Reloading

[Nickweis]

I have 260 rem on an AR platform and I'm looking for a load with a high BC that will easily punch out to 1000 yrds. And preferably be above 2800 fps. I have been looking in to 130 gr Bergers and the 140 gr SMK. Powder, either H4350 or rl17. Brass I have regular and nickel plated Remington brass. Thoughts and suggestions please.

 

[mac86951]

Need more info. Barrel length will be needed and how you plan to feed in rounds as in single or magazine.

Hodgdon reloading data is free online. Use best loading practices and work up.

 

[Nickweis]

20 inch and magazine fed

 

[Lapua40X]

... Powder, either H4350 or rl17. ...

H4350 will help you avoid temperature sensitivity issues that the RL17 brings to the table.
So I'd use the H4350.
The 130 gr Berger VLD HPBT offers a BC comparable to the SMK 140 gr Spitzer. That would point me toward the SMK. Even if you can't get much over 2900 fps the added weight will buck the wind much better at those long ranges and the difference in terminal velocity shouldn't affect your bullet drop factor by more than .5 MOA at the target.
IMO, a fast moving bullet that gets pushed around by a full value wind by .5 MOA at 1K is far less desireable than a bullet that's only slightly slower but reduces the wind influence factor - which is much more difficult to control than bullet drop over a given distance.

 

[dmoran]

Since your desire is +2800-fps from a 20" barrel, forget the 140 class bullets and plan on 120 to 130's.
Consider trying Berger's "130 gr AR Hybrid OTM Tactical". It's designed for magazine feed. Link:
www.bergerbullets.com/new-65-130gr-ar-hybrid-otm-tactical/


Both your H4350 and RL17 will work. Test both and let your rifle be the judge is my advise.

My 2-Cents
Donovan

 

[Nickweis]

That is the 130 Bergers I was looking into and thank you.

 

[jonbearman]

Is the AR rifle strong enough for hot loads???

 

[mac86951]

Is the AR rifle strong enough for hot loads???

Short answer, yes.

Longer answer; it might take some work on the gas system to tune it for hot loads. There are many ways to do this, and best to work up load tests first to see if you don't have an over gas situation. Case head swipe is what will show as overgassed, or a sloppy firing pin hole allowing primers to flow.

Strong enough? Sure, my AR is chambered in 7mmRSAUM. But I did put the gas port at +2" to help with timing. I would recommend an adjustable gas block, as 308 framed ARs have less heavy buffer/bcg options when compared to an ar15.

Given the constraints on this thread, I would recommend ditching the 2800+ velocity and going with a 130-142gr bullet. Work up loads carefully and find an accuracy node, just about any accuracy node will beat 308 ballistics when both are loaded to magazine length.

Finally, if 2800+ is needed, keep in mind that factory 123gr ammo is going 2850 from a 24" barrel. The 20" would be approx. 100fps slower by my estimation, thus 2800+ from a heavier bullet is really near the upper limits. Again, work up and watch for pressure signs, but typically the gas system shows signs of over gasses or incorrect timing before the hotter loads show 'bolt action' pressure signs.


My experience is with other calibers, in this case 6.5 creedmoor. My rack sale DPMS upper came fully assembled and I mag feed 142 Sierras with 39.8gr H4350. Easy on rifle, easy on brass, and at our local MR F-class I'm happily in the 390s/400 for 600y.

A 6.5x284 it isn't.

-Mac

 

[Nickweis]

So do you think loading the 130's hot enough to get to 2800 fps be to hot for it? And if so would that adjustable gas block work. What is the BC one the 123's I can't imagine it's over .45. What was your velocity with those 142 sierras

 

[barefooter56]

Nick,
It depends on where the rifle is more accurate. Accuracy trumps velocity always. An adjustable gas block would be a good thing to have though. Sierra uses the G1 BC for their bullets so be sure to look at what the BC velocity range is. The G7 BC we use is good at any velocity. We do list the G1 BC for shooters who have a ballistic program that will only recognize the G1. fOR OUR 6.5 130 GR Hybrid ,OTM , Tactical bullet the G1 BC is .560 and the G7 is .263. Minimum twist rate required is 1-10". Optimum twist rate is 1-9".
HTH!

 

[mac86951]

So do you think loading the 130's hot enough to get to 2800 fps be to hot for it? And if so would that adjustable gas block work. What is the BC one the 123's I can't imagine it's over .45. What was your velocity with those 142 sierras

An adjustable gas block will allow you to restrict the gas to the bolt, in theory delaying the moment in time when the bolt tries to extract the case. You can load ARs hot, but brass life will quickly suffer. Truthfully, the location of gas port (ie carbine or rifle length) along with gas port size (in this case adjustable) and powder burn rate all work together. I prefer to close the gas port and work up loads for accuracy first, then open port enough to lock bolt back on last shot from the mag. Not ideal for 3-gun, but great for brass life. Before you buy parts, go work up loads and see what your rifle does. No one here can give you the ultimate load for your rifle, that's up to you. We can help get close.

I'm assuming you are doing precision rifle competition, thus I'd suggest a 123. A 142 will be fine, but mag feeding and deep seating is why 6.5 creedmoor is still around.

Next question for you, what is your intent and goal?

2600-2650fps is my expected velocity, but I havent measured. I'm on brass reload #8, and I like hornady brass, others who push higher pressures have other opinions.

Final suggestion, a peel n stick Velcro pad on the brass deflector.


-Mac

 

[Nickweis]

Who makes a good 123 gr and/or adjustable gas block.

 

[mac86951]

Who makes a good 123 gr and/or adjustable gas block.

Sierra, hornady, berger, lapua, look all around that range.

Gas block: wait and find your accuracy node first. Jp, PRI, uhhh, others I forget at the moment..

-Mac

 

[Nickweis]

Ok thank you I've got some more research to do now

 

[Brians356]

I'm curious, what's the significance of 2800 fps for your application? It seems like an arbitrary number without more context.

 

[22BRGUY]

Nickel is a harder metal than just brass. I USED TO many years ago use nickel plated brass in my 22 250 but was advised they "could" scratch" the chamber. I threw them away from that point and haven't used any since. Other opinions welcome.
Best Wishes

 

[ebb]

Read the paragraph at JP rifles about reloading for the 260, it may help. I am at the exact same point with almost the exact same rifle. I started back when bullets were hard to find and used Nosler 123 custom competition and IMR 4350. With this load the gun is less than 1 moa but I am still looking.