Max bullet weight for a 40-82?

[Kev18]

I was wondering what the max weight is for this cartridge. My rifle has a slow twist so it does not stabilize the longer bullets. Factory loads used 260grn bullets, which I use now. but I would like to go alittle heavier. There is already a mold I can order on Accurate molds. It is 300grn.

I have multiple articles on the caliber and the most people have went is 310 grns with good accuracy from what I can see. The bullet needs to stay under an inch in length to stabilize.

The rifle is an original 1886 MFG 1889.

[Lead pot]

You have to know what the ROT (rate of twist) is in your barrel. Weight can be regulated quite a bit by changing the ogive profile. A blunter ogive will be heavier than a say money type. Look at it as maximum length, the weight will increase by weight of the alloy mix and ogive shape.

[Kev18]

You have to know what the ROT (rate of twist) is in your barrel. Weight can be regulated quite a bit by changing the ogive profile. A blunter ogive will be heavier than a say money type. Look at it as maximum length, the weight will increase by weight of the alloy mix and ogive shape.

the twist rate is a 1-28. My barrel is 26 inches.

[17nut]

28 is slow!
You will pretty much max out at 0.9" bullet length.
Weight and speed will push it slightly either way but length is key.
Given a 0.9" cylinder from pure lead you'll get @330grains.

[Kev18]

I ordered a mold from accurate Molds.

[Kev18]

I just got my mold in yesterday and it looks really nice! I casted a few bullets and they came out nice.

[Rick B]

Looking forward to a detailed shooting report. Accurate Molds is a very good mold maker. Which mold number did you order. Will you Loads testing, be black or smokeless
Rick