I thought some of you might find this interesting. I've had a couple boxes of 150 Grain Nosler Partitions lying around, so the other day I thought I'd load a few and see how they shot in my Model 70 Winchester, with a 24" bbl. I also had a pound of Accurate 3100, and figured, I'd try that along with some IMR4831.

The first string was with IMR 4831, the velocity was a whopping 2950 fps. Now get this, with 58 grains of 3100/150 Nosler Partition, the velocities were 3050 fps. These loads are supposed to be around 2800 fps. I was very surprised, because the temperatures were in the 60's, and I had only shot 130's in any of my 270's. I can't wait to shoot the same loads in my 26" Sendero. Is 3200 possible?

Jerry

Jerry, I own and shoot and have shot a LOT of 270's. Those speed are extremely high with a 150. I can almost assure you that you are in a high pressure situation...a lot of folks wiser than I, including manufacturers, advise that speed itself is a pressure indicator.

If you are seeing no pressure signs, other than the speed, I would say take a look at your chrono, maybe confirm it with another if that's possible, the speed you are getting with IMR 4831 is near what I see (in 23 & 24" barrels) with 130 grain pills and near max charges.

You may just have fast barrel in that one rifle--but good luck either way!

quote:

Originally posted by Fish30114:
Jerry, I own and shoot and have shot a LOT of 270's. Those speed are extremely high with a 150. I can almost assure you that you are in a high pressure situation...a lot of folks wiser than I, including manufacturers, advise that speed itself is a pressure indicator.

If you are seeing no pressure signs, other than the speed, I would say take a look at your chrono, maybe confirm it with another if that's possible, the speed you are getting with IMR 4831 is near what I see (in 23 & 24" barrels) with 130 grain pills and near max charges.

You may just have fast barrel in that one rifle--but good luck either way!

There is a lot of wisdom in this post.

I am not really worried about, in this case, excessive pressures. All the loads have been verified, powder charges are as listed in the Powder Data Guides, and the scale is a new Dillion electronic! The chronograph is a Pact, and it also has been checked out recently by Pact. No bolt click or really flat primers. I have heard, but donot know if it is true,that Accurate 3100 is an H4831 Clone. In that case it would be near impossible to load enough powder in the case to blow up the gun. Funny thing with this 270, the 130's run right where they ought to with IMR4831 right at or a little less than 3100fps. If I were a velocity guy, I could be howling at the WSM guys, but I am not, LOL! I see ABSOLUTLY no problem as things are now, except, how's this possible?

Jerry

Jerry, I think yours is a case of the old axiom that every rifle is an individual. In my actual experience, and alos according to Quickload, the speeds you are getting are reverse to the powders, said another way, IMR 4831 is faster than 3100.....

You are right on the edge according to Quickload with 58.0 grains of 3100, but it does show 2900 FPS as an estimate, so seems OK. On the IMR 4831 at Max, it shows 2926. These loads are at the absolute max, so your rifle could very well stand it without issue, and in the couple of the other data I checked, some showed you as over max, and several did not with the 3100 at 58 gr. It isn't common in my experience to get the velocities you see spouted off from folks with the loads they list in the real world, and SAME barrel lengths, so having a rifle that does as good or better is nice.

It sounds like you just got a 'good-un'!

PS, QL shows you getting to 2958 with 3100 and 2978 with IMR 4831 and a 26" Barrel.

Your results are very similar to what I am getting with the same bullet/powder combinations you are using. I have used both in two different rifles with similar and excellent results. They are my "go-to" elk loads.

Several years ago I had 3050 with 150 grainers and from a 22" Featherweight 270 and Re19. On the same day and the tim of powder I had 3220 from 180 grain 300 Winchester. One of those Rem 700 stainless in the cream and grey laminated stocks, 24" barrel.

Ohler 35 and all was well with differen loads from different rifles on the same day.

The only other time I have had very high velocities was with 110 grains Sierra in Pre 64 Fetherweight 270. The powder had been pulled from militart 30/06 and was very similar to 4320. Velocity was 3450 with the 110s

quote:

Originally posted by Jerry Eden:
I thought some of you might find this interesting. I've had a couple boxes of 150 Grain Nosler Partitions lying around, so the other day I thought I'd load a few and see how they shot in my Model 70 Winchester, with a 24" bbl. I also had a pound of Accurate 3100, and figured, I'd try that along with some IMR4831.

The first string was with IMR 4831, the velocity was a whopping 2950 fps. Now get this, with 58 grains of 3100/150 Nosler Partition, the velocities were 3050 fps. These loads are supposed to be around 2800 fps. I was very surprised, because the temperatures were in the 60's, and I had only shot 130's in any of my 270's. I can't wait to shoot the same loads in my 26" Sendero. Is 3200 possible?

Jerry

I would think that 3150-3200fps would be possible when shifting to a lighter bullet (13% lighter) and the extra two inches of barrel should get you there.

When I had a 270 I was loading 130g with 62.0g of H4831 in a WW case and out of a 22" barrel I was getting 3050fps over the chronograph. I never messed around with the 150g. bullets at all.

Good luck on you and hope that the load also meets the accuracy that you are looking for.

The load wasn't with 150s, it was 130s; but years ago I clocked 3150 (average of five shots) out of my 22" BDL in .270. The load was 60 grains of AA 3100 pushing a Speer Grand Slam, lit with a CCI 200. Additionally, the COL was set ~.010" off the lands... No over-pressure signs, easy extraction, and long case life. No wonder they say the .270 shoots like a magnum. Mine sure does!

I like the " 270 shoots Like a Magnum". I never thought of my 270's that way, but! Nice to see others are experiencing the same results as me. Accuracy with both of these loads was 1-1.25" @100 yds. Good enough, but the same rifle with 130 BT'S shoots under .75". I know that is spliting hairs, what else can be said. I have been getting way over 3200fps, with the 130's in my Sendero, with IMR4831, and .25 groups sometimes, mostly bug hole 3 shot groups.

I have been fortunate enough to draw a number of elk tags here in Arizona. For elk I like the 35 Whelen, but the best "drops" of elk have been with the 270, even better than the 375 H&H.

Thanks for all the additional input.

Jerry

With the 150 gr. bullets my 270 liked velocities of around 2850 fps. I killed all kinds of game with Partitions, Hotcors and Spire points with never a problem. If I need more speed than that I'll pull my 7MM RM out of the safe and take it. The 7MM RM is still in almost pristine condition since it has only been taken to the range once a year for 30 years.

Sounds like you may have a chrono issue. When I get super high velocity readings, I check a couple of variables with the chrono. #1 Am I too close to the chrono and maybe getting a muzzle blast reading. #2 Is the sun shining on one of the screens more than the other? I have had the best readings with the light source directly above or directly to either side. Not in front or behind. With my chrony, I get a big difference in readings if I change the angle of the chrono to the direction of bright sunlight. If the chrono shakes when you shoot through it, you are probably too close. You will get a high reading then also.

Here's the velocties I got yesterday with the 26" Sendero. Actually I was a little surprised that they were only slightly higher that the 24" Model 70. Model 70 with 55/IMR4831/150 Partition, velocity was 2931 fps. with an extreme spread of 23. The same load in the 26" Sendero 2982 fps, with an extreme spread of 21. That's only a net gain of 51 fps, for 2" of barrel length.

58/Accurate 3100/150 Partition, Model 70, 3067 fps, with an extreme spread of 18. Sendero 3089 fps. with an extreme spread of 26. Thats only a 22 fps gain for 2" of barrel length. The 3100 load shot MUCH better in the Sendero, as far as groups, sub .75". As I said earlier the Pact Chronograph, was checked by Pact, then compared to loads, that the performance was known. It is right on.

Just goes to show you, every sitiuation is different, in every rifle! You know I know all this, but it is interesting to occasionally revist this stuff. One thing though, with this load and either of my 270 Winchesters, I would'nt hesitate to shoot, within my shooting range limits, ANYTHING in North America!

Jerry

Barrel length and increased velocity don't necessarily correlate. With the exact same loads my 22" 270 is consistently faster than my 24" 270.

I have two rifles chambwered to the .270 Win. that have 24" barrels.One, an FN mauser gives 2950 FPS and the other 2930 FPS with the Sierra 150 gr. game King or the 150 gr. Nosler partition using the now discontinued podwer WMR. Accuracy from both rifles is superd with both averaging.75" to one inch depending on how well I happen to be shooting. cases have been loaded 5 times so far and primer pockets are still tight.
Paul B.