Benchrest Hand-Loading

[HALODIN]

I'd like to understand hand-loading from a benchrest perspective. So in terms of what makes the difference between a standard match round and a benchrest hand-loaded round, which parts of the process produce the biggest gains? Does it looks something like this?

1) 25% good quality brass
2) 15% Powder accuracy
3) 15% Seating depth (COAL/distance from lands)
4) 10% Good quality propellant
5) 9% Neck tension (uniformity)
6) 7% Neck concentricity
7) 6% Weighing and sorting bullets into batches
8) 6% Meplat trimming and bullet tipping to increase BC
9) 5% good quality primers
10) 2% Uniform flash hole and primer pocket

[ukrifleman]

I'd like to understand hand-loading from a benchrest perspective. So in terms of what makes the difference between a standard match round and a benchrest hand-loaded round, which parts of the process produce the biggest gains? Does it looks something like this?

1) 25% good quality brass
2) 15% Powder accuracy
3) 15% Seating depth (COAL/distance from lands)
4) 10% Good quality propellant
5) 9% Neck tension (uniformity)
6) 7% Neck concentricity
7) 6% Weighing and sorting bullets into batches
8) 6% Meplat trimming and bullet tipping to increase BC
9) 5% good quality primers
10) 2% Uniform flash hole and primer pocket

If you want to go down that route, I would also add bullet run-out.

ukrifleman

[HALODIN]

It's not that I want to go completely down that route, but perhaps there's bits of it that are worth including in my reloading process, I guess I won't know until someone can estimate what impact each of these or other processes have on accuracy over and above manufactured match ammo.

I had to look up what run-out was, I've never noticed it with any of my rounds, but I guess you'd need a concentricity gauge to accurately check for it.

If you want to go down that route, I would also add bullet run-out.

ukrifleman

[AlieN]

I'm far from an expert on this, having been hand-loading for only a short time, but it seems to me that your list describes only the hand-loaded round in isolation. You are describing high quality components and consistent manufacture.

What about tailoring the round to the rifle? I would have thought that that also has a significant bearing on the resulting consistency.

To give an example, if you read about the ladder or OCW load development methods, both seem to advocate getting to a point where the powder load is in the middle of a sweet spot, such that slight variations of powder weight have little variation on the shot placement.

Regardless, I hope others chip-in to this thread as I am interested in the discussion.

AlieN

[HALODIN]

You and me both. You could spend thousands of pounds on the equipment and components to test all of that and you still might make a mistake and draw the wrong conclusions. I'd rather not reinvent a wonky wheel if I don't have to... I'm hoping someone can put all of this in to a framework I can start adding to.

I'm glad you brought up "OCW load development", that was something I meant to go back and read about, but I lost my bookmark. Hopefully someone with some nerdy benchrest hand-loading experience will be along soon!

[The Gun Pimp]

OK - having shot benchrest for over 20 years nationally and internationally. Here's my take on it.

The basis of any accurate cartridge is good quality brass - the Lapua 220 Russian case is the best that Lapua make - they ensure that - they don't want to lose this one!

The next component is the bullet - custom bullets are made by one person on one machine - not spit out in their thousands from half a dozen different mechanically operated machines. Your box of factory bullets WILL vary.

Some cartridges are more 'inherently' accurate than others - the 6PPC is one of the best - there are plenty of others - 6mmBR, 7mmWSM.

Case prep is important - our case-necks are concentric - achieved by neck-turning and are a close fit in a 'true' custom chamber. Yes, trim them to length and uniform primer-pocket depth.

Neck-tension confuses a lot of shooters. Benchresters run quite low neck-tension and load bullets out into the lands. When you chamber the round, the bullet is pushed back to exactly the same point each time. With high neck tension and factory bullets this won't happen - you'd be better loading off the lands 10 thou or so.

Personally, I don't batch weigh brass or primers or bullets. I don't moly, I don't point or trim meplats. That goes for 6PPC or 7mmWSM. Federal primers are often preferred but others may work as well or better.

If you are using a standard rifle and want to achieve best accuracy - use good brass - like Lapua, don't shoot 'em more than 6 or 7 times. Use good dies - Forster make just about the best 'press' dies. Use Berger bullets.

[Laurie]

Your list omits the single most important item - the bullet. A US Army study yonks ago concluded that ~80% of ammunition grouping ability came from the bullet. And for the handloader that's not just make or manufacturing precision / consistency - it's also the bullet's compatability with the barrel and chamber dimensions. So the first step is to ascertain which bullet your barrel likes. Since BR shooters draw on a very small pool of components and chamber reamers, not to mention hand-made bullets, the rifle is almost built to shoot one or two bullets very well. For the more general accuracy nut, it's about trying various likely suspects from different makers to see what offers promise.

Then the second biggest factor is powder choice and determining the charge weight(s) that really work. Some cartridges are pretty forgiving on powder choice, but even then there will usually be one or two grades that suit the cartridge design, bullet weight, and rifle better than others. And, it's not a simple burning rate issue. 6mmBR Norma with 95s-108s suits H. VarGet exceptionally well, also Viht N150 which people wouldn't normally associate as a VarGet subsitute and most other things are also-rans when it comes to obtaining BR levels of precision, although every now and then somebody produces a killer combination for their rifle with H4895. Despite a plethora of powders with similar burning rates to Viht N133 and Hodgdon unsuccessfully trying twice now to persuade BR shooters to switch to its products as their first choice (H. Benchmark and IMR-8208 XBR), almost every serious BR shooters worldwide still uses N133 in their 6PPCs. (Although in the US Western Powders / Accuracy seems to have something called LT32 that's getting followers.)

Everything else falls into counting for 10% or less. That's not to say they're unimportant as at least basic quality is needed. A good combination can be wrecked by rubbish or overworked brass in any set-up, or cases that have been poorly and inconsistently sized producing large headspace variations, primers that have been poorly / inconsistently seated. In fact, getting the ignition side wrong is one of the easiest ways of producing poor ammunition, likewise a firing mechanism fault giving an inconsistent strike. Some combinations sometimes seem to work better with a single primer make and model, the CCI-450 SR Magnum having acquired a near legendary status with 6BR, BRDX, BRX, Dasher etc shooters, but then somebody shoots a world record group using the Fed 205M.

It's not feasible to say that case make or primer model choice is worth a quantifiable x% to accuracy - this game simply doesn't work like that. Get any single element seriously wrong though and it becomes the weak link in the chain that kills performance and doubles or trebles group sizes. At this level of precision, ABSOLUTELY EVERYTHING is important and has to be 100% right and compatible.

[HALODIN]

I already use Lapua brass in my .260 and I agree it seems top notch. The only issue I seem to have is an occasional variance in my seating depth when using reused brass. Sometimes it's a bit hit and miss as to whether I can get it within 20 thou of my prescribed COAL. On closer inspection it seems to be a neck tension issue, so I might look in to neck-turning to see if that helps. I am very consistent when I seat the bullet, so clearly something else is going on. By the way, where do you source hand made bullets from?

Thanks for your pearls of wisdom.

OK - having shot benchrest for over 20 years nationally and internationally. Here's my take on it.

The basis of any accurate cartridge is good quality brass - the Lapua 220 Russian case is the best that Lapua make - they ensure that - they don't want to lose this one!

The next component is the bullet - custom bullets are made by one person on one machine - not spit out in their thousands from half a dozen different mechanically operated machines. Your box of factory bullets WILL vary.

Some cartridges are more 'inherently' accurate than others - the 6PPC is one of the best - there are plenty of others - 6mmBR, 7mmWSM.

Case prep is important - our case-necks are concentric - achieved by neck-turning and are a close fit in a 'true' custom chamber. Yes, trim them to length and uniform primer-pocket depth.

Neck-tension confuses a lot of shooters. Benchresters run quite low neck-tension and load bullets out into the lands. When you chamber the round, the bullet is pushed back to exactly the same point each time. With high neck tension and factory bullets this won't happen - you'd be better loading off the lands 10 thou or so.

Personally, I don't batch weigh brass or primers or bullets. I don't moly, I don't point or trim meplats. That goes for 6PPC or 7mmWSM. Federal primers are often preferred but others may work as well or better.

If you are using a standard rifle and want to achieve best accuracy - use good brass - like Lapua, don't shoot 'em more than 6 or 7 times. Use good dies - Forster make just about the best 'press' dies. Use Berger bullets.

[HALODIN]

Interesting perspective thanks. I guess the amount of variables is my stumbling block, I want to be scientific about it, but as you say you can have the right combination and have one small aspect wrong and it can skew your results. To some extent I feel like I'm p*** in to the wind, I've found the best bullet from a collection of bullets, then experimented with varying grains of powders and now I'm experimenting with seating depth, but sometimes the group size goes all over the place and I don't think it's me, I think it's in the reloading process. Somewhere, sometimes there seems to be a random element... I guess that's the point of this thread, trying to work out what I can improve to be more consistent. Does the way the powder lies in the brass affect the performance?

Your list omits the single most important item - the bullet. A US Army study yonks ago concluded that ~80% of ammunition grouping ability came from the bullet. And for the handloader that's not just make or manufacturing precision / consistency - it's also the bullet's compatability with the barrel and chamber dimensions. So the first step is to ascertain which bullet your barrel likes. Since BR shooters draw on a very small pool of components and chamber reamers, not to mention hand-made bullets, the rifle is almost built to shoot one or two bullets very well. For the more general accuracy nut, it's about trying various likely suspects from different makers to see what offers promise.

Then the second biggest factor is powder choice and determining the charge weight(s) that really work. Some cartridges are pretty forgiving on powder choice, but even then there will usually be one or two grades that suit the cartridge design, bullet weight, and rifle better than others. And, it's not a simple burning rate issue. 6mmBR Norma with 95s-108s suits H. VarGet exceptionally well, also Viht N150 which people wouldn't normally associate as a VarGet subsitute and most other things are also-rans when it comes to obtaining BR levels of precision, although every now and then somebody produces a killer combination for their rifle with H4895. Despite a plethora of powders with similar burning rates to Viht N133 and Hodgdon unsuccessfully trying twice now to persuade BR shooters to switch to its products as their first choice (H. Benchmark and IMR-8208 XBR), almost every serious BR shooters worldwide still uses N133 in their 6PPCs. (Although in the US Western Powders / Accuracy seems to have something called LT32 that's getting followers.)

Everything else falls into counting for 10% or less. That's not to say they're unimportant as at least basic quality is needed. A good combination can be wrecked by rubbish or overworked brass in any set-up, or cases that have been poorly and inconsistently sized producing large headspace variations, primers that have been poorly / inconsistently seated. In fact, getting the ignition side wrong is one of the easiest ways of producing poor ammunition, likewise a firing mechanism fault giving an inconsistent strike. Some combinations sometimes seem to work better with a single primer make and model, the CCI-450 SR Magnum having acquired a near legendary status with 6BR, BRDX, BRX, Dasher etc shooters, but then somebody shoots a world record group using the Fed 205M.

It's not feasible to say that case make or primer model choice is worth a quantifiable x% to accuracy - this game simply doesn't work like that. Get any single element seriously wrong though and it becomes the weak link in the chain that kills performance and doubles or trebles group sizes. At this level of precision, ABSOLUTELY EVERYTHING is important and has to be 100% right and compatible.

[The Gun Pimp]

The best way to learn the 'secrets' of benchrest quality handloading is to rub shoulders with those who do it.

You ain't too far from Diggle - we have a couple of Oundle shooters visit us regularly.

Tip - don't increase the fit of the case to the chamber neck by neck-turning - counter productive!