What to do when published data is so different?

Seebass

Seebass

New member
I’m getting ready to build a load for my new .243. I’ve got Varget and 55g Nosler BTLF’s.

Published data for Hodgdon is 37.1g min and 39.5g max.
Published data for Nosler is 41.5g min and 45.5g max.

That’s a big difference in starting points!! What would you do, where would you start?
 
That is quite the discrepancy isn't it? I know that in general that the data from Hodgdon leans toward the mild side. Everyone wants to be on the safe side these days so often max loads are way under actual max. Lawsuits are Bad Things for big companies.

I know that I have loaded 44 grains of of Varget in my Ruger No 1 .243 and they were great. Used this for both the 55 grain and the 58 grain bullets. No pressure signs at all and cloverleaf 100 yard groups. Yes, I know that everyone says to work up to the hotter loads and I am not going to disagree with that but for me I would be more inclined to use the Nosler data than the Hodgdon. I've loaded many many loads right out of the Nosler books for decades and never a problem.
 
Carlos, I went with the Hodgdon Data with the 243 Win and the Nosler 55 gr Lead Free BT Varmint Bullets. I used the minimum load for lead bullets with Benchmark powder.

I found the Published data for Hodgdon Varget is 37.1g min and 39.5g max for the Nosler 55 gr for Lead Free bullets.

Is the Published data for Nosler Varget 41.5g min and 45.5g max load data also for Lead Free bullets or is it for lead bullets?

The longer Lead Free bullets may very well have more pressure than the shorter lead bullets.

One thing is for sure with a 55 gr bullet in a 243 Win it doesn't have to be near a max load to be going pretty fast.
 
I shoot the 243 Win 55gr NBT-LF also and had a similar dilema with IMR 8208 XBR. My rifle loves lead 55gr NBTs with 42.5gr so I was hoping the lead free version would be similar. I have seen cautiins that lead free bullets require a slightly reduced charge over lead due to higher pressure.

For reference, I started my 8208 XBR testing as follows with 3-shot loads:

243 Win
55 NBT-LF
Win brass
CCI 200 primers
coal 2.660"

39.5
40.0
40.5
41.0
41.5

24896786738_5847f5abf7_c.jpg


I totally pulled the first shot of 42.0 oops. Several of those shot really well but I saw no signs of pressure so I loaded up some more 5-shot test loads:

41.0
41.5
42.0
42.5

38738966852_2da81e637b_c.jpg


Again several shot really well. 42.5 was perhaps the best by a hair, no primer flattening, but a couple of the 5 fired cases showed traces of very light ejector swipe. Velocity was 4050 fps SD 40. I stopped there and haven't finished testing, got busy with another project. I will probably drop down to 42.0 and then mess with the seating depth at 200-300 yards.
 
I loaded 80g GMX’s to 2.56”. I’m going to test one last time at 2.54” because groups have continued to tighten with no pressure signs. Those are long bullets!!
 
I decided to go with the Hodgdon data just to be conservative. Plus I’ve never been one to want the super fast load... I’d rather be accurate than fast.

I went up charges and added a couple different seat depths at 38.5g (mid charge) just to see if there is a difference.

https://flic.kr/p/212scmu

I’ll be heading out tomorrow morning to test. I’ll let you all know how it goes. I’m hoping the 10 twist likes the 55g BTLF and this next one is quick and easy!!

Carlos
 
Originally Posted By: SeebassWhat to do when published data is so different?



Substitute your own for your rifle... Dan
 
Im shooting a max load of h4895 with the 55 combined technology out of my winchester coyote lite 243... shoots great in mine..
 
It was windy out today!! I had to back my truck in next to my bench to use as a wind blocker so I could get a steady rest. 10-15mph with gusts higher.

https://flic.kr/p/E3BFDS

I shot #1 then adjusted my scope left a bit for the next few. After shooting my 38.5g tests and seeing shrinking groups with 2.61” right at 1” and then open back up with 39g@2.71” I decided to stop.

I really like where 38.5g @2.61” and shortening is headed. I will now make a few tests at 38.5g @2.59”, 2.57” and 2.55”. I’m fairly confident I’ll find a really accurate load somewhere within this next test.

With the left over loaded test rounds I’m going to push them all down to 2.60” and see how they do. I may even load a few extra 39.5’s to the shorter depths just for fun. I’ll be back after my next test!
 
if possible i always try to save my test load shooting for calmer days. trying to shoot for load development with a crosswind can really screw with your data.

if you had to put your truck in the way just to get steady on the rest, personally i would have gone home and waited for another day.
 
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