270 Load Data

M

Mopp

New member
EE Expired
Rating - 100%
11   0   0
Location
Kamloops BC
Loading 270 with 130 and 150 grain SP and using 4831SC with good results. I have found several recipes for 4831 Alliant ... Can anyone advise, based on their own experiences, if this the same powder as 4831 SC ? There are several conflicting views published on this question .....

Gentlemen: Thanks you all for your cogent comments and ideas. I am going to adopt a simplistic approach and stick with 4831 for the next year or so and see what develops !
 
Last edited:
Alliant doesn't manufacture a powder labelled 4831... do you mean IMR? Not the same powder, IMR 4831 is slightly faster than H4831. For what it's worth I stuck with Hodgdon when I had my .270. Not worth the trouble of switching powders unless for some reason you can't find H 4831.
 
Yeah, 4831 is either H or IMR. Alliant rifle powders are all Re then a one or two digit number. 4831 doesn't even fit their naming convention.

H4831 and H4831SC use the same load data.

I prefer IMR 4831, you can get a bit more performance out of it compared to H. I'm getting 3050 fps with 140 TGKs and I'm still a few grains below the highest charge I worked up to with no pressure signs. Accuracy is one ragged hole at 100, with an ES of 12 fps and SD of 5 over five rounds.

Not sure I could stuff enough H4831 in the case to get there even though I can seat fairly long.

Also... do you want to take someone's personal opinion on whether two powders are the same or not? I sure wouldn't. Lots of dumb people say lots of dumb things on the internet. I would verify everything in load data and on the manufacturer's site.
 
Last edited:
After conducting much research for load development for the 270 Win., I've found that H-4831, IMR-4350, IMR-4831 and Reloder-22 are the most common powders utilized. I've started load development for the 270 using these powders with the 130 gr. accubonds. Phase one starts this Sunday at the rifle range..
 
H4831Sc is the best for win 270. I load Nosler 130, 140, 150 and 160 grains with it. All under 1 moa with my Sako A7.
 
Anyone tried IMR 4451? I'm debating giving it a go but I'm not sure if I'll get anything better out if it than 4831. Does the copper fouling reducer make any real difference?

I dunno what I'm looking for by way of improvement - I'm getting top accuracy and velocity with 4831, but I'm tempted to try 4451?
 
flashman2 said:
Anyone tried IMR 4451? I'm debating giving it a go but I'm not sure if I'll get anything better out if it than 4831. Does the copper fouling reducer make any real difference?

I dunno what I'm looking for by way of improvement - I'm getting top accuracy and velocity with 4831, but I'm tempted to try 4451?
Click to expand...

In my humble opinion IMR 7977 produces better results than IMR 4451 with a 270 Winchester shooting 140 Nosler AccuBonds and 150 Nosler Partition bullets. I use a Beta Chrony and I am shooting a Weatherby Vanguard Series 2 rifle with a 24" barrel. As an example, with the 150 NPT i am getting a consistent 2950 fps without any pressure signs at 62.0 grains in my rifle. This combination shoot just under a MOA at 100 yards. I haven't finalized that load yet and my shooting technique perhaps could be also further improved.
 
Carbon12 said:
In my humble opinion IMR 7977 produces better results than IMR 4451 with a 270 Winchester shooting 140 Nosler AccuBonds and 150 Nosler Partition bullets. I use a Beta Chrony and I am shooting a Weatherby Vanguard Series 2 rifle with a 24" barrel. As an example, with the 150 NPT i am getting a consistent 2950 fps without any pressure signs at 62.0 grains in my rifle. This combination shoot just under a MOA at 100 yards. I haven't finalized that load yet and my shooting technique perhaps could be also further improved.
Click to expand...

Thanks for that. Did you try 4451 or 4955 as well?

62.0 for 2950 with a 150 grainer is a bit under book performance. Not surprising, as my S2 has a loooooooong throat and to get 20 thou off the lands I'm .100 to .150 over SAAMI max OAL. I've been able to load up well well over max for IMR 4831 without a hint of pressure signs, but I backed it off to a bit over max where the best accuracy and lowest SD was.

7977 is definitely on the slow extreme for a .270 - what made you go with that over 4951? I've found my S2 to be very long throated and it definitely prefers a slightly faster powder. 7977 is obviously workable, but IMR recommends it as a magnum powder, while recommending 4451 and 4955 for the .270.
 
flashman2 said:
Thanks for that. Did you try 4451 or 4955 as well?

62.0 for 2950 with a 150 grainer is a bit under book performance. Not surprising, as my S2 has a loooooooong throat and to get 20 thou off the lands I'm .100 to .150 over SAAMI max OAL. I've been able to load up well well over max for IMR 4831 without a hint of pressure signs, but I backed it off to a bit over max where the best accuracy and lowest SD was.

7977 is definitely on the slow extreme for a .270 - what made you go with that over 4951? I've found my S2 to be very long throated and it definitely prefers a slightly faster powder. 7977 is obviously workable, but IMR recommends it as a magnum powder, while recommending 4451 and 4955 for the .270.
Click to expand...

Thank you flashman2 for your informative reply. I also have a Weatherby Vanguard S2 in 270 Win with a long jump gap, as per Weatherby's rifling throat design approach. I choose IMR 7977 deliberately over IMR 4451 and IMR 4955 because of the slower burn rate. I got curious when I saw it was recommended as the top powder for the 25-06 so I researched why. Basically because of its load density it fills the case up to 100 to 101 % of its free volume with the bullet seated long, which is a lightly compressed load. At the Hodgdon reloading site the max load, which is compressed with the bullet seated short, is only 53,000 PSI at 60.8 grains (produces 2940 fps). SAMMI max pressure for the 270 Win is 65,000 PSI. This is very generously under. I have experimented with a powder drop tube and I can fit an uncompressed 62.0 grains in (99% to 100% case fill) and get to the 2940 fps. I use Redding graphite powder to lubricate the shank of the bullet before I press it in so that if further reduce clean brass neck on bullet gilding friction to produce a very consistent neck friction/tension. I suspect even with 62.0 grains, seating it long, and graphite bullet lubrication, I am still well under the SAAMI max pressure. I get absolutely no high pressure signs on either the case or the primer. If I wanted to compress my load a little bit, say 101 to 102% of case volume, I could add 1.0 grains in and most likely get 2975 fps or 3000 fps which out pressure signs and still be under SAAMI max pressure significantly. I am testing a charge ladder in this load from 62.0 to 63.0 in .2 grain increments to find out where the high pressure signs start. If I reach 2975 fps 3000 fps before reaching it I will stop anyway because I want to stay at a lightly compressed load (101 - 102%). I would dearly love a 150 grain Nosler partition load for deer that has a muzzle velocity of 3000 fps out of my rifle. I use Nosler brass and Winchester LR primers. The way Hornady explains how this works with slow burning powders is that there is less of a pressure spike but more of an even step of pressure over a longer time period to produce a greater impulse to the bullet (Force X time = impulse) which allows for a higher velocity without an increase in max pressure. Obviously a rifle with a long jump gap and a 24" barrel helps pull this off (which the WVS2's have). This is the principle of how rockets work ... a rifle bullet is subject to the exactly the same physics. It just doesn't carry its propellant and its impulse cure is much shorter than a rocket's. Hornady's Superformance product line is build on this physics principle. So that is why, in my humble opinion, I think IMR 7977 works better for a 270 Win in a 24" barrel with bullets seated long. This approach using IMR 7977 achieves the highest velocities for heavy for caliber bullets for the 270 Win, such as the 150 grain Nosler PT's. For lighter bullets, such as the 130 grain, IMR 4451 and IMR 4955 are better choices because they will produce higher velocities.
 
Interesting. Maybe they changed the description after they introduced 4955 (if my memory serves, it was brought out after 4451 and 7977) but IMR lists 4451 and 4955 for .270 Win now and 7977 as a magnum propellant, which makes sense given where 7977 is in the burn range.

Hodgdon also lists the pressure for the 150 gr / 60.8 of 7977 as 61,300 PSI, not 53,000. 53k isn't much over start load pressure. It can't be 53k CUP either, because that's over the SAAMI MAP. Anyway, it's still well under max. I don't think there's any way you could physically stuff enough 7977 in the case to go over pressure. I find the Hodgdon data can be well on the conservative side too compared to other load data like Sierra.

Regardless, the load is working for you - 2950 with a 150 grain bullet is great performance. Nothing much to improve upon there. The only question it raises for me it that it's taking more powder than it should to hit the "book" velocity. Expected of course, since you're seated well over SAAMI COAL which will drop your pressure. But... I would hope for that extra powder to net some advantage in velocity.

I would have thought 7977 would be too slow, but I guess now I'm gonna have to order a pound of it and a pound of 4955 and experiment. Always good to get first hand experience and not just rely on the manufacturer's description and make a guess off the burn rate charts.

Anyway, my real purpose in asking about the Enduron powders is if you've noticed any reduction in copper fouling as advertised? I can get about 50 rounds before groups start opening up, and if I could stretch that it would be nice. I'm taking the rifle to NZ next year for a few months of hunting and if I can eliminate having to clean the bore out in the bush that would be great. Not having to use up my precious airline ammo allocation on fouling rounds would stretch what limited amount of ammo I can take 10% farther.

Honestly, I should probably leave well enough alone - I'm getting top accuracy and velocity with single digit SDs with IMR 4831 as it is, but... perfection is the enemy of good enough.
 
flashman2 said:
Interesting. Maybe they changed the description after they introduced 4955 (if my memory serves, it was brought out after 4451 and 7977) but IMR lists 4451 and 4955 for .270 Win now and 7977 as a magnum propellant, which makes sense given where 7977 is in the burn range.

Hodgdon also lists the pressure for the 150 gr / 60.8 of 7977 as 61,300 PSI, not 53,000. 53k isn't much over start load pressure. It can't be 53k CUP either, because that's over the SAAMI MAP. Anyway, it's still well under max. I don't think there's any way you could physically stuff enough 7977 in the case to go over pressure. I find the Hodgdon data can be well on the conservative side too compared to other load data like Sierra.

Regardless, the load is working for you - 2950 with a 150 grain bullet is great performance. Nothing much to improve upon there. The only question it raises for me it that it's taking more powder than it should to hit the "book" velocity. Expected of course, since you're seated well over SAAMI COAL which will drop your pressure. But... I would hope for that extra powder to net some advantage in velocity.

I would have thought 7977 would be too slow, but I guess now I'm gonna have to order a pound of it and a pound of 4955 and experiment. Always good to get first hand experience and not just rely on the manufacturer's description and make a guess off the burn rate charts.

Anyway, my real purpose in asking about the Enduron powders is if you've noticed any reduction in copper fouling as advertised? I can get about 50 rounds before groups start opening up, and if I could stretch that it would be nice. I'm taking the rifle to NZ next year for a few months of hunting and if I can eliminate having to clean the bore out in the bush that would be great. Not having to use up my precious airline ammo allocation on fouling rounds would stretch what limited amount of ammo I can take 10% farther.

Honestly, I should probably leave well enough alone - I'm getting top accuracy and velocity with single digit SDs with IMR 4831 as it is, but... perfection is the enemy of good enough.
Click to expand...

Thank you flashman2 for your reply. I apologize for the error of quoting the 53,000 PSI maximum pressure for that 270 Win load, I meant the 61,300 PSI value. The 53,300 PSI is related to the 30-06 maximum pressure of the Superformance load for 150 grain that I am working on (again substantially under the 60,000 PSI maximum for that cartridge as well on the Hodgdon reloading site). I whole heatedly agree with you about the Hodgdon reloading site maximum load values being conservative. It is a trend I have noticed accross the 270 Win and 30-06 Springfield cartridges. And indeed, you really cannot practically stuff more than 62.0 to 63.0 of powder in the 270 Win case even with a flat bottomed bullet seated long and using a 12" powder drop funnel to pack it.


A hunting trip to New Zealand for a few months! Nice! Wow I envy you! Well that is an interesting question that you pose with copper fouling. I have not done significant testing of exclusively IMR 7977 through the 270 Winchester yet since I also have been using Hornady Superformance ammunition as well. However, after shooting a block of 40 rounds of IMR 7977 reloads I have not noticed any, or it may be very slight, copper fouling at the muzzle, where copper fouling usually shows up the worst. Carbon deposites ... yes ... but everytime I complete my shooting for the day or for the shooting session I run a bore snake through the barrel 3 to 5 times to get rid of as much loose carbon as possible. I still do not notice any copper fouling or have my groups affected. Granted as the shooting day progresses everything from the barrel, ammunition, and the action warms up and this probably opens up the shooting groups more than just copper fouling and I haven't done enough cold barrel testing to make a judgement on the effects of just copper fouling alone. My best groups are usually from a cold barrel like most shooters. So I will keep your question in mind when I conduct my summer reload testing. When I dial in my 270 Win hand load I will conduct more accurate shot group testing. I suspect a lot of other shooting variables (rifle rest, temperature, shooting style, etc.) would need to be addressed before one can isolate the effect of just copper fouling. I think the best "test" for copper fouling is to monitor its presence (or absense) from the muzzle while shooting reloads exclusively with IMR Enduron powders. In my opinion the reduction of copper fouling is quite noticeable from the IMR Enduron series of powders when I compare it to the Hodgdon's Superformance powder which does not have that technology but is a great powder for metering and pressure uniformity.
 
You must log in or register to reply here.
Back
Top Bottom