6mm Creedmoor Small Primer question

[NNYShooter]

I'll start this by stating that I'm pretty new to hand loading, and my Speer manual has absolutely nothing about 6mm Creedmoor in it.

I'm loading for a Howa 1500 with a 26 inch barrel and a 1:7 1/2 inch twist. Started with Hornady brass, 42 grains of H-4350, Hornady 105 grain Match BTHP, and Large Federal gold medal match primers. I was getting sub MOA groups consistently at 100 yards. Smallest group being about .25 inch. Thinking to improve on this I purchased some Lapua brass because of the better quality and hype. In doing this I mistakenly purchased brass with small primer pockets.

So, starting fresh with my new brass, cci br-4 primers (only ones available at my local shop), 41, 41.5, and 42grains of H- 4350, and Berger hybrid 105 grain bullets, my groups opened up to about an inch and a half and dropped about an inch low and to the left. I assume it has something to do with the primers. I guess my question is if increasing my powder charge will tighten it back up? Maybe change out primers. I'm thinking I may have to switch back to the Hornady 105s to eliminate extra variables. I have 100 Lapua cases that I'd like to use for this rifle if I can. Hope y'all can point me in the right direction.

 

[Supersubes]

It only comes in a small pocket version. Virgin brass? If so, it’s probably a neck tension issue. If you treat the necks as you would if you were reloading it from the fired state, it will perform very well. It definitely has nothing to do with the primers. Pretty much everybody uses 450’s or BR4’s. Also, you changed every component except the powder, so you’ve got some work to do. It ain’t the primer though.

 

[NNYShooter]

It only comes in a small pocket version. Virgin brass? If so, it’s probably a neck tension issue. It definitely has nothing to do with the primers. Pretty much everybody used 450’s or BR4’s.

Yes, its virgin brass sized with a Redding full length s type bushing die. Bushing is .269 which should give me a thousandth to 1 1/2 thousandth neck tension.

 

[Supersubes]

Yes, its virgin brass sized with a Redding full length s type bushing die. Bushing is .269 which should give me a thousandth to 1 1/2 thousandth neck tension.

Usually Lapua brass is undersized, and lacks sufficient chamfer in the inside of the necks. If you were not running an expander ball, you’re bushing likely didn’t touch the neck, and it remained undersized. You can take some measurements of the Virgin neck vs loaded neck to get an idea where you’re at. It also has smaller internal capacity than Hornady, which you may have already noticed.

 

[NNYShooter]

I used the expander ball, but didn't measure. Will try that next. I did notice the smaller volume, but had read about it before hand or I probably wouldn't have. I also didn't notice the lack of chamfer and the bullets seated fine. I assume the neck tension issue meand less pressure and may be the reason for the lower impacts. That would mean getting a smaller bushing should solve my issue?

 

[Ranger188]

Your primers won't make that much difference to you.
When switching components, always start a little lower with your powder charge.
The Lapua brass has less internal volume, so it won't take as much powder to get
the same speed as the Hornady. SRP brass is a good thing. Most of us use the CCI 450 primers in SRP Lapua brass
They are cheaper the the BR'4's Your twist rate and bullets are fine.
Your running your test groups to far apart. Load at .2 or no more than .3g apart. Might take a
little more shooting, but that's good practice time behind the trigger.
You should find a good node in the low 41's and high 41's and in the low 42's
Be careful at that point, you could be pushing pressure.
Once you do your testing, do not change anything other than powder charge.
when you find a good group, you can go .1 powder change to either side to maybe
tighten up the group some more.
Once your find a good group, then you can start with changing the depth of the bullet
in the case.

 

[NNYShooter]

Your primers won't make that much difference to you.
When switching components, always start a little lower with your powder charge.
The Lapua brass has less internal volume, so it won't take as much powder to get
the same speed as the Hornady. SRP brass is a good thing. Most of us use the CCI 450 primers in SRP Lapua brass
They are cheaper the the BR'4's Your twist rate and bullets are fine.
Your running your test groups to far apart. Load at .2 or no more than .3g apart. Might take a
little more shooting, but that's good practice time behind the trigger.
You should find a good node in the low 41's and high 41's and in the low 42's
Be careful at that point, you could be pushing pressure.
Once you do your testing, do not change anything other than powder charge.
when you find a good group, you can go .1 powder change to either side to maybe
tighten up the group some more.
Once your find a good group, then you can start with changing the depth of the bullet
in the case.

Thanks Ranger. I appreciate the info. I've been watching for pressure signs, but have been pretty conservative with my charge weights. I guess the only option is to start from the begining and work it all out again. It was a lot of fun the first time around, and it's getting warmer here, so it will just be better. I'll work up more loads closer together and take it from there. Thanks again.

 

[ShtrRdy]

I'm pretty new to the 6mm Creedmoor but I also use Lapua brass and found that the CCI 450 primer works best. I'm also using the Berger 105 Hybrid and H4350. Groups are 1/4" to 1/3" and 3060 fps out of a 25.5" barrel.

I add some weird behavior out of the unfired brass and started using Imperial Dry Neck Lube before seating a bullet.

 

[TX_Punisher]

Interested in the howa 6mm barreled action.

-have you checked the freebore from the factory? If so, what did you find? I’ve heard in the .185 area.

-what stock and mag are you feeding from?

-what cbto and coal are you loading to?

Thanks for the info. Sounds like you’re on the right track with your load development.

 

[Kadams1563]

Who sizes new Lapua brass?

Just seat a bullet, shoot, start better load development.

 

[NNYShooter]

Haven't been on in a while, but wanted to thank you all again for the help. Between all of you, and my local old timer, I'm shooting one ragged hole at 100 yards and stay sub MOA out to 450, which is as far as I can go in my area. I'm now looking into signing up for a long range, or precision rifle school in the spring. It took me most of the summer to get here between work and real life getting in the way, but it was a great experience. Thanks again to all of you.

 

[Bache Kermooni]

Haven't been on in a while, but wanted to thank you all again for the help. Between all of you, and my local old timer, I'm shooting one ragged hole at 100 yards and stay sub MOA out to 450, which is as far as I can go in my area. I'm now looking into signing up for a long range, or precision rifle school in the spring. It took me most of the summer to get here between work and real life getting in the way, but it was a great experience. Thanks again to all of you.

Great news. So what was the final solution? Small or large primer? Which brand? What loading process? And which pill - Hornady or Berger?

 

[Cody S]

get a magnetospeed. once you find a speed a bullet likes in your gun with a certain powder it usually holds true if you start switching things like powder lots. for me it was about 3100 with 105hybrids h4350. even switching brass and barrels and guns, I've found the speed thing seems to work.

 

[Bache Kermooni]

Thanks for the advise Cody. I finally broker down and now use a LabRadar. The screen ones are too light sensitive and the Magneto effected the POI once removed. My semi-custom 6mm Grendel shoots 0.25" groups. I am building a 6mm Creed and just ordered a Howa 1500 SA 24" HB barrelled-action from Brownells. I am strictly a hunter (accuracy crazy, though) and my favorite barrel maker (Pac-Nor) just burnt down to the ground :-( But I will give this a run. If accurate, I will send it to my smith to turndown the barrel and accurize. Hopefully a McMillan Game Scout will be ready for it by then.

I have decided on the Peterson brass with large primers and the Berger 105 VLD Hunting pills. Hopefully it will work.