270-300 Win Mag now feasible

[Big Jake Duke]

This may be interesting reading for you.

Optimal Barrel Time Paper

So more powder, right?

 

[Longtooth32]

Ill do a ladder around this and see if there are any improvements to be found.

Something i found interesting is that the seating depth was the same as the us869 load that was a 3-4 inch disaster. So is it seating depth or the right powder vibration?

In this case it looks like i stumbled upon the correct combo.

I am stuck at a mag length of 3.36"...so my issue is a powder issue...I was "shotgunning" my groups with the heavy Bergers until I got to the 75-76 grs of Retumbo. I actually got good groups at 77grs of Retumbo @ about 3250fps+...but it was on the hot side...

 

[270DT]

Went back to the range today with chronograph in hand and this is what I left with. These are MAX loads for my rifle and my setup so follow at your own risk.

270-300WM

130 grain Swift Scirocco

MAX load IMR7828 ( 75 grains - 3,505 fps )

at 75.5 grains had first signs of pressure, sticky bolt lift- stopped at that point.

140 grain Nosler Accubond

Max load IMR7977 ( 75 grains - 3,301 fps )

Also at 75.5 grains had first signs of pressure, sticky bolt lift - stopped

Kind of weird to me the pressure showed at the same powder weight, but it did.

Just remember there are old reloaders and bold reloaders but no old bold reloaders!

 

[Big Jake Duke]

Went back to the range today with chronograph in hand and this is what I left with. These are MAX loads for my rifle and my setup so follow at your own risk.

270-300WM

130 grain Swift Scirocco

MAX load IMR7828 ( 75 grains - 3,505 fps )

at 75.5 grains had first signs of pressure, sticky bolt lift- stopped at that point.

140 grain Nosler Accubond

Max load IMR7977 ( 75 grains - 3,301 fps )

Also at 75.5 grains had first signs of pressure, sticky bolt lift - stopped

Kind of weird to me the pressure showed at the same powder weight, but it did.

Just remember there are old reloaders and bold reloaders but no old bold reloaders!

Try a little faster powders than 7977. With the 130-140 class you can get great performance with powders as fast as imr4350. I havent shot 130s, but i send the 140s out over 3400fps accurately. How was accuracy?

 

[270DT]

Yeah I wanted to give the 7977 a try but it's a little slow, maybe better with the 150s. I had the magnetospeed stuck on the barrel so wasn't really shooting for accuracy was more interested in speeds and pressure signs. That being said at 100 yards with the magnetospeed attached and variance in powder weights all my shots probably stayed within 1.5"-2". Surprised me it stayed that tight with the magnetospeed attached. So far I am really impressed with the round and the Pac-Nor barrel. Believe it is going to be a shooter and better than my capabilities.

Will give IMR 4350 a try next time out with the 140s. I also broke down and ordered Quickload so will share that data with you guys soon.

Right now still trying to figure out what powders and weights work, once I get those down then I will settle down and shoot for accuracy.

 

[Longtooth32]

Yeah I wanted to give the 7977 a try but it's a little slow, maybe better with the 150s. I had the magnetospeed stuck on the barrel so wasn't really shooting for accuracy was more interested in speeds and pressure signs. That being said at 100 yards with the magnetospeed attached and variance in powder weights all my shots probably stayed within 1.5"-2". Surprised me it stayed that tight with the magnetospeed attached. So far I am really impressed with the round and the Pac-Nor barrel. Believe it is going to be a shooter and better than my capabilities.

Will give IMR 4350 a try next time out with the 140s. I also broke down and ordered Quickload so will share that data with you guys soon.

Right now still trying to figure out what powders and weights work, once I get those down then I will settle down and shoot for accuracy.

I finally got out and shot some of the lighter weights in my 270 Wby.

With 79 grs of H1000, pushing a 130gr SST, with an ave speed of 3590fps on the left…

With 78 grs of H1000, pushing a 140 SST, with an average speed of 3567fps on the right.

I only loaded up three rounds instead of my usual five rounds…

I actually had a round of 130SST go 3712fps, but that was a too hot round…

Again, my reloads in my gun...

 

[270DT]

This is a 270-300 Win Mag wildcat with my rifle, loads and brass, follow at your own risk.

I also hit the range this morning and wanted to try some of the new IMR powders, IMR 4451 and also IMR 4955. I was shooting the 130 Swift Scirocco with Fed 215s.

IMR 4451 has about the same burn rate as IMR 4350.

MAX load with first signs of sticky bolt lift was 69.0 grains at 3,472 fps. Accuracy was great all through the range from 65.5 through 69 grains. Will definitely save this for a hunting load probably sticking with 68 grains right at 3,410 fps. I also like the "marketed" consistency and cleaner burning technology of the new Enduron series of powders that IMR came out with. Haven't shot enough of it yet to see if it does what it says yet.

Moving to IMR 4451 which is slower, around H4831. I got MAX load with sticky bolt lift at 68 grains with a velocity of 3,335 fps. I had higher expectations for this powder but didn't work in my rifle.

I am not getting the velocity that you guys are getting but then again I am also trying some different powders. I am not necessarily wanting to get to ludicrous speed as think bullet failure on game would be an issue and if going to something like a Barnes TTSX think it will just zip through but I still think I have room for more velocity if I can find the right combination for my rifle.

I am going to work with the 140 Nosler Accubond and the 150 Woodleigh PP next and will keep you guys posted. Probably going to try H1000 and Retumbo for those and see what happens.

 

[270DT]

Longtooth32 great shooting man and I think you have hit ludicrous speedgun)

Just curious what your seating depth is on the 130SST and also have you measured your case capacity in H20? I was curious to run that in Quickload to see what data it generated.

 

[Longtooth32]

Longtooth32 great shooting man and I think you have hit ludicrous speedgun)

Just curious what your seating depth is on the 130SST and also have you measured your case capacity in H20? I was curious to run that in Quickload to see what data it generated.

According to Nosler, the 270 Wby holds anywhere from 79 to 81 grains of H2O...

I am sure my loads are hot. I loaded the 130s and 140s to mag length @ 3.35"

 

[270DT]

PM sent

 

[CogburnR]

I shot a few 165g Matrix,

RL 33, went up to 82g at 3179, no pressure yet but in the area I think(bolt closes easily on fired case). This may be getting pretty good as it also shows accuracy at this speed.

H1000 up to 75g at 3159, the bolt still closes on the fired round but with resistance... no other signs. Showed some promise of accuracy.

7977 up to 75g at 3100, same deal as above, bolt closes with resistance on fired case... no other signs. Probably within a couple grains of getting extractor marks.

 

[Longtooth32]

Longtooth32 great shooting man and I think you have hit ludicrous speedgun)

Just curious what your seating depth is on the 130SST and also have you measured your case capacity in H20? I was curious to run that in Quickload to see what data it generated.

According to Hodgdon reloading data…max for those weights are 81grs of H1000 for the 130s and 80grs for the 140s…but that seemed awfully hot...

 

[Longtooth32]

To help people out that want to try RL26 with the 170 Bergers…again my gun my loads…270 Wby, 28" Benchmark barrel...

Started out (just a guess) way low in starting powder weights…

I was shooting out of the back of my truck with sustained winds of 12mph…

Left to right 63 grs ave 2838 fps , 64grs ave 2867 fps, 65grs ave 2867,

66grs ave 2947fps, (got bored and jumped some weights) 69grs ave 3077fps, 70grs ave 3127 fps.

No pressure signs at 70grs of RL26 and that is the highest weight charge that I loaded…All the ESs where in the mid teens.

 

[CogburnR]

I hit pressure at 72g of RL26 with the 165 Matrix. Velocity was good but grouping not so hot, still good enough to go back to it sometime.

I am loading further pressure series of RL33, I will be loading more Retumbo, H1000, and 7977 for grouping. I will probably try a group with 81g of RL33 at 3150fps or so but fully expect to hit 3250+ before max.