Hi all - Happy New Year

I'm preparing for my first high power match this weekend and will not be able to sight in at all ranges until practice time just before the match.

When zeroed at 100 yards, I needed an additional 5 1/4 minutes to get to 200 yards. Is there a way to predict how much more elevation I'll need to reach pigs, turkeys and rams?

.316 calibre, 157.3 grain, LFN cast bullet, with gas check, estimated B.C. is around 0.2291 based on looking at similar designs on NOE web-site
18.4 grains IMR 4227

Thanks,
-Steve

I zero my 260 at 200m These are the numbers on my turret.
200 - 0
300 - 2
385 - 5
500 - 10

That should get you on the animals.

I have the Sierra ballistic program. I need the FPS to get the bullet drop. What caliber is the gun?

JIM PENDLETON

Jerry G wrote:I zero my 260 at 200m These are the numbers on my turret.
200 - 0
300 - 2
385 - 5
500 - 10

That should get you on the animals.

Thanks Jerry

JIM PENDLETON wrote:I have the Sierra ballistic program. I need the FPS to get the bullet drop. What caliber is the gun?

JIM PENDLETON

Hi Jim,

It's a Long Branch No. 4 Mk 1* action with Churchill Arms wood and 5 groove barrel. Groove diameter is .3155, so I size to .316 - I don't know actual muzzle velocity; am guessing that it is in the 1800 FPS range based on similar reports for my light load. I guess it's time to invest in a chronograph. Any recommendations?

.316 calibre LFN bullet, weighs 157.3 grains before sizing with a .30 calibre gas check
18.4 grains IMR 4227
estimated muzzle velocity - 1800 FPS range
estimated B.C. is around 0.2291
measured drop between 100 yards and 200 yards is 5 1/4 minutes

Is the Sierra ballistics program a good "starter" program for new casters?

Thanks,
-Steve

This one is a pretty good trajectory calculator;

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

i don't shoot cast rifle bullets, so take this with a grain of salt. With a BC of .300 and a MV of 1950 I get something like 5, 13, 19, and 34 minutes for CPTR. Your MV and BC estimates needed revision to match the two data points you provided.

The jbm ballistics calculators are online, so you can play with the numbers to get some idea of the values when you change inputs.

http://www.jbmballistics.com/ballistics ... tors.shtml

Calculations based on guesstimates of BC and MV are only useful as a very rough guide.

I have 2 shootable Lee Enfields. One is a Churchill arms that I bought mail order from either Eatons or Sears. It came with a scope and ammo. The other is a full military Long Branch with bayonet made in 1950. I played with the FPS to get your 6" drop at 200yards. I came up with 2000FPS. Using that the drops I came up with were

100 0
200 6MIN
300 14 MIN
385 23MIN
500 38 MIN

I shoot a lot of cast bullets and I found the Sierra program close. I have the older program which works good but I hear the new one is better. I have a Shooting Chrony with a remote readout which works quite well.
I do not think that the bullet has enough power to knock the ram over. I have the same problem in Pistol Lever Action. I use a 22LR. The only way I can get a ram is to hit in the rear leg and shove it off the stand. I usually get zero rams.
Let us know how you make out.

JIM PENDLETON

mshelton wrote:This one is a pretty good trajectory calculator;

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

Brd_Hntr wrote:i don't shoot cast rifle bullets, so take this with a grain of salt. With a BC of .300 and a MV of 1950 I get something like 5, 13, 19, and 34 minutes for CPTR. Your MV and BC estimates needed revision to match the two data points you provided.

The jbm ballistics calculators are online, so you can play with the numbers to get some idea of the values when you change inputs.

http://www.jbmballistics.com/ballistics ... tors.shtml

Calculations based on guesstimates of BC and MV are only useful as a very rough guide.

Thanks for the links guys - this is exactly what I needed.

Playing with the numbers, I was able to adjust muzzle velocity to match my two data points and come up with a drop chart. Projected MV is 1980. From a 100 yard 0, I'll need 5.3, 13.1, 22.0 and 36.2 minutes for CPTR. With this info I'll have reasonable starting points for sighting in.

Many thanks!
-Steve

JIM PENDLETON wrote: I played with the FPS to get your 6" drop at 200yards. I came up with 2000FPS. Using that the drops I came up with were

100 0
200 6MIN
300 14 MIN
385 23MIN
500 38 MIN

I shoot a lot of cast bullets and I found the Sierra program close. I have the older program which works good but I hear the new one is better. I have a Shooting Chrony with a remote readout which works quite well.
I do not think that the bullet has enough power to knock the ram over. I have the same problem in Pistol Lever Action. I use a 22LR. The only way I can get a ram is to hit in the rear leg and shove it off the stand. I usually get zero rams.
Let us know how you make out.

JIM PENDLETON

Thanks for your help and research Jim. I think you're right about not having enough power to deal with rams. I'll have to work on a hotter load and/or heavier projectile.

-Steve

Jbm is really good. I went from 100 yard zero to on target at 1000 yards using jbm and guessing my muzzle velocity.

I publish a ballistics spreadsheet for Excel for free. Makes stuff like this ridiculously easy. I use the same basic math as JBM (Pejsa model). It's what I use for getting my initial dope before a match. Supports temp changes throughout the day. Does not calculate subsonic flight trajectories so with <2000fps stuff hitting the rams there may be some tweaking needed. Support is free and unusually fast (unless I'm at a match). It's made to be printed out. I also offer printed copies on Revlar waterproof media. SC members get any of my offerings at 50% off which is substantially under my production cost.

Download at ballisticxlr.com and get support at ballisticxlr@gmail.com.

Revlar is made from plastic. It's completely waterproof, tear proof and abrasion resistant. For more info check out www.relyco.com pages are about 70 cents a piece but if you call them up they'll send you 3 pages of any thickness for free to try out. Works on most laser printers but you'll want to set the corona wire temperature to high for best results (sometimes this is via the humidity setting).

JIM PENDLETON wrote:Let us know how you make out.

I had fun! And, I knocked over a few critters too.

The ballistics programs helped me get a zero on paper at the reduced ranges:

caseyboy wrote:The reduced range is 200yds, 240yds, 280yds and 310yds with the animals scaled down appropriately for the distances.

After sighting in on paper, I had a few minutes to try off-hand and was surprised when my first shot knocked over a ram; the same one I was aiming at. I did much better during practice than during the match.

We shot 2 matches, and I got to start on turkeys.

Compared to paper, I was shooting consistently low, and ended up adding a couple MOA at each distance when shooting critters offhand compared to shooting paper from the bench.
My scores were about what I expected:
Match 1: 3,0,2,1 C,P,T,R for 6/40 (holding high on most critters)
Match 2: 3,3,2,2 C,P,T,R for 10/40 (adjusting scope upwards after 1'st bank until a few missed shots were high instead of them all low)

I've got lots to work on:
- bench technique for load development
- a load that groups 4" or better @ 200 yards for the LBT 316-160-LFN (and then repeat with the NOE 316-202-RN)
- a lighter trigger
- bedded action

A big thanks to the friendly shooters at Alberni Fish and Game for your patience and warm welcome. Also, thanks to the Steel Chickens community for helping me get started.

I'll be back...
-Steve