Over the past few years I’ve often been asked how to get the results I do from handloads in my 9.3 x 62 Mauser. My loads basically equal factory loads from a 9.3 x 64 Brenneke, surpass factory loads of a .338 Winchester Magnum, and are on the heels of a .375 H&H. How is all that possible from a cartridge not much larger than a .35 Whelen? Good question.
(Typical result from the 286gr Nosler Partition from my TIKKA T3 Lite in 9.3 x 62. Adding 9 fps for correction to muzzle = 2622 fps) (Left click on pics to enlarge)
There are a number of parameters that determine the end ballistics of any rifle that is being handloaded, regardless of caliber. They are the following:
- MAP — maximum average pressure as well as its duration — or as some state it: “the pressure under the curve” — meaning if a graph were made it would look something like the profile of a salt water cat fish starting with its mouth, over its rounded abrupt head, then gradually sloping to its tail. But all oceanic cat fish don’t have the exact same profile, some are larger and others smaller than average. Or, to say it differently it would be the average of the highest part of the pressure curve, though that curve will attain its max point at variable distances from where the bullet enters the rifling depending on several factors including, but not limited to, the bullet, powder type and burn rate. Some translate MAP as “maximum allowable pressure”. That’s not exactly so if they mean “maximum peak pressure”, which is MPP. Some of the pressure readings will exceed average and others will be less than average, thus making things “average”. PSI in such conditions are of necessity “average”, not fixed. There is therefore an allowable differential from shot to shot that will not likely exceed 5000 psi from lowest to highest. The average will likely be somewhere in the middle.
- BARREL LENGTH.
- EXPANSION RATIO.
- POWDER TYPE & BURN RATE.
- AMOUNT OF POWDER.
- BORE SIZE.
- VOLUME OF CHAMBER
- FREE BORE or LEADE
- BULLET TYPE & CONSTRUCTION
- BULLET WEIGHT.
- PRIMER TYPE
- CONDITION of BORE.
- RATE of BARREL TWIST.
- TOLERANCE of BORE vs TRUE BULLET DIAMETER.
- CARTRIDGE OVERALL LENGTH.
- CARTRIDGE BRAND.
- RIFLE BRAND, TYPE, AGE & CONDITION.
- Any other possible variables, such as ambient temps and powder lot.
ALL of the above are involved in the results I’ve obtained from handloads in my TIKKA T3 Lite chambered in 9.3 x 62 Mauser.
In addition, matters of personal philosophy regarding any handloads for any rifle is involved as well as personal experience over several decades of fabricating countless thousands of loads for centerfire rifles from .223″ to .458″.
With that as a preamble, I’ll begin to spell out in detail the product of sending a 250gr – 9.3 out the 22.5″ barrel of my TIKKA at 2700 +fps, a 286gr at 2600 +fps, and a 320gr at 2400 +fps. The actual average numbers are: 2714 fps, 2622 fps and 2464 fps. You could calculate the kinetic energy at the muzzle for each but I’ll save you the effort. They are:4088 ft-lbs, 4365 ft-lbs and 4314 ft-lbs. MAP for each is approximately 64,000 psi. I have other loads that are less energetic, and for a purpose, but the three mentioned are those in which others show interest, and the 286gr heads that list. Indeed, it should as it appears to be the best balanced in overall internal and external ballistics for a variety of game from medium to large. One powder is used for each of those three bullets, and gives safe performance that no others can come to within 170 fps of, that I’ve yet tried to this point in time. That powder is RL-17.
Let it be said, however, that I started the reloading process for the 9.3 x 62 in the use of RL-15 as I already had “tons of” experience with it in several “mediums”, including .35 Whelens, a .350 Rem Mag and a .375 H&H, so thought it would likely be “best” in the 9.3 x 62. Also, I’ve given H414 a fair try as well. It’s a good performer but can’t match RL-17, at least in my experience in my rifle even though they are “supposed to” have the same approximate burn rate.
Down range energy at 500 yards for the 250gr AccuBond is over 2000 ft-lbs, and the 286gr Nosler Partition is about 2100 ft-lbs, depending of course on ambient conditions that I think will not affect in a practical sense the outcome on a game animal if the bullet in question is placed correctly. 500 yards is a loooong way out there! And I would only take such a shot on a large animal under suitable conditions with a solid rest. The 320gr Woodleigh isn’t as accurate in my rifle as the other two, but might be preferred on a brown bear or Cape buff at less than too far — whatever that might be. Since I’ve been in neither of those situations, I take it that the outfitter would have made those decisions well ahead of the fact.
BACKGROUND and HISTORY:
a) Philosophy of handloading: That has developed with time and experience. For example, the two premium Nosler loads (250gr AccuBond and 286gr Partition) at 2714 fps and 2622 fps respectively, have load densities of 109.5% in Hornady cases at a COL of 3.37″. There are many loads in recent manuals for common cartridges fired in strong modern bolt-action rifles that match or exceed that degree of load density. Some are as high as 115% with the right relatively slow burning powder for the cartridge and bullet employed. Some reloaders will not go there for their own reasons — that’s their business, not mine. But neither is it their business IF I choose to use a relatively slow burning powder for a particular application which might allow better overall safe performance, even at less PSI, than a “normal” powder for that application might allow.
As an example of the above, there is a fairly familiar person on a couple of well-known outdoor forums who is about my age with considerable experience as an agent for African hunting. According to him, he also has shot a lot of game in Africa, large, medium and small. One of his rifle favorites has been in 9.3 x 62. But in America he favors the .338 Win Mag for larger game. Nothing wrong with that as it’s his business. However, having read my stuff on the 9.3 x 62 he contacted me about my formula in the use of RL-17. Later, on a forum, he said it didn’t work much better than RL-15, when he was asked about it. But what he didn’t say was that he doesn’t like compressed loads. He has expressed that on numerous occasions. That’s his business, but to be fair about it he should have admitted that he didn’t make use of the information I provided him with.
I know for a fact that my top compressed loads employing RL-17 evidence LESS PSI than RL-15 at an increase of 170 fps over the latter shooting the same, or similar weight bullets! That’s an increase of over 500 ft-lbs at the muzzle! And that particular load from RL-15 was only safe in cooler temperatures, not in the heat of July. On the other hand, the top load making use of RL-17 has proven completely safe regardless of ambient conditions. I know that from experience — not theory!
Also, there are several on those forums whose background and experience is European who have used either factory loads or matching handloads in their 9.3 x 62s. The information they have provided is traditional — nothing new employing modern rifles and components.
The 9.3 x 62 is still relatively unknown in North America, but is coming on strong in the last ten years or so. Most add it to their arsenal for reasons known only to them, but from chatter on the forums it appears evident that it’s just another “toy” — you know, “I’ve got one of those too”, sort of thing. Some have owned one for years and it’s never been fired; not yet at least!
There are others, of course, who are serious about it and want to know how to get the best performance possible in a safe manner — I write for their benefit.
I’m not naive enough to think that my 9.3 x 62 can actually match top ballistics from a .375 H&H or .375 Ruger when each is loaded with the best powders, same weight bullets in equal length barrels, and at the same MAP. If I owned, for example, a new .375 H&H with a 24-inch barrel and loaded it max with a 300gr AccuBond, I’m quite certain that 2650 fps could be safely attained. I don’t entertain a hint of a doubt. Cut the barrel to match my barrel length of 22.5″ and I think it would be reasonable to attain 2600 fps from the same 300gr. That’s 4503 ft-lbs. Mine will make 4395 ft-lbs from the 286gr Nosler at an average of 2631 fps — which on average I’ve attained on several occasions. Does 105 ft-lbs matter very much on game that might go 2000 lbs? On the other hand, most (not all) .375 H&H’s come with 24″ barrels. In such a case the esteemed H&H can nudge 5000 ft-lbs — check Barnes manual #4. For myself, however, the weight and handiness of a compact powerhouse would be lost, as well its utility as a do-it-all rifle. The Ruger Hawkeye in .375 Ruger seems better suited in it’s 20″ format as a “do-it-all”, but it’s ballistics are really little better than my 9.3 x 62 that can push a 300gr at 2550 fps and a 320gr at 2460 through the use of RL-17.
So, which is better? Flip a coin. The Ruger is heavier and louder, having more recoil unless the muzzle brake is screwed in place that makes it just as long and MUCH LOUDER! For those reasons I feel no urge to switch to the .375 Ruger. As previously stated in my writings, if a .375-magnum caliber were wanted for whatever reason or notion, it would be the .375 H&H.
(The TIKKA T3 Lite in 9.3 x 62 Mauser)
b) PRAGMATISM: some of which has been expressed in the above. Yet, there are other practical reasons for me choosing the 9.3 x 62 Mauser. Let me enumerate them:
1 – Ballistics can equal or exceed any of the “Mediums” I’ve previously owned, including .338s, .358s and the .375. The .338s include two Winchester Magnums; the .358s include two each of the .350 Rem Mag and the .35 Whelen; and the .375 includes three H&Hs — a 22″, a 24″ and a 26″. It was only the 26″ that surpassed the ballistics that I currently receive from my 9.3 x 62.
2 – I’d never previously owned a centerfire magazine rifle with its combination of ballistics and handiness as in my TIKKA T3 Lite chambered in 9.3 x 62 Mauser.
While anything is possible, yet my 9.3 will never be used on brown bear, grizzly, Cape buff or elephant during my ownership, yet the 9.3 x 62 has been successfully employed on each, and found not wanting, as well as all of Africa’s plains game to such small creatures as oribi. Therefore, plans for it’s use on coyote and wolf are still in my thinking, not even to mention the largest ungulates of North America.
Regarding the PARAMETERS mentioned at the outset:
MAP >> As previously expressed in numerous blogs: I use 64,000 PSI (piezo) as a guide for top loads. My rifle will easily handle that being of new manufacture in which the .338 Win Mag has also been chambered by TIKKA.
BARREL LENGTH >> 22.44-inch (570mm). Ideal for this application.
EXPANSION RATIO >> is the ratio of case volume to barrel volume. The higher that number, the more efficient a rifle is. Mine is 9+ with its 22.5″ barrel. A 24″ .338 Win Mag is 7+. Therefore the 9.3 x 62 has an efficiency of over 28% more than a 24″ .338 Win Mag. That explains why the 9.3 x 62 can match or exceed the ballistics of a .338 Win Mag with a longer barrel burning more powder in the process. A .375 H&H is about equal to the 9.3 x 62 in expansion ratio — it is equally efficient. 70 grains of the right powder in each will give approximately equivalent ballistics, in other words.
POWDER TYPE and BURN RATE >> Double base powder has more energy than single base due to a percentage of nitroglycerin in addition to nitrocellulose. RL-17 is a double base powder. IMR 4350 is a single base powder (nitrocellulose). They have a similar burn rate (depending on application), but RL-17 has more energy. For a cartridge that has minimal shoulder, such as the 9.3 x 62, IMR4350 is usually considered too slow and bulky to get best performance — as in a .375 H&H or 9.3 x 62 for example. So, RL-17 also would normally be considered too slow if load density was only 100% — and it likely would be at about 60 grains in a Norma case at a COL of 3.29″, as one example. But give it a compressed load of nearly 110% in a Hornady case and magic happens!
THAT IS NOT A RECOMMENDATION FOR ANYONE! It is simply an EXPLANATION of the process I’ve developed over time and with experience in arriving at what appears to be from all evidence a safe maximum load. It is also accurate, consistent and stable under diverse climatic conditions.
AMOUNT OF POWDER >> That will depend largely on all the other factors listed here, such as COL, POWDER TYPE, etc. I started at where I ended with RL-15 and worked up from there. 66 grains of RL-17 gave exactly in MV and accuracy, as well as POI, what 60 grains of RL-15 gave behind the 286gr Nosler. In fact, in placing the RL-17 target over the RL-15 target, they perfectly matched in location and extreme spread from three-shot groups. Two things were different though — recoil; RL-17 burning six grains more produced noticeably increased recoil, but at significantly reduced PSI. 60 grains of RL-15 was 1.5 grains more than max according to the Nosler Reloading Guide #6. I’d tried their suggested max behind the 286gr Hornady and it about matched their results with good accuracy. But their brass was Norma and they used the standard COL of 3.29″. I finished off a wounded bear with the 286gr Hornady in the Fall of 2011. The following Spring (2012) I began working with RL-17 and the 286gr Nosler Partition at a COL of 3.37″ — which is max in the clip of my TIKKA for smooth functioning. I also found that the former max load of 60 grains of RL-15 behind the 286 Hornady, that produced 2460 fps (same as the 66 grains of RL-17) in the cool Fall temps of 2011, was way too hot and erratic in the warm temps of May 2012! So I continued working with RL-17 behind the 286 Nosler. But I increased the load from 66 grains that gave 2460 fps (corrected to muzzle) at a COL of 3.37″ to 68 grains. That gave an average between 2546 to 2549 fps with good accuracy. And no signs of pressure beyond what the 58 grains of RL-15 was showing behind the 286 Hornady at a tad over 2400 fps. I thought that might become my “supreme load” for the 9.3 x 62. But, of course, with NO signs of undue pressure throughout the process of employing RL-17 under the 286 Nosler, I just HAD TO TRY 69 grains, and maybe 70! So, I tried them! 69 was just OK… BUT 70 was magic! With a consistent accuracy of sub-moa when I was on my game, and regular MVs between 2610 and 2640 fps, the actual average over two years of shooting that load = 2622 fps/4365 ft-lbs. And new cases fired once look like once-fired .308 Win factory loads (of which I’ve several in my collection from the range).
(A once fired .308 Winchester factory load case on left. The once fired 9.3 x 62 case on right. Primer flattening on each is identical, so it is not necessarily any indication of excess pressure.)
BUT, as a note of CAUTION it should be pointed out that the above load gives about 64,000 psi according to QuickLoad. Also, there is NO MORE EVIDENCE of EXCESSIVE pressure than I’ve witnessed from any magnums of the past for which I’ve made handloads. That would included many thousands in total for the 7mm Rem and Weatherby, several .300 magnums, .338 and .340 magnums, .375 H&Hs and the .458 Win. In between those were several non-magnum mediums, so-called, plus the .350 Rem and my son’s .356 Win. So I know a little bit about “reading pressure signs”, though there are those who deny that’s possible — even though it’s regularly done by professionals. “Start with the lightest loads and only proceed to the next level if safe to do so based on careful observance of any SIGNS of excess pressure. Never exceed published maximum loads. If there are SIGNS of excessive pressure reduce loads by a couple of grains…” – from manuals.
DISCLAIMER: Of course, I can’t assume responsibility for what one may or may not do with respect to the information provided herein. There are too many variables, the main one being the differences in people and their way of doing things, including thought processes and experience. Then too, the great variation in rifles and handloading components stand second in determining the outcome of any hand-made ammo reproduction.
That’s all folks… for now!
Next time: BORE SIZE; CHAMBER VOLUME, FREE BORE, etc.
Shalom (PS – the angiogram indicated I needed some stents… four of ’em. A stay of 24 hrs at the hospital and home the next day. Have to take a couple of extra pills but feeling great!)
BOB MITCHELL