.338 Lapua Mag - 300SMK and H1000

[TrapperT]

I thought I would add another post regarding load development for my .338 Lapua. As some of you may be aware, I have tried various powders in my .338 LM. The list of powders are - RL25, RL22, H4831SC, Retumbo and now H1000. I'll list my rifle specs again:

M2008 Action
28" Bartlein Barrel, 1:9.7 twist, MTU Contour
Badger FTE Break
All put into an AI chassis

Here is the link when I first got the rifle and initial load development - http://www.snipershide.com/forum/ubbthre...rue#Post1281494

Here is the link to my other load development: http://www.snipershide.com/forum/ubbthre...rue#Post1556572

Approximately 1 week ago, I decided to try Retumbo with 300gr SMK's. I wanted to do this because I like Hodgdon powder and to see if I could bring down my ES. My ES with RL25 was hovering around the 20fps range.

<span style="font-weight: bold">NOTE: I am using 300SMK's which have been coated with BN.</span>

I ran an OCW at 100 yards and here is what I found when using Retumbo:

I could push the 300SMK to 2850fps but the average ES for the 5 different loads I tried was still around 20fps. Also, I found that I could not get any decent groups using Retumbo. My best group (3 shots) was around .75 MOA.

<span style="text-decoration: underline">H1000 Development:</span>
Yesterday I decided to try H1000. I did this after talking with Tom Sarver at the TVP shoot on 1-3-2010. So I did another OCW test at 100 yards using my standard brass prep and using charge weights from 90.5gr to 93.0gr's. I used the 90.5gr charge as my sighters and therefore I shot those all in a row. After that, I proceeded with the OCW as usual. The target is below:

I was very pleased as I saw a reduction in my ES along with the groups tightening up. The largest group was .844" and the smallest at .192". Obviously the 91.5gr was my first node (.192") with 93gr being the second node (.294"). The 93gr load is tempting, but the ES was 21 while the 91.5gr load had an ES of 8. I will now try this at distance and see if everything continues to hold up.

A few observations during my load development with the powders listed above (this applies to my rifle so please keep this in mind. YMMV):

- RL25 and RL22 do perform well, but I found them to be more temp sensitive than Hogdgon (no surprise here)
- I also found RL25 and RL22 to be inconsistent in terms of grouping at distance
- H4831SC and H1000 are definitely "cleaner" burning
- It seems as though a really slow burning powder (i.e. RL25, Retumbo) may not be optimal for my .338 Lapua. A slightly faster powder gave me better results.
- The 250gr Scenar's are fairly predictable in terms of flight even at a mile (Shot these at TVP in January)

In closing, I hope this has helped people when loading for the .338 Lapua Magnum. Obviously rifles vary and what works well in mine, may not work well in yours. <span style="text-decoration: underline">Also - All information given in these posts are "at your own risk". You are responsible for you own reloads and developing those reloads for your rifle. </span>

Thanks again to Tom Sarver, George and Moon, Marty, Zac Smith, Desert HK, Lt. ArcLight and many other people who were gracious enough to share information.

Tony

 

[tjonh2001]

Re: .338 Lapua Mag - 300SMK and H1000

what did you use as your final load with h1000 and what kind of speed?

 

[acloco]

Re: .338 Lapua Mag - 300SMK and H1000

Are these groups at 100 yards? Might try working your loads up at 200 or 300 yards.

 

[Armorman]

Re: .338 Lapua Mag - 300SMK and H1000

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: TrapperT</div><div class="ubbcode-body">
- The 250gr Scenar's are fairly predictable in terms of flight even at a mile (Shot these at TVP in January)


</div></div>

What bullet are you using with the H1000....300 smk's or 250 scenars?

I'm seeing some very nice results at 1 mile with H1000 and 250 gr scenars.....2914 fps at muzzle and 1090 fps at 1760 yards. I'm so happy with this 250 gr load that I see no need for a 300 gr bullet out of a standard 338 Lapua chambering at that distance. These 250 sceanars are flying very nicely for me with H1000.

 

[ChadTRG42]

Re: .338 Lapua Mag - 300SMK and H1000

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: acloco</div><div class="ubbcode-body">Are these groups at 100 yards? Might try working your loads up at 200 or 300 yards. </div></div>
+1. These long heavy bullets need some distance to know how they will really shoot. You may see your results at 300 yards are different from the data you get at 100 yards. 100 yards is good for finding your velocity spread and to see how the long range load shoots at 100.

 

[WoodyF15]

Re: .338 Lapua Mag - 300SMK and H1000

Just worked up my second 100 rds in my Savage 110BA in .338LM. Shot 50 with H1000 and 50 with N570. 14 of the rounds showed extraction grove expansion which made it tight/difficult to get them into the case holder to reload. Anything over 90.0 gr of either powder showed expansion. Shooting Lapua 300 gr Scenars in Lapua Brass. Bullets 0.005 off the lands with a length (off the ogive) of 2.9625. My BA's fire formed ammo averaged 2.328 (shoulder) with the Hornady headspace gauge. So I'm shooting with near zero headspace and 5 thou off the lands but getting expansion at 2.4 gr less than Lapua's recommended Max load. My 90.5 gr loads are 2720-2745 fps. Anyone else seeing this? or got any recommendations? I'm reloading the second 100 with 89.5-90 gr of N570 and 89.0-89.5 gr of H1000.

 

[TrapperT]

Re: .338 Lapua Mag - 300SMK and H1000

Kinda surprised to see this old post up again.

Woody - I just talked to a friend of mine and he worked up a load for his Savage and ended up at 91.5 gr of H1000 jumping his bullets about .010". Speed was around 2800fps. No issues with pressure. High neck tension can create pressure. If you are not expanding the necks on new Lapua brass, then your neck tension is to high (this has been my experience).

BTW - Since this post was written, I have found that loads I developed at 100 yards have held up all the way to a mile.

Tony

 

[WoodyF15]

Re: .338 Lapua Mag - 300SMK and H1000

Thanks Trapper, I'm using a Hornady full length sizing die and a Wilson Arbor Press bullet seater. My runout is .002 or less. This was new brass so annealing would not have made sense. Any suggestions on relieving neck tension? I've read about 10,000 different ways.

 

[TrapperT]

Re: .338 Lapua Mag - 300SMK and H1000

Expander mandrel from Sinclair, K&M, 21st Century will all work.

 

[l115a3]

Re: .338 Lapua Mag - 300SMK and H1000

Thanks for sharing.


I will get a new AI-AX 338 for next month, so any suggest powder to start?

I also prefer 300gr bullet.