Short barrel ballistics

[CLP308]

Both of my rifles are carbines with 18 1/2" barrels. The first is a Rem 788 in .243 my father bought new in 1980 as a truck gun when we farmed. We went to Oklahoma that year(1980) prarie dog hunting. I know it will reach out there because he was shooting them out past 500 yds with it sporting an old Weaver 10X target scope.

My other rifle is a Rem Model Seven in .308 Win. I bought it to be my mountain gun for white tails here in PA. I bought it tin 1997 new and love it because its so light and easy to carry.

My question is how much velocity am I giving up compared to th 24" barrels? I have shot under two deer in the last couple of years that were out at 200-250 yards with my .308. I didn't think I would need any holdover looking at the ballistics charts, but evidently the short barrel is affecting the .308 more than the .243. I shoot 168gr Barnes XLCBT with 44gr of Accurate 2230, this is supposed to give 3090 fps out of a 24" barrel. I have also used H4895, but don't get as good of accuracy. My Data is right from Barnes and is the max load with no pressure signs.

Thanks,
Chris

 

[NomadPilot]

At least one guy on SH shoots his 18" 308 at 1000 yards, so there's no reason you can't kill a deer at 250.

YouTube - 18" Barrel to 1000 yards

Create an accurate ballistics table (with the real MV, not supposed) and you should have no problem.

 

[CLP308]

Does a faster burning powder have less difference since it will completely burn in the shorter barrel? I dont have a chrono or long distance range. Eventually I will get a chrono.

 

[NomadPilot]

A faster powder will certainly be better suited to your 18" barrel than a slower powder. However, with that said, Hodgdon lists some 308 pistol loads with Varget and 4895, both of which are slower than your 2230.

I guess what I'm getting at is this: What you're using will probably work just fine. You just need to learn its trajectory, build an accurate dope card, validate the predicted drop, and go from there.

 

[Ernie]

Since I do not have any rifles, all of my LR rigs are single-shot specialty handguns with barrels from 15 inches to just under 18 inches.
I have chamberings from the 223 Rem. to the 338 Lapua Improved (338 AX).
I routinely shoot out to 1200 yards on steel with these handguns, and sometimes further.
I would would guesstimate about 40 fps per inch,but 35 fps per inch may be closer. I assume I will lose about 300 fps compared to typical rifle lengths.
I do not use the faster powders.
Example
6-284 with 115 DTACs - H-4831sc
6.5-284 H-4350 (140 VLD's) and sometimes Hybrid 100V
284 Win (140 NBT) H-4831sc
7mm Rem Mag Imp (180 JLK) H-1000
6.5 WSM (130 Berger) H-1000
7mm Dakota (200 gr. Wildcat) Retumbo
338 AX Retumbo (300 grain SMK or Berger)
7mm SAUM H-1000 (162 A-Max)

Both of my rifles are carbines with 18 1/2" barrels. The first is a Rem 788 in .243 my father bought new in 1980 as a truck gun when we farmed. We went to Oklahoma that year(1980) prairie dog hunting. I know it will reach out there because he was shooting them out past 500 yds with it sporting an old Weaver 10X target scope.

My other rifle is a Rem Model Seven in .308 Win. I bought it to be my mountain gun for white tails here in PA. I bought it tin 1997 new and love it because its so light and easy to carry.

My question is how much velocity am I giving up compared to th 24" barrels? I have shot under two deer in the last couple of years that were out at 200-250 yards with my .308. I didn't think I would need any holdover looking at the ballistics charts, but evidently the short barrel is affecting the .308 more than the .243. I shoot 168gr Barnes XLCBT with 44gr of Accurate 2230, this is supposed to give 3090 fps out of a 24" barrel. I have also used H4895, but don't get as good of accuracy. My Data is right from Barnes and is the max load with no pressure signs.

Thanks,
Chris

 

[CLP308]

I looked back through my load notes and I was mistaken. The load I shot under with was 42 gr of H4895for a published velocity of 2750. I'm new to this long range thing but am looking at buying an old BDL my local shop has in .264 Win Mag.$500 bucks and the ser # puts it in the mid '60s. Or would I be better off with a newer gun in 7 Mag? Im kinda drawn to old/differrent guns.

 

[liltank]

I'm shooting 178 and 175 BTHP's right around 2500fps in my 18". Haven't really found a holy grail of powders to improve on that. I am currently using IMR4895. Seems to work pretty good.

Tank

 

[CLP308]

Barnes no longer makes the XLC which achieved higher velocities than the TSX. But the Accurate 2520 and 2230 both show higher velocities than either 4895. And I get better accuracy. I will have to find a spot where I can set up targets every 50 out to 500 yards. What kind of targets are best to use? Whats the proper way to set up for checking trajectory?

 

[Hntbambi]

I too have a Rem 7 in 308 Win. I compared Southwest Ammo's 175 SMK load in it vs my 700PSS. The 700 PSS with 24" barrel is shooting 2650 fps and the Model 7 with 18.5" barrel is shooting 2495 fps. Which is about normal for each inch of barrel difference for a cartridge of that size. Mine is not accurate enough to consider it a 500 yards deer gun though.

 

[1300meters]

well i answered a similar question. I shoot two 7mags one with a 24 inch tube one with a 26 inch tube both top of the line same ammo handloads. only 25fps diff. forget published drop tables. suggest shooting @ 200 yd. zero then move on out to 300.If you shoot longrange move on out note temp,humidity wind. make your comeups for that weapon and load it will give you a baseline.checking all attachments for any loose or un-even torque. good shooting.gun)