So I recently picked up a LR-308 with the heavy 24" stainless bbl. I'm seriously considering cutting it down to 20" and threading it at the same time. The riddle is: Should I cut the barrel at all? The rifle will eventually be a supressor host and I'd like to have some manueverability with the rifle with or without the can attached. This will be a field gun and not a bench shooter. I'm pretty new to the long range game so this is pretty much uncharted water for me.
- Thread starter Surveyor1653
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Re: To cut or not to cut
If you're going spend the money to have it cut down,crowned (I'm assuming), and threaded, and you know it will be suppressed in the future I'd take it down to 18". Taking 6" off the muzzle would probably be equal to a can, a Ti can anyway. Especially if it's a heavy contour SS barrel. Just my opinion.
If you're going spend the money to have it cut down,crowned (I'm assuming), and threaded, and you know it will be suppressed in the future I'd take it down to 18". Taking 6" off the muzzle would probably be equal to a can, a Ti can anyway. Especially if it's a heavy contour SS barrel. Just my opinion.
Re: To cut or not to cut
I agree with jason. Those LR 308's are heavy guns for a field gun. I would cut it to 18 also. In fact I am doing the same thing with a 24" creedmoor at the moment. You lose much less velocity than people think in the 2500-2900 FPS range.
Put "velocity loss per inch of barrel" in google and read some of the articles and tests people have done.
This was a pretty good article on Chuck Hawks site that goes into it ..........
"Velocity loss (or gain)
It is worth noting that the velocity figures published in ammunition brochures and reloading manuals are sometimes taken in barrels different in length from those supplied on many rifles. I have seen various estimates of how much velocity is lost (or gained) when a barrel is not the same length as the test barrel in which a cartridge was chronographed. Here are some of them.
The 2001 Edition of the Shooter's Bible states, in the introduction to the Centerfire Rifle Ballistics section, "Barrel length affects velocity, and at various rates depending on the load. As a rule, figure 50 fps per inch of barrel, plus or minus, if your barrel is longer or shorter than 22 inches." However, they do not say what category of load to which this 50 fps average pertains.
Jack O'Connor wrote in The Rifle Book that, "The barrel shorter than standard has a velocity loss which averages about 25 foot-seconds for every inch cut off the barrel. Likewise, there is a velocity gain with a longer barrel." He went on to illustrate this using a .30-06 rifle shooting 180 grain bullets as an example, so his estimate was obviously for rifles in that general performance class.
Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:
• MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps.

The 45th Edition of the Lyman Reloading Handbook also has a table showing Center Fire Rifle Velocity Vs. Barrel Length. Their figures apply to barrels between 20 and 26 inches in length and agree with the Remington figures. The Lyman table shows the following approximate velocity changes:
• For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.
The 43rd edition of the Lyman reloading Handbook gave some concrete examples of velocity loss for specific calibers and loads. The Lyman technicians chronographed some high velocity cartridges in rifles with barrels ranging in length from 26 inches down to 22 inches with the following results:
• The average loss for the .243 Win./100 grain bullet was 29 fps per inch.
The average loss for the .264 Win. Mag./140 grain bullet was 32 fps per inch.
The average loss for the .300 H&H Mag./220 grain bullet was 25 fps per inch.
For standard high intensity cartridges in the same test, the Lyman technicians chronographed the cartridges in barrel lengths ranging in length from 24 inches down to 20 inches with the following results:
• The average loss for the .270 Win./130 grain bullet was 37 fps per inch.
The average loss for the .270 Win./150 grain bullet was 32 fps per inch.
The average loss for the .300 Sav./180 grain bullet was 17 fps per inch.
The average loss for the .30-06/180 grain bullet was 15 fps per inch.
The average loss for the .35 Rem./200 grain bullet was 11 fps per inch.
After a bunch of disclaimers, the Lyman people concluded, "The rule of thumb is that high speed, high pressure cartridges shed more speed in short barrels than do the low speed, large bore types." It's funny, but that is what I had suspected all along!"
Good luck
I agree with jason. Those LR 308's are heavy guns for a field gun. I would cut it to 18 also. In fact I am doing the same thing with a 24" creedmoor at the moment. You lose much less velocity than people think in the 2500-2900 FPS range.
Put "velocity loss per inch of barrel" in google and read some of the articles and tests people have done.
This was a pretty good article on Chuck Hawks site that goes into it ..........
"Velocity loss (or gain)
It is worth noting that the velocity figures published in ammunition brochures and reloading manuals are sometimes taken in barrels different in length from those supplied on many rifles. I have seen various estimates of how much velocity is lost (or gained) when a barrel is not the same length as the test barrel in which a cartridge was chronographed. Here are some of them.
The 2001 Edition of the Shooter's Bible states, in the introduction to the Centerfire Rifle Ballistics section, "Barrel length affects velocity, and at various rates depending on the load. As a rule, figure 50 fps per inch of barrel, plus or minus, if your barrel is longer or shorter than 22 inches." However, they do not say what category of load to which this 50 fps average pertains.
Jack O'Connor wrote in The Rifle Book that, "The barrel shorter than standard has a velocity loss which averages about 25 foot-seconds for every inch cut off the barrel. Likewise, there is a velocity gain with a longer barrel." He went on to illustrate this using a .30-06 rifle shooting 180 grain bullets as an example, so his estimate was obviously for rifles in that general performance class.
Other authorities have tried to take into account the different velocity ranges within which modern cartridges operate. The Remington Catalog 2003 includes a "Centerfire Rifle Velocity Vs. Barrel Length" table that shows the following velocity changes for barrels shorter or longer than the test barrel length:
• MV 2000-2500 fps, the approximate change in MV per 1" change in barrel length is 10 fps.
MV 2500-3000 fps, the approximate change in MV per 1" change in barrel length is 20 fps.
MV 3000-3500 fps, the approximate change in MV per 1" change in barrel length is 30 fps.
MV 3500-4000 fps, the approximate change in MV per 1" change in barrel length is 40 fps.

The 45th Edition of the Lyman Reloading Handbook also has a table showing Center Fire Rifle Velocity Vs. Barrel Length. Their figures apply to barrels between 20 and 26 inches in length and agree with the Remington figures. The Lyman table shows the following approximate velocity changes:
• For rifles with muzzle velocities in the 1000-2000 fps range, the change in velocity for each 1" change in barrel length is 5 fps.
For rifles with muzzle velocities in the 2001-2500 fps range, the change in velocity for each 1" change in barrel length is 10 fps.
For rifles with muzzle velocities in the 2501-3000 fps range, the change in velocity for each 1" change in barrel length is 20 fps.
For rifles with muzzle velocities in the 3001-3500 fps range, the change in velocity for each 1" change in barrel length is 30 fps.
For rifles with muzzle velocities in the 3501-4000 fps range, the change in velocity for each 1" change in barrel length is 40 fps.
The 43rd edition of the Lyman reloading Handbook gave some concrete examples of velocity loss for specific calibers and loads. The Lyman technicians chronographed some high velocity cartridges in rifles with barrels ranging in length from 26 inches down to 22 inches with the following results:
• The average loss for the .243 Win./100 grain bullet was 29 fps per inch.
The average loss for the .264 Win. Mag./140 grain bullet was 32 fps per inch.
The average loss for the .300 H&H Mag./220 grain bullet was 25 fps per inch.
For standard high intensity cartridges in the same test, the Lyman technicians chronographed the cartridges in barrel lengths ranging in length from 24 inches down to 20 inches with the following results:
• The average loss for the .270 Win./130 grain bullet was 37 fps per inch.
The average loss for the .270 Win./150 grain bullet was 32 fps per inch.
The average loss for the .300 Sav./180 grain bullet was 17 fps per inch.
The average loss for the .30-06/180 grain bullet was 15 fps per inch.
The average loss for the .35 Rem./200 grain bullet was 11 fps per inch.
After a bunch of disclaimers, the Lyman people concluded, "The rule of thumb is that high speed, high pressure cartridges shed more speed in short barrels than do the low speed, large bore types." It's funny, but that is what I had suspected all along!"
Good luck
Re: To cut or not to cut
I have a lr308 that used to be a 24" bbl. Had it cut down to 16" threaded and crowned. It shot 1/2 moa to 500yds at 24". I was worried what it would do to the accuracy, but it shot a little less than 3/4" moa afterwards. It sure made it easier to manuever it around through the trees. Never chronod the load to know what the actual velocity loss was.
I have a lr308 that used to be a 24" bbl. Had it cut down to 16" threaded and crowned. It shot 1/2 moa to 500yds at 24". I was worried what it would do to the accuracy, but it shot a little less than 3/4" moa afterwards. It sure made it easier to manuever it around through the trees. Never chronod the load to know what the actual velocity loss was.
Re: To cut or not to cut
I'd definetly go 18 if you are running a can.
I'd definetly go 18 if you are running a can.
Re: To cut or not to cut
A good frieend of mine cut his DPMS heavy barrel down to 18 inch from 24 and threade it, it shoots as good as before and is very manageable with a can on.
hope this helps.
A good frieend of mine cut his DPMS heavy barrel down to 18 inch from 24 and threade it, it shoots as good as before and is very manageable with a can on.
hope this helps.
Re: To cut or not to cut
Hey, lads: Thanks very much for all of the feedback. 'Going to do a little bit more reading, as suggested, and consult with the 'smith who's doing the cut-down work for me.
A side note: The barrel will be re-crowned when it's cut and threaded.
I have some furniture, rings, and glass picked out. Now I just have to start buying it a piece at a time. The barrel work is going to be surprisingly inexpensive. I've already started picking up spare mags, as I got some smoking deals on them. Hopefully I'll have it up and running in the next few months and can start getting some quality time with her. Thank you, again, for the input.
Hey, lads: Thanks very much for all of the feedback. 'Going to do a little bit more reading, as suggested, and consult with the 'smith who's doing the cut-down work for me.
A side note: The barrel will be re-crowned when it's cut and threaded.
I have some furniture, rings, and glass picked out. Now I just have to start buying it a piece at a time. The barrel work is going to be surprisingly inexpensive. I've already started picking up spare mags, as I got some smoking deals on them. Hopefully I'll have it up and running in the next few months and can start getting some quality time with her. Thank you, again, for the input.
Re: To cut or not to cut
Surveyor,
I have a NIB 18" lightweight DPMS LR-308L barrel that i'm not doing anything with. This barrel weighs just over 2lbs, so its actually lightweight.
If you cut down your 24" barrel to 18", you will only loose about 1-pound. If you dont believe me, check out the difference between teh DPMS LR-308 & the LR-308B only 1.55pounds difference in weight. some of that is also the shorter hndguard.
I can trade it for your 24" barrel, or sell it outrigth...PM me if interested.
Surveyor,
I have a NIB 18" lightweight DPMS LR-308L barrel that i'm not doing anything with. This barrel weighs just over 2lbs, so its actually lightweight.
If you cut down your 24" barrel to 18", you will only loose about 1-pound. If you dont believe me, check out the difference between teh DPMS LR-308 & the LR-308B only 1.55pounds difference in weight. some of that is also the shorter hndguard.
I can trade it for your 24" barrel, or sell it outrigth...PM me if interested.
Re: To cut or not to cut
Is the barrel new or used? Depending on how much use it has seen I would just buy a 18" barrel and have it threaded for the can.
Regardless I would go to 18" for a can host based on what you said you want.
Is the barrel new or used? Depending on how much use it has seen I would just buy a 18" barrel and have it threaded for the can.
Regardless I would go to 18" for a can host based on what you said you want.
Re: To cut or not to cut
I cut one down to 18 a while back it shot better short.It makes it more rigid.I didnt even have to open the gas hole.
I cut one down to 18 a while back it shot better short.It makes it more rigid.I didnt even have to open the gas hole.
Re: To cut or not to cut
As another option, a buddy had the DPMS 24" fluted barrel and wasn't happy with the weight and balance or the accuracy. He sold the barrel on Gunbroker and bought a 20" Lilja, and had a much better balanced, more accurate rifle with very little cash outlay.
As another option, a buddy had the DPMS 24" fluted barrel and wasn't happy with the weight and balance or the accuracy. He sold the barrel on Gunbroker and bought a 20" Lilja, and had a much better balanced, more accurate rifle with very little cash outlay.
Re: To cut or not to cut
Can't cut a rifle length to 16...
I do say 18" though. Wish I'd have gone that route when I had my 20" made.
Can't cut a rifle length to 16...
I do say 18" though. Wish I'd have gone that route when I had my 20" made.
Re: To cut or not to cut
Wow. More to think about. The bbl is used but barely. It's interesting all of the comments directing toward the 18" bbl. Some of the "wisdom" I've received directed me away from the 18" for a variety of reasons. Good info, guys. Thanks, again.
Wow. More to think about. The bbl is used but barely. It's interesting all of the comments directing toward the 18" bbl. Some of the "wisdom" I've received directed me away from the 18" for a variety of reasons. Good info, guys. Thanks, again.
Re: To cut or not to cut
I would go with 18"
I would go with 18"
Re: To cut or not to cut
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Surveyor1653</div><div class="ubbcode-body">Wow. More to think about. The bbl is used but barely. It's interesting all of the comments directing toward the 18" bbl. Some of the "wisdom" I've received directed me away from the 18" for a variety of reasons. Good info, guys. Thanks, again. </div></div>
I have found that most older guys who have not spent much time looking into why they have things the way they do but rather that is how they use it so you should also(I wouldn't call it wise advice) I can do everything I want to do with a 18"
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Surveyor1653</div><div class="ubbcode-body">Wow. More to think about. The bbl is used but barely. It's interesting all of the comments directing toward the 18" bbl. Some of the "wisdom" I've received directed me away from the 18" for a variety of reasons. Good info, guys. Thanks, again. </div></div>
I have found that most older guys who have not spent much time looking into why they have things the way they do but rather that is how they use it so you should also(I wouldn't call it wise advice) I can do everything I want to do with a 18"
Re: To cut or not to cut
Inogame said:
Re: To cut or not to cut
I have a couple of other questions regarding this project. Given that the rifling in these DPMS barrels is 1:10, what effect (if any) will that have with an 18" bbl?
Also: I had considered having a thread protector made from the cut barrel section. Should I do this and just shoot it slick or install a comp/brake? I had thought about going ahead with the YHM Phantom adapter but if I change my mind on the can I have someone else's adapter on my rifle. Whether I do that or put another can-incompatible piece on the muzzle I'm still buying two pieces of gear so.... Any recommendations on brakes? I was thinking about the JP Bennie Cooley pending the suppressor purchase.
I have a couple of other questions regarding this project. Given that the rifling in these DPMS barrels is 1:10, what effect (if any) will that have with an 18" bbl?
Also: I had considered having a thread protector made from the cut barrel section. Should I do this and just shoot it slick or install a comp/brake? I had thought about going ahead with the YHM Phantom adapter but if I change my mind on the can I have someone else's adapter on my rifle. Whether I do that or put another can-incompatible piece on the muzzle I'm still buying two pieces of gear so.... Any recommendations on brakes? I was thinking about the JP Bennie Cooley pending the suppressor purchase.
Re: To cut or not to cut
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gpz750</div><div class="ubbcode-body">
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: gpz750</div><div class="ubbcode-body">
Inogame said:
Re: To cut or not to cut
did you cut it yet??
did you cut it yet??
Re: To cut or not to cut
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: attherange</div><div class="ubbcode-body">did you cut it yet?? </div></div>
Haha, dang: You guys work faster than me. No, it's going in on Sunday. I'm having the 'smith at our home range work on it. I'm going out to shoot and figure I'll drop it off while I'm there.
I've decided to go on down to 18" and see what kind of stick I get. Our range only goes out to 300 but I'll be able to get onto a 1200m range in September. Probably not going to have time (for sure the talent) to stretch the legs that far but I'll be able to see how she handles out around 600 and 800, at least. Better than me, probably.
If you guys want evidence I'll put some pictures up starting with it intact and then go on from there.
I can't tell you how much I appreciate the input.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: attherange</div><div class="ubbcode-body">did you cut it yet?? </div></div>
Haha, dang: You guys work faster than me. No, it's going in on Sunday. I'm having the 'smith at our home range work on it. I'm going out to shoot and figure I'll drop it off while I'm there.
I've decided to go on down to 18" and see what kind of stick I get. Our range only goes out to 300 but I'll be able to get onto a 1200m range in September. Probably not going to have time (for sure the talent) to stretch the legs that far but I'll be able to see how she handles out around 600 and 800, at least. Better than me, probably.
If you guys want evidence I'll put some pictures up starting with it intact and then go on from there.
I can't tell you how much I appreciate the input.
Re: To cut or not to cut
ehehe, just giving you a little push, not trying to rush you. 18" will handle great even with a can on it. I shot an 18 inch .308 bolt at 600 and it was lots of fun, 750 was a bit more difficult than a longer barreled one, technique had to be near perfect, it was a good chalenge.
I am sure you'll enjoy yours.
cheers.
ehehe, just giving you a little push, not trying to rush you. 18" will handle great even with a can on it. I shot an 18 inch .308 bolt at 600 and it was lots of fun, 750 was a bit more difficult than a longer barreled one, technique had to be near perfect, it was a good chalenge.
I am sure you'll enjoy yours.
cheers.
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