Low pressure loads for 243?

[rifleman762]

I don't know why they would say that since as far back as the '60s Dupont declared that IMR 4895 could be safely reduced to 2/3rds of the maximum charge. I'd be willing to bet that like IMR 4350 and H 4350, or H414 and Win 760, or H-110 and Win 296, the only difference today between IMR and H 4895 is the label on the bottle. If there is a difference its very slight, as there can be in lot to lot variations of any powder, and certainly not in the same way that IMR 4831 differs from H-4831.

I didn't realize that about IMR 4895...I would assume that the old DuPont 4895 could have been a bit different than what's sold today? I wasn't around in the 60's ;-). Heck, my dad was a toddler in the 60's...

 

[Hitzy]

Isn't IMR made in Canada and H made in Auzzieland?
There are some identical Win and H powders rebranded, not sure there are any IMR and H in the same category.

 

[nitro-express]

I’m in need of education on this topic. I’ve been researching and have come across H4895 as being recommended for reduced loads, as much as 60% according to Hodgdon.

I don’t have H4895 on hand, but I do have IMR4895. I’m finding conflicting information on whether the IMR can be substituted for the Hodgdon. Have any of you done this and had good results?

My brother fooled with 4895 and reduced loads in the 243, IIRC an accurate load was a bit allusive. You are not concerned about accuracy, and if I read the addendum correctly, it asks for a lower velocity load than you'll get with 4895 (either one)

The author used 5 grains of Red Dot. Red Dot is a very flakey fast burning powder with a fair amount of Nitro Glycerine in it. It will still bang with enough pressure in a big combustion chamber. A reduced load of 4895 will probably give you too much velocity for the intended job.

WRT reduced loads, if you are not using a cast bullet, the only data I'd follow is the data that Speer has. For most calibers they list a reduced load, usually with one of their FMJ bullets to use on fur bearing animals and such. I did a quick look on the Speer site and for the 243 with a 90 gr bullet. ( I assume that because you did not list a bullet brand or weight that you haven't bought any bullets yet.) Speer suggests Accurate 5744 (reduced load) Winchester Federal 210 primer with 21.0 grains giving you 2105 fps and with 23.0 grains you get 2273.

BTW, 5744 is much like SR4759 and it works well for reduced velocity loads. Pressure is still high enough for everything to work as it should, but velocity is less than a normal load. Speer used to have a good write up on that, I assume they still have some verbiage on the subject.

I've done enough experimenting to know what I think is safe, at least safe enough that I'd pull the trigger. I would use the Speer load for shooting the impregnated bullet, and perhaps the Red Dot load for the JB lap process.

5 grains, perhaps. 8 gr will get you about 1600 fps. I would use a shooting method that would ensure that the powder was against the primer.

But, as they say, you are on your own. What I've written is for entertainment purposes.

Nitro

 

[john-brennan]

IMR 4198 is great for reduced loads I was using 20gr with a 95gr BT for my 10 year old and he had no problems with that. Then I went to 30gr of IMR 4895 with the same bullet once he got used to shooting a bit 2-300 rounds.

 

[Ganderite]

Click the link I posted in post #7 and scroll down to addendum. It’s a firelapping/handlapping process using 5 rounds at reduced pressure. The author used 5 grains of red dot in his 308 to lap his barrel, but the only pistol powder I have on hand is Titegroup which I don’t think is suitable for the task, which is why I’m hoping to use the IMR4895 I have on hand.

Did not see that.

I was involved in the original firelapping project.

Do not use 4895.

You want a faster powder and and lower velocity.

Titegroup is a bit fast. Find some Blue dot, red dot or Unique.