IMR 7977 with 150 BT in 270 Win - Very Promising

[NYDAN]

The only load data I found for a 150 gr. bullet in the 270 Win was on the IMR website. The loads they list are as follows:

Case: Winchester
Bullet: 150 HDY SP
Primer: WLR
Barrel: 24"
C.O.L.: 3.285"

Starting Load is 56.5 gr. = 2717 fps
Max Load is 60.8 gr. = 2940 fps

I made up the following loads:

Case: New Norma
Bullet: 150 gr. BT
Primer: WLR
Barrel: 24"
Bullet Jump = .050"
Case capacity = a huge 72.0 gr. water

I loaded and shot one each of the following charges and got the resulting velocities:

59.0 gr. = 2737 fps
59.5 gr. = 2754 fps
60.0 gr. = 2772 fps
60.5 gr. = 2801 fps
61.0 gr. = 2873 fps

On average I achieved lower velocities than the published data. However that is not surprising since that is often the case with the large capacity of my chamber. I don't usually achieve published velocities. However, the QL projections using my case capacity usually are pretty close. Unfortunately the IMR 7977 isn't in the QL yet.

The surprise factor came with the accuracy.

The first three shots were touching resulting in a .35" three shot group.

The fourth and fifth shots printed higher on the target but was expected.

All-in-all the five shot group was 7/8" high by .55" wide. That was with powder charges from 59.0 gr. to 61.0 gr.

I am thinking I could shoot bug holes at 59.5 gr.

I am going to load about 5 cartridges at 61.0 gr. and see how that groups. 61.0 gr. is a compressed load and I couldn't really get too much more in the case.

I think that if I used previously fired brass I might be able to achieve 2900 fps. But, I would be happy with velocities around 2850 - 2870 if they group well.

 

[DrMike]

That is, indeed, fine accuracy. If that is sustained, you are in the money.

 

[kraky]

Been bouncing around the I net and found a few range reports. It looks faster than h1000 and really really close to re25 in speed.

 

[hubcap]

Seems to me the BT,s would do 2940 in the ww cases. The norma cases must be real light compared to the ww cases. :?:

 

[NYDAN]

UPDATE!

I loaded 10 cartridges with 61.0 gr. of IMR 7977. I shot six at 100 yards and achieved a 3/4" group. I shot four at 200 yards and the group opened up to almost 3". I am not sure why. Three shots were within 1.1" but the fourth was out. It was a little breezy. Maybe I caught a gust with that shot.

The bad news was the velocity variation in the ten shots. The velocity ranged from a low of 2824 fps to a high of 2892 fps. The ES was 68 fps and the Std was 20. In all honesty I did better with IMR 7828ssc in the velocity range of 2900 fps.

I will deer hunt with the 150 gr. BT and 57.0 gr. of IMR 7828ssc this year.

Dan

 

[DrMike]

Your SD is still within acceptable limits. I operate on the principle of +/- 1% as acceptable SD. You may be witnessing induced yaw, though I doubt it given that the sole deviant may have been an exception.

 

[Ridgerunner665]

Might try a magnum primer....that may get the SD down.

Some of these newer powders, with their high tech coatings, are harder to ignite.

Sent from my XT1080 using Tapatalk

 

[NYDAN]

Might try a magnum primer....that may get the SD down.

Some of these newer powders, with their high tech coatings, are harder to ignite.

UPDATE
RidgeRunner,

You are so correct. I loaded up some cartridges with 60.0 gr. of IMR 7977 and with WLRM primers. I loaded four with 150 BT's and four with 150 SST's. I also added 0.010" to the bullet jump. I shot them yesterday. The results are below.

150 BT's
2842
2842
2812
2824
Ave. 2830
ES 30
Std 14

150 SST's
2861
2855
2873
2801
4 shot Ave. 2847
3 shot Ave. 2863

The BT's grouped at about 0.7" (first three at 3/8")

The first three of the four SST's grouped at about 0.5" The fourth had a lower velocity and dropped lower on the target.

So the using the magnum primers resulted in both a higher velocity (for 60.0 gr.) and more consistent velocities.

I am going to experiment some more with this powder and with the 150 gr. bullets.

Dan

 

[JD338]

Dan,

It looks like you are well on your way. I have always felt that 3 shots test the load, 5 shots test the shooter.
My rule of thumb is to use a magnum primer at 60.0+ grains.
Don't sweat it if your SD's are in the 50-60 range, some of my better groups were not single digit SD's!

JD338

 

[SJB358]

Very nice. Looks pretty danged promising. That 7977 looks real good so far. Bet it would work excellent in my 270 WSM as well. Great speeds for a 150.

 

[preacher]

Seems like good stuff. I have to say that I got over, think way over, 3000 fps with the 150 BT and R26 out of a 22' barreled BAR. I have yet to try it out of my new 24" CDL, but will pretty soon. I really think and this is me just guessing of course, that anywhere from 2800+ to 3000fps with any 150 in a .270 has to be a real killer! I "know" what a properly loaded 30-06, .280 and .308 will do, but I am just now playing with the ol .270. I think it will shine with the 140-160gr bullets in these new, modern powders.

 

[Silentstalker]

Fantastic results! I am shooting the 150 gr. BT out of my .270 Win. I use the H 4831 at 2875 out of a 24" barrel. It is a hammer on muleys. I love the 150 gr. BT!

 

[lhsako]

Might try a magnum primer....that may get the SD down.

Some of these newer powders, with their high tech coatings, are harder to ignite.

UPDATE
RidgeRunner,

You are so correct. I loaded up some cartridges with 60.0 gr. of IMR 7977 and with WLRM primers. I loaded four with 150 BT's and four with 150 SST's. I also added 0.010" to the bullet jump. I shot them yesterday. The results are below.

150 BT's
2842
2842
2812
2824
Ave. 2830
ES 30
Std 14

150 SST's
2861
2855
2873
2801
4 shot Ave. 2847
3 shot Ave. 2863

The BT's grouped at about 0.7" (first three at 3/8")

The first three of the four SST's grouped at about 0.5" The fourth had a lower velocity and dropped lower on the target.

So the using the magnum primers resulted in both a higher velocity (for 60.0 gr.) and more consistent velocities.

I am going to experiment some more with this powder and with the 150 gr. bullets.

Dan

> whats a max charge w/ this powder?

 

[NYDAN]

> whats a max charge w/ this powder?

60.8 gr. with a 150 gr. Hdy SP.

 

[NYDAN]

UPDATE!

I gained some more velocity using once fired brass. Here are some velocity results from 01/24/16.

New Norma Brass
60.5 gr. IMR 7977
WLRM
150 BT

1 - 2886
2 - 2892
3 - 2867
4 - 2879
Ave - 2879
ES - 25
Std - 11

One fired with light load Norma Brass
60.5 gr. IMR 7977
WLRM
150 BT

1 - 2892
2 - 2879
3 - 2904
4 - 2886
Ave - 2890
ES - 25
Std - 10

One fired with heavy load Norma Brass
60.5 gr. IMR 7977
WLRM
150 BT

1 - 2936
2 - 2911
3 - 2923
4 - 2930
Ave - 2925
ES - 25
Std - 10

On the last two loads I got 3 in a 0.6 in. group and one 0ut. VERY PROMISING. I am going to try seating deeper 0.010" at a time to see if I can pull the four shot into the 0.6" group.

There is a lot more room for the powder in the once fired cases. It is easier to fit the powder. The 60.5 gr. of powder is below the neck so I am barely (if at all) compressing the powder.

The magnum primer resulted in much more consistent loads.

 

[gerry]

Great sounding load you have there. I miss the 270 Win but had to move it out to buy the Sako 30-06, definitely going to have another 270 Win whenever funds allow again. I really have come to enjoy the round a lot.

 

[SJB358]

That's a great load right there. Can't wait to see it shake out. Does it seem like you could get more speed with the 7977?

Sounds pretty accurate as well. A 270 slinging a 150 Nosler at 2900 is big medicine.

 

[Bruce Mc]

60.8 is what Hodgdon shows as max, but with a 150 hornady. It shows 61,300 psi. There might be little more wiggle room there. I'm fixing to give that combo a try with a 150 Partition.

 

[NYDAN]

Does it seem like you could get more speed with the 7977?

Scotty, I am not sure if you are asking if I could get even more speed with the 7977 than I am now with the 7977 or if I could get more speed with the 7977 than I could with other powders.

The IMR website shows 2940 fps with 60.8 grains, with a WLR primer, and with the 150 HDY SP. I think that is one of the fastest book loads for a 150 gr. bullet in the 270 Win that I have seen.

There is not much room left for more powder. When I used new Norma brass 61 grains was well up into the neck. I have more room with the once fired brass but I am reluctant to go higher than the 60.5 gr. of powder since I switched to a magnum primer.

I did not see any indication of pressure signs using IMR7977 up to 61.0 gr. with WLR primers nor up to 60.5 gr. with WLRM primers. I would guess that a more adventurous person could get to 2940 fps.

I could get 2900 fps with IMR 7828 SSC but I had to be careful to use new brass. If I used brass that had been fired a few times I would start to get pressure signs. That made me uncomfortable.

I also achieved 2900 fps with RL22 but I didn't follow up very much with that powder.

Based on the few times I have shot the IMR 4451 and the IMR 7977 I would say that there is noticeably less copper residue in the barrel.

Dan

 

[AK7AN]

Has anyone tried this powder with 140 gr Accubonds? I plan on working up a load with these bullets for my wifes 270 in a Ruger M77 22 inch tube, and my Weatherby Vanguard 24 inch tube. Have a Mule deer hunt planned in Coloardo this fall and these accubonds should fill the bill nicely.