gingerbreadman Posted February 20, 2003 Share Posted February 20, 2003 can you find me the ballistic co-effiecient for these bullets .270 cal 130 grain rem. core lock .270 cal 150 grain hornady spire point .30 cal 165 grain rem core lock .30 cal 165 grain hornady spire point .30 cal 180 grain rem core lock .30 cal 180 grain horn spire point .30 cal 180 grain horn spire point boat tail .30 cal 190 grain horn spire point .30 cal 190 grain horn spire point boat tail .30 cal 200 grain horn spire point .30 cal 220 grain nosler partition semi spire point .30 cal 220 hornady round nose and can you also explain to me how the bullet gets its ballistic co efficient????? thank you all muchly -gbm- Link to comment Share on other sites More sharing options...
kimel Posted February 20, 2003 Share Posted February 20, 2003 Chpt 12 of the latest Speer Reloading Manual (#13) has a very nice discussion of what BC is and how it is derived. I shant repeat it hear as it is somewhat lengthy. You should be able to dig the BCs for these bullets up on the various manufacturer's web sites...assuming these bullets are still in production. If not, find someone with a collection of old loading manuals and you can probably dig them up given a bit of work. Hope that helps. Cheers! Kevin Link to comment Share on other sites More sharing options...
tightloop Posted February 21, 2003 Share Posted February 21, 2003 I am curious, how is this information going to help you? If you take an arrow and a bowling ball which weigh the same amount and launch them at the same speed, which one will fly farthest? which one has the highest BC? can you tell just by looking? (Edited by tightloop at 2:23 pm on Feb. 21, 2003) Link to comment Share on other sites More sharing options...
gingerbreadman Posted February 21, 2003 Author Share Posted February 21, 2003 Quote: from tightloop on 11:42 am on Feb. 21, 2003 I am curious, how is this information going to help you? If you take an arrow and a bowling ball which weigh the same amount and launch them at the same speed, which one will fly farthest? which one has the highest BC? can you tell just by looking? (Edited by tightloop at 2:23 pm on Feb. 21, 2003) i dunno you tell me, why do trajectory tables and programs ask for the BC of the bullet...... if im confused help me out here, why is a 180 boat tail better than a 180 flat base???? -gbm- Link to comment Share on other sites More sharing options...
benos Posted February 22, 2003 Share Posted February 22, 2003 gbm, "why is a 180 boat tail better than a 180 flat base????" The boat tail is tremendously better because the tapered shape of the back of the bullet works to lessen the turbulance caused by the air rushing around the rear of the bullet as it flies through the air. Think of the air as water - What would be the best shape to cut through the water with the least resistance? It should be streamlined on both the front and the back. be Link to comment Share on other sites More sharing options...
tightloop Posted February 22, 2003 Share Posted February 22, 2003 GBM you got it from the Ghost Dog himself. Less turbulance and less drag. Most modern boattail designs are usually from 7 to 9 degrees. In truth, the boattail design shows insignificant performance gains in either trajectory, accuracy or drift until you reach about 300 meters, then it shows improvements in each of those catagories. the reason software programs ask for the BC is to compute the shape of the projectile when they calculate the velocity and drop, same reason for asking if it is flat base or boattail. May I suggest that you go to your local sporting goods/reloading center and pick up a copy of every current reloading manual avaliable and really read what they have to say in the sections B4 the load data for any of the cartridges. You wouldn't begin to work on your hotrod Stang without a copy of the '70 Chilton's manual on your bench would you? Same for reloading. Link to comment Share on other sites More sharing options...
gingerbreadman Posted February 22, 2003 Author Share Posted February 22, 2003 Quote: from tightloop on 10:09 pm on Feb. 21, 2003 GBM you got it from the Ghost Dog himself. Less turbulance and less drag. Most modern boattail designs are usually from 7 to 9 degrees. In truth, the boattail design shows insignificant performance gains in either trajectory, accuracy or drift until you reach about 300 meters, then it shows improvements in each of those catagories. the reason software programs ask for the BC is to compute the shape of the projectile when they calculate the velocity and drop, same reason for asking if it is flat base or boattail. May I suggest that you go to your local sporting goods/reloading center and pick up a copy of every current reloading manual avaliable and really read what they have to say in the sections B4 the load data for any of the cartridges. You wouldn't begin to work on your hotrod Stang without a copy of the '70 Chilton's manual on your bench would you? Same for reloading. I have copies of every bullet manufacturer but they are old ones i picked up from a gun show for $5 a piece.... Id like to be able to afford more reloading books but there over $30 a copy up here in canada.... I will read my old ones again and try and grasp all these technical terms... thanks guys.... and yes i have read many articals and manuels while i was building my drag car and as it turns out reloading and shooting is just as indepth as making horse power and it also requires as much due care and attention.... thanks again guys.... -gbm- Link to comment Share on other sites More sharing options...
bhg Posted February 22, 2003 Share Posted February 22, 2003 Check out this link...I think it is table 3 that gives more info about bc's. Alot of other good info there also. http://www.stevespages.com/page8.htm Link to comment Share on other sites More sharing options...
tightloop Posted February 22, 2003 Share Posted February 22, 2003 GBM Is cost really an issue? You talk about dropping 2500 on your credit card to outfit a new rifle and scope, how about spending 150 to really understand what you are trying to do? (Edited by tightloop at 11:45 am on Feb. 22, 2003) Link to comment Share on other sites More sharing options...
shaughn leayme Posted February 22, 2003 Share Posted February 22, 2003 The Hornady reloading manuals have the BC's for thier bullets. Remington may be able to supply you thiers. The BC listed are only a guide, since the velocity affects the actual BC. To explain how to determine a bullets actual BC, would take a lot of effort and you would also need a ogive chart, that is part of what determines a bullets BC. Boat tail and bearing surface and even caliber affect what the outcome would be. 165 Horn sp .387 180 H sp .425 180 H spbt .452 190 H spbt .491 190 H BTHP Match .530 (Not suitable for hunting) 220 H rn .300 200 Nosler Spitzer Partition (couldn't find a listing for 220) .481 Link to comment Share on other sites More sharing options...
gingerbreadman Posted February 23, 2003 Author Share Posted February 23, 2003 Quote: from tightloop on 11:53 am on Feb. 22, 2003 GBM Is cost really an issue? You talk about dropping 2500 on your credit card to outfit a new rifle and scope, how about spending 150 to really understand what you are trying to do? (Edited by tightloop at 11:45 am on Feb. 22, 2003) would buying updated reloading manuels really help me out? i dont see what i missed here, i asked for the bo of these bullets so i could relate it to my trajectory program, thanks for the link and info -gbm- Link to comment Share on other sites More sharing options...
tightloop Posted February 23, 2003 Share Posted February 23, 2003 GBM The short answer is YES, it will help you. Most if not all current reloading manuals show the BC of each bullet they make at the pertinent velocities as well as other useful data. If you are loading a trajectory program which asks for this data, you will also need a chronograph to determine tha actual velocity and the instrumental velocity with each load and each bullet; another purchase. Have fun and be careful (Edited by tightloop at 11:23 am on Feb. 23, 2003) Link to comment Share on other sites More sharing options...
gingerbreadman Posted February 23, 2003 Author Share Posted February 23, 2003 Quote: from tightloop on 11:50 am on Feb. 23, 2003 GBM The short answer is YES, it will help you. Most if not all current reloading manuals show the BC of each bullet they make at the pertinent velocities as well as other useful data. If you are loading a trajectory program which asks for this data, you will also need a chronograph to determine tha actual velocity and the instrumental velocity with each load and each bullet; another purchase. Have fun and be careful (Edited by tightloop at 11:23 am on Feb. 23, 2003) well i got a birthday coming up maybe ill ask for a reloading manuel, the local gun show is also around the corner so ill look then, i allready have a chronograph..... -gbm- Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now