Thread: What's the Deal?

When Abe built my barreled action he said my MAB barrel was very tight. He even had to make a new pilot for the reamer, so that might be why I'm slow also?

Originally Posted by L.R

Yes Gimp all of that sounds reasonable. Looks like Normies 42gr load may be a bit slower than 2644 tho unless something else is drastically wrong.
The load I use now in my 6.5x47 is only 41gr of H4350 and 130 VLDs, its slow at 2777fps but you can't argue with the accuracy even at 1k.

If he's getting pressure at 42gr 2209 with 140 he should be getting the speed too. It'd be very very unusual to get 200 fps less than everyone else with the same cartridge/powder/bullet combo. Pressure and speed come with each other.

Originally Posted by Normie

When Abe built my barreled action he said my MAB barrel was very tight. He even had to make a new pilot for the reamer, so that might be why I'm slow also?

No not really. Should be faster if anything with less powder.
Hence my question of measuring length of the 2 cases.

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Just done in JBM. ANything not right with my inputs? Corrections are still out.

Trajectory
Input Data
Manufacturer: Hornady Description: Amax (Litz)
Caliber: 0.264 in Weight: 140.0 gr
Ballistic Coefficient: 0.299 G7 (ICAO)
Muzzle Velocity: 2634.0 ft/s Distance to Chronograph: 4.0 m
Sight Height: 5.28 cm Sight Offset: 0.00 in
Zero Height: 0.00 in Zero Offset: 0.00 in
Windage: 0.000 mil Elevation: 0.000 mil
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg
Wind Speed: 1.0 m/sec Wind Angle: 90.0 deg
Target Speed: 0.0 mph Target Angle: 90.0 deg
Target Height: 30.0 cm
Temperature: 25.0 °C Pressure: 29.92 in Hg
Humidity: 60 % Altitude: 100.0 m
Vital Zone Radius: 5.0 in
Std. Atmosphere at Altitude: No Pressure is Corrected: Yes
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Mark Sound Barrier Crossing: No Include Extra Rows: No
Column 1 Units: 1.00 cm Column 2 Units: 1.00 mil
Round Output to Whole Numbers: No
Output Data
Elevation: 1.316 mil Windage: -0.039 mil
Atmospheric Density: 0.07251 lb/ft³ Speed of Sound: 1135.7 ft/s
Maximum PBR: 306 m Maximum PBR Zero: 260 m
Range of Maximum Height: 145 m Energy at Maximum PBR: 1471.9 ft•lbs
Sectional Density: 0.287 lb/in²
Calculated Table
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(m) (cm) (mil) (cm) (mil) (ft/s) (none) (ft•lbs) (s) (cm) (mil)
100 -0.0 -0.0 0.0 0.0 2483.0 2.186 1916.3 0.128 0.0 0.0
125 -1.3 -0.1 0.1 0.0 2444.5 2.152 1857.3 0.161 0.0 0.0
150 -3.7 -0.2 0.3 0.0 2406.4 2.119 1799.8 0.195 0.0 0.0
175 -7.2 -0.4 0.5 0.0 2368.5 2.086 1743.6 0.230 0.0 0.0
200 -11.9 -0.6 0.8 0.0 2331.1 2.053 1688.9 0.265 0.0 0.0
225 -17.8 -0.8 1.2 0.1 2293.9 2.020 1635.5 0.300 0.0 0.0
250 -24.9 -1.0 1.6 0.1 2257.2 1.988 1583.6 0.336 0.0 0.0
275 -33.4 -1.2 2.0 0.1 2220.8 1.955 1532.9 0.373 0.0 0.0
300 -43.2 -1.4 2.5 0.1 2184.8 1.924 1483.5 0.410 0.0 0.0
325 -54.4 -1.7 3.1 0.1 2149.1 1.892 1435.5 0.448 0.0 0.0
350 -67.0 -1.9 3.8 0.1 2113.7 1.861 1388.6 0.486 0.0 0.0
375 -81.1 -2.2 4.5 0.1 2078.7 1.830 1343.0 0.525 0.0 0.0
400 -96.7 -2.4 5.3 0.1 2044.0 1.800 1298.5 0.565 0.0 0.0
425 -113.9 -2.7 6.1 0.1 2009.6 1.769 1255.2 0.606 0.0 0.0
450 -132.7 -2.9 7.0 0.2 1975.5 1.739 1212.9 0.647 0.0 0.0
475 -153.2 -3.2 8.0 0.2 1941.6 1.710 1171.7 0.689 0.0 0.0
500 -175.5 -3.5 9.1 0.2 1908.1 1.680 1131.6 0.731 0.0 0.0
525 -199.6 -3.8 10.2 0.2 1874.8 1.651 1092.5 0.775 0.0 0.0
550 -225.5 -4.1 11.4 0.2 1841.8 1.622 1054.3 0.819 0.0 0.0
575 -253.4 -4.4 12.7 0.2 1809.1 1.593 1017.2 0.864 0.0 0.0
600 -283.3 -4.7 14.1 0.2 1776.6 1.564 981.0 0.909 0.0 0.0
625 -315.4 -5.0 15.5 0.2 1744.4 1.536 945.8 0.956 0.0 0.0
650 -349.5 -5.4 17.1 0.3 1712.4 1.508 911.4 1.004 0.0 0.0
675 -386.0 -5.7 18.7 0.3 1680.7 1.480 878.0 1.052 0.0 0.0
700 -424.7 -6.1 20.4 0.3 1649.2 1.452 845.4 1.101 0.0 0.0
725 -465.9 -6.4 22.2 0.3 1618.0 1.425 813.7 1.151 0.0 0.0
750 -509.6 -6.8 24.2 0.3 1587.0 1.397 782.8 1.203 0.0 0.0
775 -556.0 -7.2 26.2 0.3 1556.3 1.370 752.8 1.255 0.0 0.0
800 -605.0 -7.6 28.3 0.4 1525.9 1.344 723.7 1.308 0.0 0.0
825 -656.9 -8.0 30.5 0.4 1495.7 1.317 695.3 1.362 0.0 0.0
850 -711.8 -8.4 32.9 0.4 1465.8 1.291 667.8 1.418 0.0 0.0
875 -769.7 -8.8 35.3 0.4 1436.2 1.265 641.1 1.474 0.0 0.0
900 -830.8 -9.2 37.9 0.4 1406.9 1.239 615.2 1.532 0.0 0.0
925 -895.3 -9.7 40.6 0.4 1377.9 1.213 590.1 1.591 0.0 0.0
950 -963.2 -10.1 43.4 0.5 1349.2 1.188 565.8 1.651 0.0 0.0
975 -1034.7 -10.6 46.3 0.5 1320.9 1.163 542.3 1.713 0.0 0.0
1000 -1110.1 -11.1 49.4 0.5 1292.9 1.138 519.5 1.775 0.0 0.0
28/03/13 18:51, JBM/jbmtraj-5.1.cgi

Originally Posted by Normie

My scales are shit really and walk a little but I do re-zero them before each drop of powder. They are always between .2gr out which should be normal for digi scales?? They are Smart Reloader's basic digital model so maybe my weights are out. Would explain the SD being 20fps.

Hey Pete I did a ladder with Hybrid 100V too. Got good results of 150fps more with no pressure signs. Results in Reloading area if you're interested.

Yeah, I saw that, looked like good speeds, might be best to just go with it, as long as it's temperature stable and actually available...

Id say Normies barrel is getting on the short side to get those speeds from a 260, and as you know a longer barrel will get more velocity for the same pressure, so pressure and velocity are not exclusive to each other.

If his loads are doing the 2644 the crony says they are then it only really leaves a scope adjustment issue dosent it?

Originally Posted by Normie

Just done in JBM. ANything not right with my inputs? Corrections are still out.

Missing line of sight angle... But it doesn't make much difference at 5°

Originally Posted by L.R

Id say Normies barrel is getting on the short side to get those speeds from a 260, and as you know a longer barrel will get more velocity for the same pressure, so pressure and velocity are not exclusive to each other.

If his loads are doing the 2644 the crony says they are then it only really leaves a scope adjustment issue dosent it?

It could be an issue of the scope being near the edge of adjustment and the adjustment fucking up because of that - how much travel have you got from zero? Up, and sideways. I had a VX3 that would go sideways when you got near the top.

Barrel length doesn't make that much difference.

Originally Posted by R93

No not really. Should be faster if anything with less powder.
Hence my question of measuring length of the 2 cases.

Sent from my iPhone using Tapatalk. So please forgive my sausage fingers!!!

May explain early pressure signs tho.

Originally Posted by gimp

It could be an issue of the scope being near the edge of adjustment and the adjustment fucking up because of that - how much travel have you got from zero? Up, and sideways. I had a VX3 that would go sideways when you got near the top.

Barrel length doesn't make that much difference.

I dont agree with you on barrel length, I find it makes a big difference especially on 6.5's. Build yourself a short barreled 6.5x284 and see how it goes, they are fucken useless!

It also could be the 'bullets can lie' thing - if you're not shooting something easily measurable it's possible to draw wrong conclusions from your results. Rocks/banks aren't so scientific.


Basically I think he just needs to go confirm zero, re chrony, check scope travel, make sure everything is tight, and shoot more logging the results.

Originally Posted by L.R

I dont agree with you on barrel length, I find it makes a big difference especially on 6.5's. Build yourself a short barreled 6.5x284 and see how it goes, they are fucken useless!

We're talking a 22" .260 here though, not 12”....

But on the subject,

Tussock cut his 6.5x47 from 26" to 22" with loss of 10fps. His load of 42gr was exactly the same as mine (my load development initially consisted of pinching ammo from his shed when I was in a hurry) and doing about 2fps different average out of my 20” to his 22”

We got nearly 2900fps from a 20" barrelled BSA 6.5x55 back in 2009 with N560 when we got snowed in and had nothing better to do, without any real pressure signs

Norway has a 18.5" 6.5-284 and enjoys it - although he is very conservative with his loading compared to all of us.

Zero is 10 mil up from bottom (2 turns x 5 mil p/turn) I think I have 30 mil total elevation so should be in the middle of adjustment range. 22" is short but not that short I think tight bore might have more to do with the slow factor.

I don't have direct access to anywhere to shoot really only through Leathel. Next time we go I'll measure 5 shots through chrony check zero and set up the gong this time and get a little more scientific up in this bitch.

Nothing to do with the bore unless you are coppering/fouling up.
You can possibly eliminate the concern of what I think it is, buy measuring the brass.



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Originally Posted by Normie

Zero is 10 mil up from bottom (2 turns x 5 mil p/turn) I think I have 30 mil total elevation so should be in the middle of adjustment range. 22" is short but not that short I think tight bore might have more to do with the slow factor.

I don't have direct access to anywhere to shoot really only through Leathel. Next time we go I'll measure 5 shots through chrony check zero and set up the gong this time and get a little more scientific up in this bitch.

On the tighter bore barrels I have done loads for an with yours and Adams is tight on his wsm. They have all got pressure before others had with same projectile powder combos in most cases can be couple of gr earlier. all still shot well apart from Adams only likes some projectiles.

It don't explain the big adjustment to get right drop tho and the speed was never down as much as yours only 100fps ish. Just go through everything again and double check it all. I'd think you will find little fault in there somewhere. Am check scope as well make sure clicks aren't smaller than what they say. . . . .No one has said that yet?

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