338 lapua imp. range report

[steeltraps]

Thanks. My last 4 builds with Bartlein have been great! I use to only run Kriegers. But the 2 Kriegers I got last were slow. So I have been running Broughton and Bartlein. My 28 inch Bartlein on my 338 imp. cleans better than ANY barrel I own! My Retumbo load gave me 2936-2955 fps and fair accuracy. But it had a ES of 19 fps over 10 shots. Where RL-33 and H-1000 has given me single digit ES. I am hoping to get to shoot some more 1000-1100 yard groups this saturday with my 284 shehane and 338 imp. Since I know how to post pics now, I will try to post some up sunday when I get home from Jackson county Alabama. I will try to find some N 570 and see what it will do before I go saturday. What is a good starting load for 338 lapua imp with 300 gr OTM berger?

 

[HuntFarther]

Thanks. My last 4 builds with Bartlein have been great! I use to only run Kriegers. But the 2 Kriegers I got last were slow. So I have been running Broughton and Bartlein. My 28 inch Bartlein on my 338 imp. cleans better than ANY barrel I own! My Retumbo load gave me 2936-2955 fps and fair accuracy. But it had a ES of 19 fps over 10 shots. Where RL-33 and H-1000 has given me single digit ES. I am hoping to get to shoot some more 1000-1100 yard groups this saturday with my 284 shehane and 338 imp. Since I know how to post pics now, I will try to post some up sunday when I get home from Jackson county Alabama. I will try to find some N 570 and see what it will do before I go saturday. What is a good starting load for 338 lapua imp with 300 gr OTM berger?

The best place to start on n570 is to have the powder in hand. It is almost impossible to find.

 

[DM770]

Thanks for sharing your rigs data. I have one that I am just starting to get to know and it is nice to see some info on others. Great to see someone else running a 338LMAI.

 

[JeffVN]

After you get some in hand.... yeah that is the hard part with V.V.570 these days (and I saw that the price is going to be OBSCENELY HIGH - like $40.00+ per pound - if you can find it)

I started at 96 gr. (quick load told me this was going to be nominal pressure) and shot 1 shot at 1 grain increments over a chronograph looking at velocity and watching for pressure signs. I was looking for 3,000 fps and found it under the pressure max. For me P-max was in the realm of 103 gr. (flattened and cratered primers, sticky bolt).

I did and do all my accuracy testing at 525 meters and beyond (my home range has steel targets and impact berms set up at 200, 300, 400, 525, 800 and 850 meters - I set up my target next to the steel and blast away), knowing that the velocity was going to be in the desired zone. If my rig shoots well at 525+ meters it will shoot anywhere.

With RL-33 I did the same thing and reached 3,100 fps (109 gr), but it was at the top of the pressure curve and was compressed (that is saying something since I drop through a 6" drop tube I rarely see compressed loads- as in loads that go crunch when you seat a projectile). I used the 3,000 fps node (105.5) knowing it was not going to be close to over pressure during the Vegas summers.

Jeffvn

 

[steeltraps]

Thanks for the info. I have lots of powder hoarding freinds. I can swap 2 cans of Retumbo for 1 can of N570. Threw a friend of a friend. I worried some about RL-33 sensitivity myself. I have shot it in Alabama at rocks , in 92 degree weather and had 1 out of 15 rds that had a VERY light ejector mark. Iwas at the end of the 15 rds string, the round didnt chamber the way thothers did . I was trying .366 bushing, this was before I settled on a .365 bushing. I have man size targets at 500, 600, 800 ,1100, and 1800 yards at cornfeild I shoot across. Usually 500 yards is where I start with my 338 lapua imp. Cant wait till this weekend to get 284 shehane , 338 lapua, and 338 Lapua imp. out and do some shooting.

 

[ELR Researcher]

steeltraps and JeffVN:

As I suspect you realize, "338 LM Imp" is not a "standard". There is the ".338 LAPUA MAGNUM IMP 40 DEGREE" (PTG online reamer listing), the 338 Allen Xpress, possibly the 338 Yogi is also a 338 LM based improved, and CH4D lists a 338 LM Improved, an Improved KS, and an Improved PT. I'm assuming the PTG (online reamer listing) is not an AI (i.e., an actual Ackley Improved "standard" for "AI") since Dave does not list it as AI. So there are a bare minimum of 4-5 "versions". [Seriously disconcerting when you are trying to match dies to your rifle - and that without even touching the question of throat lengths.]

Which "version" do each of you have?

FYI - PTG does not put the reamer drawing number on their reamers or invoices, only the name. If you ordered based on a PTG reamer drawing, however, the drawing will have a reamer number on it.

 

[steeltraps]

To be 100% honest I don't know what my reamer was. I know my friend got it from a guy on Snipershide, it has a .370 neck 0 freebore. I always have him custom make my dies FROM the the reamer that does the barrel. I think mine is 338 Lapua Imp 40 degree with .370 neck and zero freebore. He did my barrel and dies and sent it back, now I wish I had just bought a reamer, because I LOVE this build and would like to do another one some day!

 

[JeffVN]

Mine is nearly but not identical to a 338 LM Ackley. Mine was designed to have a "no turn" but "snug" neck - as in 3 thou neck clearance - based upon the Lapua Headstamp brass that I had (and still use - with going on 10 reloads on them).

I've seen the buffet of dies out there called 338 LM Improved or Ackley. Which is why I went with a custom sizing die based upon my own 2x fired brass. I know that doesn't help anyone except me, but since I own the reamer I am good-to-go for the next 10-12 barrels that I chamber up with my reamer.

When dealing with anything that is "improved" it is hard if not impossible to perfectly match the reamer to the available dies. In all such circumstances (338LM Improved, 30-06 Improved, 7/30-06 Improved) I have opted for the more expensive, but guaranteed to work, approach of custom dies.

I own all of the "Improved" reamers mentioned above - as well as the reamer for my tight-neck cartridges (7WSM, 7 Dakota).

JeffVN

 

[steeltraps]

When to club to shoot friday. Shot out to 1100 yards with 338 lapua imp. It was to hot so I ran my cameras instead.