Confused about my 270 Win Reloads

[dak0ta]

Can you guys help me figure out my next step? All reloads are 3.405" COAL for my rifle, just off the lands.

May 1, 2019 I loaded FL sized brass IMR 4831 53.5gr, 54.0gr, and 54.5gr. I got 0.81" (53.5gr), 1.76" (54.0gr), and 2.73" (54.5gr) at 100 meters.


Ok, so I try my uncle's RCBS NS die with the two most accurate loads 53.5gr and 54.0gr and shoot groups on Aug 2, 2019. Accuracy opens up at 100 meters with both loads: 1.42" (53.5gr) and 2.71" (54.0gr). At 200 meters the 53.5gr opens up to 2-4".




I was confused and wanted to try NS with a Lee Collet Die to see if there was better performance, so I loaded up 53.5gr and shot at 100 and 200 meters today, Aug 23, 2019. Even worse accuracy, and it may be due to my unfamiliarity using the Lee Collet die. I also reloaded a batch of FL sized 53.5gr and it shot as great or better than the first loading in May.

Lee Collet Die 53.5gr 2.95" @ 100m

Lee Collet Die 53.5gr 3.72" @ 200m


Lee FL Size 53.5gr 0.79" @ 100m with 1 flyer.


So at this point I have two options. I can adjust the powder charge if NS. I've read that a fire-formed case may have increased velocity with the same weight of powder, and decreasing the powder charge may help improve accuracy. Should I try loading the NS brass at 53.0gr (1/2 a grain less) and see if the groups shrink back down to sub-MOA? At this point, I need a load for hunting season and I'm going to settle on FL sized 53.5gr and raise the elevation a bit to zero at 200m for whitetail/mule deer this Fall.

Any further suggestions?

 

[Stevenvalleyky]

If I'm not mistaken, neck sized brass should have more volume than full length sized brass. So, the same powder charge should result in lower velocity in the neck sized brass since more capacity with the same charge will result in lower pressure.

 

[dak0ta]

If I'm not mistaken, neck sized brass should have more volume than full length sized brass. So, the same powder charge should result in lower velocity in the neck sized brass since more capacity with the same charge will result in lower pressure.

However, since the brass is already formed to the chamber, none of the energy is required to expand the case like in the first firing, hence more of the energy is directed at pushing the bullet down the barrel resulting in higher velocity? Anybody can confirm this?

 

[Stevenvalleyky]

However, since the brass is already formed to the chamber, none of the energy is required to expand the case like in the first firing, hence more of the energy is directed at pushing the bullet down the barrel resulting in higher velocity? Anybody can confirm this?

The case will still expand to the dimensions of your chamber and then spring back a little. I'm not sure how much energy is actually used expanding a full-length sized case versus just a neck sized case.. thats an interesting angle I've never considered.
My gut tells me said the increase volume with an equal charge will still result in lower velocity using neck sized brass as I still think it don't be a bigger factor then they little bit of energy saved not expanding the case as much. Maybe someone will chime in with the finitive evidence one way or the other. Maybe it's a wash and powder charge being equal will result in equal velocities with both.

 

[edwardware]

It sounds like you're swapping equipment instead of working up a load. Pick a die set, bullet, and COAL, and load a 10% increments ladder. Shoot 5 shot groups, preferably on consecutive days, and then see what you know.

 

[murf]

that bullet may be too heavy for the 1-10 twist of the 270 cartridge. if you are shooting deer, try a 130 grain pill.

luck,

murf

 

[JFrank]

Can you guys help me figure out my next step? All reloads are 3.405" COAL for my rifle, just off the lands.

May 1, 2019 I loaded FL sized brass IMR 4831 53.5gr, 54.0gr, and 54.5gr. I got 0.81" (53.5gr), 1.76" (54.0gr), and 2.73" (54.5gr) at 100 meters.
View attachment 856552

Ok, so I try my uncle's RCBS NS die with the two most accurate loads 53.5gr and 54.0gr and shoot groups on Aug 2, 2019. Accuracy opens up at 100 meters with both loads: 1.42" (53.5gr) and 2.71" (54.0gr). At 200 meters the 53.5gr opens up to 2-4".
View attachment 856553

View attachment 856554

I was confused and wanted to try NS with a Lee Collet Die to see if there was better performance, so I loaded up 53.5gr and shot at 100 and 200 meters today, Aug 23, 2019. Even worse accuracy, and it may be due to my unfamiliarity using the Lee Collet die. I also reloaded a batch of FL sized 53.5gr and it shot as great or better than the first loading in May.

Lee Collet Die 53.5gr 2.95" @ 100m
View attachment 856555
Lee Collet Die 53.5gr 3.72" @ 200m
View attachment 856556

Lee FL Size 53.5gr 0.79" @ 100m with 1 flyer.
View attachment 856557

So at this point I have two options. I can adjust the powder charge if NS. I've read that a fire-formed case may have increased velocity with the same weight of powder, and decreasing the powder charge may help improve accuracy. Should I try loading the NS brass at 53.0gr (1/2 a grain less) and see if the groups shrink back down to sub-MOA? At this point, I need a load for hunting season and I'm going to settle on FL sized 53.5gr and raise the elevation a bit to zero at 200m for whitetail/mule deer this Fall.

Any further suggestions?

Where did you get these powder charges you are testing??
Did someone give you these recipes?

 

[rsnell]

The 49th edition of the Lyman reloading Handbook lists 53.0 - 57.0 grains of IMR 4831. The 10th edition of the Hornady Handbook lists 49.5 - 56.1 grains of IMR 4831. This is for a 130 grain bullet in a 270 Winchester. Headspace could also be a problem.

The maximum cartridge length in the Lyman manual is 3.250 inches for a Sierra SBT #1820 bullet and the Hornady manual is 3.210 inches for a Hornady SST bullet. Since bullet lengths vary even in one lot number, you may have to make this measurement yourself.

 

[shooter1niner]

Your next step should be to stop and take a breath... you must be tired !

You have given a lot of info but nothing on your shooting technique. Shooting from a rest, bags, elbows, etc. Rest, bags under stock or barrel, front and rear? It appears that the range is changing as well.

I like the cross target just the wrong color for me. I prefer 1" black cross and find it easy for me to nestle the junction of the crosshairs into a corner of the cross. I usually pick the lower left but it doesn't matter which you use. Is there a headspace problem? Will 3.405 fit the rifle magazine? Your ammo has to fit in the magazine for hunting right. Your load development should be based on what fits I would think. For my .30-06 I use IMR 4895, for my .280 Rem I like IMR 4350.

Again, is there a headspace issue? Has this rifle been shot enough to be considered shot out? Lots of questions. edwardware in post #5 brings up a good point, that being, introducing these variables isn't making this easier... What will the longest distance you shoot? The hottest load is rarely the most accurate. If you have exhausted the testing with these components then and only then switch to another bullet or powder. IMO... Good luck.

 

[JFrank]

Well then I suppose his rifle didn’t read those books.
I would certainly test those perimeters for myself by way of a powder charge ladder or ocw.

 

[Bfh_auto]

How well can you shoot your rifle with factory ammo?
You are running around Willy Nilly. Take a step back and get a process to follow.
If you're hunting, use a full length die and size it until the bolt can close without any drag.
Next find a seating depth. With a 270 keep at least .277 in the neck. Make sure it fits the magazine. Then worry about seating just off the lands.
Start at starting charge and work up by .3gr loading 3 if each. Shoot them using a front and rear bag.
There are quite a few 270s that won't shoot 150s very well.

 

[FLIGHT762]

Going to go in another direction here. Have you checked the torque settings on the stock screws? Could they have become loose? How about the scope ring caps? Are the screws tightened to spec? Could they have become loose? Have you cleaned out the copper fouling out of the barrel with a good copper solvent?

Why are you seating bullets way out to the lands with a COL that will not fit into the rifle's magazine in a hunting rifle?

I have a Remington 260 Rem. Mountain Rifle that shoots well with a number of loads.

There may be something else going on here?

I checked a friend's rifle the other day, the stock screws were loose. That can cause issues.

 

[kwg020]

I would start with a different powder. I seem to get my best accuracy in any caliber with a faster burning powder. I would check my barrel for copper build up and if there is none switch to a faster powder. Something like Varget and Winchester 748 or 760. Something on that line. You will not get the velocity of a slower powder but I prefer accuracy to blinding speed any day.

kwg