Hybrid 100v and the 280 Ackley Imp?

[midnightmalloy]

UPDATE! well i have had some time and have been shooting my new 280ai and have had some questions. I have loaded retumbo, h4831sc and hybrid 100v. I thought i was going to get more velocity out of the h4831sc and the retumbo but not as much as i wanted. the real suprise was the hybrid 100v. I have a sako 75 LH in a Mcmillan sako 75 stock with a 25" benchmark 3 groove 1:9 twist. Im using new nosler brass, cci BR primers, and 168gr berger hunting vld's. so here are the max loads i tested and what i found:
Retumbo:
started at 61gr
63gr 2800fps
64gr 2840 slightly flattened primers but bearly noticable
H4831sc
started at 54gr
59gr 2768 fps no pressure (this is a max load for 160gr accubonds in the nosler data and they say this gets 2990fps)
60gr 2790 fps bearly see any flattening at all of the primer
61 gr 2835 fps little flatter but nothing alarming

With both of these powders i thought i would be getting 50-100fps more? i have a 25" #5 contour so its not a barrel lenght issue, so what gives?

then i just tried some hybrid 100v since its loaded in the 280 rem and the pressures were low with good velocity so i thought i would strart low and see what happened.
Hybrid 100v
started at 51 gr sinve thats the max load for the 280 rem and the pressure as stated was low.
worked up in 0.5gr increments and didnt see any pressure
57gr 2966 fps
57.5gr 2972 fps
58gr 3014 fps (primers started to show slight signs of pressure, nothing alarming)
58.5gr 3042 fps flatter primers
59gr 3064 fps hot load flat primers this is too much for me to want to load.

I wanted to use an extreme powder for the temp sensitive but i just am not getting the velocity with them as i am with the hybrid 100v. Am i doing something wrong here? any tips or suggestions would be good. I know i could use a magnum primer but i have 3k benchrest primers so i really dont want to buy any more.

[cowboy]

Originally Posted by midnightmalloy

UPDATE!
With both of these powders i thought i would be getting 50-100fps more? i have a 25" #5 contour so its not a barrel lenght issue, so what gives?

I wanted to use an extreme powder for the temp sensitive but i just am not getting the velocity with them as i am with the hybrid 100v. Am i doing something wrong here? any tips or suggestions would be good. I know i could use a magnum primer but i have 3k benchrest primers so i really dont want to buy any more.

3

Having two 280AI's in the family - both have 25" Kreiger barrels and both use 168 VLD's, I would be very surprised if you can get up to 3000 fps with any Hogdon powders unless you really push the envelope at max. My son has reached 3000 but only with RL22 and we have pretty much tried everything.

Couple of questions for you:
- Are you 100% confident on your chrony readings?
- At what distance in front of the muzzle are you setting your chrony, and are you backing that distance out on a ballistic calculator to get closer to your true muzzle velocity?
- What elevation are you?

I've settled in on H4831sc at 2840 fps with the 168 VLD and after 20 some deer, elk, antelope, bear, and a sheep I just don't feel another 160 fps would have killed anything any better.

My whole key on this velocity thing has changed after many years of chasing more velocity all the time - which load shoots the best? And I don't mean at 100 yds off a bench. After you've went through way too many barrels it'll finally hit you.

[Forrest Ebert]

OK, you have gotten the speed that you are looking for but what about accuracy? You have not mentioned how any of those loads group? I personally would not worry about speed if your groups look like a shotgun blast at 100 yrds. You may indeed need to use a magnum primer especially if you plan on using these loads when the climate is cold ? Really anything over 60 grains of powder benefits from the use of a magnum primer. I think if your groups are good at the 28-2900 mark and use one of the loads you listed you will be more than happy with the performance of the Bergers on game ! Remember that bullet is designed to penetrate about 2-3" before it does it's job ! Please let us know about your accuracy with the loads you listed?

[midnightmalloy]

Originally Posted by cowboy

3

Having two 280AI's in the family - both have 25" Kreiger barrels and both use 168 VLD's, I would be very surprised if you can get up to 3000 fps with any Hogdon powders unless you really push the envelope at max. My son has reached 3000 but only with RL22 and we have pretty much tried everything.

Couple of questions for you:
- Are you 100% confident on your chrony readings?
- At what distance in front of the muzzle are you setting your chrony, and are you backing that distance out on a ballistic calculator to get closer to your true muzzle velocity?
- What elevation are you?

I've settled in on H4831sc at 2840 fps with the 168 VLD and after 20 some deer, elk, antelope, bear, and a sheep I just don't feel another 160 fps would have killed anything any better.

My whole key on this velocity thing has changed after many years of chasing more velocity all the time - which load shoots the best? And I don't mean at 100 yds off a bench. After you've went through way too many barrels it'll finally hit you.

The distance from chrono to muzzle is about 10 ft. I didn't have a tape measure but used steps so it was within 1-2 ft at the most. I just forgot the tape measure is all. Should I be placing it further than that? On the groups I can only shoot to 200yds at the local range so if you have any additional tips on that then shoot. I usually find where the max load in my rifle is then work from there. So haven't done too much accuracy testing.

[cowboy]

Originally Posted by midnightmalloy

The distance from chrono to muzzle is about 10 ft. I didn't have a tape measure but used steps so it was within 1-2 ft at the most. I just forgot the tape measure is all. Should I be placing it further than that? from .

All I'm saying is that you need to keep in mind that the chrony is measuring velocity 10' in front of the muzzle. Running that through a ballistic calc. gives me an adder of 14-15 fps at the muzzle.

If 10' from the muzzle is working for you - go with it. If you start seeing velocities, ES, and SD numbers not very uniform I have found on some calibers where 10' just isn't enough distance as the muzzle blast was doing some strange things with the velocities.

I pretty much set my chrony 15-20 ft in front of the muzzle and then I know I'm not getting any effects from muzzle blast. I go to a ballistic calc. and set that number up at the distance of my chrony and get my true muzzle vel.

Good Luck

[midnightmalloy]

Originally Posted by cowboy

All I'm saying is that you need to keep in mind that the chrony is measuring velocity 10' in front of the muzzle. Running that through a ballistic calc. gives me an adder of 14-15 fps at the muzzle.

If 10' from the muzzle is working for you - go with it. If you start seeing velocities, ES, and SD numbers not very uniform I have found on some calibers where 10' just isn't enough distance as the muzzle blast was doing some strange things with the velocities.

I pretty much set my chrony 15-20 ft in front of the muzzle and then I know I'm not getting any effects from muzzle blast. I go to a ballistic calc. and set that number up at the distance of my chrony and get my true muzzle vel.

Good Luck

Ok thanks I will try it at 15 ft next time. What's the "added factor" for setting it 15ft vs 10ft? I ordered a rcbs chargrmaster so this should be an improvement on my balance beam and should help es, sd etc.

[cowboy]

Originally Posted by midnightmalloy

Ok thanks I will try it at 15 ft next time. What's the "added factor" for setting it 15ft vs 10ft?

Just go into a ballistic calculator and play with the velocity until you get whatever fps your chrony is getting at the distance you set it at and look at the muzzle velocity at point 0 yds.

If you've never played with a ballistic calc. just PM me and we can find you a number of them on the internet that are very good and I'd be more than happy to walk you through it.

Just remember that no matter what caliber you shoot at whatever velocity it is the bullet starts slowing down the exact instant that it leaves the barrel. Heck - if I could I'd set my chrony out at 100-200 yds and really get good data - but that's not practicle for a number of reasons.