Tuned Loads

[George D]

I've read and heard a great deal about "tuned" loads perculiar to each gun. The story is that for each projectile there is a load that will shoot more accurately than any other load and there will be one projectile that will give the most accurate load of all. Legend has it that each gun will differ in its preference and even guns of the same model will have a different "tuned" load.

Does anyone (particularly those with Ransom rests) have accuracy results that can contribute to this debate?

[Patrick Sweeney]

I have found that otherwise nearly identical handguns can show marked accuracy preferences with factory ammo.  Whether each "loves" a particular load, or that some generally-effective load exists, I haven't done enough work.

I do recall that some gun writers have favorite loads that they believe shoot well in most guns, but their proof breaks down in two aspects:  They usually shoot over sandbags (sandbag work not done by a GM is not definitive) and they are happy with accuracy that is "good enough" and not looking for the absolute gilt-edged result.

[Alan550]

Accuracy will vary from gun to gun with the same load.  You just have to invest the time, money and effort into finding what works in yours.  You may get some good starting basics from other shooters, but, in the long run, you'll need to "fine-tune" those to your particular firearm.  

 Example:  My best friend and I both shoot 9X23s using Starline Super-Comp brass and Federal primers.  His gun has one of the new Scheumann AET gain twist barrels, while mine is a Nowlin barrell.  Both are 6" with a comp.  His load is 5.3 gr. of W231 while mine is 4.9 of Hodgdon titegroup.  The best accuracy out of both guns was achieved after MANY load tests and run through a Ransom rest.  He gets under .5" at 50 yds, and with his load, I can't get better than 1.25" at the same distance.  My load runs around .72" @ 25 yds, and won't get under an inch in his.  

  Each gun will be different as to the load it prefers.  Even rimfire guns with sequential serial numbers won't shoot the same ammo to the same accuracy level.  It's a long tedious process to try to find the most accurate load for your particular gun, but will pay off, once you find it.

  Alan~^~

[Shipster]

What Alan550 said.  It has been my experience that each firearm has it's own personality, whether it handgun or rifle it is "To each it's own."

[George D]

Alan,

You didn't mention the projectile you were using in the 2 loads. Do you think that the projectile is less critical than the powder weight , or that an accurate load can be found for any projectile by varying the powder weight? Was there any correlation between accuracy and velocity?

(Edited by George D at 9:09 am on Nov. 5, 2002)

[ErikW]

George you need to back up and define what you mean by the term "load," or use an entirely different term.

[George D]

Erik,

I am talking about mainly handloads and would define a load as comprised of projectile (design, weight) and powder ( Brand, type, weight). The combination of these components (as well OAL and case brand) produces a velocity and a power factor.

Ahhh. I've just realised what you mean. In my question to Alan I should have specified "powder load". I'll edit that now. Thanks Erik.

[Patrick Sweeney]

What compounds our problem is the PF threshold.  It does no good to produce a tack-driving load that posts a 163 PF.  Bullseye & PPC shooters don't care, so long as the gun cycles and the bullet exits the cardboard target backer.

Yes, you can sometimes markedly improve the produced accuracy of a firearm by selecting the components it "desires."  But it takes careful testing to produce real data, and not a load used because of a single unrepresentative group.

[George D]

Hi Patrick,

I guess this thread carries on from the discussion we had on the "light loads for 44 mag" thread.

I agree that "it takes careful testing to produce real data" and would be interested to know your (and others) test procedures. Do you test a number of projectiles with a number of powder weights or settle on one projectile and test that with different powder weights.? What powder weight increments do you use for testing.? Have you noticed any correlation between velocity and accuracy or between velocity standard deviations and accuracy.?

P.S.   PPC shooters using 38 special have the opposite problem in that they have a safety ceiling on Power Factor.

[Patrick Sweeney]

My procedure depends on my desired outcome.  If I want to load, say an Open gun, the primary problem is feeding the comp.  I'll start with a narrow range of powders, and try powders with likely bullets, looking for feel at major, then testing accuracy.  If I don't like the feel, there is no point in testing for accuracy.

If what I'm doing is loading a bullet, then that's the constant.  Say I want to load a heavy hunting load with an LBT wide flat 260 in .44 Magnum.  I'll switch powders with that bullet until I get the accuracy and power I want, regardless of powder or charge (within pressure limits, of course.)

Final accuracy testing is not less than the average of four, five shot groups form the Ransom rest.  More would be better, but the 4/5 level gives useful information without spending the whole day on one load.

If accuracy is really important (like a Bianchi load) then finalists are sorted out with new, inspected brass.  Until then all testing is done with random brass, except for the full-power redline .44 Magnum-type loads, which are tested with sorted and trimmed but not new brass.

Yes, it is as much work as it sounds like.  But if you have to know, you have to do it right.

[George D]

Thanks for the comments Patrick.

You're absolutely right about the work involved but, if ya gotta know, ya gotta know. There is even more work if a Ransom is not available and resort has to be made to sandbagging. I like to see consistency over about 10-12 six shot groups and I record the size of the best 6, 5 and 4 shots in each group. Over the years I've tried a few different powders but the availability is slim out here in the colonies so I've settled on WST. I usually test 2 different projectiles and select a range with .3 grain increments, then once I narrow the range I go down to .1 grain increments.

It is indeed a jolly way to spend Sunday afternoons.