270 caliber taken to a totally differnet level, 195 gr ULD RBBT....

Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Buffalobob

Are you refering to momentum as energy? There are two ways to get momentum that i know of, one is weight and the other is velocity and sometimes you can have both. And just as i said earlier you have to be shooting at very long ranges for these heavy bullets to pay off.

I understand that you are saying the heavy weight bullets don't slow down nearly as fast as the lighter bullets. But it takes a long distance to see the advantages of the heavyer bullet. Maybe i would understand more if i had the room to see these heavy bullets work.
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Lovetohunt,

Your not looking at the intended advantage for such a bullet, it is not bullet drop that we are looking to decrease really. Its wind drift that will get you at any range, bullet drop is easy to figure, consistant and basically unchanging.

Wind is the killer to long range shooting but lets look at several different areas.

First off lets look at drop and wind drift of the two bullets with the specs you offer for the 195 and 130 gr bullets in 270.

First number will be for 130 gr bullet / second 195

Yards..........Drop............Wind drift
500.........-16"/-19.5"........12.6"/7.7"

750.........-62"/-71"..........33.4"/18.0"

1000........-150"/-160"........60.6"/33.5"

1250........-302"/-277"........104.6"/54.7"

1500........-549"/-479"........166.6"/82.6"

1750........-936"/-732"........247.5"/118.1"

2000........-1498/-1067".......343.8"/162.0"

I will admit that for bullet drop, the 130 will be flatter shooting out to about 1150 yards where the 195 had caught up to the fast lighter bullet. Again, if trajectory is your major concern and you will not be shooting out past 1000 yards, the 130 will shoot flatter then the 195 gr ULD RBBT.

now lets look at wind drift. And this is not just a long range advantage, the heavy bullet has a dramatic advantage from the start. At 500 yards the 130 will drift close to 13" compared to just over 7.5" for the big bullet. Now this may not seem like alot but at 500 yards if you misjudge the wind by 5 mph it may make a huge difference in the result of the shot.

At 750 yards the spread has grown even more, +33" of drift for the 130 gr with only 18.0" of drift for the 195 gr pill. Already getting to nearly 1/2 of the wind drift of the lighter bullet.

At 1000 yards we get even closer to 1/2 the wind drift, 60.6" compared to 33.5".

From this range out, the wind drift of the heavy bullet wil be 1/2 that or less then the light bullet. This is the major advantage of the heavy bullet. I will give up a couple more inches of drop for basically 1/2 the wind drift at any range any day of the week.

That is not all though. If your an energy person, the 195 gr pill will be packing basically 1000 ft/lbs MORE energy at 500 yards then the 130 gr bullet will have, 3113 ft/lbs compared to 2187 for the 130.

At 750 yards we are pushing 1100 ft/lbs more energy. At 1000 yards the advantage is 2130 to 1011. At 1250 yards its 1750 to 670 ft/lbs. Basically keeps this spread from there out.

Retained velocity is a bit of a suprise as well. At 575 yards the heavy slower bullet has caught the 130 gr pill, 2606 fps(130) to 2608 fps(195). It goes south fast for the 130 from there out.

At 750 yards the 130 gr pill has 2280 fps left, the 195 has 2420 fps.

At 1000 yards, the 130 pill is moving at 1871 fps, the 195 still has 2220 fps.

At 1500 yards the 130 gr pill is traveling around 1240 fps which is not enough velocity for most bullets to even expand at basically eliminating the effectiveness of the bullet on game without a head or CNS impact. The 195 gr pill however will retain this same velocity out to 2425 fps and thats at sea level!! Roughly offering another 1000 yards of effective bullet performance.

This is all well and good but back to your original question. If your not going to shoot past 600-800 yards why not use the 130 gr bullet which is flatter shooting. There is a legit arguement for that position but in my opinion. For that range of hunting at deer size game with these types of rounds, that will be a severe strain on the light weight bullet to hold together.

The big 195 gr ULD RBBT however will perform very well and penetrate most anything on this half of the planet. You get the advantage of 1/2 the wind drift and more energy and velocity for better bullet performance on game without bullet failure.

In my opinion, no matter if I were hunting at 300 yards or 1200 yards, if I were using a 270 AM or 277 AM or a 270 STW or 270 RUM for that matter, it would be stoked with a 195 gr ULD RBBT in the appropriate twist barrel for each rounds velocity potential.

Just my opinion though!!

Have a good one,

Kirby Allen(50)
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

BuffaloBob,

I agree 100% /ubbthreads/images/graemlins/grin.gif

Kirby Allen(50)
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Kirby,

Thanks for the great explanation! I didn't think about the cross winds making that big of a difference. The winds are probably not as bad here as they are where you live, a lot more trees to help with the wind. In the picture of the 2370yard shot of you, there is only one tree, no woods. Makes a lot of sence. The wind is just not a big problem here. I worry more about bullet drop or just plain shakeing from excitment. /ubbthreads/images/graemlins/grin.gif

I agree also that those 195 will stay together better than most bullets but the barnes 130xlc will stay together as good or better than any bullet. I have shot a ton of deer at all kinds of ranges and speeds with the barnes and they penetrate great. This being said a big deer here is 200lbs.
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Man I can't wait to get my hands on some of them. Doing load development with the 169.5 ULD RBBT left me very please. I couldn't get a group to shoot over 3/4" @ 100 yards. Now my 277 AM can really run with the 195's. When might some more be available?
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Lovetohunt,

Yes the 130 gr XLC will be a killing machine at those velocities!!!

Kirby Allen(50)
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Srhaggerty,

Send an e-mail to Richard telling him your the second guy to have a 277 AM on the planet. He will take care of you!!!

They should be ready soon, I think the jackets were on order a bit back. Send Richard an e-mail at [email protected]

Glad to hear your rifle is shooting well. The 195 gr pill would be better for moose!!!

Kirby Allen(50)
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Kirby,

Any different throat considerations for the 195 vs the 169.5?

Also, what would be the recommended powder for the heavier bullet, 869 or 872 or either?
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Roy,

Since your rifle will be a single shot I would recommend throating the rifle so that the 169.5 gr ULD RBBT was seated just above the base of the neck/shoulder junction. This will allow the use of both bullets with adiquate neck tension on both and use up as little case capacity as possible. You may need to pull the bolt to eject a live round though.

This is pretty much how Richard 277 AM is throated and it worked very well with 169.5 gr ULD RBBTs and 195 gr ULD RBBTS. You do not want to stick yourself with only one bullet choice so this throat length is about the best. Will even work with lighter bullets in the 140 and 150 gr range if needed.

Either WC872 or US869 will work great. From what I am seeing, US869 will get you to top pressures about 3-4 grains faster then WC872. THis is with the lots I have so it will surely chance from lot to lot.

Both will work very well though.

Kirby Allen(50)
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

I will have to rattle his cage a little on that. I will be ordering the Swaro rangefinder from BJ next week so I am hoping to have some chucks dying a ways out there next weekend.
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

First number will be for 130 gr bullet / second 195

Yards..........Drop............Wind drift
500.........-16"/-19.5"........12.6"/7.7"

750.........-62"/-71"..........33.4"/18.0"

1000........-150"/-160"........60.6"/33.5"

1250........-302"/-277"........104.6"/54.7"

1500........-549"/-479"........166.6"/82.6"

1750........-936"/-732"........247.5"/118.1"

2000........-1498/-1067".......343.8"/162.0"

I will admit that for bullet drop, the 130 will be flatter shooting out to about 1150 yards where the 195 had caught up to the fast lighter bullet. Again, if trajectory is your major concern and you will not be shooting out past 1000 yards, the 130 will shoot flatter then the 195 gr ULD RBBT.


what would the the wind and drops be for the 169.5 bullets
 
Re: 270 caliber taken to a totally differnet level, 195 gr ULD RBBT...

Here are the numbers using the same specs as the 130 and 195 gr load.

Yards............Drop..........Wind
500..............-15"..........9.5"

750..............-64"..........23"

1000.............-151".........43"

1250.............-287".........71"

1500.............-488".........109"

1750.............-774".........159"

2000.............-1173"........221"

Its alot closer to the 195 gr ULD RBBT but still the 195 has a pretty significant advantage in wind drift. In all honest, either the 169.5 or 195 gr will be head and shoulders above anything else out there in 270 cal or even 7mm or 30 cal with the velocity potential they have.

Good Shooting

Kirby Allen(50)
 
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