.277" 169 wildcat bullet

[goodgrouper]

Wow. Been so long since I've been here that I almost forgot how to make a new thread!

Anyhow, I've just completed load development on three rifles chambered in a semi-overbore cartridge using the above mentioned bullets. 100 yard testing showed "ho-hum" performance but when I got the deviations down (by changing charges, powders, and seating depths) the loads that the gun favored sure were impressive at long range.

I've mentioned I've seen this before many times and many people have called me crazy for it but here's three guns in a row that shot 3/4 MOA at times at 100 yards and then proceeded to drill 1/2 MOA at 1000 yards and one gun even went under 1/3 MOA at 650 yards!

Bottom line: big bullets need some time to dampen the precession and the bigger they are, the easier it is to see. These beauties are so long they almost need to be measured with a yardstick.

Wildcat guys, if you're listening, the J4 jacketed RBBT's work great in their original form with twist rates as advertised. And as long as you don't try running them through a 3 groove barrel, they work great from what I've seen thus far.

 

[Len Backus]

Good to hear from you!

 

[royinidaho]

Holey cow! Where ya been.

Thought you found a girl or somethin'

I have one of those $#@$^^%*&( 3 groove barrels.gun)gun)

The 169s shoot great. The 195s come apart.

Will be working with Paul this weekend to learn what we'll learn.

My knees are on the ground and my hands folded with my head bowed as I think that the 169 is the perfect Woof fodder. Not because of weight but because of BC and the wind.

I have no comprehension as to how a group can get smaller as distance stretches but my 270 AM does shows the improvement that you describe.

BTW, Its good to hear from you.

 

[eddybo]

Glad to see you back....you are not crazy I have seen the same thing happen numerous times.

 

[goodgrouper]

Thanks guys. It's good to be back if only for a little while.

No "extracurricular" endeavors yet Roy. Just been hitting the benchrest scene hard this year. Put several thousand miles on the old truck going to competitions all over the western U.S. and the season ain't over yet!

I haven't even killed ONE rockchuck this year! I'm having withdrawals. Paper just doesn't give the same "splat" that a big old Idaho alfalfa-fed chuck does.

As my luck would have it, no tags in several states again this year so there might not be a lot to report here. I am helping a few friends with some elk tags but only inbetween benchrest matches so who knows what's going to happen. I'll post anything I can of interest!

 

[7mmRHB]

The three guns that GG is talking about are 270 AMPs which are wildcats based off the 7mm Dakota brass necked down and improved. They push the 169.5 Wildcats at 3050 fps with 70 to 71 grs of Retumbo or 69 grs of H 1000. Pretty potent little round with the B.C. at .750 at our elevation of 5000'

Kirby did his usual great Smithing and we thank him for his efforts.

Grouper did his stellar load development and was being modest when he said they all shot 1/2 MOA!!! they will do way better than that in decent conditions!!!

Project components

Predator actions
Jewell triggers
Rock Creek #4 fluted, 1 in 9 twist bbls
Manners Superlight carbon fiber stock
APS PK brake ( these suckers really work!!!!)
Leupold 6.5 - 20 x 40 LR w/ M1 turrets and Signature rings w/ 20 min. inserts
All up weight at 8lbs 4 oz

Sorry, I don't have the talent to put their pics on LRH --------- RHB

 

[Fiftydriver]

Jim,

I have seen this alot with all of my wildcats using the Wildcat bullets(old versions which I am sure are the same). Even more dramatic the longer the bullet or the faster they are driven.

I was driving the 169 gr ULD to 3400 fps and at 100 yards, it was common to see 3/4 moa groups and then by 500 yards those groups would tighten up to consistantly well under 1/2 moa and carry out to very long distances with that level of accuracy or better.

The 200 gr ULD was even more dramatic. In fact my personal rifle in my 7mm AM would average between 3/4 and 1 moa at 100 yards. In fact I was very unimpressed with its performance, That is until I tested it at 800 yards one morning and it was punching pretty consistant 4" groups at that range.

It has been so consistant that I tell all my customers to not even worry about 100 yard groups and to set up at 500 yards or more when doing load development if possible.

Good to hear those three AMPs are behaving for you!!!

 

[Pdvdh]

Same here. But I have not yet seen a group at a greater distance measure fewer inches in diameter on paper than I have at shorter ranges.

I have experienced the bullet's rate of spread/dispersion diminish over increased yardage. 168gr VLDs in 7mm RM. I had already read of that phenomena on this Forum so I took it in stride when I experienced it for myself. Now I start load development @ 300yds.

 

[Buffalobob]

I'm in Sydney NE in a motel just a block from Cabelas and will make Casper Wy by tomorrow. Season opens on the 15 and it appears from the Casper weather forecast that I might get some low winds on the 16th to try a shot.

I'll give you a call when I get a cooler full of meat and head toward Utah.


Long ago when I first encountered the precession issue I knew very little about ballistics and just decided that I was a better shot when the target was further away.

 

[Fiftydriver]

I have not seen smaller "inch" measured groups at long range then at closer range but I have relatively consistantly seen smaller "MOA" measured groups at long range compared to closer range.

That said, I often see "inch" measured groups remain the same from 100 to 150 to 200 and at times out to 300 yards. They do not decrease in size but often them are extremely similiar in group size.

Its my opinion that if you are shooting an extremely long, high BC bullet to moderate to high velocity in a barrel that has a 1-9 or faster twist, you should never pass up a 3/4 moa at 100 yard load before testing at longer range.

Especially if the 3/4 moa groups are even triangles or round in shape. Another reason that if its possible, get off 100 yard paper as soon as possilbe, you will learn much more even at 300 yards or better yet 500 or farther.

The BC that GG and 7mmRHB are getting, 0.750" at 5000 ft elevation is nearly identical to what I have always gotten with this bullet. I have to use 0.740 BC at my 3500 ft elevation and all of my customers have used this same or similiar BC so its not a fluke for sure, there has been ALOT of feed back on this bullet and has pretty much always been a performer.

 

[Long Time Long Ranger]

It has been so consistant that I tell all my customers to not even worry about 100 yard groups and to set up at 500 yards or more when doing load development if possible.


Yes, and I have done this for many years and for good reason. GG is right on and certainly not crazy. Years ago in my line of work I had the good fortune to work with ballistics research done by the military. Unfortunately I can't describe this very well in print. When you look at groups shot by the rifle it is not throwing bullets out in this direction or that to get a group. The bullets are traveling along a somewhat circular path around the center of your aim. In other words as you look at the bullets hitting the target there impact depends on where they were in this circle when they impacted the target. If you could see one bullets impact on targets from 100 to 1000 yards that bullet may impact low left at 100 yards and high right at 300 yards and anywhere along that semicircle as it traveled downrange. This gives you your groups as the bullet travels downrange depending on where it is in that semicircle when it impacts the target.

Now for what GG experienced and Fifties advise on testing loads. As the bullet leaves the muzzle there are tremendous forces placed on it as we all know. These cause the bullet to be more erratic at close range than long range. (Look at the slow velocity small powder charge loads that consistently win 100-200 yard matches. Bullets fired from these rounds are more stable quicker out of the barrel.) As the bullet travels downrange it continues to stabilize and the rotation around the axis gets tighter and tighter. Therefore the MOA of your groups get smaller the further a bullet travels downrange. With the axis being your aimpoint and rotation being the semicircular path the bullet is traveling.

Now, I have always been a long range hunter and not a target shooter so my concerns are different in picking a caliber and a parent case. Those slow little cartridges do great up close for punching paper beause they are so stable quick out of the barrel. But to take big game at a 1000 yards you need a lot of punch. Therefore huge cases with huge high BC bullets. Unfortunately these are very erratic out of the barrel and the most difficult to stabilize. So typically a shooter will notice this phenomenon much more out of this type of rifle. Therefore do your range testing a long way out there if you can.

The past couple of days I have shot antelope at 639, 729 and 813 yards. All one shot kills right through the chest with a 338-378 wby that groups about an inch at 100 yards and consistent 3" groups at 600 yards. They were long high BC bullets that many would not have realized were very accurate had they only shot at 100 yards.

I hope some of this helps, like I said I can't realy describe this very well in print.

 

[Long Time Long Ranger]

Well I don't have the quote thing figured out, but the first sentence is the quote by fifty. I do know how to shoot though.

 

[shootinfool]

awsome. I am getting excited! I have been in need of a good long range high ballisitc coefficient .277 bullets to shoot that will preform as well.

 

[padd54]

I am new here, where can I get some these bullets?
Thanks,
Ray