too short case for 455 Webley

[Tony750]

Hi fellow reloaders,

I have a question regarding the following.

I want to reload the Webley mkii as close to the original mil spec as possible. But, I live in Europe, and it is almost impossible to find 455 webley brass for reloading. However it is possible to find brass for the slightly shorter 450 Adams. I am in the posession of 265 grains hollow base webley bullets.

The Adams brass I can obtain has a length of 17.9 mm (.707in) against the original webley mkii case length of 19.6 mm (.776in).

I do have reloaddata for the original case length (mkii in .776in). I would like to try to match the original mil spec loads for this gun but my question is, what would be the effect of the shortened case?

I am always careful ofcourse, but would it be possible to simpy seat the large webley bullet a little bit less deep than normal? Just in such a way that the OAL will be very close to the original Webley case? Would there be any consequense in doing that?

Thanks in advance!

 

[Edarnold]

As long as you keep to the original Mk II overall length, the case volume should be the same, and so the pressure would be the same as if you used the longer cases. The only problem could be accumulation of fouling in the cylinder chambers, which could making using the Mk II ammunition difficult. A good cleaning would cure that. It's common to use .38 Special ammunition in .357 Magnum guns without problems, as well as .44 Special in .44 Magnum guns. For very heavy-for-caliber bullets, some people will use the shorter case with the bullet seated long to get better guidance in the chamber.

 

[Tony750]

Thank's, that is helpful.

However is the difference in case size not too much? 1.6mm difference is quite a lot. However the 265HBRN is quite a long type bullet... but still. Is the difference is case length not too much? What do you think?

 

[Jesse Heywood]

I was looking at this last night. Couldn't locate a dimensioned drawing of the bullet to determine the seating depth. The cartridge has three bands, thus two lube grooves. Photos of loaded 455 cartridges show the bullet seated with the crimp in the first groove.

Since you need to leave the second lube groove in the case, you will not be able to seat much shallower. Some solutions:
1. Go to the cast boolits forum and check there. http://castboolits.gunloads.com
2. Cut down 45 colt cases by removing .020 from the back side of the rim.
3. Fill the case (to the seating depth) with Trail Boss powder. Best choice if you can get the powder.
4. Fill the case with black powder and compress.
5. Obtain the actual volume (using water) of both cases, minus the seated bullet and compare to the load data for both cases, and work up a load from that. Not a good option with a valuable gun.