Want to use data for heavier bullet

[Mr_Flintstone]

I’ve been loading MBC Cowboy #18 78 gr Hi Tek coated bullets in .32 H&R magnum cases using Hodgdon’s 77 gr data online, but I’d like to try some other powders. Lyman #48 has data for 85 gr cast bullets with a similar profile, but they are a little heavier. Would I run into any problems loading these 78 gr bullets with the 85 gr load data for Bullseye and Unique from Lyman? I thought that maybe I’d drop the max load by about a tenth of a grain or two to make up for the difference in weight. What do you guys think?

[bmortell]

normally the heavier projectile powder charge data would be lower which is why its safer to use data from heavier boolits. also need to consider the amount of case volume the base takes up. a deep seated light boolit might have a lower safe charge than a long seated heavy boolit for example, but that's normally not the case.

[Hick]

A heavier bullet will tend to give higher pressures than a lighter bullet (It takes more pressure to get the heavier bullet moving). So, if you have data for a heavier bullet, it is normally OK to use a lighter bullet. You should still start at the lower end of the loadings (The starting load) and work your way up as usual.

[Mr_Flintstone]

The loads for the 85 gr bullets are somewhat higher than the 77. I suppose the lower data is to keep the velocity of the lighter bullets at about 1000 FPS or less. I think the Hi Tek (12 bhn) bullets can probably take the higher velocity, but I’ll still work them up from the low end.

[Outpost75]

In the .32 H&R Mag. I use the Accurate 31-105T bullet with 3 grains of Bullseye or 7 grs. of Alliant #2400. Approximates factory loads ~1000 fps and are accurate.

256693

[Mr_Flintstone]

I’ve loaded a 98 gr bullet very similar to that with 6.3 gr 2400. I’ve never run a chrono on them, but they shot true, and were very consistent. I’ve just been loading the lighter bullets for light plinking. I was just afraid that if I pushed them too hard, then accuracy would suffer.

[Larry Gibson]

Mr. Flintstone

In small cases such as the 32 H&R magnum pressure with a given powder is more about the seating depth (not to be confused with the OAL) when bullets of only 10 gr +/- are used. I have demonstrated that with numerous cartridges including the 32 H&R magnum by actually measuring the pressure.

Also, load data in manuals, including Lyman's, are held to pressures that were established when the 32 H&R was chambered in H&Rs alloy framed revolver. Steel framed revolvers [Rugers, S&Ws and Ubertis] can handle higher pressures. The newer made cases [original Federal cases were prone to crack/split with mild factory pressure loads] can also easily handle higher pressure. Whether or not your 77 gr bullet will give leas pressure than a specific Bullseye load for an 85 gr cast bullet is, as previously mentioned, dependent on the seating depth of each. However, if your using a modern steel framed revolver then there is a considerable safety margin with the data listed in the Lyman manual. Use the 85 gr load data but always start with the "start" load and work up to the "max" load as is always ]or at least should be] recommended.

[jrayborn]

I load for a lot of different cartridges that are somewhat obscure. Load data for heavy bullets has always worked well with lighter bullets for me.