Long Range Masterpiece

The Shilen-McMillan-Gritters .300 Remington Ultra Mag

Perhaps I speak for most readers when I say there is nothing that makes me feel as good as whacking a target at long range with the first shot.  I don’t know why, for I could go 100 straight in trap or skeet and maybe feel the same way, but I will never know, as I know I will never do it.  Placing one bullet inside a saucer, or shooting a teeny group sitting with a tight sling at 700 yards, is for me cause to celebrate.  Failure to do so is depressing.

Even though the name of this magazine is The VARMINT HUNTER, my guess is that a lot of folks who read this magazine have a hankerin’ for long range shooting, and not necessarily with a typical varmint rifle.  Though he doesn’t write about busting PDs with it, Steve Timm loves a .280 Ackley Improved, and for good reason.  Its ballistics actually beat those of one of my favorite long range loads, a 7 mm Remington Magnum.  Shooting 150 grain Nosler BTs at 2910 fps, my old favorite may not have been sexy, but it was a death ray.

I say was, because Doug Shilen and Gordy Gritters gave new life to the ol’ girl.  Call it performance-enhanced gunsmithing, for what I have in my hands is the deadliest long range rifle I have ever owned.  And believe it or not, it is one of the most accurate rifles in any caliber that I have ever owned.

The original gun was a Remington 700 ADL that I bought back when I lived in Alaska. I stocked it myself with a Brown Precision stock, bedded it with Brownell’s AcraGel, and installed a Timney trigger.  The rifle has been on countless hunts in Alaska, one Africa trip (where it blatted a zebra, a gemsbok, and a bunch of smaller stuff), a trip to Mongolia, and a few antelope hunts. I shot the rifle religiously nearly every week at various ranges and had complete confidence in it.  But all the buzz about the .300 Ultra Mags got me to thinking it was time to send off for another Shilen laser pointer.  I like 5 ½ contour barrels, but I decided to go with a straight 5 contour for this project.  The later measures .7 inches across the muzzle compared with .75 inch for the 5 ½ contour.

At the same time, I thought it would be interesting to try a McMillan stock.  These days Gordy Gritters does all my work so I called him to get some advice on a stock that made sense in terms of the concept of the rifle.  Gordy recommended the A-4 model from McMillan.   I ordered one from McMillan and had it sent to Gordy.

Shilen fitted the barrel to the action; when I received it I sent it directly to Gordy to have a Vias muzzle break installed (Gordy’s choice, not mine) as well as bed the barreled action to the stock. Gordy checked out the work done by Shilen and pronounced that they had done a great job – a credit to Gordy’s ethics.

Scope choice for this gun was a little difficult.  My favorite scope for long range work is a Leupold 6.5-20X, namely because in my experience the windage and elevation adjustments track with precision and the optics are very bright compared with the champion of reliable tracking, the Weaver.  Lately I have heard lots of good things about the Bushnell 4200 series as well as Sightron scopes, and I was half tempted to try one of those.  But, since the rifle already had a 6.5-20X Leupold, I stuck with it.  Back before laser rangefinders were available, I sent this same scope to Dick Thomas at Premier Reticles to get one of his custom reticles installed – in this case, one designed to estimate range.  The system worked wonderfully for me a decade – in fact, I used it to kill an antelope at 460 yards and a Dall sheep at what I thought was about 360 (the terrain prevented me from pacing off the distance).  But laser rangefinders have eliminated the requirement for these range estimation reticles, so these days I either buy my Leupold scopes with a Mil-Dot reticle installed or have Premier install one for me.  Premier supplies Mil-Dot reticles for Leupold and using Premier does not void the original Leupold warranty.  For Leupold owners, Premier is the only way to go.  The scope for this project got a retrofit to a Mil-Dot, the second custom reticle in that scope from Premier!

Like a gourmet cook with lots of things on the stove, I waited and tried to anticipate.  The barreled action came back first – I was practically hyperventilating as I opened the box containing my newly minted prize.  “What is this?” I thought as I examined the barreled action...it appeared that Gordy had drilled holes in the barrel instead of fitting a muzzle break.  But the plastic bag from Vias provided the only clue I needed – Gordy’s metalwork was so superior that the break appeared to blend in perfectly with the barrel!  My intention was to bed the barreled action in the old stock and start breaking in the barrel.

A few weeks later Gordy sent me a note announcing the arrival of the McMillan stock.  I again stopped by the UPS office to drop off a long brown box, and like a father expecting, began to mark time.  While Gordy bedded the action, the UPS woman who knows me by name dropped off another package – this one containing the Leupold scope, now sporting a Mil-Dot reticle.  Shortly thereafter, the box from Gordy showed up at my doorstep.  Show time had arrived.

I broke the barrel in by first shooting ten shots and cleaning after each shot.  Then I began to shoot three shot groups, cleaning after every group.  I started with Hodgdon H1000 and Nosler 180 grain BTs.  The results were okay, but not great – groups were in the 8’s and 9’s.

Midway through the barrel break-in process I hit my first snag – discharging gas had burned through the thin wall of the muzzle break.  I called Gordy, who told me to send it back.  Gordy had turned the break within minimum tolerances, but apparently a diameter of .7 inches in a .308 barrel is not enough in this caliber.  A short time later I had the new break, this one turned with a bit more diameter, without charge.

All groups plopped in under an inch, but nothing approaching a ragged hole.  Since I had previously had good luck with H4831SC in .300 RUM, I decided to try that.  The Hodgdon manual recommends 89 grains as a max load, but in my experience Shilen barrels return maximum pressures and maximum velocities below published maximums, so I decided to start with 87 grains of H4831SC (not that starting at max loads is wise anyway).  My first group plunked in at .34 inches at 100 yards.  Muzzle velocity was 3330 fps.  Similar groups followed suit.

I took the rifle out to the 700 yard line, came up 41 clicks, and let ‘er fly from a sitting position with a bipod.  The first group was less than four inches.  Of course, I was ecstatic.  I loaded more rounds and fired them into similar small sized groups.  But after shooting a few groups, I noticed a flyer...then another.  The flyers were always in the vertical direction – never horizontally.  They were not that far out – perhaps 4 inches high or low, but enough to lead me to believe something was wrong.  I decided to shoot over a chronograph to see if velocity was jumping around.  Bingo!  That was the culprit. 

I experimented with overall length, thinking perhaps that it might have something to do with inconsistent velocity.  I switched back to H1000 powder, but unlike my Sendero .300 RUM, which loves the stuff, it produced groups of around 7 inches at 700 yards.  I tried different primers, to no avail.  Then I got a present – two pounds of Retumbo, a new powder from Hodgdon designed to shoot moderate to heavy bullets with high velocity out of high capacity cases.

Retumbo has proved to be an incredible propellant.  The published maximum for the .300 RUM with a 180 grain bullet is 100 grains; that is supposed to produce 3300 fps from a 24 inch barrel.  I found 96 grains of Retumbo spit Nosler 180 grain BTs out at 3350 fps.  Accuracy at 700 yards is amazing.  What is especially amazing is the almost total lack of vertical group dispersion.  Five shot groups rarely exceed 3 inches of vertical dispersion at 700 yards.  Velocity is good without any hint of excessive pressure.  Cases last forever, a claim I cannot make for the H4831 load.

If the .300 Ultra Mag has a downside, it is recoil (not to mention its voracious appetite for powder).  There are lots of ways to mitigate recoil, but the Vias muzzle break is a wonderful piece of equipment.  I now own three of these, and they are worth their weight in gold when using high velocity, hard kicking rifles.  While loud, they are constructed in such a manner as to keep the noise level down, while still minimizing recoil.  Still, a .300 RUM with a muzzle break is on the fringe when it comes to using my Harris bipod position with the buttstock on my right knee – the rifle often smacks my forehead causing rivulets of blood to pour forth.  Bubble wrap tapped to the forehead helps, but it isn’t proper dress code for those who want to maintain cool points.  Shooting the rifle off the bench is absolutely not a problem.

The Mil-Dot reticle made by Premier Reticles is without question my favorite reticle, at least on a rifle designed for long range.  I always click my elevation knobs to eliminate holdover, but have almost given up on the practice of clicking windage knobs – the Mil-Dot reticle is that good.  It is fast, and allows me to make last second corrections with precision.  Calculating exactly how much I want to hold off for windage is very easy.  The last time I fired this rifle at 700 yards I could tell there was a wind, but it was swirling around me.  I peered through the scope and could barely see my target – two young popple trees had been growing like gangbusters nearly covered my target.  However, I could see the 3 inch bullseye.  I carefully considered the wind, but I could not see any mirage.  Consequently, I held dead center – no correction for wind – and pressed the trigger.

The drive downrange proved disappointing, for there was no bullet hole on the 24 inch wide target.  Since I was downrange, I remove the popple trees blocking the view of my target and decided to try again.  This time, when I peered through the scope, I could see mirage sweeping across the target at about a 30 degree angle.   Clearly, there was enough wind to cause a miss if uncorrected.  I drove back to the firing line, used the Mil-Dot reticle to estimate a 12 inch windage hold-off, and let her fly.  The bullet struck two inches to the left of center.

Much of my ability to connect at long range lies with the McMillan stock.  This choice was another Gordy Gritters recommendation.  The A-4 has a nearly vertical grip for the shooting hand.  The stock is not a thumbhole, but rather one in which the wrist of the stock connects to the very bottom of the stock, providing a generous “window” for the right hand.  This stock is especially comfortable to shoot off the bench, sitting, or prone.  It has an adjustable cheek piece to provide a perfect “spot weld,” to borrow an old army term.  The recoil pad is soft and shaped quite nicely.  The bottom of the forearm is dead flat, obviously great for shooting off bags.  One other minor point: the sling swivel studs are firmly attached to stock, unlike less expensive stocks – an important consideration for those who shoot with a tight sling or use a bipod often.  Gordy also said the stock is easy to bed, and as usual, his work was flawless.

McMillan stocks are not inexpensive, and some readers may wonder why they should fork over enough money to buy a rifle barrel when cheaper stocks can be had, sometimes for less than $100.  It is a good question.  Last night I tried to bed an injection molded stock for a new Remington Model Seven.  Like all other inexpensive stocks, I was disappointed.  It is virtually impossible to bed these stocks stress-free the first time.  I am sure I will get it right, but it will take time.  If you elect to float the barrel, you must provide quite a bit of space around the barrel because these stocks flex a lot in the forearm.  McMillan stocks do not have these problems, and unlike rifle barrels, you will never shoot them out.  An investment in a McMillan stock is an investment for a lifetime.

While the action may be the soul of a rifle, the barrel is where the heart is, and this one had a heart of gold.  With the exception of H1000 powder, it shot everything into ½ inch or less at 100 yards.  Even the H1000 loads shot under an inch; but a group in the 8s and 9s isn’t what this rifle is all about.  One thing I loved about this barrel was that, within reason, overall length didn’t matter much – one clump after another.  I experimented with the overall length quite a bit, and was quite pleased that moving the overall length by as much as .01 inches had virtually no effect with the loads this rifle liked.

For those who drool over detailed load notes, I hate to disappoint you, but I tend to choice a set of components, and if they shoot, I am happy.  I started with case prep.  I took a bag of 100 brass cases, sized them, deburred the flash holes, and then lightly neck turned them.  Next, I weighed the cases.  The case weights fell into three distinctive, but equal in number, groups.  I think I discarded three cases that were completely outside the norm.  Since I now own three .300 RUMs, I simply bagged each group of three and labeled it for each rifle.  I had 31 cases of almost identical weight from which to start load development.

Ever since Remington 9 ½ M primers shrunk group sizes considerably in an old rifle, I have always favored this primer for large capacity cases.  Like you, however, I have always heard others praise how wonderfully the Federal 215 primer ignites those big “magnum” charges as if they were so much lighter fluid.  So I called Sinclair and ordered 1000 primers in both Federal Bench Rest and Remington flavors.  While I tried both, in the end, the Remington primers proved to be the most accurate with the most consistent velocity.

Like all projects in the last several years, I used Redding bushing dies to load the cases.  Redding does not make a competition seater for the .300 RUM, but it does make bushing sizing dies.  I have one of each in .300 (one set is in Phoenix, the other in Minnesota) and love each as if they were my children.

As stated earlier, I began with H1000 – when I started this project, Retumbo was just a press release.  H1000 just did not cut the mustard, and while H4831 was accurate, it seemed to infrequently toss a bullet out of the muzzle with inconsistent velocity – enough to cause vertical misses at long range.  And because I shoot in a variety of temperature conditions, I really wanted to use Hodgdon’s Extreme powders.  So while I wasn’t desperate, I was a bit anxious as I screwed the top off the Retumbo.  It didn’t take long to discover 96 grains of Retumbo produced fantastic groups and superb accuracy.  I have fired several 5 shot groups at 700 yards from a sitting position with a bipod that measured less than five inches.

If you think I am thrilled with my Shilen-McMillan-Gritters rifle, you are right.  What would I have done differently?  Not sure.  It remains to be seen how fast the barrel erodes – 100 grains of powder through a .30 hole is a lot of flame.   But then again, it isn’t a gun you are going to shoot a lot anyway, and with two other .300 RUMs, I can shoot the round a lot without worrying about barrel erosion.   I can tell you this: that short Ultra Mag, especially in a switch-barrel Remington Model Seven, would be the ultimate.  Hmm... the GSSB – Gritters-Shilen Switch Barrel.

Until then, I will be content to smack a paper plate every time from 700 yards with using field positions.  Should it ever be asked to draw blood, it will be up to the task.  That much I know.