H2O weight for 284 Shehane

[1shot]

Does anyone have an accurate H2O weight for the .284 Shehane using Lapua brass? I have a chamber that measures .485 at the shoulder instead of the print on QL with .475. That said, my water volume is 10.0 gr. less than the default setting on QL. Any help would be appreciated.
Thanks,
Lloyd

 

[ShootDots]

Hey Lloyd, I had read in 2 different places (I believe one of them was on this site) that the Shehane has 3.3grs more water capacity than the standard .284. However, I have found that if you want to retain primer pockets, you will get an honest 1.5 grs more of POWDER>>> and that's it.. I have had 3 Shehanes and 1 "straight" .284, I do have some experience in this arena..

 

[Laurie]

In my two rifles it's 68.4gn v 66.7gn, so not a large increase even allowing for variances in weighing. Both Lapua brass but different lots. My N165 load for the 284 is 57gn and that for the Shehane is 59.7gn, both 180s in the lands but different models (Sierra MK for the 284 and Scenar L for the Shehane). Both are compressed loads, both are relatively mild and the Shehane is actually slower than the straight version by around 25 fps. (Bartlein on the 284, Benchmark on the Shehane). Some Shehane brass is on its 8th loading and primer pockets are as tight as new cases.

 

[savagedasher]

Does anyone have an accurate H2O weight for the .284 Shehane using Lapua brass? I have a chamber that measures .485 at the shoulder instead of the print on QL with .475. That said, my water volume is 10.0 gr. less than the default setting on QL. Any help would be appreciated.
Thanks,
Lloyd

Take two of your cases put a spent primer in up side down put the case on your scale and zero it fill the case with h20 Make sure your case is full dry all the water off the case and see what the weight is. Check both and you should have a good average . Larry

 

[1shot]

Take two of your cases put a spent primer in up side down put the case on your scale and zero it fill the case with h20 Make sure your case is full dry all the water off the case and see what the weight is. Check both and you should have a good average . Larry

Larry,
That is exactly what I did and came up with 68.5.

 

[savagedasher]

Larry,
That is exactly what I did and came up with 68.5.

Now do all your brass and watch your ES go down when you sort by volume. Larry

 

[1shot]

In my two rifles it's 68.4gn v 66.7gn, so not a large increase even allowing for variances in weighing. Both Lapua brass but different lots. My N165 load for the 284 is 57gn and that for the Shehane is 59.7gn, both 180s in the lands but different models (Sierra MK for the 284 and Scenar L for the Shehane). Both are compressed loads, both are relatively mild and the Shehane is actually slower than the straight version by around 25 fps. (Bartlein on the 284, Benchmark on the Shehane). Some Shehane brass is on its 8th loading and primer pockets are as tight as new cases.

 

[1shot]

Laurie,
I knew I could count on you for to give me reliable data, Shoot Dots ditto for you as well.
Thank you all very much.
Laurie,
You stated that the Shehane was 25 fps slower than your "straight" 284. What are the velocities that you are getting and do think it could be slow barrel or slow lot of powder.
Lloyd

 

[Laurie]

Laurie,
You stated that the Shehane was 25 fps slower than your "straight" 284. What are the velocities that you are getting and do think it could be slow barrel or slow lot of powder.
Lloyd

That's difficult to tell, 1shot. A combination of three factors I reckon - barrel differences; bullet differences (SMK maybe generates higher pressures than the Scenar) and powder lot as I (deliberately) bought and started on a newer batch with the Shehane and kept on with my existing supply with the straight 284 rather than have to change lots with both cartridges early on.

At low round counts, the 284 was running around 2,825 fps but now at around 850 rounds has speeded up to 2,847 fps. The Shehane with its Benchmark barrel struggled to get much over 2,800 originally, but as it was shooting exceptionally well I wasn't bothered by that and wasn't prepared to change powders. It settled around 2,820 after maybe 100 rounds, but I suspect it's now shooting a bit faster too, maybe actually a lot as these barrels seem to 'speed up' with a few hundred rounds down them.

The Shehane has only ever been used with N165 and I intend to stick to that. (I had tried various slower burners in the straight 284 - H. Superformance, IMR-7828ssc, Reload Swiss RS70, H4831sc with 180s in it alongside N165. Some of them give considerably higher MVs than the Viht powder, but overall I got better - and crucially - more consistent results with N165.) Returning to the Shehane, its Benchmark barrel seems to like the 180gn Lapua Scenar L better than either Berger VLD or SMK 180s.

So far as the 284 and its Bartlein goes which I've been running for a longer time, I acquired a huge number of 180gn Sierra MKs packed loose at a never to be repeated price that make Berger 180s (which the rifle didn't love anyway) look as though they have pure gold rather than gilding metal jackets. It took a bit of experimentation and work, but with BTO measuring and batching, trimming and pointing plus load development I ended up with a combination that holds 1,000 yard elevations very well indeed. At that time the barrelled action was in a stock with balance and handling problems for F-Class and I just couldn't get comfortable with it leading to shots pulled laterally unless I remembered to pull the buttplate really hard back into my shoulder. I now have a new Dolphin Gun Co. chassis stock and need to put the rifle back together and see how it shoots later this year. It should all being well be my mid-range gun with the Shehane kept for 900 and 1,000 yard matches and maybe the occasional 1,000 yard BR match. As the 284's Bartlein has a gain twist ending up at 1 in 8", I'll be able to try the 183gn SMK if it ever reaches here. I also bought up the last of one of our Berger importers' stock of the exceptionally long 175gn Berger XLDs which I've yet to try in it. (They didn't perform well in the Shehane Benchamrk's 1 in 9" barrel.) Finally, I have a second load for this rifle that I use occasionally at shorter distances with batched and prepped Winchester 284 brass, 168gn Berger VLD and IMR-4831.

 

[Keith Glasscock]

It is odd to see the variation in H2O readings.

My STRAIGHT 284 is at 67.4 - go figure.

Lapua 6.5-284 necked up, neck turned to .013, fired in a .315 neck chamber done with a PT&G 284 Norma/Lapua reamer. Headspace is nominal (.001 over go gauge). Redding 284 FL sizing die barely moves the brass, so it isn't an oversize chamber.

 

[1shot]

Kieth,
Laurie and I are only .1 gr. apart. I had one at 68.5 and the other at 68.4. 1/10 of a grain of water ain't much.
Lloyd