Speer Hot cor 270 Winchester

[Ctgrizzly2hunt]

After reviewing the Speer book for the Winchester 270 on the Hot cor 150 grain, they are listing the coal at 3.270" and that doesn't fit my gun. my coal is at 3.235" for the hot Cor. I'm using IRM 4064 for powder, starting load at 41.0 per book at 3.270 coal. Since my coal is less should I reduce the amount of powder?

 

[gamestalker]

Seat the bullets to the OAL that fits your firearm.

As to decreasing the powder charge, no, your already at the starting charge, going any lower could cause other risks. Bullets not making it out of the barrel, and low pressures can allow gases to blow by the shoulder.

BTW, is there some reason why you are going with 4064? There are a number of slower burning powders that would perform much better with that heavy 150 gr. Hot Core.

GS

 

[Tony k]

BTW, is there some reason why you are going with 4064? There are a number of slower burning powders that would perform much better with that heavy 150 gr. Hot Core.

My guess is that it's the only usable powder for this application he has, or it's the only powder he can get without going on a wild goose chase. In my area, rifle powders can be pretty scarce still. IMR4064 us usually available at my nearest walmart.

How do you think IMR7828 would do in this scenario? It's slow burning, but the problem is see is that a lot of the 7827 loads for 270 are compressed at the upper end of the spectrum. Combine that with the fact that the OP is already having to load short oal and you have some constraining factors. but still, that's what I'd try with this bullet.

Let us know how it goes, CTgrizzly2hunt.

 

[gamestalker]

IMR-7828 is an excellent powder for the .270 win. and would very likely shine with heavier bullets like the 150 gr.. By nature it fills the case well, this doesn't make it any more risky to work up than 4064, and very likely a lot easier to manage than 4064 would be.

GS

 

[Ctgrizzly2hunt]

Doesn't it increase the presssure with smaller coal length? 4064 was the only powder available at the time, I had Speer deep curl 150 grains and did get under 1" grouping with that powder. I'm not sure how is the 7828 better than 4064?

 

[sage5907]

41 grains of IMR 4064 with the Speer 150 grain HotCor is a minimum load for the 270 Winchester. With that load increasing the bullet seating depth to fit your rifle would make little difference in pressure. The 270 Winchester is a high intensity cartridge designed for much higher pressures and you can get higher velocities and stay withing the pressure limits by using powders like IMR 4831 and IMR 7828. Your load is developing a velocity of only 2450 fps and it is common to load powders like IMR 4831 and IMR 7828 to velocities around 2800 fps.

 

[Tony k]

I've only been reloading for a couple years, grizzly, so take anything I saw with about a pound of salt.

My understanding is that as a rule of thumb, use slower burning powders with heavier projectiles. I think slower powders produce better velocities with relatively heavy prjectiles, AND, slower powders often fill the case more, which tends to yield more shot-to-shot burn consistency (and tighter groups).

One inch groups at 100 yards is my goal with any work up, so if I were in your shoes, I'd be happy with the results you got.

On the other hand, my Speer manual #14 has a maximum claimed velocity with 150gr/4064 as 2635fps. Compare that to the max claimed velocity of 150gr/7828 at 2907fps. Not saying I expect to achieve those velocities, but it suggests that I should expect better velocity out of 7828 than 4064 with your bullet. I'd want to try 7828 and see If I could get as good of groups with it as you got with the 4064.

Accuracy is king, but accuracy with more velocity is usually better.

 

[sage5907]

Tony K, the reason for using slower burning powders in the 270 Winchester is that it is an over bore cartridge which means that the cartridge case is very large when compared to the bore diameter. Faster burning powders like IMR 4064 create pressures faster under that condition so the result is high pressure with low velocity. Slower burning powders like IMR 4831 will give the same pressures but increase the velocity by several hundred fps. The loads listed in the Speer manual do not exceed 52,000 cup as established by the SAAMI and that applies to IMR 4064, IMR 4831 and IMR 7828. I have shot hundreds of HotCor bullets and they preform really well at velocities from 2700 to 3000 fps.

 

[gamestalker]

I hope I didn't imply that 4064 is the wrong powder, that wasn't my intent. What I was trying to relate is that a slower burning powder is usually more appropriate / optimal, especially when using heavier bullets for a given cartridge. Pressures build slower, thus delivering more consistent accuracy and velocities, as well higher velocities. But if you can get acceptable velocities with 4064 that satisfy or other serve your purpose, go for it. But if you conclude that velocity doesn't seem suitable, I would then consider switching to a slower burning powder, rather than attempt to stretch the limits of 4064 with a 150 gr. bullet.

But more to the OP question, is that there is no need to decrease the charge to below published minimum because oal is shorter, and probably not great direction to go with this powder. Bottle neck cartridges aren't in the same league as handgun cartridges is this respect, so don't worry about pressures spiking higher with a shorter oal. There is far more to be concerned about when the bullet is seated up to, or into the lands, that's when pressures begin to spike with bottle necks, slow or fast burning powders alike.

GS

 

[Ctgrizzly2hunt]

Thank you for all the input, I'll start with the starting load per 4064, and work my way up. I'll pick a bottle of 7828 to try out if I can find one

Just want to say this site has been very helpful, i just start reloading this past year and done a lot of reading and gotten good information from this forum. I always use the load data from the books I have. I been reloading rifle and pistol.

 

[41 Mag]

Like these fine folks have pointed out, seat to the longest length your magazine will allow the bullets to function through.

Starting out at the "Starting" charge weight you will not see anything unusual. The length in the books is a good guide, but a "guide" non the less. Sometimes it works out, sometimes not. Just work up slow and look for accuracy.

One thing I have found is that some of the plastic tipped bullets, (not in your case but as something you might see later on,) have had a tendency in some of my rifles, to hang up in the tiny gap between the top of the mag well and the bottom of the chamber, when feeding them fast.

I hunt feral hogs, and I always make sure that the rounds will feed through a full magazine, as it is a real bummer to have the second or third one jam up like that, right when your on a bunch of hogs. I will make up 5 dummy rounds seated to the length I want to start out with and run them through several times as fast as I can. If I have no hiccups I load away. If I hit a snag though I will seat them in a bit deeper, usually about .010 - .020" and try again. This however is with the plastic tipped one. I have yet to have a lead tipped one do this.