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Rifle Reloading Guide
Rifle Magazine
December - January 1999
Volume 34, Number 6
ISSN: 0017-7393
Number 202
On the cover...
The Lone Star Remington-style rolling block rifle
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Accurate Arms XMR-4064

In reviewing its products, the folks at Accurate Arms Company concluded a void existed in its single-base, extruded powder line. While offering an impressive list of ball powders, 11 in number, and four more shotshell propellants, Accurate’s line of extruded, single-base powders numbered only four (plus the extruded, double-base XMP-5744). A perceived gap between XMR-2495 (now discontinued) and the slower XMR-4350 needed to be addressed. It has, and the result is XMR-4064.

When asked about the introduction of yet another powder, Accurate’s Ted Curtis put it quite succinctly.

"Among single-base, extruded powders, the medium-burning rate powders enjoy the highest sales. Accurate lacked an extruded powder in that burning range and decided to do something about it."

Accurate XMR-4064 is imported, as are all Accurate powders. The manufacturer in the Czech Republic is Synthesia, a subsidiary of parent Aliachem. As noted, the powder is extruded and single base, meaning no nitroglycerin is added. Deterrents are used to control burning rate, and the powder is graphited to improve flow properties. Bulk density, or grams per cubic centimeter, is .900, which compares favorably with other powders in this range. (I have two charts that list IMR-4064’s bulk density - one at .890, the other, .910.) Grain (kernel) lengths are quite short with dimensions approximately .058 inch in length and .031 inch in diameter.

The powder is suitable for a wide range of calibers. In the .22-250 Remington, XMR-4064 shines with bullet weights from 53 to 70 grains. It is particularly useful in the .243 Winchester with 70-grain bullets and in the slightly more spacious 6mm Remington with bullets from 70 to 100 grains. It also produces the highest velocity, or very close to it, of all Accurate’s extruded powders with light bullet weights in the .250 Savage, .257 Remington Roberts, .25-06 Remington, .260 Remington, .270 Winchester and .308 Winchester. Its performance is particularly noteworthy in the .30-06 in bullet weights of 150 to 190 grains.

As part of the printed label on the powder canister, four cartridges are singled out and loading data provided. These are the .243 Winchester with a 70-grain bullet (42.0 grains at 3,479 fps), the .308 Winchester with a 168-grain hollowpoint boat-tail (HPBT) bullet (43.0 grains at 2,571 fps), the .30-06 with a 180-grain HPBT bullet (48.5 grains at 2,712 fps) and the .416 Remington Magnum with a 400-grain roundnose bullet (80.0 grains at 2,419 fps). As with all Accurate rifle and handgun data, these are maximum loads and must be cut by 10 percent to determine a proper starting load.

When I began my review of the powder, I first conducted a metering consistency test. Ten consecutive drops from the RCBS Uniflow measure, set at a nominal 50.0 grains, produced an extreme spread of just a bit over .2 grain. This is as well as extruded powders meter. No shooter, competitor or not, will fail to be served by this level of consistency.


To test the powder I chose two old favorites: the .243 Winchester and the .30-06, both in Remington Model 700 actions. The .243 is chambered in a heavy-barreled short action, the .30-06 in a standard-barreled long action. The Hornady 70-grain SXSP bullet was used in the .243. For years I have used this bullet in this gun with IMR-4064 or VARGET with great success. I do restrict velocity to about 3,250 fps, as beyond this bullets disintegrate - purely the fault of a rough barrel, not the bullet. A 40.0-grain load of IMR-4064 gave 3,231 fps; the same amount of VARGET measured 3,249 fps. A like charge of XMR-4064 clocked 3,154 fps, just a bit slower. As the maximum charge with this bullet is 42.0 grains, I’ve got plenty of room to make up the difference. I probably won’t, though, as five-shot groups averaged almost exactly one inch at 100 yards. That’s as well as this gun shoots, especially with relatively light bullets.

In the .30-06 I tried two bullets, a 150-grain Hornady Spire Point InterLock, purely a hunting bullet, and the Sierra 168-grain hollowpoint boat-tail Match, a superb target bullet. I’ve often referred to this gun as well-worn, something of a clunker. A solid 1.5-inch group at 100 yards can be predicted with most bullets. With the 150-grain bullet I again compared XMR-4064 to previous tests with IMR-4064 and VARGET. Fifty-one grains of IMR-4064 pushed the bullet at 2,842 fps; a switch to VARGET gave 2,871 fps. The same charge of XMR-4064 lit up the screens at 2,780 fps, as before, a tad slower. Accurate’s maximum is 52.5 grains, but I won’t need it, as five-shot groups averaged 1 3/8 inches, exceptional for this bullet in this gun.

My day was made, however, when I got to the Sierra 168-grain bullet. Fifty grains was the powder charge. Using IMR-4064, the chronograph recorded 2,623 fps; with VARGET, 2,680 fps. XMR-4064 split the difference this time with 2,649 fps, perhaps suggesting a reaction to increasing bullet weight relative to caliber. Three, five-shot groups averaged .75 inch! Again, Accurate’s maximum load was higher, at 52.5 grains, but I know when I’m happy.

When Ted Curtis was asked about relative burning rates, he said Accurate took five different IMR-4064 lots, averaged their performance and attempted to match the results. Since I only worked with one lot of each powder, I can’t comment on their success, but judging from the performance I experienced, I’d say they did well enough. Handloaders wishing to test XMR-4064 for themselves should first obtain a copy of the 1999 Reloaders Guide, free from Accurate Arms (call 1-800-416-3006). The powder is available in one- and eight-pound containers.

For users of Lee Precision powder measures and their volume measuring density (VMD) approach to predicting volumetric settings, XMR-4064's VMD is .0746.

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