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The All-New Big .45 SUPER Thread!

58K views 61 replies 32 participants last post by  RedTeam98 
#1 · (Edited)
-Original:
http://www.glocktalk.com/threads/45-super.1382239/

-The original thread contains 57 pages with almost 1,500 posts over the last 4 years. It has huge amounts of discussion and information on what works and doesn’t, including the hows and whys. It also includes much more load workups and detailed observations than are included here. If you read this post and decide to pursue a .45 Super setup, I would STRONGLY encourage reading through the original thread. While I tried to be as objective as possible, there will naturally be some of my own interpretation and sentiment in this summary so going straight to the source will give you perhaps “rawer” data as well as more varied opinions.

-I won’t pretend to be a pioneer for this information. I only contributed a bit of theory and provided some of the higher-end load data. However, the community’s ever-evolving current understanding of the capabilities and limits of a good .45 SUPER setup is the result of years of collection and experimentation by dozens of people. I am just compiling the information so it is easier to digest for someone looking to get into loading for this cartridge. Plus I figured it could be a good way to re-ignite the discussion to incorporate new thoughts and questions.

-I am sure I butchered or forgot information here and there, so if you see anything inaccurate based on the original thread just let me know and I’ll edit it into the original post.

General:
-This thread is about .45 SUPER or what some are now calling “.45 Rowland.” That is, taking normal-dimension ACP and Super brass and loading to well beyond SAAMI’s .45 Super numbers, to pressures reserved for the .460 Rowland and beyond. From here on, handloads loads using .45 ACP or .45 Super cases pushed beyond regular .45 Super levels will be referred to as “SUPER” loads. It is primarily dedicated to handloaders, but much of the basic information about compensators can apply to someone looking to fire factory .460 Rowland as well.

Why not just use .460 Rowland?

-The Rowland case is extended in order to prevent it being chambered in guns not designed for it. As the overall cartridge length remains the same (and is limited by the magazines from which they are fed), there is no increase in internal powder capacity. Thus, other than being available as a factory round its ONLY advantage is relative safety from not being able to load them into regular ACP guns—however, a careful loader and shooter can avoid these issues. (I have seen a 9mm cartridge loaded into a .40 pistol result in the barrel flying downrange and the slide punching into the shooter’s face, so being careful is still always important).

-Factory .45 Super Specs:
185gr @ 1300fps (694 ft-lbs)
200gr @ 1200fps (639 ft-lbs)
230gr @ 1100fps (618 ft-lbs)
28,000 PSI.

-Factory .460 Rowland Specs (approximate):
185gr @ 1560fps (1000 ft-lbs)
200gr @ 1450fps (933 ft-lbs)
230gr @ 1340fps (917 ft-lbs)
~48,000 PSI (40,000 CUP)


Glock Models
-The most commonly-used variant is the Glock 21. Glock 20s can be converted to shoot SUPER as well, using the standard barrel / slide combinations for any other conversions.

-A surprising amount of success has been found with the G30 (SF / Gen 4). Case support with aftermarket barrels matches the full-sized G21. I would not be surprised to see 1000 ft-lbs exceeded with a G30, as with a decent compensator the only real limitations would be one's tolerance for recoil, and the relatively short barrel lengths (would be like using a ~2.75"-barreled revolver!).

-One user has played with a G36 / G30S with limited success. The narrower slide is lighter in weight, and the barrels (even aftermarket ones) are designed with a larger scallop from the feed ramp to the chamber. However, 700ft-lbs was achieved with relative safety, and 750+ was recorded before brass began to bulge.


Cases
-.45 ACP shares a parent case with the .30-06, and is actually FAR stronger than the guns for which it is originally designed.

-Starline has confirmed their .45 Super brass has the same strength as their .460 Rowland brass. It is generally hypothesized that +P Brass and Starline .45 Super brass are of roughly the same strength, with +P brass being measurably thicker and the Super brass being supposedly created from a metallurgically-stronger material.

-Using Standard Cases: Over time several people began to push regular cases very hard and found them to be more than sufficient. I broke 1200ft-lbs of energy using once-fired regular ACP cases in a purpose-built G21. Granted, I threw out the brass after observing excessive case-head expansion, but they took it! Exceeding 1000 to 1100ft-lbs of energy is no problem for regular ACP brass, depending on barrel length.

-The bottom line: Regardless of what you use, work up slowly. Bulging brass will be your first indicator that something is wrong, but with a well-built setup you will not likely see this.

-Case Life: If able, keep track of your case-head expansion. When loaded “only” to Rowland levels, one could expect to reuse regular ACP multiple times. However, much beyond that and I started approaching my personal limit of comfort for reuse. But, case head expansion is definitely your most reliable indicator of when you should toss a case.

-Here are some bulges:



Barrels
-Storm Lake, KKM, and LW all make perfectly good barrels. Outstanding numbers (1100+ ft-lbs) and accuracy (2.5-5 MOA) have been achieved with all three makers.

-One significant improvement that can and is often made to any aftermarket barrel meant for hand-loaded .45 Super / .45 Rowland is to ream the chamber’s throat. This allow heavy bullets to be seated far longer than would fit into a factory chamber, which in turns allows for more powder without increasing peak pressures, and thus greater velocities. Mine has probably among the deepest throats, with about .65” of freebore before the actual rifling starts. As a result, it takes more powder to reach the same velocities recorded by others, but seems to top out higher.

-The important thing is that your barrel provides good chamber support, which is not a concern for any of these. Even if you are not using a thread-on compensator, factory Glock barrels do not have appropriate chamber support for anything approaching even factory .45 Super levels.


Compensators
-Why use a compensator? Especially compared to a 10mm Glock 20, the bullets are heavier and the slide is lighter. Thus, for the same energy levels, there will be significantly more momentum in the SUPER cartridge, and a little less mass in the slide to absorb it. Thus, there are two problems you run into:
1) The slide moving too fast and hitting the frame, eventually resulting in frame damage around the RSA.
2) The slide moving too fast to pick up the next round—basically, the slide outrunning the magazine spring.

-A good measure of relative slide speed is how far the cases are ejected. If you are shooting standing up, if the cases are landing within 1-2 feet of your shoes, you are probably at the low limit of reliable function. The solutions would be to increase charge weight, reduce recoil spring weight, or reduce the weight / number of ports in your compensator. On the other end, if your cases are landing much further than, say, 8-10 feet from your shoes, then you are at the lower limit of possible frame damage with prolonged shooting, and should seek greater compensation if not a heavier recoil spring or lighter charges.

-The compensator, through its weight (especially for steel varients) and from the collection of gas energy, slows down the initial rearward motion of the slide (via the barrel). This serves two purposes:
1) It delays slide / barrel unlocking. No matter what is in your brass’s headstamp, if the slide pulls it out of the chamber too early, with perhaps 5-10k PSI still pushing against the case walls, you are going to hand a bad time.
2) It reduces the peak velocity of the slide.

-A few people have used stronger recoil springs in the magazines, or even stuffed two springs into one mag (reducing capacity by one or two rounds) in order to compensate for this. However, I would generally say this is probably a bandaid to the obvious problem of extremely-high slide velocities.

-Some have approached Rowland-level loads with non-compensated guns by using heavy recoil springs and doubled-up magazine springs. My personal testing with 250gr bullets at about 1000fps using a near-stock setup resulted in 15-20 feet of ejection—I could shoot, see my new bullet hole, then turn to track the brass before it hit the ground. Hot 10mm loads pushing 200gr bullets that hard also see pretty far ejection distances, and they have more slide mass on their side. So, YMMV. In any case, standard .45 Super-level loads would probably be reasonably safe if you have appropriate barrel support and a stout recoil spring. Nobody has objectively measured frame damage (seen as “mushrooming” around the base of the guide rod), or determined the point where it negatively affects safety or reliability. Realistically, that point is pretty far down and you could probably shoot hundreds of loads ejecting 15’ without any big issues, but I wouldn’t want to be the one to test it. Some have reached standard Super-level loads with stock-length G21 barrels using only 22-24lb recoil springs. Some have seen bulged brass at these levels. If you wish you pursue this route (Stock barrel, without a comp), be aware that muzzle flip is not going to be insignificant, ejection distance will certainly be beyond ideal levels for frame longevity, and you will be at increased risk of case failure.

-Here is a picture of the kind of frame damage you want to avoid. This was from shooting less than 250 rounds of 250gr bullets at 1000fps, but with nothing more than a 24lb recoil spring to slow the slide. These loads generate about 25% more momentum (and thus force) than a standard 230gr ACP load, and a recoil spring alone was likely not enough to account for it. Realistically, such damage would likely become cosmetically hideous before it actually negatively affected safety or function, but it is certainly an indicator of a pretty imbalanced Super setup even if it seems to function adequately.


-A few manufacturers make adequate compensators for warm SUPER loads. However, they tend to be designed to still function with factory ACP loads, and thus either incorporate relatively inefficient designs or are simply too small to be very effective against high-level loads. Still, 900 ft-lbs can be reached with reasonable safety and longevity using several factory comps, and more has been achieved but with arguably higher slide speed than is ideal. One decent example that comes to mind is from Carver Customs, but several other makers have worked well (Lone Wolf, KKM, YHM, etc):

http://w.iwebcenters.com/bbenterpri...s/45-acp-gap-carver-lw-glock-4-port-combo.cfm

-The best results by far have come from custom compensators designed by someone both well-versed in compensator design, AND who is not necessarily focused on maintaining function with factory ACP ammo. That is, purpose-built SUPER compensators tend to be both larger--with larger and more baffles--and heavier, especially if made of steel. One of the guys who has made a big contribution to the recent developments in .45 SUPER is es350. He is a machinist and will work with you to make the best compensator to suit your needs, for a very fair price. Send him a PM!

-Recoil springs can compensate a little for using a smaller comp. The benefit here is being able to shoot factory or near-factory loads by using the stock or lighter RSA. My setup requires a 13lb recoil spring to function, and brass still lands at my feet unless I am pushing a 250gr bullet beyond 1350fps, largely due to the weight of the of the compensator in addition to the efficient port and baffle design.

-What makes a compensator work?

Consider the recoil-reducing effect in two parts:

First, the gases behind the bullet hit the baffles, in effect "pushing" the brake and muzzle forward. The larger the internal volume available for the gases to spread out against the baffles, the better. If there is not enough volume for the gases to easily diffuse away from the rear of the bullet (i.e. the internal volume in front of each baffle is too small--from either too many baffles stacked together or a too-small compensator in general), a significant portion of the gas will simply bypass the baffles and exit behind the bullet. Basically, the ports / expansions chambers (the open space between baffles) have to be large and long enough that a large portion of the gases can expand to fill that area in the short time before the bullet passes the baffle and the gases follow it to the next port to try again.

The second part is the "rocket" effect of the high-pressure gases being redirected. This, IMO, is somewhat secondary compared to the first effect, illustrated by the success es350 has had with compensators with side ports. Still, the effect is there, and if not quantifiably document, it has at least been observed and understood. One caveat to the above requirement of large volumes in front of the baffles for expansion is that this larger volume directly equals reduced gas energy and thus reduced rocket effect. I would not call it a complete trade-off, but at the same time I would not put recommend more than, say, 40-50% of the circumference of the compensator ported (at least with the gas volumes we are dealing with).

In short, focus on creating larger baffles, with a little more space between them (es350 has had great luck with .25"). Second, I would definitely not angle the baffles themselves, as a rearward angle basically creates a taper that actually encourages the gases to follow the bullet instead of stop at the baffle and exit the ports. The ports themselves being angled is probably insignificant, and IMO any potential benefit from the *slight* rearward thrust is likely offset by the increased "backpressure" at the ports causing a little more of the gases to follow the bullet out. ((To clarify, I am describing the baffles as at least the inner 0.75" of the compensator--the bullet hole plus about .10-.12" on all sides. You want this part flat. The remaining "tunnels" which further direct which direction (top / sides) the gases vent is what I am describing as the ports)).

As an example, look at the design of all the most effective (i.e. used in competition) compensators, and you will notice trends that follow the above description. The LW Compensator is, IMHO, somewhat of a gimmicky design. Rearward-angled compensator ports like those found on big rifles are only beneficial (and still mildly) because of their size, the volume available inside the comp (notice they are like 3" long and 3" wide with a good 1" or more between baffles), and the fact that they have 15-20 times more gas to work with than we do, heh. But don't ignore that the actual baffles are like 2 square inches of perpendicular surface, because that is what is doing most of the work.
 
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#44 ·
On page 2 of this thread, ES 350 has a post. If you click on his username you can send a private message via the conversations feature.
 
#47 ·
I just loaded up and shot some 45 Super last week for the first time. Gun was a M&P 45 2.0 with Carver custom comp. The factory barrel is fully supported like the XDM. I was using the stock recoil spring assembly, but have a Wolff 22 lb spring and guide rod on order.

I used cast and powder coated bullets weighing 263 grains. OAL was 1.150"

CCI 300 primer and 800x powder. Fired WCC headstamp 45 acp brass.

At 8.5 gr 800x, I achieved an average velocity of 1037 fps. Cases were getting ejected 15-20 ft despite the comp, so I ordered a 22 lb spring.

The case web measure .478" after firing, as opposed to .474-.475" after firing standard 45 acp ammo. Is this acceptable expansion? Should I be using Starline 45 super brass?

I have no intention of upping the powder charge, as 1000k fps is what I was looking for.
 
#48 ·
Need some help guys, I've been playing with a 255 grain Lee .45 Colt bullet that I cast myself in my Aluminum framed 1911 .45 Super and at 9.7 grains of 800x I'm getting 1215 fps and pierced primers with this bullet. I have loaded many 250 grain HSM bullets over the years up to 11 grains of 800x and over 1300 fps without a problem. Could it be because I have to seat the bullet deeper because of its wider nose to keep it out of the rifling that's causing the issue? Thanks
 
#54 ·
I'm gonna guess that what you need is a bullet similar to a LBT-style WFN. The LBT notion was to keep more of the weight forward, out of the case, leaving more room for powder.
I realize that a true (LBT-schema) WFN won't run in a 45acp-chambered 1911 unless the chamber is reamed to lengthen the throat to accommodate the WFN bullet. And then there is the potential issue with magazines if the meplat is too wide.

Hope this helps.
 
#49 ·
New to the forum and to Glock. Just acquired a gen 4 G21 in 45 and waiting on a LW threaded barrel. I have a YHM Sidewinder and will shoot with the can on for most shots other than load development. I have several suppressor and host combinations and hope to use this one for some hunting this fall. I like to keep everything subsonic. Looking forward to following this thread .
 
#50 ·
Here is my current project: LWD large frame and 6" long slide. Bar-Sto 45 ACP barrel throat long. 22lb tungsten recoil spring. Will cycle normal 45 Super charges fine. Will not lock back on standard 45 ACP rounds. I don't want to push it too hard until I get a comp for it. I want to get the frame engraved but I haven't found anyone that will do the LWD frame.
955012
 
#57 ·
Has anyone tried Ramshot Silhouette in the 45 Super? The burn rate charts have it quite a bit faster than both Power Pistol and Longshot, but looking at the available data seems to indicate it is much closer and seems to give higher velocity at lower charge and lower pressure.
 
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