Enduron 4166 .308 vs. 6.5 Creed

[endlesscoffee]

Hey all.
So this is my first year reloading and I've been doing ok given the circumstances. I've been reloading for my 6.5 this season while my .308 was at the shop. Got my .308 back and would like to start some development.
So looking at the charts I understand enduron 4166 has a faster burn rate than H4350 which I was using for my 6.5. I've got a good amount of 4166. For the 4166 should I use it for my .308 or my 6.5. I know lowlight had a thread on it for the 6.5, but haven't seen much else. I've got a lot of 168smk I will be using to burn through this winter for practice. Then I'll pick up something heavier after that. For my 6.5 I've been using some 140 HPBT hornadys I got on sale. Factory seconds, but they do ok.
.308 22" 1:10 RHT
6.5 24" 1:8 RHT
Thanks for the help

 

[Steel head]

It will work but you’ll probably find pressure before full speed.
The hodgdon website has data for it.

 

[PinesAndProjectiles]

4166 is similar to Varget, so if you’re running lighter weight bullets in the 6.5, it should work. 140s are most likely too heavy.

 

[endlesscoffee]

4166 is similar to Varget, so if you’re running lighter weight bullets in the 6.5, it should work. 140s are most likely too heavy.

I picked it up for that reason. So it sounds like use it for the .308.
Does running a heavier round cause stability issues or is it pressure with the heavier 6.5? Thanks for the help.

 

[PinesAndProjectiles]

Using a faster powder with heavier bullets causes pressure.
I can’t answer why, but I expect it to have something to do with the initial movement of the bullet.
I believe it to be because The faster powders expend energy much faster than the bullet can move, thus causing pressure.
But, I’ve been wrong before

 

[supercorndogs]

I don't think I have tried it in my 308. I tried it in my 6.5 Grendel, but it was kind of bulky. I have been using it in my 22-250, and I like it for that. I am sure it would work fine for 123 and lighter bullets in my 6.5 Creed. When I worked up a load for 123s I used RL15, but mostly just because there was jug already open.

 

[Doom]

Haven’t used it but 4166 is essentially a newer double base formulation to meet newer environmental regulations with a burn rate about the same as 4064 in the 308.

Might be OK in 6.5C with lighter bullets.

 

[918v]

I used 4166 in 308 with 175s and it was too fast burning my liking. It’s gonna be a fail in the 6.5

 

[Shoots 700's]

Works well in the dasher

 

[endlesscoffee]

I used 4166 in 308 with 175s and it was too fast burning my liking. It’s gonna be a fail in the 6.5

Could you explain the symptoms of too fast burning? Thanks for the info!

 

[supercorndogs]

I would assume he means getting too much pressure before getting to the velocity you want.

 

[918v]

I would assume he means getting too much pressure before getting to the velocity you want.

Yes. Varget, 4064, AR Comp are way better.

 

[endlesscoffee]

Yes. Varget, 4064, AR Comp are way better.

Yeah. And unfortunately probably not going to be available for some time.

 

[Steel head]

Yeah. And unfortunately probably not going to be available for some time.

Just run the 4166, it’s not perfect but I’d be surprised if you can’t get it be plenty accurate.
You’ll probably be about 100-150 fps slower at safe pressure levels than the slower powders but then there is established and tested data for it.
For the 308 you’ll be in normal territory with it.

 

[endlesscoffee]

Ya this is my plan. I think I'll use it for the bunches of 168s I have for practice through the winter. Hopefully I'll get some more powder before next season. If anything like you said, I'll have data for it. Now if I can get this scale to be consistent....

 

[Oldloser]

I use 4166 in 308 with 175 SMKs with a savage factory 24 inch barrel. Best load is 42.2 grains @2645 FPS. Brass is LC LR. It does well with 168s - I observed two shooters using with 168s it recently and they did well.

 

[bluejay75]

I use 4166 in 308 with 175 SMKs with a savage factory 24 inch barrel. Best load is 42.2 grains @2645 FPS. Brass is LC LR. It does well with 168s - I observed two shooters using with 168s it recently and they did well.

How accurate and repeatable is your load?

 

[Baddog 0302]

Might want to book mark this site
Hodgdon reloading Data

 

[spife7980]

Using a faster powder with heavier bullets causes pressure.
I can’t answer why, but I expect it to have something to do with the initial movement of the bullet.
I believe it to be because The faster powders expend energy much faster than the bullet can move, thus causing pressure.
But, I’ve been wrong before

Could you explain the symptoms of too fast burning? Thanks for the info!

As a bullet moves down the bore there is the a space/volume from case capacity and then space in the bore behind the bullet as it moves down the barrel when fired.

As powder burns it creates gas at a certain rate to fill a space.

For the best performance you want a powder that’s pushing the bullet down the barrel and converting to gas to fill that volume behind the bullet as it’s created in a manner thats proportional to the force it takes to move the bullet and fill that space created behind it correctly for optimum velocity.

If a powder is too fast for a bullet weight you are making gas and getting to pressure levels before the bullet has moved to place to accommodate that volume of gas which means you can only load so hot and thus so fast before the case starts to give out on you. A light bullet is easier to move (newtons laws of momentum)and thus moves more easily/quickly down the barrel and makes volume more quickly which is why lighter for caliber bullets need faster burn rate powders.

If a powder is too slow burning it’s making all of its gas too slowly and the pressure behind the bullet is low and thus velocity is low. Heavy for caliber bullets accelerate more slowly down the barrel and so slower powders match up to that better.

 

[Oldloser]

How accurate and repeatable is your load?

I’m not sure I can give you an answer. My 308 is a POS savage. It’s POI changes every few dozen rounds. I also use a 20 dollar scale to weigh powder. My ES is about 60 and SD is about 12. But once I figure what ithe savage wants to do that day, I can hit 8 inch targets at 800 yards all day long.

The guy I know who shoots 168s, and has a great rifle, can hit 4 inch targets regularly at 800 yards. He love

So it seems to be pretty consistent.

My new rifles are 6 dasher and 6.5x47L and I’m testing loads for both tomorrow using it.

I think you can google IMR 4166 and your caliber and find lots of info.

 

[endlesscoffee]

As a bullet moves down the bore there is the a space/volume from case capacity and then space in the bore behind the bullet as it moves down the barrel when fired.

As powder burns it creates gas at a certain rate to fill a space.

For the best performance you want a powder that’s pushing the bullet down the barrel and converting to gas to fill that volume behind the bullet as it’s created in a manner thats proportional to the force it takes to move the bullet and fill that space created behind it correctly for optimum velocity.

If a powder is too fast for a bullet weight you are making gas and getting to pressure levels before the bullet has moved to place to accommodate that volume of gas which means you can only load so hot and thus so fast before the case starts to give out on you. A light bullet is easier to move (newtons laws of momentum)and thus moves more easily/quickly down the barrel and makes volume more quickly which is why lighter for caliber bullets need faster burn rate powders.

If a powder is too slow burning it’s making all of its gas too slowly and the pressure behind the bullet is low and thus velocity is low. Heavy for caliber bullets accelerate more slowly down the barrel and so slower powders match up to that better.

Thank you for this explanation. I had read it's a varget substitute, but understood it had a different burn rate. The max on hodgden is listed at 43.5 for 4166 and 46 for Varget which seems like a pretty big difference. I had to put the load development on hold yesterday as my scale was all over. I'll try again on Monday.

 

[bluejay75]

I’m not sure I can give you an answer. My 308 is a POS savage. It’s POI changes every few dozen rounds. I also use a 20 dollar scale to weigh powder. My ES is about 60 and SD is about 12. But once I figure what ithe savage wants to do that day, I can hit 8 inch targets at 800 yards all day long.

The guy I know who shoots 168s, and has a great rifle, can hit 4 inch targets regularly at 800 yards. He love

So it seems to be pretty consistent.

My new rifles are 6 dasher and 6.5x47L and I’m testing loads for both tomorrow using it.

I think you can google IMR 4166 and your caliber and find lots of info.

The one thing that made my Savages more consistent was to either put them into Accustocks or HS Precision Stocks. Tightening the headspace shrank groups as well. Thanks for the tips.