What bullet speeds should be expected?

[delta1]

What bullet speeds should be expected with-
30 inch heavy 1-18 twist
555 grn postell
65 grn Goex FFG
70 grn Goex FFG

[montana_charlie]

1150 to 1250 fps ...

But, your number is twenty grains heavier than the usual Postel bullet.

CM

[Don McDowell]

1050-1100 fps.
Here's some sample of velocity tests I ran a few years back with 530 gr bullets.
All goex powder, and speeds averaged, none of the loads listed had over 20 fps extreme spread. 15 ft from the muzzle
3f express 72 grs 1273 fps
65 grs 1208 fps
60 grs 1163 fps
2f express 70 grs 1210
cartridge 70 grs 1141

[delta1]

Reason I am asking is, I borrowed a chronograph. Measuring at 10 ft my speeds with 65 grn Goex FFg are 1047- 1075 fps with the 555 grn.
With 70 grn Goex FFG it is 1120-1140 fps with the 555 grn
All powder is weighed to within 1/10 grn and a 5 second pour through a 30 inch drop tube. bullet is seated over a .030 veg wad with the upper gg showing. This puts me .010 of the lands.
I am beginning to think perhaps the Chrono is off but all groups show speeds within the above margins.

[Don McDowell]

No I'ld say your chrono is telling it to you straight.

[delta1]

Well now to try them at ranges beyond the 200 yd mark. And try and tighten up the sd a little bit.

[Don McDowell]

Might want to go up a couple grains with the powder and get a little more compression , to see if those sd's will tighten up some.

[delta1]

Don:
Will do that, from what I read it should be in the single digits. Will these speeds and a mid range vernier tang get me out to 700 yds? Thats as far as I have here at the house.

[Don McDowell]

Unless your front sight is real tall you shouldn't have any problem making 700, the 1000 might not make it.
Hopefully you can get the sd under 10.

[delta1]

I will give it a whirl and see what happens. Sure do wish the old eyes were about 60 years younger though.

[Don McDowell]

Don't sweat the age thing , most of us doing this are a heck of a lot closer to retirement than highschool...

[Kenny Wasserburger]

Compression, Primer wads, or pistol Primers, Anneal cases. these all will lead to Lower ES. Neck tension or the bullet hard into the lands-Consistant start pressure, = Consistant ES-SD.
with Goex my 45-70 really liked around .250-.280 compression


Stuff all learned the hard way. FWIW.
KW
The Lunger

All the above of course is with BP, anything else, all bets are off.

[delta1]

I shall give it a try one item at a time.

[Don McDowell]

In addition to Kenny's excellent advice, fouling control is vitally important in reducind SD. Bore condition being as close to the same as possible from one shot to the next will help alot.

[delta1]

Don:
Are you saying I should be patching between shots?

[Don McDowell]

I think that patching is easier to keep a consistant bore condition than a blowtube, but if a person stays well hydrated and uses a consistant pattern the blowtube can be quite good.

[Kenny Wasserburger]

Don brings up the biggest bugaboo also, fouling control. What ever you use it has to be exactly the same each shot, or indeed you will have greater spread in you ES.

Bench shooting for chrono work is an art form almost into it's self. Consistant Grip, shoulder pressure also play into the Getting of consistant numbers. Along with a host of other things bags and the like.

I do agree that Wipping will yield the most consistant bore condition for Chrono Work. I have had excellent numbers though blow tubing, so it can be done either way.

My 5@200 record though was shot wipping, as was my Mile record of 5 hits in a row. Both from a good bench rest set up.

KW
The Lunger

[delta1]

Well here is the first round of trying to get a closer ES and SD let me know what you think so far and what i should work on next if anything.
Started with a clean bore by running a dry patch to take out any oil that may have been left in the bore.
Fired a fouler round and wiped the bore with a wet patch followed by 2 dry patches. Each round fired hereafter was followed by a wet patch and 2 dry patches.
The Brass was weighed and kept to within 1 grain.
All primers are the same for every load.
Bullets were crimped in all bullets would turn in the brass after the crimp. So a fairly light crimp.
Here are the powder charges and speeds, only change this time out is the powder charge.
Bullet is a 555 grain Postell style. Five rounds for each powder weight

All speeds through the chronograpgh are in the order the round was fired.

65 grains Goex FFG 1083-1089-1078-1082-1068

66 grains Goex FFG 1079-1083-1088-1097-1076

67 grains Goex FFG 1092-1096-1095-1083-1098

Compression plug was left alone for all powder charges, so seating depth for the 555 grn was the same.
All rounds where fired on the 200 yd target and marked. All rounds went into a 5 inch high by 3 inch wide group.

[Don McDowell]

That 67 gr load is looking pretty good.

[delta1]

My next test will be by adding an extra .030 wad. just to see if the extra compression will tighten up the SD. Although the 67 grain load is very close to what I am looking for. What seems to be odd is in each powder group there is one that is quite a ways off. I tried to keep the patching and time between rounds as even as possible.
I t was a little cool out at 22F but the shooting shed made things tollerable.

[fouronesix]

Yes, all your numbers sound right and the SDs are good and low- can't beat that!

One thing about shooting heavy lubed cast and especially BP cast loads with heavy lube and wads is the amount of debris that goes along with the bullet as it passes through the sensor zone. I usually set the chrony at least 15 ft in front of the muzzle. Even then, once in a while, I get weird readings because of all the junk flying along with the bullet. Just a heads up in case you see anything odd with some of the readings.

[MT Chambers]

Swiss Bp or KIK can add as much as 100fps to some loads....don't know where you would get it in your neck of the woods.....Ben

[delta1]

Ben"
The best I can do for powder here is Goex FFG. I have 6# of Goex cartridge I have been hoarding. and have 5# of 1F Curtis and Harvey but it seems finer in granulation compared to Goex 2F.
But then I don't know to much about BP in the first place. Perhaps someone will chime in on the Curtis and Harvey granulation.
By the way am enjoying working with your bullets.

[fouronesix]

delta1
Just FYI
Here's the Mean Velocity and Standard Deviation of velocity numbers for your three 5 shot trials. These aren't just so-so numbers these are excellent numbers. Plus, each graduation of charge increase tracks perfectly- no anomalies.

65gr, MV 1080, SD 7.8
66gr, MV 1085, SD 8.3
67gr, MV 1093, SD 5.9

[delta1]

delta1
Just FYI
Here's the Mean Velocity and Standard Deviation of velocity numbers for your three 5 shot trials. These aren't just so-so numbers these are excellent numbers. Plus, each graduation of charge increase tracks perfectly- no anomalies.

65gr, MV 1080, SD 7.8
66gr, MV 1085, SD 8.3
67gr, MV 1093, SD 5.9

Thank you for the numbers. Looks as though I could use any of them. Next will be to see how they work out at distances past 200 yds. I can do 700 here at the house and the temps to stay reasonable, at least in the upper teens F.