated, but load them only up to 45 super velocities, and keep my 460 brass for hot loads. 450gr RN usually used for my 45 colt loads work in 45 super brass@900FPS, and out of my Rowland have been epic for bowling pin shoots. I don't shoot a ton of FMJ 45 bullets, usually like HAP/XTPs better for accuracy, but have loaded them to 45 super and 460 velocities, they are fine in the super, but not as accurate as I would like in the 460, although I tend to prefer 185-200gr bullets in that caliber to keep velocities up, recoil lighter, and brass lasting longer.

 

[Magnumite]

Got ya there. No comp for the Super. I have the 10 I built so the Super and 10 is close in power. I was pondering the comped barrel for a Rowland caliber.

 

[Magnumite]

Well, I ordered, received and installed an EGW flgr for it. Weight here is the goal since heavier recoiling pistols tend to beat themselves and the shooter up less. Not that i have issue with the recoil but just keeping things pleasant. Relative to handling the pistol is actually not too bad considering the long slide and extra weight.

I shot the beast but only with 45 ACP 230 ball. I have’t loaded any ammo at Super/SMC level nor have I received any Underwood or equivalent ammo. This was a wringing out foray. Targats attached. S&B and WWB used. For the guys that recall shooting 38 Specialnloads in their 357 Magnum revolvers…that is what shooting this gun with 45 ACP ammo is like. I was concerned it may not cycle set up for the heavier caliber but it ran 100%.

Targets speak for themselves. Shot standing, two hands at the labeled distaces. 4 cups of coffee didn’t help a great deal…lol. The one target indicates the elevation screw actually backed off (about 3-4 clicks) since there was no detent tension screw in it. That has been rectified. The rear sights were set about 1 1/2 turns up. I have since lowered the front sight a smidge since high velocity rounds tend to shoot lower. Final finishing (completion) will be done after all test firing is completed. Then I will have a 45 ACP/Super conversion pistol set up for myself. I am considering fitting the Marvel 22 conversion to it. I don’t like conversion pistols bit this one makes sense…to me…for me.

 

[Magnumite]

Okay…a little bit more. That is a little bit more relative to the size of it all. Time wise…good chunknof time…3 hours at least to get this area ‘roughed in’ and ready for detailing and chasing the serrations.

Let me start by saying serrating and checkering (‘nuther gun) stainless inhales. Talk about gummy feeling file cuts. Also the peak of the serrations and the frame surface were just about even. But no matter how I looked at it, the frame looked proud of the serrations. So I shadow boxed the frame down to the bottom of the slide rails were both slide and frame coincide. Feedback?

Anyway… pics

 

[Magnumite]

Okay…so since the original 45 ACP slide overhang the rear of the frame even more I felt compelled to deal with it. I moved the rear of the slide forward, kept the arcs and curves. Then I used an old dull crosscut file to matte it.

 

[Magnumite]

A little Oxhpo-Blu later…

 

[lazarus]

I love the updates on the project.

 

[Magnumite]

Thank you. Where to go with it is clearing up.

 

[Magnumite]

Shot the pitol with almost two boxes of Underwood ammo, rated as follows:
185 gr JHP @ 1300 fps, 693 ft-lbs;
230 gr JHP @ 1100 fps, 617 ft-lbs.

This factory ammo was selected because it is a high pressure round and I wanted indicators and shooting feel to guide my finding safe limits in ammo performance.

The initial setup was 25 pound mainspring, flat bottom firing pin stop with forward relief cut at the top (Harrison type cut), extended Wolfe ‘strongest’ recoil spring. The properly fitted recoil spring which measures 15 pounds at full compression, seems light at a glance. However, considering some of the specifics which mitigates the recoil it seems adequate. AND it is a total b***h to load into the slide assembly so it must provide adequate force to some reciol absorption. Things considered in the cycling assembly are:
1 inch more compressed spring length;
longer barrel and slide;
bull barrel.

In character recoil is 45 ACP…just considerably more of it and sharper. And louder. Some quick muzzle rise to about 50 degrees. Same familiar roll. I did change to a 28 pound mainspring. The pistol was more stable, muzzle rose about 25-30 degrees, and much more back into the hand. If any of have shot a 38 Special LCR with 158 grain ammo..the recoil was similar.

The pistol needs more grip…texturing is effective, just need grips which are more hand filling. Front sight will be trimmed and finished another .020” to bring the rear sight down a little more. Cosmetic touches and completion.

The pistol works. Meant as a magnum class fun gun, perhaps a silhouette pistol, and a Maryland legal hunting pistol (with handloads). Group pics attached and the groups explained. Group shooting was done at 25 yards (indoor range limit) since this isn’t meant as a close in action pistol. Standing, two handed. Four shots were fired at 10 yards to get the sights reasonably close. Then shooting at 25 yards with not too much ammo b’cuz its so expensive. Handloads will offer much more shooting.

Pictures. shots labeled ‘CALLED’ are called fliers considerably out of the group. The remaining shots were as I called them.
Pic 230 grain picture #1:
10 yards purple shots were to check sight ekevation
10 yarrds red shots, after sight correction
Green shots are the group.

230 grain puc #2 as indicated.

185 grain pics #1 a d #2 as indicated.

Considering the shots were landing as I called them I would estimate the pistol is a shooter

 

[Magnumite]

Cleaned up slide serrations, hammer narrowed to prevent interference in hammer cut out in slide, thumb safety scallop cleaned up, all carbon steel surfaces cold blued.