setting up loads for rifles - whats your story

It might be adventagous for podium shooters to share their secrets on how and what they do to develop loads in rifles, things like neck thickness, concentricity, fire forming, ballistic harmony, rifle harmonics just to name a few.

If you think you have valuable information to contribute then please post i am sure someone will utilise the info.

cheers Les

Oh well looks like i will have to get the debate started.

I guess from the outset you are contemplating a neck size for your new barrel and potentially new rifle.

I recently shot a 280AI that used to belong to the late Ian Davis the rifle was in pieces without a trigger stock was an offset unit but needed some work.

I had the rifle bedded by Russel Lamaitre who did a great job and equally to the task the finnishing touches was a very very good paint job by the Gun Pimp Paul Deehan who also has done some reall head turning work on other rifles.

the chamber and neck was already done and a post it note gave the neck diameter etc.

The Neck was 312 and i could only get Nosler custom brass for the 280 after trying to get hold of some rws or lapua.

so i measured the bullet diameter and then set about case prep to match the chamber.

This process meant after i prepped the case by expanding the case neck then trimming to uniform size then tested concentricity.

The bushing i decided on was 308 that gave a nice ballance when the projectile was put in the case to finish at 310 two thou off the maximum of the chamber neck. Some folks like more room that this but i like to run the neck close as i don't have the projectiles into the lands i have the majority of my rifles 3-5 thou off.

There are threads for case prep if you want to go back and source it.

Now for the load.

Primer selection is also a choice , CCI, Federal etc etc i have had most success with the CCI primers they are reasonably hard in the cup and can take reasonable pressure loads.

As for powder i looked in the Recent ADI released book and check pressure readings in their test barrels  and 2217 showed good speed with reduced pressure when compared to others like 2213sc. So i looked at a nice custom action and thought well 9.5 twist barrel Nesika action should reasonably handle a reasonably stiff load at the bottom end of higher pressure so 58 1/2 grns was the choice.

Not having fired the rifle before i was a little hesitant to fire that first shot without hanging on for dear life but infact the rifle although weights only 16lbs it was ok to shoot. It certainly is not a free recoil rifle unless you would like a march or nightforce eyebrow.

The rifle produced about a 43 mm group to take the smallest group for the day and showed real potential as a shooter.

With Bullet prep pointing, measuring batching i am sure i can half this group MPI.

hope this gets things moving.

G'day Les,
This is a pretty big subject and worthy of more contributions than it's getting....bit hard to keep it short though so I thought I might add just a few thoughts about some of the decisions needed when getting a rifle custom made ( as opposed to buying a second hand or pre made version).
I think I will also stay away from the quagmire of action & barrel selection which is probably a  topic in it's own right.

The obvious advantage to having a custom job is that you have total control over most elements of the build.

There are a few questions you must firstly ask yourself.
1; "What will I use it for?"  To use me as an example I wanted to mostly shoot the 500 fly but also needed it to be ok at  both shorter & longer distances with the possibility of also shooting F class. So it needed to weigh less than 22lb to be F class legal...might as well make it light gun legal for 500 fly, ie under 17 lb!

2; "What calibre will it be? ie, What case will I use?  I selected the 6 BRX because it was similar but not the same as the Dasher my mate Trevor Bent had.The Dasher , or anything built on or around the 6 BR, was clearly a very accurate round capable of everything I wanted it to do.

3; "What projectile will do the job?" Very important decision this ( some might say the most important decision of all) as it will have a significant bearing on the chambering of the barrel as well as the rifles ability to be competitive at the distances you wish to shoot! I chose Ken Melgaard's 103 grn copperheads.

Having decided on a case & projectile you then need to get to the specifics of the chamber. So..more questions!
How long will the chamber & what will the  neck diameter  be?  I knew the Dasher & BRX were very similar. Both are formed from 6 BR brass and have very similar powder capacities. I knew from discussions with Trevor that the 6 BR brass became shorter when fire forming to a Dasher so I obtained a Dasher case and measured it,- 1.545" (reduced from 1.555).
Next, seat a projectile and measure the neck diameter of the case, - .2675. I can now make decisions about chamber dimensions. A .269 neck will allow me to get away  (just) without turning necks and  a chamber length of 1.560" would allow cases to grow a little when fired without having a large carbon collecting area at the end of the chamber just before the start of the rifling- perfect.

It must be said that the neck diameter with a seated projectile can change from case brand to brand and also batch to batch within the same brand, so... take care  with this one!

We had one more decision to make! "What will the freebore be?"  This number is determined by the projectile selected. My instructions were to make sure the bearing surface / boat tail junction of the projectile sat just above the neck / shoulder junction of the case.
A reamer was purchased with the previously mentioned dimensions but with a deliberately short freebore ( to enable the reamer to be used for other, shorter bullets like the 87 grn V-Max) A separate throating reamer was then used to cut specifically for the 103 grn Copperheads!

With the benefit of hindsight I could probably have had a bit more free bore cut in to accommodate  longer projectiles like the Sierra 107 ( this is something I could still do ) but one downside to the BRX is that you end up with quite a short necked case which doesn't allow much flexibility in projectile selection like a standard 6 BR will with it's very long neck!

So there you have it, there a quite a few decisions to make & it might seem a bit back to front but I reckon working this way will give you the best chance of getting a good accurate rifle built.

 Then you go to load development which I think is another story!

Regards,
Belly

To add on from Les and Michael, another thing to think about and is often over looked is rifle balance, especially where the weight is, I see a lot of guns with big barrels, short stocks and the balance is terrible. You need to keep weight on the rear bag, in a heavy gun this isn't a big issue as you can add as much weight as you want, but a light gun is a different story, I guess PVM's set up is about perfect, the barrel is heavy enough to get a stable POI without being a monster, the stocks a long enough to keep some weight on the rear bag and comes in well under weight for light gun and being a 6mm is pleasant to shoot which makes it a good "PACKAGE", might not have the best ballistics, or the heaviest barrel but it works.
Stepping up in size (7mm plus) in light gun takes some thought, off set stocks etc etc.
Matt P