bullet coefficientcy

Spacedone · Member Joined: Nov 04, 2005 Posts: 266 Location: missouri

im trying to use the ballistic program and i need to find the bullet coefficeint for 150 grain and 180 grain bullets and i refuse to shoot thru my chrono at 100 yards to find the speed diferential. does anyone know a better way than shooting at a target at 100 yards with the chrono being 100 yards away.

ive only had it 3 weeks and really dont want to take the chance of blowing it away.

my 150 grain hornadys average 2720 fps at muzzle and my 180 grain seirras average 2560 fps

shrpshtrjoe · Posted: Thu Nov 24, 2005 7:46 am Post subject: Re: bullet coefficientcy

Howdy Spacedone. If ya put your load data in the point blank program the version ya download, click on the ballistics calculator and then on view data it will show your velocity for various yardages ( you can set the yardage increments) .
Joe

Spacedone · Member Joined: Nov 04, 2005 Posts: 266 Location: missouri

i killed my button buck this year with 303 enfield 150gr interloc and 41.4 gr acc 2520 with a muzzle vel of 2720 fpspoa at 100 yards and blew out a chuck of meat bigger than both fists fron its back leg.

was very awesome. i hit it in the hindquarters {only part i seen well and it fell and flopped twice and was dead. simply amazing kill potential.

im trying to work up a 303 load equal to a low vol 30-06 load for elk.

im using imr 3031 for 180 gr sierras and acc 2530 for 150 gr interlocs.

im working on improving the drop at a 300 yard range.

i really like the accurate 2520 for the 150 gr interlock and the imr 3031 for the 180 gr

shrpshtrjoe · Posted: Thu Nov 24, 2005 9:51 am Post subject: Re: bullet coefficientcy

Spacedone wrote:

i killed my button buck this year with 303 enfield 150gr interloc and 41.4 gr acc 2520 with a muzzle vel of 2720 fpspoa at 100 yards and blew out a chuck of meat bigger than both fists fron its back leg.

was very awesome. i hit it in the hindquarters {only part i seen well and it fell and flopped twice and was dead. simply amazing kill potential.

This responce is not meant to be disrespectful it's just my opinion. I have VERY strong feelings on shot placement i feel we owe it to the animals we persue. I'm glad you recovered your deer a lot of deer shot through the hind quarters are not recovered that quickly. If the only part of the deer i could see was the hind quarters (imo) then there is no shot. I have seen deer shot through the hind quarters pulling them selves with there front legs and the shooter running after it trying to shoot it again, it's not a pleasant site. You said your's dropped i'm glad but it is uncommon. I am a moderator on this fourm but as i stated this is my opinion, and not that of this site. I'm not trying to start world war three but i had to voice my opinion.
Joe

Spacedone · Member Joined: Nov 04, 2005 Posts: 266 Location: missouri

the only time ive ever had a deer get away in 40 years of hunting was when the sks came out and i tried it. i had 2 run off from heart shots. 50 yards using 123 grain softpoints using a scope.

i could have shot thru the brush for a heart shot but will not shoot at anything i dont see. my thinking was knock it down and kill it with a second shot. my point was that wasnt needed a hind quarter shot killed it dead. it never got up. remember im in south central missouri and most deer hunting here is in brush country. few long open fields.

brush hunting is not for the sometimes hunter. you must have quick shot placement and quicker backup shot placement.

i took no insult just you dont know my hunting conditions here. it had jumped up ran 50 yards and stopped and looked back at me i assume because it did stop with just the butt end showing in a brush thicket {which describes my land best}

here you need to learn to track well or even heart shots can get away. i have had to track a dead dear 2 miles before.

DallanC · Site Admin Joined: Jan 18, 2005 Posts: 3572 Location: Utah

I once cancelled a magazine subscription because they advocated hind shots, something I disagree with Confused

Anyway back to the subject you can find the ballistic co-efficent for most bullets from the MFG directly. For some things like chinese AK rounds generally someone out there on the net has done the legwork for you and either found the value or approximated it. If I dont know a bullets BC and dont want to shoot it to find out, I'll approximate it by looking at Sierra or another MFGs data on a similar bullet.

Sounds like most of your shots are close range in brush conditions. Generally unless you are shooting a muzzleloader BC will be completely irrelvant.

-DallanC

Spacedone · Member Joined: Nov 04, 2005 Posts: 266 Location: missouri

i was invited to a paid for elk hunt in colorado next year and im trying to work out the best 300 yard load for a 303 enfield no4 mkI* longbranch.

standard bought loads drop like 13 inches at 300 yards and im just getting started reloading.

so far at a very average load ive gotten my enfield shooting 2720 fps at the muzzle and im trying to figure drop.

as a rule i dont do hind quarter shots or neck shots i strive for heart shots using a scope but there are exceptions to every rule.

Handloader · Posted: Thu Nov 24, 2005 4:20 pm Post subject: Re: bullet coefficientcy

Spacedone: I tend to be a bit too detail oriented in developing loads, but, hey its something I enjoy. In reality, in the fields of game hunting, my best method is to actually zero the rifle at a realistic range, often 200 yards, and simply shoot the 300 yd target to find the actual drop. What I have found out is that the choicie of bullet shape for any given weight has only marginal effect at the 300 yd range.

Other factors influence ballistic coefficient besides mere distance. Elevation, low humidity and temperatures can make a difference as well.

Best of luck on your upcoming hunt.

Spacedone · Member Joined: Nov 04, 2005 Posts: 266 Location: missouri

right now im at 1400 ft and 40 degrees. next month i expect freezing temps.

i can set any round to hit a 300 yard target. which will be extreme range for my 303 enfield for elk even tho it will shoot alot farther. ill be using a scope so im trying to make a perfect load for a 300 yard range yet still be reasonable and closer ranges.

my light load of 150 grain interloc with 41.4 grains accurate 2520 shoots 2720 fps and at a 200 yard poa drops 9 inches at 300 yards and shoots 2 inches high at 100 yards which is very acceptable but is abit light in bullet weight to be as effective as i think i need.

while my 180 grain seirra spitzer i dont know the BC for knowing its not the .411 my interlock is so im getting a unreasonable reading.

im pretty simple using only imr 3031 and accurate 2520 powder and im still working on the 180 with the imr.

Handloader · Posted: Thu Nov 24, 2005 7:19 pm Post subject: Re: bullet coefficientcy

Spacedone: it's good to see someone use a 303 for hunting and recognize its value in that area.

I regret being a little dense but I am not too sure what exactly you want in terms of information. DallanC's comments about finding the bc is the best way I know to find the information you seek. Too, knowing the velocity at the muzzle, the zero of the rifle and the drop of the bullet by 300 allows you to calculate the bc figure. There are formulas for that sort of stuff. Or you can look in several manuals and find the drop figures @ 300 and interprolate the bc for your bullet.

You probably have the Sierra manual already and, it seems, you have a chronograph, so forgive me if the following info is redundant to your efforts:

Sierra 180gr SPT @ 2500fps, zeroed for 200yds results in a drop of 10.45 inches @ 300yds (Sierra manual, pg 871). Set zero @ 255yds and the maximum BPR is 305yds.

Ballistic tables are mathematical and theoretical but also close to what I have duplicated at the range. Variables mentioned in a previous post effect bc but not as much as most believe if the range is under 300yds. PACT chronographs have a nifty program that allow those of us that have no social life to while away the time changing these variables and seeing the results.

Spacedone · Member Joined: Nov 04, 2005 Posts: 266 Location: missouri

i only have the lee loading book as im very new to reloadingand the imr powder booklet.

ive had my chrono 2 weeks and have just started testing powder loads.

i have my original comercial no 5 jungle carbine ive had since i was 8 years old 39 years ago which i killed my first deer with at 8 and until two years ago when i bought my "new" 1942 all number matching no 4 mkI* longbrach in sport wood uncut metal which im working these loads out four.

i also own a 1942 no 1 mk III lithgow cadet rifle {wore out but a oz lithgow}

for the price and effectiveness on any north american game the enfield cant be beat for dependability as its made for combat conditions but is getting hard to buy ammo for.

a standard enfield using factory ammo will kill elk at upto 1000 yards with a 4-5 foot drop but im wanting to set mine up for 300 yards max range shooting a 180 grain sierra spitzer handloaded to shoot as flat for all ranges upto 300 years which i feel is my max range using a scope freehand.

sighting 2 inches high at 100 yards will put me at 0 POA at 200 yards and like 10 inch drop at 300 yards with like 1500 ft lbs of energy. right now using imr 3031 36.1 grains 180 gr spitzer im getting 1 inch groupings using a bypod and 3.5x10 power scope which is acceptable but i know my enfield is capable of doing better with the proper handload and since i have a year to get started i figure nows the time to start learning.

30-06 is a target rifle

8mm mauser is a hunting rifle

303 enfield is a combat rifle.

the enfield is easy aquired cheap and will kill any game from elephant to kodiak designed to shoot every time you pull the trigger no matter the conditions.

i love mine.