Crimping match loads for the 300 WM

[hrfunk]

I'm getting higher ES and SD numbers than I like for my match 300 WM loads. I'm thinking about adding a crimp to the case mouths to give the bullets a more uniform pull. With other cartridges I don't crimp my match loads, but I thought it might be beneficial in this case. Do any of you crimp your accuracy loads in the Win Mag? If so, does doing so have any adverse effects on accuracy or case life? I'm using 190 gr. SMK's with H1000 powder if that makes any difference.

Thanks,
HRF

 

[Cacciatore]

Crimping bullets without a cannelure, which includes the 190smk, is not the best way to fix your problem that is, if the problem has to do with neck tension. Doing so may even deform the bullet. The best way to achieve a uniform pull is to make sure your neck tension is consistent. In 300wm I am loading 77.9gr. H1000 behind a 190smk. They shoot absolutely great out of the TRG-42. When I size, I use a redding full length bushing die, with the proper busing for winchester cases. The neck tension is very light (I can seat the bullet deeper if I press hard enough), but it is consistent.

 

[hrfunk]

My ES numbers are consistently running in the 55-65 fps range with SD figures of 23-26. I'm new to the 300 WM but not to reloading. These numbers just seem high to me and I think I should be able to do better.

Thanks,
HRF

 

[Rob01]

How close to the max charge are you? What powder? You should definitely get better numbers than that but crimping wouldn't be what I would try.

You shouldn't need a crimp and as mentioned crimping noncanulare bullets isn't the best for accuracy. All I use on my 300WM is .003" of neck tension.

 

[Greg Langelius *]

If that works, it's a good answer.

I do it differently. I manage (did not say 'control') neck tension by varying the length of the neck that gets resized. More length, more tension, less length, less tension. The adjustment is made by raising or lowering the height of the die within the press. This allows a F/L die to be used for neck-only, and to be further adjusted to 'manage' average neck tension. This is actually a very old H/L technique that dates back to Benchrest shooting in the days when F/L dies were all that were easily/widely available.

I have a way of testing tension, but it's not quite ready for prime time as of yet, and is based on subjective judgment an not on any numeric standard.

Greg

 

[hrfunk]

I'm using a 190 grain Sierra Matchking, with H1000 powder. The Sierra manual lists the max load of H1000 at 77.6 grains. I'm currently working between 76.0 and 76.8 grains. I think I'm going to go a to 77.2 and 77.6 for my next two batches of experimental ammo to see if that makes any difference. I've seen some other manuals that list max loads of H1000 up around 80 grains, so I'm wondering if that might be my problem.

HRF

 

[Rob01]

Sierra manuals are notoriously conservative. I use 77.8grns with 208 AMAX. Slowly work up some and keep an eye on the neck tension and I think the numbers will drop.