Need some help: 338 LM

[hafejd30]

Using 300 smk/RE33/lapua brass/Fed 215- bullet .010 off lands

I anneal every firing. Maybe not annealing enough?

I ran this combo in my factory barrel and was quite accurate. Running the same combo in my new Shilen select match and seems to be shooting some wild velocities, and accuracy reflects it.

Shot 1 3/4" group at 500 the other day. Reloaded same thing up to confirm I was g2g. Shot last night and shot over 6" at same distance. Didn't have a chrony with last night but 2 shots were bout 1 1/2" apart, other was 6" high. What I'm noticing is even .3 grains in powder is the difference between 8" and 3" groups at 500. Never seen a barrel fluctuate so much in that small of a difference

Anybody experienced this with any rifles that could shed some light here.

I'm Gona back the bullets off the lands to .015. Also have some retumbo powder to try.

Feel free to share some load data with a similar combo as well, thank you

I should add I was using cci 250 in my factory barrel. But ran out and switched to the Feds

[LongRange]

different barrel different load...the bore is most likely tighter than the factory barrel...i dont shoot a 338 but IMHO you should back the bullet off to .020-.025 drop the powder charge and work back up...i also had the best luck with CCI 250s in my 300....the 215s always gave me high or erratic ESs...ive also had the best luck with all the bullets ive shot at .015 to .035 off the lands.

[hafejd30]

Thanks LR. Was hoping you'd see this post. Think I'll give the .020 a try. I changed primers for the simple fact that you still can't seem to find anything powders, primer etc when you need it. A match fed 215 is like locating a pink unicorn right now. I'll also try some retumbo as well and see what happens

[LongRange]

stick to the CCIs...all the primer testing ive done in the past has shown the CCIs to produce the lowest ESs.

[hafejd30]

Will do. My lgs will have some for me this week. I run cci in everything else and always have good results. But sometimes you have to go with what's available at the time. Once I find a load I stock up on the components well ahead of when I need them. I'll have 1000 cci 250's to start with

[NRFJR]

With the 250 and 300 gr SMKs I have not been able to get them to group in my .338 LM rifle with the stock barrel or the new 30 inch custom McGowen without being at least .020 and .025 - .035 works better for me. I have noticed that at 400 yards and up .1 grains of powder make a difference in groups with my new barrel. I have not worked with RE33 enough to give any advice about the powder but I am working with it. I started out (3 years ago) working with and perfecting loads with IMR 7828 Fed 215 or Tul-Ammo LRM and Lapua brass for 3016 fps with the 250s and US 869 for 2957 fps with the 300s. Both loads are sub MOA at 100 yards. The 250s and 7828 are my go to load as it produces 2.16 in. 5 shot groups at 600 yards. Just my 2c. Hope this helps in some way.

[hafejd30]

Thank you for the response. Anything helps. I actually picked up some CCI 250's at cabelas lil while ago. Will try that and seating off the lands further. I will update. Won't get to test until next week tho

[LongRange]

Will do. My lgs will have some for me this week. I run cci in everything else and always have good results. But sometimes you have to go with what's available at the time. Once I find a load I stock up on the components well ahead of when I need them. I'll have 1000 cci 250's to start with

man only a 1000 and your stocked up?...i get down to about 5k and am worried im going to run out LOL!!

[hafejd30]

I have 7000 for my 260. I'll stock up when this gun shows some promise. And being a 338 lapua the 1000 primers will Proly last a barrel lol

[psharon97]

I guess I don't shoot as much as others. It's taken me 7 years to run through a brick of small rifle primers for my 223. I should really shoot more lol.

[yobuck]

With the 250 and 300 gr SMKs I have not been able to get them to group in my .338 LM rifle with the stock barrel or the new 30 inch custom McGowen without being at least .020 and .025 - .035 works better for me. I have noticed that at 400 yards and up .1 grains of powder make a difference in groups with my new barrel. I have not worked with RE33 enough to give any advice about the powder but I am working with it. I started out (3 years ago) working with and perfecting loads with IMR 7828 Fed 215 or Tul-Ammo LRM and Lapua brass for 3016 fps with the 250s and US 869 for 2957 fps with the 300s. Both loads are sub MOA at 100 yards. The 250s and 7828 are my go to load as it produces 2.16 in. 5 shot groups at 600 yards. Just my 2c. Hope this helps in some way.

I'm having some difficulty with those velocity numbers from a 300 gr bullet from what I'm assuming is an unimproved Lapua case?

[hafejd30]

I'm having some difficulty with those velocity numbers from a 300 gr bullet from what I'm assuming is an unimproved Lapua case?

Some of my loads I've tried are in the high 2800's almost 2900. That's only going to the book max listed. The 30" barrel makes a decent difference. .5 grains less in my Shilen barrel is pushing the 300 smk almost 50 fps faster than my factory barrel

That's my rifle tho not NRFJR's rifle. Mine just aren't grouping well enough yet to pursue those faster loads

[NRFJR]

I'm having some difficulty with those velocity numbers from a 300 gr bullet from what I'm assuming is an unimproved Lapua case?

No it is not an improved and the loads that I have worked up very carefully and meticulously (over 3 years time), shot several times (50 or more each), every load has been shot with a strain gauge, chronographed and documented. These loads are way over book max and over pressure, the very reason I did not post the loads. I am using these loads to try to shoot accurately at a mile + and I am still doing development with several other different powders and bullets.

[yobuck]

After re reading his post, I'm assuming he's talking bullet weight and not primer #s.
I think 2850 fps would be more realistic with a 300 gr from the standard lapua case.
3000/3050 fps would be max for the 378 Weatherby case with the 300 gr bullet
even from longer barrels. It is a common mistake for people to use lighter bullets in
the 338s for the sake of more velocity.
Not debating what primer might perform better in a given gun, but fact is fed 215s are the
hottest primer on the market as for spark. Which is why they are popular with shooters using
very large capacity cases. On a very cold day with a large case full of slow powder, it could be
more important. Small groups are nice, but not really all that necessary for hunting.

[hafejd30]

Happy to report things are going much better thanks to the help I got from you guys. Tested 7 loads tonight and 3 grouped under 3" at 500 yards. Forgot my chrony so not sure on speed but I will have it with when I test different seating depths. Best group was 2 1/4"/ worst 4.7" at 500

[hafejd30]

Posted a thread titled "338 Lapua- Final Results" for those interested in the final outcome. Big thank you to all who helped both on open forums and pm's

[geezerhood]

I anneal every firing. Maybe not annealing enough?



This is something new to me, annealing after every firing. Is it a common practice now for precision shooters? I have been out of the loop for several years, but I used to anneal only when I felt it was needed after several reload cycles. I would usually neck size and reload at least 4 times before I decided to anneal the necks.

[hafejd30]

The problem I had wasn't anything to do with annealing. But I was trying to find the issue and looked into everything. I have a Bench Source annealer so it takes literally 10 minutes to anneal each time. I did notice a difference, smaller group/half the ES when I tested annealed brass vs brass fired Proly 3-5 times. I've never tested once/twice fired etc. if I were using some complicated method that took lots of time I'd look into that but with how simple this machine is I just always do it. I know guys that anneal every other firing or every three etc and they get good results. It all comes down to what you consider accurate at longer ranges and what your annealing process requires for time/prep

[geezerhood]

Sounds like something to check into. I don't have an annealing machine, but at the price of 338 Lapua and 300 Ultramag brass, I should probably get one.

How many reloads can you get annealing every 2 to 3 times?

[hafejd30]

No idea on an exact count.
That will depend on quality of brass, how hot the loads are etc. My 308 had several brass that were well into the teens. That was before I started loading 100 at a crack. Now my casings only have 5 on them for my 260, which is what the 308 was switched to. Eventually your primer pockets will loosen up or you'll change barrels and what not. When I switch barrels I start with new brass. My Lapua just went to there 3rd loading on 45 pieces of brass. We'll see how long they hold up. 260 brass is almost free compared to the LM