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+--- Thread: Barrel Length Query (/showthread.php?tid=9830)
Barrel Length Query - 1750Shooter - 09-09-2015
Gun club just setup a 1000 yd. range & we are going to be starting to shoot LR silhouette. I'm going to try to use my 18" Grendel AR for starters, but was wondering of going to a 24" barrel would be any help. Thanks for any input.
Barrel Length Query - CPT.CRAZY - 09-09-2015
I've shot my 18" out to 1200 yrds, but IMHO a longer barrel will make a difference if yiu are fighting any cross wind.
Barrel Length Query - LR1955 - 09-09-2015
1750Shooter Wrote:Gun club just setup a 1000 yd. range & we are going to be starting to shoot LR silhouette. I'm going to try to use my 18" Grendel AR for starters, but was wondering of going to a 24" barrel would be any help. Thanks for any input.
Since you will be using an optic, and given the ballistics of a 2500 fps or less bullet, and that you said you would use your 18" Grendel 'for starters', just use what you have and if you are happy then keep using it. The extra 50 fps or so you may get from a 24" barrel is something you probably can't measure and the longer barrel may give you more balance problems when shooting standing.
For any of the shooting sports, use what you have for starters while seeing what equipment works and what doesn't. Then spend money.
Remember that in the shooting sports, the easiest point you can make is the one you buy.
LR55
Barrel Length Query - LRRPF52 - 09-09-2015
What altitude is this range at?
Barrel Length Query - 1750Shooter - 09-09-2015
LRRPF52 Wrote:What altitude is this range at?
About 5500'
Barrel Length Query - LRRPF52 - 09-09-2015
You'll be fine with 18". Your station pressure is probably going to average ~24.4" Hg. The 18" will push 123gr supersonic well past 1400yds at that altitude.
Using the Litz G7 BC for the 123gr SMK (.260), you'll still be supersonic at 1450yds starting with a 2500fps mv. Your difference in drop at 1000yds between an 18" and 24" will be .8 Mils. Wind deflection difference will be .1 Mils.
Buy lots of ammo, and go shoot that bad boy.
Barrel Length Query - NugginFutz - 09-10-2015
I recently shot some proof loads in both my 18" BHW and 22" BHW. I shot the 123 AMAx through both, with CFE223 and IMR8208XBR. The 31.5 gr of CFE drove the 123 through the 18" barrel at 2509 fps, whereas the 22" barrel achieved 2647 fps. With 28.0 gr of 8208, the results were 2409 fps for the 18" and 2524 fps for the 22" barrel.
Code:
Temp Powder Charge 18" 22" Diff
81 'F CFE 223 31.5 2509 2647 138
81 'F IMR 8208 XBR 28.0 2409.2 2524.4 115.2Long and short of it is that Apples:Apples, the 4" of difference the two barrels gave me an average increase of 126 fps. Extrapolating, another 2" for the 24" barrel, it could offer an additional 60 fps, for a net of ~185 fps.
Also, it looks as if the CFE benefited from the additional length more than the 8208 did. I suspect that this had something to do with the 8208 burning faster than the CFE, but I have no other data to support this hypothesis.
So, should your shooting abilities exceed the reach of your current 18" setup, it looks to me like an additional 4-6" of barrel can up your MV between 115 - 207 fps (using the above loads as a baseline).
Barrel Length Query - biodsl - 09-11-2015
NugginFutz Wrote:I recently shot some proof loads in both my 18" BHW and 22" BHW. I shot the 123 AMAx through both, with CFE223 and IMR8208XBR. The 31.5 gr of CFE drove the 123 through the 18" barrel at 2509 fps, whereas the 22" barrel achieved 2647 fps. With 28.0 gr of 8208, the results were 2409 fps for the 18" and 2524 fps for the 22" barrel. (SNIP) Long and short of it is that Apples:Apples, the 4" of difference the two barrels gave me an average increase of 126 fps. Extrapolating, another 2" for the 24" barrel, it could offer an additional 60 fps, for a net of ~185 fps.
I'm pretty impressed with these numbers. They significantly exceed the general 20-24 fps per inch guideline. Not to totally hi-jack this thread, I'd be interested in hearing from other BHW 22" owners (I think there are a few) if they achieving similar velocities. 31.2 grains of CFE behind the 123 grain AMax is only netting me 2468 fps out of a 20" Lilja. Elevation is essentially sea-level.
Barrel Length Query - NugginFutz - 09-11-2015
biodsl Wrote:... 31.2 grains of CFE behind the 123 grain AMax is only netting me 2468 fps out of a 20" Lilja.
In the same series, I ran 31.2 gr of CFE through the 18" BHW and averaged 2488.8 fps with the 123 Amax. The BHW's do tend to run faster MV's for the same recipes. I believe it was GLShooter who said that the BHW P3's were essentially like getting an extra 2" of barrel.
biodsl Wrote:... Elevation is essentially sea-level.
At the muzzle, it really doesn't make any difference.
Barrel Length Query - 208Grendel - 10-01-2015
biodsl Wrote:I'm pretty impressed with these numbers. They significantly exceed the general 20-24 fps per inch guideline. Not to totally hi-jack this thread, I'd be interested in hearing from other BHW 22" owners (I think there are a few) if they achieving similar velocities. 31.2 grains of CFE behind the 123 grain AMax is only netting me 2468 fps out of a 20" Lilja. Elevation is essentially sea-level.
I'm pushing a 123 gr AMAX through a 22" BHW 1x8 twist at an average of 2,456 fps with 30.6 gr of CFE223. Elevation = approx. 2700 ft.
Barrel Length Query - SG4247 - 10-01-2015
For that type of shooting i would say 22".
I say 22" for both weight and MV in Grendel.
Personally, I always struggle with the 18" for long range. I have shot several and find them generally to be too light weight overall and too short making it difficult to keep steady on the rest or bags. They are very sensitive to trigger pull weight which is critical. My shortest AR long gun is 20" with weight added to the stock. The others are all 22"-26".
You have to be a really good to manage a short light barrel in the long game.
So the next question is barrel diameter...
Barrel Length Query - Grendelseeker - 08-09-2016
NugginFutz Wrote:In the same series, I ran 31.2 gr of CFE through the 18" BHW and averaged 2488.8 fps with the 123 Amax. The BHW's do tend to run faster MV's for the same recipes. I believe it was GLShooter who said that the BHW P3's were essentially like getting an extra 2" of barrel.
2 questions-
What kind of chrono are you using that gives you .decimal accuracy/readouts?? The doppler radar one? Or is this just a product of averaging odd numbers?
BHW's site does not show any 6.5G barrels. What's up with that? Are we still in Grendeland here?
Barrel Length Query - terrywick4 - 08-09-2016
Grendelseeker Wrote:2 questions-
What kind of chrono are you using that gives you .decimal accuracy/readouts?? The doppler radar one? Or is this just a product of averaging odd numbers?
BHW's site does not show any 6.5G barrels. What's up with that? Are we still in Grendeland here?
BHW uses 264 LBC I think
Barrel Length Query - NugginFutz - 08-09-2016
Grendelseeker Wrote:2 questions-
What kind of chrono are you using that gives you .decimal accuracy/readouts?? The doppler radar one? Or is this just a product of averaging odd numbers?
BHW's site does not show any 6.5G barrels. What's up with that? Are we still in Grendeland here?
My chronographs both read to the nearest fps (neither is the LabRadar). The decimal cited in that post was simply the average of the shot string(s), carried to the nearest 1/10th.
terrywick4 Wrote:BHW uses 264 LBC I think
Correct. While they had a limited run of SAAMI 6.5 Grendel chambers, they've now gone back to exclusively chambering the .264LBC.