Need new powder for 1:7 twist 243

[Recko555]

Hello,
I have a 243 with a 1:7 twist Brux barrel shooting 110 smks. I am using 45.0 grains of H1000 and getting 2913 fps (magneto speed). If I go higher in charge weight with H1000, I start getting heavy bolt lift.
So I am wondering if H4350 or N160 would be a better powder choice to get more speed? If so, which one would be better?

 

[#40Fan]

Reloder 26.

https://www.longrangehunting.com/threads/reloder-26.172482/

 

[urbanrifleman]

N160 smoked H1000 for speed in my rifles. Not even close.

 

[1lnbrdg]

6MM SLR here and I'm running Brux barrel also but shoot either N-165 or H-1000 46.5 to 47.5 without any issues whatsoever. I've not yet had any pressure issues with either powder at those levels. I know, different barrels / different results .....

H-4350, if you get 1,000 accurate rounds out, you are living on borrowed time past that as far as barrel life.

N-165 and H-1000 are cooler burning so give longer barrel life. N-160 is reputed to be cooler burning also but my 1 foray with it left me scratching my head.

I have a 1lb container of H-100V that is reputed to be cooler burning than the H-4350 but have yet to try it. It should be somewhere in the N-160 speed range but as I said, I still haven't tried it yet. Someone told me that case volume with it could be an issue.

 

[SteveOak]

H1000 has an energy content of HodgdonH1000 3630 kJ/kg

VihtaVouri N560, N565 and N570 all have an energy content of 4000 kJ/kg or about 10% more so you will get more velocity from them and N565 should be very close in burn rate.

I do not know their comparative bulk densities.

 

[Shawnba67]

I ran a 30" Xcaliber 6 groove 7 twist 243 sammi throat. I did not find but about 10fps difference between the 110s and 105s.
RL26 gave me 3300fps as a working load shot a couple matchs with it but it wasn't stable enough to suit me(this could have been bullet failure as I since retired the barrel for wonkyness that can only be suitably explained by bullet failures, if i had to guess if guess core melting)
H4381Sc for 3260fps (105s)
I ran a load of h4350 (40gr I think). Never chronoed it but it shot very well. Was less than 7 mil come up to 1k
I could not break 3000 with book data and H1000. It shot well single digit ES

 

[Capt. Oblivious]

Try some N165 or N160

 

[1lnbrdg]

6MM SLR here and I'm running Brux barrel also but shoot either N-165 or H-1000 46.5 to 47.5 without any issues whatsoever. I've not yet had any pressure issues with either powder at those levels. I know, different barrels / different results .....

H-4350, if you get 1,000 accurate rounds out, you are living on borrowed time past that as far as barrel life.

N-165 and H-1000 are cooler burning so give longer barrel life. N-160 is reputed to be cooler burning also but my 1 foray with it left me scratching my head.

I have a 1lb container of H-100V that is reputed to be cooler burning than the H-4350 but have yet to try it. It should be somewhere in the N-160 speed range but as I said, I still haven't tried it yet. Someone told me that case volume with it could be an issue.

I'm on my 3rd barrel shooting the same 500 pieces of brass, haven't lost a primer pocket yet on any of it and it's mostly all with N-165 or H-1000 except for ~600 rounds fired with N-160.

From the looks of my primers, with the H-1000 and N-165, I don't think you can get enough powder in the case with either of these 2 powders to over-pressure.

 

[Dgd6mm]

I run almost 50 grains of H1000 in my 1-8 twist 28" .243 barrel Hornaday 105 Match bthp. Started life at 3153 fps. After 1100 rounds 3110 fps. No heavy bolt lift or pressure issues. I will be going to another powder in another 100-200 rounds to bring speed back up for the remainder of the barrel life. This is my PRS rifle.

 

[Recko555]

I don't have any primer issues, just bolt lift. All my testing so far is on new Lapua brass.
I am going to give N160 a try and some 105 hybrids (when they become available again).

 

[hunter243sgk]

That h-100v is a good powder for the 243.

 

[SteveOak]

Try some N165 or N160

Vihtavuori N160 has an energy content of 3650 kJ/kg
Hodgdon H1000 has an energy content of 3630 kJ/kg
Vihtavuori N165 has an energy content 3600 kJ/kg


Nice powders but they have the same energy content as H1000 so there will be little or no difference unless there is a significant difference in bulk density.

 

[urbanrifleman]

Vihtavuori N160 has an energy content of 3650 kJ/kg
Hodgdon H1000 has an energy content of 3630 kJ/kg
Vihtavuori N165 has an energy content 3600 kJ/kg


Nice powders but they have the same energy content as H1000 so there will be little or no difference unless there is a significant difference in bulk density.

In terms of barrel life, true, but as far my findings that is where the similarities end.

 

[JBT47]

Viht powders are much cleaner burning compared to H1000 if that matters to you.

 

[Yote Hunter]

Reloader 23 or 26

 

[Recko555]

Reloader 23 or 26

I do string firing and need them to be stable for the entire string. I have heard that could be a problem with those powders.

 

[Recko555]

Viht powders are much cleaner burning compared to H1000 if that matters to you.

The worst part of shooting for me is cleaning barrels. So if they clean easier or quicker, I am up for that!

 

[Yote Hunter]

I don’t know about string firing but have read that Reloader 23 is one of the most temperature insensitive powders there is. I love it in my 22-250 Ackley With heavy bullets and 284 shehane

 

[SteveOak]

Vihtavuori N160 has an energy content of 3650 kJ/kg
Hodgdon H1000 has an energy content of 3630 kJ/kg
Vihtavuori N165 has an energy content 3600 kJ/kg


Nice powders but they have the same energy content as H1000 so there will be little or no difference unless there is a significant difference in bulk density.

In terms of barrel life, true, but as far my findings that is where the similarities end.

I know it is unusual but my post was in the context of responding to the question asked in the OP. How to get more speed.

 

[Zero333]

I find it odd that 45 gr of H-1000 is the max in your barrel with 110 smk.

You should be able to start at 45 gr.

How much freebore does the chamber have ???

What COAL are you loading the cartridges ???

What brass are you using ???