Custom Drop Compensator

[spradley19]

I have been thinking about having a drop compensator made for my .300 RUM. I have a 6.5x20x50 Leupold VXIIILR scope. I do my own reloading and have a load worked up that is working pretty good. I was hoping someone has already been down this road and could give me some advice or answers. Do drop compensators work? If so, how far out are they accurate? I would appreciate any information. Thanks

[Buffalobob]

Do you know how to use the ballistics program - Eskimo JBM or other good ballistics program? It will help a lot if you do.

Secondly, how far would you like to shoot.

Thirdly, do you travel to far away places to hunt?

Fourthly, it is easy to make your own.

Fifthly, it is hard to BDC the wind so you pretty much need to learn to dial anyway.

Finally, with your scope, a simple drop chart is far easier than a BDC but if you prefer a BDC that is fine also.

If you can answer the questions above then I can help you with your question.

[spradley19]

I have never used any of the ballistics programs. I am sure I could figure it out though. I have used some of the ballistic sites on the web.

At this point I do not intend to shoot over 1200 yards. I do not travel to far off places. I realize altitude needs consideration. I hunt anywhere from 2000ft to about 850 ft. About 90% of the time I would say 2000ft to 4000ft.

I have never considered making my own. I have made my own drop charts and have no problem going that route if it is better. Sounds like it might me easier.

I just wanted to know if they are accurate and reliable.

Finally I realize wind is a horse of a different color. I feel it needs to be addressed with every pull of the trigger.

[Buffalobob]

First things first- working with a drop chart is a lot more flexible and in the end you will learn more.

If you wish to make your own, then I updated a thread I started a few months ago and being as I have the exact same scope as you, I can help you through making your own if you wish. The scope in the pictures is obviuosly a Nightforce but the principle is the same with a Luepold.

Old Fashioned Turret Wraps.

This is JBM- Eskimo

JBM - Calculations - Trajectory


You should go there and check the differences in adjustments at 1K for a 50 degree change in temperature and make a note of it. Then do the same for a 1000 ft change in altitude and make a note of the difference.

In case you overlook it, the second column over on the right side at the bottom where it says "Drop Units- second column" should be in "MOA" because that is what your scope is adjusted in.

The checking of the difference temperature and altitude changes make is important for you to personally do so you know for a fact what your particular cartridge and rifle do under different conditions. Don't just take my word for it. Remember this is the internet and you can get some really bad advice.



If you should decide to just go with a drop chart you will also have to correct it for temperature changes. The temperature I normally enter is the early morning temperature for the time of year I am hunting. its up to you what you enter but you need to remember it and correct for it if need be.

if you wish to have a company custom make you one then that is up to you and I have no advice to offer. I make my own.

[300rum]

Hi Spradley

Fallow Buffolobob advice, and do a chart for every location where you are hunting.
Also you can do in this way:

Take a sticker paper cut it to the same width as your target knobs and stick it to the knob.
Get a ballistic chart for your hunting location in clicks and:
- Mark your zero
-Dial in elevation from 50yard to 50yards and mark with a marker on the sticker.
- When you are done you will have a full roll of paper with gradation from 100 to 1000yards attached to your elevation knobs.
Easy and very cheap $2.00 US.

Don’t forgot to dial back to zero after you are done.

Chris

[filatiev 2]

hi Spradley,
I've had very good luck with sending my scope tp Leupold and having them do this. You can give them different altitudes and they can give you different dials. I shoot a 7 stw and shot a bull at 531 and 466 yards and my buck at 432 yards this year.

Roy

[vinny]

I don't know if I can help you but I got an Ipaq pda for xmas with Exbal ballistics software. Now I plugged in my #'s for a 308 baer and shot out to 850 yards limited by space. The drop chart it produced was accurate in 50 yard increments, as far as I can tell. If you would like pm or email me with your #'s and I'll plug them in and send you what I get. It'll be a good lesson for me, and I might be able to help someone in the process. Let me know.
Vinny