500 Maximum, Martin Custom Sixguns

The .500 Maximum, or Linebaugh Long as some call it, is the edge of usable
handgun power.   At least that’s what we’ve been told. Recoil accounts range
from “it’ll make you physically ill” to “it can part your hair”. But I never
believed any of that. In truth it’s a .500 Linebaugh plus 0.20”, no more, no
less. I’ve worked with Linebaughs for years and am no worse for wear. Sure
they kick, but with practice they become tamable side-arms. Furthermore,
my 500s fling 435 grain casts between 1,100 – 1,300 fps. All the thump I’d
ever need from a handgun, right? Rationally speaking the answer is yes.
Testosterone is a bitch though and often boots logic to the curb.   I wanted
more horsepower and the .500 Maximum fits the bill. I equate it to spraying
nitrous on a big-block. The baseline is plenty but it's nice to have a little
extra throttle.

In August 2011 I acquired a like-new Ruger .357 Maximum. With two of the
same model NIB, the third would be sacrificed. It was time to find out what
all the .500 Max hype was about.   The gun was stripped down to its frame
with the rest being boxed and set aside. A Bisley kit was immediately fit and
a cylinder was machined from 17-4 stainless. Par Nor supplied the barrel
blank in 1:16” twist. Length was set to 6.5”. The conversion is the standard
five-shot job. We went oversized on the cylinder, re-timed the gun, and
matched the bolt to the cylinder stops so there’s no side-play. The most
critical tolerance was front to back. A little end-shake can quickly become a
lot of end-shake at these levels.

Similar to the Linebaugh and Bowen conversions, we machined an integral
band to support the ejector housing. A homemade aluminum post sight was
screwed on top along with a generous glob of Loctite. My eyes love contrast.
A black notch rear behind a silver blade helps me land the target. On paper it
sounds like a horrible combination but I recommend giving it a try. Others
have shot my guns and are pleasantly surprised.

Testing was done in November 2011 while the gun was still in the white. Cast
Performance’s 435 grain WFN was the beta slug. These aren’t the bullets I
plan to use but I had a few hundred on-hand and was eager to dent primers.
Fueled by 44.0 grains of AA1680 they went 1,500 fps. Recoil was brisk but
something of a letdown.

Before I undertook load development and bulk case forming I sent the gun to
Mahovsky’s for their Metalife treatment. For those not familiar with the finish
it’s basically hard-chrome; really good hard-chrome. Metalife is 71 on the
Rockwell C scale, can be had in brushed or high polish, and has a maximum
build of only 0.0002” (so there’s no impact to function or tolerances). $150 is
the current rate for a revolver and that includes a lifetime guarantee. Better
yet, their turnaround averages 30 days. They’ve done a dozen plus guns for
me and I can’t recommend them enough.

Grips and indecision. I was originally set on English or claro walnut from
Cary Chapman. He’s top shelf and did claros for my .500 Linebaugh Bisley.
Then I came across factory Rugers in gray laminate. The pair was the early
version, circa 2005. Light in color and a tad thicker than the current Bisleys
they fit perfectly. No exposed edges and no unsightly gaps. Just as
important, they fit my hand. I may still have CLC cut walnuts but for now
these will do. My Maximum returned from Mahovsky’s right before
Christmas. A knurled Belt Mountain basepin and a Bowen target rear sight
rounded out the project.

When the .500 Maximum was introduced in 1991 cases could only be made
from .348 Winchester. That was a problem because .348 production is
sporadic. Hornady did a run of Maximum a few years back but they've since
vanished. As with all Hornady brass, the quality was outstanding. I’ve
loaded some for a friend and was impressed; if you find a batch nab it.
Fortunately Starline catalogs .50 Alaskan hulls and that’s the preferred
parent. Simply cut to 1.62” and trim to a 1.60” final length. No inside
reaming is required. We turned mine on a South Bend lathe and de-burred
the mouths. After that proceed to the standard 3-die reloading sequence.
We made our own dies and matched them to the cylinder. Since the rougher
and finishing reamer were done in-house we ran tight chambers; ~0.0015”
over a sized cartridge. Our seater was machined minus the crimping lip. On
rounds like this I like to crimp separately using our universal die. With
removable inserts I can choose between taper or roll. While the former
works the brass less it doesn’t provide enough purchase to hold reliably.
Heavy weights and jarring recoil create a lot of jump. Most of the bullets
we'll test have deep crimp grooves so hard rolling will keep them snug. The
really large slugs, 500 grains and up, may bulge the brass where the gas
check leads into the sidewall. Years ago we made another sizing die sans the
de-capping plug. Pushing a crimped shell through removes the ring and
straightened the case.

Close friend and author Max Prasac and I have worked with our .500
Maximums for two years. In doing so we’ve come to conclusions based on
actual results, not armchair ballistics. We both agree 435’s are small for the
round. I equate them to shooting 158’s in the .357 SuperMag. They work
but you’re trying to make a deathray with lighter weights. Consider this.
435 WFNs penetrate best around 1,200 to 1,300 fps. 1,300 to 1,500 nets
you a couple extra inches in penetration, that’s it. Over 1,500 and the
meplat may deform lessening performance. Granted, 435’s can be backed
down to .500 Linebaugh smack. And if that’s your goal I suggest the smaller
framed Linebaugh. The base gun is shorter, lighter, and cheaper to acquire.
The only advantage to the longer case at these levels is marginally lower
pressure. 28,000 vs. 35,000 PSI to be exact.

Oddly, many writers and big-bore experts frown upon 500+ grain bullets in
the Linebaugh. Their position seems to have carried forward to the
Maximum. Usually 400 to 460 is the prescribed window. And while they
rarely provided the “why” they’ve hinted at three reasons: 1) They don’t
stabilize and aren’t as accurate, 2) They ramp pressure and even cause
unpredictable spikes, and 3) They under penetrate the lighter bullets.
Unfortunately these theories are rarely backed by empirical evidence.

Most published .500 Max data stops with 435’s at 1,550 fps. We almost never
get top-end loads for anything heavier. But handicapping the round mirrors
the mistake we made with the .357 Maximum. Just shoot the standard bullet
but run it 200 to 300 fps faster. Flatter trajectory, yes. Added performance,
no.

I consider 500 to 525 grains to be ideal in the Maximum. The same holds for
the .500 Linebaugh but more on that later. To date I’ve used Cast
Performance’s 525 WFN with great success on paper and steel. Max Prasac
has used it with great success on game. Over 38.0 grains of AA1680 it’ll go
1,300 – 1,325 fps from a 6.5” barrel. It adds 90 grains of weight to the
Linebaugh 435 and another 50 – 100 fps. Better yet, recoil is no worse than
435’s at 1,500 fps. Too much of a good thing you ask? Isn’t the gun being
beaten harder with these mammoths? Nope. Accurate Arms published
pressure data for the big 500 and my 525 load is 35,000 PSI. We’re not
taxing the gun. The frame and cylinder feel sidewall and head thrust, not
bullet weight. Case pressure is case pressure. To prove my point I fired
three-thousand 525 WFNs and 38.0 of 1680 is all I poured. That’s three-
thousand peak .500 Max and the gun is fine. There’s no end-shake, no side-
play, no flame cutting, and no irregular cone wear. If you think these
customs have a short lifespan think again. A well-built .500 Maximum should
last a lifetime.

One thing this article won’t do force a lot of load data. Before I even built
mine I knew it’d be fed 525’s. I also knew the powder. I’m a long-time
SuperMag shooter and my go-to propellant in 1.60” cases is AA1680. Talk to
the old IHMSA crowd and you’ll hear WW680 mentioned a lot. Winchester
discontinued it in the early 1990’s but Accurate Arms reintroduced it as 1680.
The only question was how much. Max Prasac suggested the load which was
passed to him by noted gunsmith Jack Huntington. Thirty-eight grains burns
well in a 6.5” barrel, provides plenty of speed, and keeps pressure in check.
After touching off 3,000 of these I have no reason to switch.

Hopefully I’ve convinced you these heavies won’t turn your gun into a rattle
stick. But what about accuracy? Will they stabilize, group, and fly well at
100 yards? My first 25 yard cluster from the bench put five into 1.5”. I then
moved to 50 yards and stuck eight in 3.0”. I can’t repeat those at will but my
Max routinely does 2.0” at 25 yards and 4.0” at 50. Some of the credit goes
to Par Nor and some goes to my dad’s gun making ability. Cast Performance
also drops a world class bullet. What was most enlightening though is the
chronograph story. Five shots over the screens produced the following:
1,327, 1,324, 1,327, 1,330, and 1,326. I couldn’t believe the spread, or lack
there of. I’ve never had five from a revolver span only 6 fps. This hints at
why the load is so accurate.

Other upper-end powders for the .500 Max include IMR 4227, Lil’Gun, H110,
W296, and Accurate Arms 9. Blue Dot, HS6, and 2400 work well for mid-
range. Unique and W231 are best for reduced. Since downloading the
Maximum moves me to my Linebaugh I won’t speak to the latter two
categories. And while I strongly recommend AA1680 let me touch on the
other peak power propellants (say that three times fast). 4227 is certainly
slow enough and it’ll post stout velocities. It’s accurate, meters well, and the
burn rate is suited for the case volume. The downside to 4227 is it’s messy.
If you’ve ever shot the stuff you probably noticed yellow granules strewn
throughout your revolver. Some say the particles are filler, others claim it is
unburned powder. Whatever the cause it can dirty the gun enough to impede
function. For that reason I rarely use 4227 but it’s viable in the Maximum.
Lil’Gun is another strong candidate but it has very high flame temp and can
cause premature cone erosion. Moreover it offers nothing over AA1680.
AA#9 is fine too but falls a bit short on velocity.

That leaves H110 & W296. Most manuals endorse them for the SuperMags
and Maximums but they’ve never worked well for me. Accuracy is sporadic,
there’s a higher SD over the chronograph, and pressure seems to spike
quicker in the longer brass. This doesn’t surprise me though. In the original
1991 G&A article Ross Seyfried reported odd results with H110 in his 500
Maximum. Weird performance like velocity drops when going up one grain.
Then the previous velocity returned when moving-up another grain. He also
cited excessive pressure at 100% load density. That’s where H110 and W296
are designed to operate. I can’t substantiate what I’m about to say but I
think a straight stack of H110/W296 is less efficient in a 1.60” hull. Again I
can’t prove it but I believe the .500 Maximum and sibling SuperMags are just
too long for those powders. It’s probably not as pronounced in the smaller
357 Maximum and .375 SuperMag, but the .414, .445, .475, and .500 “Longs”
thrive on rifle powders like AA5744 and AA1680. Ultimately Ross
recommended WW680 and most of the smiths that build these cannons
suggest the same (albeit AA1680). Now I’m not down on H110 and W296.
There’re stellar for wide-open performance in 1.29 – 1.40” rounds. My
Maximums and SuperMags just prefer even slower fuels.

Now let’s talk penetration. For the longest time we’ve be told the .475 out
penetrates the .500. And when the ,.500 is restricted to sub-450 grains that’s
true. The problem is these weights strangle the half-bore. Take a look at the
three bullets pictured below.

Left to right – 425 WFN .475, 435 WFN .500, 525 WFN .500. Their sectional
densities are also noted.

The 435 just isn’t long enough to wring the most from the .500. Increase the
sectional density and look out. And real world shooting supports the claim
that bigger can be better. 500 – 525 WFNs have out-drilled 435’s on test
medium and big game alike; and I’m talking very reliable, very experienced
sources here using the base 500 Linebaugh. Load the same bullet in the
Maximum and Thor’s hammer gets juiced.

A few years back a 500 grain LFN was tested at a Linebaugh Seminar. Fired
at just under 1,100 fps from a .500 Linebaugh it went 57”. Granted, these
trials can be variable but it demonstrates two things: 1) The larger caliber
500 can hold its own, and even exceed, the .475 on penetration, and 2) 500
plus grains will stabilize from the 1.40” case.

Throughout 2012 I worked with 525 WFNs in my .500 Linebaughs. Pushed by
26.0 grains of H110 velocity averaged 1,080 fps and the bullet flew straight.
Accuracy was more than respectable, it was eye opening. One-inch groups at
25 yards and two-inch groups at 50 proved my point.   And these results were
achieved in two 500 conversions. We’re not talking outliers here. I’m
convinced the Linebaugh can thrive on the heavier weights.   I haven’t
conducted penetration tests with the load but I expect it’ll out-pace the 475
(420s @ 1,300 fps). But my agenda isn’t to crown the 500 the ballistic king
and relegate the 475 to queen status.   Both bulldoze game to include the big
five.

So far I’ve shot the 525-500 Linebaugh out to 50 yards but I’ll test at 100
soon. My Maximum logged a lot of time over the proverbial football field
though with 525s. Holding 6 o’clock on a 10” paper plate I can land with
regularity. The 3-shot print shown below was actually a 5-shot attempt. The
other two impacted an inch or less from the top of the plate. Not bad, but if
machine rested the gun and the load are capable of 3” at 100 yards.

So how painful are these things to shoot? My introduction poked fun at some
of the reviews of .500 Max recoil. Joking aside, I want to give an honest
portrayal of what you’re in for. Let me start by saying this. If you can
handle full-house .454 you can handle the 500 Maximum. It’ll take practice,
patience, and some shooting aids. But they won’t go airborne unless you
limp wrist the hold. Start with a good set of gloves. Both hands should be
protected at these levels. Years ago I purchased a $4 pair of gardening
gloves and cut out the trigger finger. They’re not fancy but they work. After
absorbing tens of thousands of rounds from the “over 45” club, my hands are
still intact. Another tip is strength conditioning. I lift a lot of free weights and
feel it helps with grip tension. Grasp the gun firmly, apply controlled force
with both hands, and drop the hammer. The gun will come back fast. Don’t
fight the recoil, just maintain a firm grip and let the gun rock to 45 degrees.
If it’s exceeding that angle I recommend more force. Make no mistake these
guns can touch your forehead.

The greatest risk in shooting these things is to your knuckles. Bisley
gripframes are an absolute must with this type of recoil. And while Bisleys do
a tremendous job in preventing roll, your middle knuckle is closer to the
trigger guard. 500 Maximum impulse tends to mate the two and most gloves
won’t save you. As you can see from my photo 50 rounds of 525’s @ 1,300+
fps can cause swelling. If you shoot enough of this beast the swelling can
become permanent. I’m living proof. But don’t let that shy you away from
building one.

Two knuckle remedies exist. If you’re like me you can opt to wrap the finger
with a lot of flex bandage. It basically “pads out” the glove enough to touch
the trigger guard. In doing so there’s no room for run. A better solution is
the Jack Huntington Bisley reshape. Jack is a world class gun builder and one
of the nicest guys in the business. If you want a 500 Maximum send him your
357 SBM and let him do his magic. You’ll not only get a precision assembled
gun, you’ll get his reconfigured grip. The change is subtle to the eye,
noticeable to the touch, and a god-send for the hand. Max Prasac’s 500 is by
JRH and I’ve had to the pleasure to shoot it on multiple occasions. After
dozens of rounds the trigger guard has never made contact with my knuckle.
The same cannot be said for my stock Bisley.

With 20 plus years on the scene I believe it’s time we take a harder look at
the 500 Maximum. When unveiled in the early 90’s it was touted as a
powder hungry, bone-breaking, eyeball rattling howitzer. But some of that
myth is unjust. Working with the round I’ve come to appreciate its
capability. I’ve also come to respect its bark. This isn’t a cartridge for
novice big-bore shooters. That said, any experienced handgunner can learn
to master one. Some say you should limit your round count per outing. I’m
the opposite. I’ve become proficient with mine through volume shooting. In
fact, most of my sessions were 100 rounds per with my best groups coming
after fifty pulls. I guess I need time to settle in, but to each is own.

Now a lot of folks will accuse me of being oblivious to recoil. That simply isn’t
true. I’ve shot 50 Alaskan revolvers as seen in the video below. I know the
difference between solid wrist therapy and over the top recoil. The .500
Maximum isn’t the latter, at least not for me. Nor is it a novelty round. It’s
a viable cartridge for dangerous game and down. The .500 S&W may be the
world’s most powder production revolver but I think the Max has it all over
the Smith. It’ll match the S&W on penetration and killing power but do so in
a smaller package (not to mention 40% less pressure). I won’t even get into
the aesthetical comparison.