H4831 Starting load for .270 improved (Edited to correct powder)

[TheSilverSlayer]

Just wanted everyone's opinion on my planned starting load for my .270 Improved.  The rifle is a 1948 FN Mauser, with a 26" barrel.  I am using once fired remington cases that were factory core-locks fired in my improved chamber.  I am planning on starting with 56 grains of H4831, and I am using the CCI L.R. Military primers.  I think they are #43 or #34 or something like that, CCI's website says they are to be considered LR magnum primers.  Anyway, I will top it all of with a 130gr Hornandy Interlock. 

Specifically, I was wondering if the magnum primer will raise pressures too high for a starting load?

[stimpylu32]

TSS

I don't see the pressures rising that much with the mag primers for a couple reasons , one being you have increased the case capisity by going with the improved and 2nd , H4831 is a very slow burning powder which in many cases requires a mag primer .

Lastly the 56g load is the starter load for the standard 270 , which you were shooting to fireform your cases .

stimpy

[victorcharlie]

You might go with a bit slower burning powder, as my .270 really shoots well with Reloader-22.

[Siskiyou]

I purchased some 130-grain Barnes TTSX bullets to load for the .270.  After getting home and opening the box I think the 110-grain bullet in for 270 Winchester may have been the better choice.  The 130-grain TTSX is very long bullet and should fully penetrate deer from one end to the other.  I took a picture to provide a comparison of five different bullets.  From left to right, 150-grain Sierra Boattail, 130-grain Barnes TTSX Boattail, 140-grain WW Silvertip Boattail, 140-grain Hornady Boattail, and the 130-grain Hornady SP. 


I have created a number of increments of test loads using IMR4350 powder and the Barnes TTSX for future testing.

A brother and I have discussed his 270 Ackley Improved a number of times.  He says in “theory” you gain about 5% powder capacity with the Ackley version.  For the purpose of this discussion let’s say that 58-grains of H4831 are maximum in the .270 Winchester cartridge loaded with a 150-grain bullet. (I have just jumped into the area of old manual versus current data and the difference between Manual A and Manual B.)  (I have manuals showing 56.0, 57.0, and 58.0 as being maximum with the 150-grain bullet in the .270 Winchester.)  I load for three different .270 Winchester rifles.  I settled on 56.5 grains of H4831 for 150-grain bullet of 30-years ago.  The exception being 56.0 grains for the 150-grain Sierra BT. 

Brother says that he is currently loading 150-grain bullets with the .270 Winchester maximum for WMR.  I do not know whose maximum he is using.  Before the reloading components crisis he purchased a bunch of 140-grain bonded Remington bullets to try in his .270 A.I.

I am well vested in H4831 and think it is one of the better powders for the 270 Winchester starting with the 4350 series.    But Victor Charlie has hooked me on the idea of trying some RL-22.  The reason is that it falls next to my old favorite WW785 on some burn rate charts.  I realize that one cannot be substituted for the other, but it looks like I should do a little R&R with it.

I think you are wise to start at 56-grains of H4831.  I normally start at my low point with three rounds, and increase in one grain increments until I am a grain or two from my goal.  I then drop to .5 grain increases.  I drop back when I start experiencing signs of excess pressure.  A second trip to the range might be warranted for fine tuning the load to the nearest tenth. 

 P.S.  The standard bullets shown have successfully taken deer, is Barnes solid copper bullet needed, I think not unless required by law, or the hunter prefers to use it.  After trying it I might prefer it.

The 130-grain Hornady Spire Point is a good bullet.  I have killed a number of deer with it using H4831 and WW785.  As I recall this recovered bullet 130-Hornady weight 84-grains.  The deer was at about 145-yards (+or-) and ran a few yards before dropping.  I heard a loud thump on impact.