Accuracy but no speed?

DeerTracker · Sep 3, 2012

Ive found some good loads for my 243 and new Tikka 270 Win.

First of all, Ive got 130gr Accubonds loaded with Win brass, CCI 250s, and 58.3 and 58.5gr H4831sc. Im only getting between 2800-2850fps. These loads shoot just under an inch consistently but just slow. Nosler book states close to 3100fps

Ive also got 150gr Ballistic Tips loaded with 54 and 55gr H4831sc with Win brass and CCI 200s. Im only getting ~2625fps from these! Accuracy is between .5 and .75" for the 54gr load and a little larger for the 55gr load. Nosler book says these should be doing about 2900fps with 55gr of H4831.

In my 243 Ive got 87gr Vmax loaded with 35.5gr, 36.0, and 36.5gr of Varget. Data says around 3100fps but Im only getting around 2950 with the 36.5gr load.

Any ideas why these are reading so low? I really hope my Tikka barrell isnt that slow. I have only tried the 4831sc powder and I have other powders I could try, but I was just hoping Id get faster speeds. Could it just be a problem with how the sun was hitting my chrono? I was shooting straight west with the sun coming up right behind me. Im not sure if it was the chrono since I shot my 7mm-300Wby and it was clocking 3300fps with 160gr ABs and that has been chronographed before so I know that was correct. Seems I hardly ever get lucky with speed and accuracy. I either get one or the other. Any advice is welcome guys.

Ridgerunner665 · Sep 3, 2012

I think that Tikka barrel is less than 24", right?

Thats why you're not getting as much velocity...that said, the velocity you are getting is about where it should be. My wifes 270 (Rem 700, 22" barrel) will only get 2,850 fps with 130 grain BT's, and thats a very warm load in Winchester brass (54 grains H4350 I think).

The 270 is one of those rounds that does lose a fair amount of velocity in barrels less than 24"...along with 243, 25-06, etc.

hubcap · Sep 3, 2012

If you have a 22 inch barrel your velocity sounds about right. I usually get just under 3000 fps with 61 grains of H4831 sc. IMR 4831 will get you 3000 easy with all the nosler bullets 130,s It takes 57 grains in my 270,s. The same thing happens with 140 grain bullets in the .270. H4831 does not deliver top velocity in my rifles either. IMR-4831 will do anything H4831 will do with about three grains less powder. Even though H4831 is often the most accurate it is not always the fastest. For me the IMR version has been just accurate as the H version.

DrMike · Sep 3, 2012

You are not that slow, and you still have sufficient velocity to drop game cleanly to way out there. QL projects that you have some room to increase your charge for a bit more velocity.

Cartridge : .270 Win. (SAAMI)
Bullet : .277, 130, Nosler AccuBond 54987
Useable Case Capaci: 60.384 grain H2O = 3.921 cm³
Cartridge O.A.L. L6: 3.340 inch = 84.84 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : Hodgdon H4831 SC

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 85 48.00 2400 1663 31364 9648 82.4 1.400
-18.0 87 49.20 2465 1754 33599 10012 84.0 1.362
-16.0 90 50.40 2530 1848 36002 10371 85.5 1.325
-14.0 92 51.60 2596 1946 38587 10723 87.0 1.283
-12.0 94 52.80 2663 2047 41378 11067 88.4 1.241
-10.0 96 54.00 2730 2151 44385 11402 89.8 1.200
-08.0 98 55.20 2798 2260 47634 11725 91.1 1.161
-06.0 100 56.40 2866 2371 51149 12036 92.3 1.123
-04.0 102 57.60 2935 2486 54955 12331 93.4 1.086
-02.0 104 58.80 3004 2605 59080 12611 94.5 1.050 ! Near Maximum !
+00.0 107 60.00 3073 2727 63572 12872 95.5 1.016 ! Near Maximum !
+02.0 109 61.20 3143 2852 68457 13114 96.4 0.983 !DANGEROUS LOAD-DO NOT USE!
+04.0 111 62.40 3214 2981 73790 13334 97.2 0.950 !DANGEROUS LOAD-DO NOT USE!
+06.0 113 63.60 3284 3114 79624 13531 97.9 0.919 !DANGEROUS LOAD-DO NOT USE!
+08.0 115 64.80 3355 3250 86014 13702 98.5 0.889 !DANGEROUS LOAD-DO NOT USE!
+10.0 117 66.00 3427 3389 93004 13847 99.0 0.859 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 107 60.00 3238 3027 76446 12990 99.4 0.939 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 107 60.00 2863 2367 51889 12129 87.7 1.114

Of course, if you choose to try this data, remember that it is not pressure tested as is data published by Nosler. Should you use it, work up safely, watching for pressure signs.

Horsethief · Sep 3, 2012

If the accuracy of these loads meets your goals, don't mess with it. If you think you can get more velocity out of it, increase by .5gn / load until either the accuracy goes down or the cases show signs of overpressure. Once (not long ago) I worked up some loads 1gn at a time, knowing they were really low to start with, but since you're already at the top of the book limits anyway I would go with the .5gn increases if you want to explore the limits of the load.

FOTIS · Sep 3, 2012

Exactly. No deer is going to notice 100 fps difference.

If you're heart set on it then try RL22 IMR 7828 and some others. It will get you over the "magical" but not needed 3k fps mark.

Horsethief · Sep 3, 2012

About a year ago I read what Melvin Forbes of Ultra Light Rifles wrote in Nosler's 6th ed reloading manual. He was writing about the 284 Win. He stated that a 140gn bullet at around 2,950fps at the muzzle ought to kill just about any big game in North America. That stuck in my head.
As I was going through different powders and bullet weights with my new 280 Rem, I had some very good groups that were loaded with more powder than book loads will show and also achieved accurate groups. Some of these loads were faster than 7mm Rem Mag loads. The most accurate load of 140gn bullets came in at an average of 2962. Weird stuff, sort of, but Mr Forbes' velocity was my goal, but so was good accuracy. I'm glad I got both. When I talked to him last week he seem glad to know he helped.

usmc 89 · Sep 3, 2012

I wouldn't worry about being 3 percent down in the velocity department, accuracy would be more of a concern.

DeerTracker · Sep 4, 2012

Thanks guys. Im not so much worried about the AB load but I just wish the 150gr load was a little faster. I have no idea why I want or think it needs to be faster. Ive got some 4831sc test loads with 140gr Hornady BTSP and still have some loads with 130gr Btips too. So Ive still got some shootin and playin to do.

jmad_81 · Sep 4, 2012

I had this same "problem" with some loads I worked up for my dads 270. It was a Rem 700 with a shorter barrel, and RL-22 wouldn't work, but RL-19 gave me a pretty good group. But, they were only doing 2700 with a 140 PT.

I never could get the book speed, so I just stayed with the load that shot the best, and loaded him up 50 (enough to last him 20 years). If you are wanting more speed, I might suggest a 270 WSM, or Weatherby.

DrMike · Sep 4, 2012

DT,

FWIW, I have a Featherweight chambered in .280. From the get-go, it ran full 150 to 200 fps less than what I anticipated from it. I discussed the issue with Ben Amonette on one occasion. He advised me to work up my loads gradually to find the sweet spot and push velocity upward while watching for pressure signs. Sage advice, that. Interestingly enough, I never did push up the charge weights as the rifle was shoot 0.25 inch groups. Pressed for time, I opted to use what I had. It has accounted for numerous whitetail and mule deer during the past number of years, and none of them ever knew they were shot with an underpowered load. The rifle did gain velocity after about 250 rounds. Today, it has around 500- rounds through it and is still shooting 0.25 inch groups with boring regularity and the velocity is right in line with my projections.

Antelope_Sniper · Sep 4, 2012

If the books were always right, there would be no reason for anyone to have a chronograph. The book was made with a minimum spec test barrel, and that's not what you are shooting.

Why are your velocities low? Could be an oversized chamber, thin brass, a slow lot of powder, or perhaps something else.

DT, what happened when you went above 58.3? Did your groups open up?
It's not a max load, so there no reason not to try. If your velocity goes up, and groups remain tight, great. If not, bring it back down.

onesonek · Sep 4, 2012

Antelope_Sniper":2g0kz5fp said:
If the books were always right, there would be no reason for anyone to have a chronograph. The book was made with a minimum spec test barrel, and that's not what you are shooting.

Why are your velocities low? Could be an oversized chamber, thin brass, a slow lot of powder, or perhaps something else.

DT, what happened when you went above 58.3? Did your groups open up?
It's not a max load, so there no reason not to try. If your velocity goes up, and groups remain tight, great. If not, bring it back down.

+1
And then, I agree with other's as well.

SJB358 · Sep 4, 2012

DT, I have found H4831 to be a great powder for accuracy, but it always seems like RL22 gives me both the accuracy and speed. I do think you have more room with the 150's, but if you know your dope, I can't see you missing out on too much. Sounds like you found the seating spot, so inching up as others mentioned won't hurt anything and you can always fall back on your known load.

PJGunner · Sep 4, 2012

"If the books were always right, there would be no reason for anyone to have a chronograph. The book was made with a minimum spec test barrel, and that's not what you are shooting."

Those were my thoughts as well. Not a .270, but I have three rifles in 7x57. Discounting the Ruger #1A with it's fat chamber, that leaves a Winchester M70 Fearther weight with 22" barrel and my custom Mauser with 23" barrel. The Mauser usually runs close to or right at 100 FPS faster than the M70 depending on the load. max loads fo the M70 are way too hot for the Mauser. I discussed this with my gunsmith and he said when he rebarrels a rifle or builds one fron scratch, he uses only match grade barrel and chambers to minimum specs. At least in that rifle the difference shows up on the chronograph. That rifle is also very accurate with even factory ammo shooting sub-MOA groups.
Looking in the Nosler manual #6, they used a 24" barrel by Shilen. methinks that's where some of the diffeence is coming from.
Paul B.

DrMike · Sep 4, 2012

my custom Mauser with 2" barrel.

What sort of pressure are you generating to get 100 fps more than a load shot from a 22" barrel? :shock:

Okay, I'm sorry, Paul. I just couldn't resist; that looked so funny. Yeah, I have one of those keyboards that doesn't always transfer my thoughts to the electronic post. :mrgreen:

Mountain Goat · Sep 4, 2012

DrMike":11xd3wap said:
You are not that slow, and you still have sufficient velocity to drop game cleanly to way out there. QL projects that you have some room to increase your charge for a bit more velocity.

Cartridge : .270 Win. (SAAMI)
Bullet : .277, 130, Nosler AccuBond 54987
Useable Case Capaci: 60.384 grain H2O = 3.921 cm³
Cartridge O.A.L. L6: 3.340 inch = 84.84 mm
Barrel Length : 22.0 inch = 558.8 mm
Powder : Hodgdon H4831 SC

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 85 48.00 2400 1663 31364 9648 82.4 1.400
-18.0 87 49.20 2465 1754 33599 10012 84.0 1.362
-16.0 90 50.40 2530 1848 36002 10371 85.5 1.325
-14.0 92 51.60 2596 1946 38587 10723 87.0 1.283
-12.0 94 52.80 2663 2047 41378 11067 88.4 1.241
-10.0 96 54.00 2730 2151 44385 11402 89.8 1.200
-08.0 98 55.20 2798 2260 47634 11725 91.1 1.161
-06.0 100 56.40 2866 2371 51149 12036 92.3 1.123
-04.0 102 57.60 2935 2486 54955 12331 93.4 1.086
-02.0 104 58.80 3004 2605 59080 12611 94.5 1.050 ! Near Maximum !
+00.0 107 60.00 3073 2727 63572 12872 95.5 1.016 ! Near Maximum !
+02.0 109 61.20 3143 2852 68457 13114 96.4 0.983 !DANGEROUS LOAD-DO NOT USE!
+04.0 111 62.40 3214 2981 73790 13334 97.2 0.950 !DANGEROUS LOAD-DO NOT USE!
+06.0 113 63.60 3284 3114 79624 13531 97.9 0.919 !DANGEROUS LOAD-DO NOT USE!
+08.0 115 64.80 3355 3250 86014 13702 98.5 0.889 !DANGEROUS LOAD-DO NOT USE!
+10.0 117 66.00 3427 3389 93004 13847 99.0 0.859 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 107 60.00 3238 3027 76446 12990 99.4 0.939 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 107 60.00 2863 2367 51889 12129 87.7 1.114

Of course, if you choose to try this data, remember that it is not pressure tested as is data published by Nosler. Should you use it, work up safely, watching for pressure signs.

In addition what others have said, notice the maximum operating pressure of the load I detailed in red(ish.) This tells me that when comparing loads with a max of 65k psi to those with lower psi or CUP limits, there can be a considerable difference in both powder charge and listed velocity. One example of this that is very common is published data for the 280 Remington. A few have stepped up the pressure limits but will still list higher allowable charges for the 270 with the same bullet weight and powder. It does make one wonder.

SJB358 · Sep 4, 2012

I am with you MG. I typically look at 65K for modern bottleneck cases and cartridges in the 06, WSM, Win Mag, RUM cases. Regardless of what is listed on SAAMI. I think as long as we are aware of what the limits are and pay attention..

DeerTracker · Sep 4, 2012

here are some target pics just for the heck of it guys. These are all from yesterday morning. I had shot all these previously and I shot all these again just to confirm the accuracy.