First loads in brand new brass

[strat81]

I have some brand new Lapua brass in 6.5 Creedmoor that I'm going to load for firing in my Tikka T3x CTR 20". I've never used Lapua brass in this gun, only Hornady.

I have read that the first firing in virgin brass can yield different results than subsequent firings.

Should I treat the first firing as a normal load? That is, should I load my preferred, expensive bullets (139gr Scenar and 140gr Berger Hybrid), powder (H4350) and primers (CCI BR4) and shoot for groups at distance and expect those results to be repeatable?

Or should I load some inexpensive bullets, powder, and primers and send them into the berm?

For the 100 pieces, I'm looking at probably 25 cents per round saved plus the time savings.

Thanks!

 

[Ccrider]

I believe that a gentle first load helps to extend the life of your primer pockets. Test for yourself and see.

 

[golong]

I think you should figure out how far off the shoulder is compared to where it will end up, and check the case volume, and then decide.

Personally, if I was going to be moving the shoulder more than 0.004 then I would load them in a test barrel and stretch them with some other bullet. If the volume is >/= 98% of the brass I am replacing I am also going to use my standard load, otherwise I am going to back it down a tenth or more. Regardless, I am only loading a few at first to test, and I am only putting rounds down a shooting barrel that I plan on shooting well/checking to see if they are shooting well; I am not going to waste 4% of my good barrel's life just to stretch brass.

I did not always have this mindset. YMMV.

 

[dgeesaman]

I’d shoot junk bullets first and get them fire formed.

the internal volume of the Lapua brass is probably different so you’ll probably need to adjust your load a bit.

 

[Dusty Stevens]

Id shoot a few once, then find your adjusted load then go with it. I dont think the case volume is going to make much difference in this case

 

[243winxb]

If running a maximum load with the Hornady brass , i would compare the weight of the Lapua to Hornady. If the Lapua is heavier, reduce the load and fire 3 as a test.

New brass has not been as accurate for me as prepped brass, when using the same brand of brass. (REM/ Win in 243. )

 

[UltraBR30]

Measure the water capacities then adjust your starting load accordingly.
Philip

 

[mgunderson]

What Dusty said. I would expect the load to change slightly switching from Hornady to Lapua brass.

Brand new brass can be a little small. With a "match" chamber the speed difference between fired and new brass should be quit small. I generally experience a slightly higher SD with new brass and slightly better scores with fired brass.

Let us know how it works out.

 

[Baddog0302]

I'm waiting on a 6CM Savage to arrive, and here are my plans;
1 Run NEW Hornady 6 CM brass through a FL sizing die ,mainly to straighten out any dents in the necks. Then the usual neck treatment.
2. Load the brass with low cost bullets [2nd] I got from Midway, these have been treated with HBN as from what I've read the 6 CM has a shorter barrel life that other smaller case 6MM. And I want to see how using HBN treated bullets effect "fire cracking" and other things that effect barrel life.
3. I plan to seat the bullets so they are a hard jam fit into the lands.
4. Because of the jam into the lands I'll use a mid point load listed for IMR 4064, that way I will get a good load density, and hopefully enough pressure to fill the case out.
5. At the range or the back yard I'll shoot till I feel the Bbl. getting warm, then do something till the BBl is cool again, either test loads in another rifle I bring ,or work on a sturdy portable shooting bench.
6. For the second and accuracy testing , I'll either neck size using a Redding collet or Lee collet neck sizing die
Hope it all works out for you

 

[MislMan]

Just my experience ... one data point. I shot 6.5 Creedmoor using Hornady brass through a 26” Kreiger barrel. Load was 41.4 gr. Of H4350 at 2708 fps. Switched to Lapua brass and found load of 40.2 gr of H4350 at 2711 fps. Start load lower than current load and work up. Also, brand new Lapua brass necks are tight. Might run a sizing mandrel down the necks to normalize neck diameter.

 

[strat81]

Just my experience ... one data point. I shot 6.5 Creedmoor using Hornady brass through a 26” Kreiger barrel. Load was 41.4 gr. Of H4350 at 2708 fps. Switched to Lapua brass and found load of 40.2 gr of H4350 at 2711 fps. Start load lower than current load and work up. Also, brand new Lapua brass necks are tight. Might run a sizing mandrel down the necks to normalize neck diameter.

Interesting. The two best loads I have were at 41.3 and 41.5 gr of H4350 with a 139gr Scenar. Groups were tight and SD was in mid-single digits.

Thanks to everyone that has responded. I'm glad we have a consensus on how to approach this.