260 Rem 20" barrel

[Trigger puller UK]

I’m having my 260 Rem AIAX re-barrelled from 26” 1-8.5 twist to a 20” 1-8 twist rate. The reason I'm doing this is to reduce the over all weight of the rifle as the type of competition shooting I take part in is practical rifle/service rifle which is multi positional, standing, sitting, knelling, and prone in the UK. The maximum range for this type of competition shooting is 600 yds

The bullets I’m hoping to use is the Lapua 144gr FMJBT, has any one got experience in shooting these bullets, and can any one advise me to what propellant would be best suited for the above combination, I would like to achieve 2650-2700 fps if practically possible.

I would be very grateful for your help in recipes that would work well in this rifle.

Thanks in advance Ady

 

[jbailey]

Re: 260 Rem 20" barrel

Why did you select that bullet? So many good, lighter 6.5mm bullets out there, that will be faster and better wind performers... If you want to use the Lapua brand, why not their 123gr Scenar?

 

[dar1246]

Re: 260 Rem 20" barrel

I would try the 123s first. Out to 600 yards they will preform great and even father. The 144s will have a little higher B.C. but the time of flight will equal the bullet out to being close in data.
If shooting the 144s. You should get around 2700 fps give or take some speed.

 

[turbo54]

Re: 260 Rem 20" barrel

For the ~140gr bullets, look to H4350. Somewhere between 43 and 44gr oughtta do it.

43.6 H4350, a Hornady 140bthp and RP brass goes ~2800fps from mine. It has a 21.5" barrel (recoil lug to crown, 1:8.5 Bartlein)

I hear good things about 123s, but haven't tried them.

 

[Trigger puller UK]

Re: 260 Rem 20" barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JamesBailey</div><div class="ubbcode-body">Why did you select that bullet? So many good, lighter 6.5mm bullets out there, that will be faster and better wind performers... If you want to use the Lapua brand, why not their 123gr Scenar? </div></div>

I selected that bullet because of its high BC, it doesn't have to be Lapua, I've shot mostly 140gr Amax up until now. I have though compared lots of bullets using ballistics program's and the 144gr out performs every thing so far.

 

[bm11]

Re: 260 Rem 20" barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">For the ~140gr bullets, look to H4350. Somewhere between 43 and 44gr oughtta do it.

43.6 H4350, a Hornady 140bthp and RP brass goes ~2800fps from mine. It has a 21.5" barrel (recoil lug to crown, 1:8.5 Bartlein)

I hear good things about 123s, but haven't tried them. </div></div>4350 doesn't produce the velocity that RL-17 does in the shorter barrels, in my experience, but yours seems to show otherwise.

I got 2800 fps easy with RL-17 in my 22" with 140 Hybrids but had a hard time breaking 2700 with h4350.

 

[Pusher591]

Re: 260 Rem 20" barrel

OP, I'm having McCourt load me some 130 VLD's that were pushing right at 2900 fps from a 21" Rock barrel, chambered in 6.5 Creed.

I'm having these bullets pointed by Copper Creek group buy and hope to gain at least 4%-8% in BC which would move the 130 VLD from .551 to .574/.585
I've done a little research and seems 4%-8% is an average gain even though, 9%-12% is advertised. If I gain the later it will just be a pleasant surprise but for now I'm estimating it on the conservative side.

That being the case, if your running a 20" 260 barrel vs. My 21" Creed barrel velocity would be close to the same probably. The numbers are very good for that. Use caution though, the load is warm (at least for my chamber/barrel) but is not excessive. The last chrono session showed an average of 2889.

 

[Cmonroe]

Re: 260 Rem 20" barrel

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bm11</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">For the ~140gr bullets, look to H4350. Somewhere between 43 and 44gr oughtta do it.

43.6 H4350, a Hornady 140bthp and RP brass goes ~2800fps from mine. It has a 21.5" barrel (recoil lug to crown, 1:8.5 Bartlein)

I hear good things about 123s, but haven't tried them. </div></div>4350 doesn't produce the velocity that RL-17 does in the shorter barrels, in my experience, but yours seems to show otherwise.

I got 2800 fps easy with RL-17 in my 22" with 140 Hybrids but had a hard time breaking 2700 with h4350. </div></div>

Yea 4350 is a little slower than RL17 but is much less temp sensitive in my testing. Light and fast bullets are always a toss up at these shorter distances. It is a balancing act between loss of BC and decreased time of flight (exposure). On calmer days you will relish the rewards of your 123's and on windy days you will be kicking your ass for not having the heavys.

 

[jfseaman]

Re: 260 Rem 20" barrel

IMHO

Your velocity goals are achievable.
Your choice on Lapua vs Hornady vs Berger but for your 1/8 twist all should be fine. I like Hornady and didn't like Lapua.
I like H4350 in my 28" 260 so far. The 20" may like RL17.
I believe you will be competitive at your max 600 yds range.

Tell us how it goes.