There was a thread on chopping barrel of 270 cal

[charliehorse]

Wondering if someone could tag me in it or link it up. Taking mine to get threaded and thinking of whacking off a couple of inches while I'm there

[Bill999]

ballistic by the inch is what i refer to

BBTI - Ballistics by the Inch :: Home

you can base most things off that to give you a good idea.

[Cigar]

I think the forum consensus is that you should chop 270 barrels into 2 inch lengths and buy a 308

[MSL]

Short barrel .270’s are just as effective as any other. If you want it short, do it.


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[Bill999]

and if you go even shorter they double as a singeing torch for pigs

[charliehorse]

Chopping it to 21 from 24.

[akaroa1]

@charliehorse I'm just about to do a short 6.8 SPC ( essentially a small case capacity 270 running lighter bullets ) and will have the luxury of starting with the factory Condender 23" barrel
I have a selection of factory ammo and will do the numbers on the stock 23" barrel
Then I have the luxury of being able to shorten in 2" increments at home and shoot on my 100m range out the workshop door and look at the numbers
Repeat until the length and velocity are what I'm aiming for.
The limited investigations I have done suggest that around 18" ( or slightly less ) should meet my needs
I can go as short as 15" and the Contender will still be legal
Being a small, modern efficient case I doubt the drop off in velocity will be very significant in the 2" increments

But it's the real world numbers I will generate from the un cut barrel that will inform the final length decision

Then thread and fit a DPT Mk2 and see if there really is a slight lift in velocity with the suppressor

[mawzer308]

Mate in short NZhunter chopped there's and it performed better than all other conventional calibers you'd think of when building such a rifle, 243, 308, 7mm08 etc. 20 inches is a good compromise but you will still get good ballistics out of even an 18inch barrel. With today's modern projectiles, you still have a genuine 500yd gun. Go for it mate.

[Ryan_Songhurst]

I've had a 19" T3 that I hunted with for a few years and none of the animals shot with it complained, longest shot on game 600yds, 150 LRAB@2850 using 2209
Also built a 16" 270 for shits and giggles, I'd still have it if I hadn't made the mistake of building it on the single worst action I've ever used (Sauer 100) 110 Sierra prohunter @3000 and 130 VLDs @2750 both loads using reloder 17

[dogmatix]

Just remember a 21" 270 will not be shooting anywhere near 3000fps.
Plus the blast will be hard on alloy suppressors. The interior will soon get etched away.
Get a steel internals can, or the DPT can with the steel baffle.

[mawzer308]

Just remember a 21" 270 will not be shooting anywhere near 3000fps.
Plus the blast will be hard on alloy suppressors. The interior will soon get etched away.
Get a steel internals can, or the DPT can with the steel baffle.

Mate respectfully disagree, 3000fps is easily achievable with 130 and even 140gr projectile weights.

[Micky Duck]

Just remember a 21" 270 will not be shooting anywhere near 3000fps.
Plus the blast will be hard on alloy suppressors. The interior will soon get etched away.
Get a steel internals can, or the DPT can with the steel baffle.

also dissagree.....and I dont use a chronicgraph....... MOST loading manuals will have yo uat that speed with 130grns....my old model 70 came from factory at 20"
if you do go short...suppress it or it will be flame thrower and your mates and the dog will desert you.... VERY hard on ears even at 20", shorter will be MUCH MUCH WORSE....

[rimubay]

I'm easily getting 2900fps out of a suppressed 19 inch barrel, 130g Accubonds and a reasonably mild load of 2209 (under ADI book max). I put some Norma factory 130s over the chrono the other day and they were doing 3030fps! NZ Hunter apparently getting 2950fps from an 18 inch barrel with 145g ELDX and Superformance.

[dogmatix]

You are all assuming the OP handloads.
Norma like most Euro ammo is always hot.
Reloading manuals tend to use 24” barrels in ideal shooting conditions for their approximate loads and velocities.

I’ll bet you $20 that most (ie US made) 130gn factory ammo won’t be going over 3000fps in the OPs rifle once it’s chopped.

[mawzer308]

You are all assuming the OP handloads.
Norma like most Euro ammo is always hot.
Reloading manuals tend to use 24” barrels in ideal shooting conditions for their approximate loads and velocities.

I’ll bet you $20 that most (ie US made) 130gn factory ammo won’t be going over 3000fps in the OPs rifle once it’s chopped.

Yeah but you did say 21inches... tbh it doesn't have to be going 3k, 2900, for general work is absolutely fine.