243Win vs 6mmBRM. Safety?

[roysclockgun]

I am working up loads for 6mmBRM. For those who do not know, this is a 30-30 case, blown out to a steep shoulder and necked down to a 6mm mouth. The case length is very close to 243Win. The bullets used for both are, of course, the same. There is very little data available for loading 6mmBRM. The manufacturer, E. Brown, only gives one formula for loading.
I am not looking to load up to max. 243WIN MV. I only want to load range ammo at low to medium velocity for that cartridge. E. Brown claims that when pressures begin getting too high, the falling block breach will be hard to open and achieve extraction.
My question is: Is it not reasonable to assume that I can load any starting load, given in data for 243Win., in my 6mmBRM?
So far, I have only used three loads in my 6mmBRM, all taken from 243WIN data. (1) 100gr. Sierra SP with 32gr. IMR4895. (2) 70gr. Speer TNT with 32gr. IMR4895. (3) 70gr. Speer TNT with 31gr. IMR4895. Any and all opinions will be appreciated.
Steven A.

 

[30-338]

When I got into the HBR matches alot of wildcats they set one rule the case had to have at least 45gr water capacity which was about what the 30-30 held.

The one I think that come close to your case is the 6x250 (45.82gr) and Hodgdon has loading data. My loading data for the 6x250 and 6HLS are for 68gr bullets and I ran them pretty hot.

Have you chrongraphed any of Brown's loads and compare them to what your getting? I seen one load for a 6x30-30 with 75gr bullet using 36gr/IMR-3031 @ 3430fps they didn't give twist or barrel length.

Well good luck

 

[tghrr]

I am also preparing to purchase a 97D in 6mm BRM and found reloading data to be scarce.

My research found that the 6mm Bullberry is basically a 30-30 necked to 6mm with no other changes. It has a case capacity about 2-3 grains less than the 6mm BRM. Load information is available in LoadData under 6mm Bullberry (20 in barrel).

Hope this helps.

I am working up loads for 6mmBRM. For those who do not know, this is a 30-30 case, blown out to a steep shoulder and necked down to a 6mm mouth. The case length is very close to 243Win. The bullets used for both are, of course, the same. There is very little data available for loading 6mmBRM. The manufacturer, E. Brown, only gives one formula for loading.
I am not looking to load up to max. 243WIN MV. I only want to load range ammo at low to medium velocity for that cartridge. E. Brown claims that when pressures begin getting too high, the falling block breach will be hard to open and achieve extraction.
My question is: Is it not reasonable to assume that I can load any starting load, given in data for 243Win., in my 6mmBRM?
So far, I have only used three loads in my 6mmBRM, all taken from 243WIN data. (1) 100gr. Sierra SP with 32gr. IMR4895. (2) 70gr. Speer TNT with 32gr. IMR4895. (3) 70gr. Speer TNT with 31gr. IMR4895. Any and all opinions will be appreciated.
Steven A.

 

[corbin9191]

Try here, http://handloads.com/loaddata/default.asp they might have some loads that you can use.

 

[roysclockgun]

Hi Corbin,
Thank you for posting that site. However, nothing there. The 6mm BRM is too new to be on reloading sites yet. Only a small amount of load data has been broadcast.
Best,
Steven A.

 

[jtoews80]

I'd be pretty cautious substituting data in a wildcat based on a 30-30 case. The 30WCF case isn't rated for all that much pressure, I haven't got a SAAMI rating, but it would be worth checking.
If it were, it's performance would be almost equal to a 308 Win.

Just my 2 cents, JT.

 

[roysclockgun]

jtoews80 did write : "If it were, it's performance would be almost equal to a 308 Win. "

That is good advice. I have been handloading for over 35 years now and on this 6mm BRM cartridge, I am beginning with low amounts of propellant and working up. The entire exercise is not to get a fast load for hunting, but only accurate loads for the range. That said, the maker of the Model 97d falling block rifle and owner of the proprietary cartridge 6mm BRM, does claim MV approaching 243Win, with his suggested loads. Although I cannot see for the life of me why anyone would take the time to neck down 30-30 ammo TWICE and then have to fireform to get 6mm BRM brass, just to match what the 243Win will already do without breathing heavy!
I have enjoyed hunting with my Browning B78 falling block rifle and wanted the Model 97d just to enjoy single shot shooting without all the expense and recoil of a 7mmRemMag, not to mention bore erosion that occurs when using a 7mmRemMag just to punch paper.
The 6mm BRM is pleasant to fire. Working up loads are just fun. E. Brown Co. reallly does push the 6.5 BRM as being a 1000 yard shooter and even great on elk! I will likely not shoot beyond 300 yards with this 6mm BRM rifle and I certainly want my 7mmRemMag in the case that I do again go after bull elk.
I have reloaded some of the fireformed cases five times now and have had only one split mouth out of 100 cases used. No signs of high pressure.
Steven A.