ball park speeds of a 140 amax in a 260 rem with a 21" barrel

LongArm

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Ball park speeds of a 140 Amax in a 260 rem with a 21" barrel? I am looking to build a new rifle. I will be shooting out to 1000yrds with a can. I do not want to have to turn the case necks. This will be mainly a mid/long range competition rifle. I would like to be close to 2800 with out pushing it to max load. Has anyone tried this? Any info will help.

Thanks,
LongArm
 

bm11

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I have a 22" and 2800's are possible with RL-17. H4895 in unsafe quantities gets you into the 2900's (loading error.)
 

Rob01

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This will be mainly a mid/long range competition rifle.
Go 24-26" if being competitive in long range competitions is your goal. You just want to throw lead then cut it short. If you don't believe me look at the line of rifles at a major long range tactical match. Bet 24-26" outnumber shorter barrels 10-1. You are building the rifle with a goal. Make the right choice for the desired goal.
 

Pusher591

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I know you stated .260 but I have a 6.5 Creedmoor with a 21" Rock barrel. My current lot of factory 140 Amax clocks consistently between 2800-2830. This is unusual but it does and the dope is dead on out to 756 yards. I dont know if its the barrel, the chamber, the ammo or a mixture of all of it. Like I said thats faster then the average for that barrel lenght in that caliber. I do see consistent .260's shooting between 2725-2775 with the 140 Amax's, I just don't know what loads they are running.
 

LongArm

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I will be running a 30p-1 can and wanted a rifle that was not 100" long to swing around and run with. I agree on the 24" barrels in comps but wanted to see if it could be done with a shorter/suppressed set up.
 

Pusher591

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Don't for get you will pick up probably 10-30 fps for freebore boost. Not all guns pick it up, but most I have seen do.
 

LongArm

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With the 24" barrel I was running I would get about 50-60fps (2830 to 2885ish) boost with my 30p1 can. That is what got me thinking about going with a shorter barrel with this build.
 
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Pusher591

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COOL! My shorty .308 use to pick up around 40-50 fps with a Surefire 762SS. As far as the length goes I'm very happy with my 21" barrel. Its the perfect balance for me.
 

turbo54

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You'll easily be able to hit 2700. 2750 is likely. 2800 is possible, but not to be counted on.

Don't forget that a 140amax @ 2700 is a DOG at 1000 yards... [/sarcasm]
 

Rob01

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I will be running a 30p-1 can and wanted a rifle that was not 100" long to swing around and run with. I agree on the 24" barrels in comps but wanted to see if it could be done with a shorter/suppressed set up.
Your money and time. Best of luck to you. Just giving you some info about what you will be up against.
 

LongArm

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I have a 22" and 2800's are possible with RL-17. H4895 in unsafe quantities gets you into the 2900's (loading error.)
Do you use R17 in yours? I have heard that the guys at TBAC use R17 exclusively for their 260's. I have also heard that is it temperamental when it comes to hot and cold and lot to lot.
 

427Cobra

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10-15 off the lands with Win 7-08 brass resized to 260, 43.7 of H4350 and CCi 200/BR2 primers yielded 2810 in my 26 inch 8 twist Bartlein
 

robp5t

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I am running 39.4 grains of Hodgon 100v and WLRM primers with the 140 Amax. I get very consistent 2700 to 2715 and is wicked accurate. I have a 22 inch Obermeyer 1in 8.5 barrel. I have not had time to shoot it at distance yet only at 100 yards.
 

LongArm

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OK so I built a 260 Remington on a defiance deviant action. I put a Obermeyer 1/8.4 tight bore barrel in it. The barrel is cut @ 25" AMU contour and is running around 2860 with 44.1g pf H4350. However it is very front heavy, and 17.2lbs with bi-pod. It is not something i'd want to run and gun with. It is however very accurate. I am thinking of cutting it down to 20" or selling it for a lighter barrel.

Based on the info above what do you think I could expect in FPS from a 20" barrel? Is it possible that by cutting it down that I might see a little less FPS loss due to it being a tight bore and slowing the bullet down more than a regular barrel of the same length? ie. the case has burnt all the powder in the first 18-20 inches and then the tight bore starts slow the bullet back down for the next 5"?
 

bh-ltr

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Go 24-26" if being competitive in long range competitions is your goal. You just want to throw lead then cut it short. If you don't believe me look at the line of rifles at a major long range tactical match. Bet 24-26" outnumber shorter barrels 10-1. You are building the rifle with a goal. Make the right choice for the desired goal.
Do you have a preference on 24 or 26? I've been considering it and I'm thinking that I'd much prefer 24 but if 26 is going to be that much better ballistically out to 1K I might just have to stomach it. I've got a while to think about it though before I finally shoot my 308 barrel out.

~Brett
 

Rob01

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I like 26". Gives very good velocities without having to push it super hard. 2" of barrel isn't that much. You want less weight then go with a lighter contoured 26". Best of both worlds.

My Creedmoor was a 28" MTU and I ran it for 3 years at matches and never had any trouble getting it around stage props or vehicles. Weighed in about 18 pounds all scoped and loaded.
 

bh-ltr

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I like 26". Gives very good velocities without having to push it super hard. 2" of barrel isn't that much. You want less weight then go with a lighter contoured 26". Best of both worlds.

My Creedmoor was a 28" MTU and I ran it for 3 years at matches and never had any trouble getting it around stage props or vehicles. Weighed in about 18 pounds all scoped and loaded.

Huh. I'm at about 17 pounds scoped and loaded with my 20" 308 now. its an LTR so I'm assuming that its a Rem Varmint contour and it had wide flutes in it. MTU is WAY heavier than Remington Varmint you must have had a much lighter stock configuration than my AICS and probably a lighter scope than a 5-25 PMII. I'm about at the weight that I'd like to be at. I would trade a bit more weight for better ballistics but I've also heard that you're quite the gorilla when it comes to strength and huffing rifles around. I'm going back and forth on a few things. But I'm thinking medium palma or remington varmint contour barrel from Bartlein at 24 or 26 inches. Then either 260 or 6.5 creed. Biding my time and collecting opinions and facts as I shoot the barrel out on the 308. ;)

~Brett
 
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Rob01

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LOL Gorilla. Maybe a little. ;) Mine is a Manners T3 stock, Badger DBM, Templar action, a S&B 5-25 in Seekins rings and Harris bipod. Must be the stock as those AICSs weigh alot.

A med palma or Rem Varmint would be good choices. Will keep the weight down and still allow you some extra barrel length to take advantage of the 6.5mm rounds no matter which you choose without having to really run them at top end as far as powder charge.

 

LongArm

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I got my barrel back from getting it cut down. Here is what I found. My Obermeyer tight bore 6.5 1/8.4 cut from 25" (running 2880 with 44.1g h4350) to 22" it is now running 2830 with 43.5gr h4350, 2844 with 43.8gr h4350, 2854 w/ 44.1gr h4350, 2861 w/ 44.3gr of h4350. I am going to try 43.2gr of h4350 to see if it groups good and is still over 2800. The 44.1gr group shot one hole 5 round groups and 1.4" @ 300yards. The 43.8gr load shot good but not as good as the 44.1gr which was my previous load. All powder loads were sub MOA. All things considered I wished I would have went shorter.

The bullet is 139 scenars
The brass is Remington
The primers are Federal