Fireforming and Loading 338 Lapua Improved

[LynnJr]

Shooters I did a little bit of a web search and I get nothing that is useful.
In this thread we can discuss how to make Precision Rifle quality brass and do some load development with RE33.
We will stick to benchrest proven steps to minimize components usage and save some time and most importantly barrel life.
Testing rig is a Savage 111 Hunter with a 32 inch Bartlein 9.36 twist barrel and Harrell's muzzlebrake chambered in 338 Lapua Ackley Improved.
In case so.some is not familiar the 338 Lapua was introduced before the 300 grain Sierra MatchKing bullet was made.
This means that when a 300 grain Sierra MatchKing is used in a standard 338 Lapua or Improved version that the boattail to bearing length surface is around 0.110 past the neck/shoulder junction. This is too short to get the maximum potential out of this combination and limits the over all length to 3.750.
Ideally we would use a different reamer or a throater and get the 300 grain bullets seated about 0.050 out in front of the neck/shoulder junction or a freebore change of 0.160 more.
For our initial fireform load we are using a Winchester Large Rifle primer and Lapua 338 Lapua brass.
Brass has not had anything done to it. It will be prepped only after it is fireformed and checks out okay.
Our powder charge is 17 grains of Red Dot. After the cases are charged we then fill them to over flowing with Tapioca pudding straight out of the box and dry.
The Tapioca when pushed by the powder charge will expand the standard brass into the Ackley Improved chamber.
Next is to pinch a case between your thumb and forefinger and tap it near the casehead to help settle the Tapioca.
It takes 10-20 taps to settle the Tapioca and this step goes the quickest.
Next we take a paper towel or ordinary toilet paper and use it as a wad to prevent the Tapioca from spilling out. I use a small screwdriver to stuff it into the neck of the case.
There is one last step to be done before firing.
Lightly lubricate the entire outside of your rounds with Imperial Sizing Die Wax. This step keeps the brass from grasping the chamber walls and improves the fit of the brass to the chamber.
After I fire these rounds we will continue on with the load development stage.

[Aidenpeacemaker]

338 big bang

Sounds like fun. I miss shooting the 338 luppy.

[LynnJr]

Here is a test piece of brass and the rifle.

[jmf_tracy]

LynnJr,
I only have RL-33 powder. Can i use this or would i need to buy a different powder for fireforming my brass? If the RL-33 is OK then how much should i use?

[bsumoba]

I'm using H1000 in my 338 Edge and am considering on trying RE33.

I never fireform using this pistol powder way and have fireformed 6 dasher and 284 shehane by just firing it with a standard 6BR load or straight 284 load. These end up being scary accurate for a fireform load. I am curious if the 338LM Imp can be fireformed with a normal bullet and accuracy is still rather good.

[LynnJr]

JMF Tracy
As Bryan posted if you only have RE33 you can simply load up your ammo and shoot it.
I think you can get about 103 grains of RE33 in the standard case before you get it compressed.
I am using the RedDot so when my load development is completed I will have two firings on the brass before I prep it.

[jmf_tracy]

OK, thanks for the reply Bryan and LynnJr.

JMF Tracy
As Bryan posted if you only have RE33 you can simply load up your ammo and shoot it.
I think you can get about 103 grains of RE33 in the standard case before you get it compressed.
I am using the RedDot so when my load development is completed I will have two firings on the brass before I prep it.

[JMP]

Guys, it depends on your bullet.
Ramshot Magnum, 7828, RL-25/26, H1000, Retumbo, N570, MRP2, RL-33, etc., will all work in a Lapua, but it depends on your load. I'd not use 7828 or Ramshot with a 300gr bullet nor would I use RL-33 with a 250gr bullet.

The Lapua has a wide spectrum. If you want to shoot 300gr lead bullets, which are most popular these days, I'd go Retumbo or N570. Personally, I favor H1000 in the lighter weight (250-267gr) monolithic bullets. If you are shooting for distance, you will probably want a solid bullet with a high BC number that you can shoot fast and accurately. For me, it's H1000 and a really big plus if you can get an RWS primer.

I personally think that RL-33 is a bit on the slow side so you'll you may need a funnel drop tube to get it compressed. I also think that 300gr bullets are a bit too heavy for the regular Lapua, especially in lead. They seem to build up pressure quite quickly and this limits fps. This is why the 300gr lead projectiles from the regular Lapua are known to go about only 2,700-2,750 with optimal accuracy.

You need to try a few different bullets and a few different powders to see what works. If you are new to loading Lapua, I'd try to get H1000 as that seems to work the best across the spectrum of all the Lapua weights.

[JMP]

Of course, if you have a true Ackley chamber, you can just shoot regular lapua cases through it, and the result will be that you end up with a fire-formed case. The neck/shoulder junction is slightly lower in the Ackley and this gives enough pressure to hold the regular case concentrically in the chamber, but not too much where it prevents the bolt from closing.

This is what happens when you close a regular Lapua case in an Ackley chamber. You can see that it is held tightly at the neck/shoulder junction so you would not need to go to a cream of wheat type fireforming if you did not want to. You can just shoot a box of regular Lapua, then load it for Ackley once it is formed.

[LynnJr]

Here are some pictures of the fireforming done in my backyard. I wrap the muzzle in and old T-shirt and a pair of jeans to keep the noise down.
You still need to shoot and let the gun cool so you don't burn out the throat even with only 17 grains of powder. Make sure you run a paperclip around the inside of the shoulder. Tapioca can get wedged against that area and it can dramatically affect case volume.
Load work up is next.