Need LR-260 loads

CowboyBart

CowboyBart

Sergeant
Full Member
Minuteman
Jun 14, 2007
483
9
North West WY
#1
I have shot my DPMS LR-260 twice and have not had good results. First set was to break in the barrel and get it on paper (2"-3" groups). Second set was with IMR 4831 and IMR 4350. This time I was shooting 5 shot groups, and they went 3" on most sets. Taking the best 3 shots of the group usually resulted in 1.25" groups with an occasional .75".
Some of the "lack of consistancy" may be me getting used to the trigger and awkward cheek weld. I have to use a hunting bullet (not a Match bullet) as I want to take this after antelope this month. I was using a 139gr PMC bullet that groups .5" from my Encore.
I'm gonna try Remington 140gr and Sierra 120gr GameKing with 4350 and Varget. Are there any powders I should stay away from w/ a semi-auto platform?? The barrel is an 8.5" twist.
Anybody have the same rifle ?? Care to share a load recipe??
 
#4
Re: Need LR-260 loads

44 grains of H4350 behind either a 123SMK or Lapua scenar in Lapua Palma cases delivers consistent 2" groups for 10 shots at 300 yards. Significantly better with less shots in the group, but indicative of excellent, and more importantly, consistent performance. This is for a fully custom AR with a 27" Kriger barrel and a bushed bolt. I actually have loaded it a bit hotter with no better accuracy and lots of marks on the case heads. Note that this load is still relatively hot and can cause popped primers in non bushed bolts (.078" diameter firing pin).
 
#5
Re: Need LR-260 loads

Currently i am running 44.5 gr RL19 with 120gr Hornady A-Max. Currently getting in THE .5-.75 moa range for 3 shots. I also had good luck with H414 and the 120 amax but settled on the RL-19. I did run the 140gr bullest and like(139/142) with great accuracy but could only get it with about a max velocity of 2650 otherwise the groups opened up dramatically. So the 120's at about 2875 worked best for me.
 
#6
Re: Need LR-260 loads

Toolmakr, have you tried 140gr bullets in your Krieger? I assume it's a 1:8 twist?

I have a 26" Krieger (1:8) that I'll be doing load development for next month. Hoping to get 2700-2800fps with 140's out of it without wrecking brass.
 
#7
Re: Need LR-260 loads

I have the same dpms rifle with 1-8.5 twist and 20" barrel. The first problem I encountered with this gun was it wouldn't cycle reloads only factory Remington loads. Changed the buffer spring to a David Tubbs flat wire and it functioned flawless. My current load is 43 grains of Hogdon 4350, with a 140 Amax bullet, CCI primers. I've tried several other powders but this one has always seemed to work best. It's not impossible with this load and a shooter to keep .5 Mao at 100 yards for sure. As I'm still working on my skill level 500 yards is more like a pattern of 5-6" I guess. I'm working on that with practice. 43 gr has it reading in at 2780 on the chrono when I checked last. I've tried to keep the barrel speed nominal to avoid burning the barrell out to fast.
 
#8
Re: Need LR-260 loads

I have never tried them in the semi, but I did briefly try the 142SMKs in my Krieger barreled bolt gun chambered with the same reamer (both are 1:8 twist)wihtout much success though I never really gave it a fair shake. The semi will make close to 3100fps if I go to 44.5 grains of H4350 with the 123's, and considering I have used the load to 1000 plus yards with very good accuracy (10" group for 20 shots at 1000yds in a match), never felt compelled to find a load for the 142's. Even though my bolt and extractor are polished and the ejector and extractor force reduced, the load will leave marks if I go above 44 grains, so I just left it alone to try and maximiize the case longevity.
 
#9
Re: Need LR-260 loads

Hate to say it, but if you can get it done, have a borescope run down the barrel and check everything out.

I had a DPMS 20" .260, couldn't get it to shoot for anything. I drove myself crazy for weeks trying everything that I could think of to get it to shoot at least 1 MOA, finally got smart and took it to my local Smith. He scoped the barrel and showed me where it looked like someone had made it in their back yard garage. Tool marks galore, no chance that barrel would ever shoot for anything.

Good News, I contacted DPMS and they said send it back. Bad News, and Long Story Short, took me about 3 months to get the replacement back.

Went to work with the replacement, running H4350 at around 42 grains with a 139-142 grain bullet, it was really trashing the brass. Big problem with the DPMS rifles is the lack of adjustable gas block. As you try to push the load in terms of bullet weight or velocity, the gas getting put into the system, it runs the action hard, and can trash the brass.

Bottom line for me, I wanted a 140 bullet at 2,700 and it didn't look like that was going to happen without a fair amount of work on the rifle or having to pitch the brass, so I decided to pass on it.

Assuming the barrel checks out:
- Might want to consider adding an adjustable gas block, if you are going to try to shoot the heavier bullets at higher velocities. May also want to look at adding a heavy buffer.
- Per comments above, you might want to try out the lighter bullets, and watch how hard you push the load.

Also per comments above, there is learning curve with an autoloader, so it just may come down to time and practice.

Best of Luck,
M Richardson
 
#11
Re: Need LR-260 loads

I'm looking at changing my DPMS barrel from a 308 to a 260 Remington due to the better BC of the bullets. I am under the assumption that the slowest powders that can be run are in the Varget/RL15 range. This thread has a bunch of H4350 class powder loads. Has anybody had any issues?
 
#12
Re: Need LR-260 loads

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jlamb</div><div class="ubbcode-body">I'm looking at changing my DPMS barrel from a 308 to a 260 Remington due to the better BC of the bullets. I am under the assumption that the slowest powders that can be run are in the Varget/RL15 range. This thread has a bunch of H4350 class powder loads. Has anybody had any issues? </div></div>

Varget/RL15 are a bit fast for 260 loads. There is an extensive thread on 260 loads in the Reloading Depot forum. If you'll look there, you'll see that many people have had good luck with 42-43gr of H4350 with 139-142gr bullets.

I have two gas guns and one bolt rifle in 260R and all three easily shoot under 1moa with that load.
 
#13
Re: Need LR-260 loads

switch to H4350 instead of IMR4350, there is a good chance it will solve your problem as it is the powder for the .260 period.
A good friend of mine has Armalite with a krieger barrel in 6.5 creedmoor and he loads it with H4350 and hornady 140 Amax and it is a tack driver at 1000yds, I run a bolt in .260 and it shoots everything from 120 to 142 SMK like a lazer with H4350.
good luck
 
#14
Re: Need LR-260 loads

Groups improved w/4320. 5 shot groups went 1.25"- 1.5", with the best 3 at .7". Thr trigger on the rifle definently needs work!! It ejected all the brass reliabley but didn't always pick up the next round. I'll go up a half a grain and see if that helps.
I tried 43gr of IMR 4350 and it beat the brass up pretty bad. I don't have any H4350
mad.gif
, just 13 pounds of IMR 4350.
Is H 4350 extruded or ball powder?? I have some Big Game and Hunter that I might try too.

This was so easy with my Encore: cheap 139grPMC bullet, cheap surplus IMR 7383 powder and cheap CCI #34 primer. = .5", 2 dead deer and 4 dead antelope.
 
#15
Re: Need LR-260 loads

The outcome was OK, but it could have been better. It took 2 shots - the first one hit too far to the rear, the 2nd was the neck shot.

Antelope12_zps404717e8.jpg


I am still not happy with the load but it was minute of Pronghorn.
I used 38gr of IMR 4320 and a Rem 120gr PSP. Rangefinder said 268 yds
 
#17
Re: Need LR-260 loads

Beatup brass sounds like excessive port pressure, which could be a symptom of too slow a powder. H-43540 is the E-Ticket propellent for bolt guns, but I suspect it's too slow to provide brass-survivable port pressures.

I went to the 140SMK to provide a shorter projectile (to facilitate better mag feeding). My current .260 is a factory repeater (Savage Predator Hunter). It is slotted to receive my old 28" .260 L-W Stainless Comp barrel.

Maybe IMR-4320 could be a better gas gun propellent. It seems to work well in the Garand. One might also want to take a look at IMR-4064. Varget might be good with the 120's.

Greg
 
#18
108g Scenar
46.5g H4350
Brass Federal
Primer WLRM
COAL 2.842 (.007 off lands)
AVG FPS 3220
G1 BC .465 G7 .231
Platform Savage Predator Hunter 10, 1/8 Twist, 24" Tube
This load is great to 1000, at 100 it shoots .25 MOA all day (5 shot group)
 
#19
Can't speak for an auto 260, but I was hoping my Beanland 260 build with 24" 8.5tw MTU Krieger would love H4350, but it just wasn't so. It shot under moa, but when I started running H4831sc my gun went from a minute gun to a sub .5" gun. The 139's (with my chamber) can't be ran very long, but they shoot bugholes with 45.1g H4831. The 140 Hybrids however I can run them out longer and get 48gr (compressed) into Rem brass, and they are running 2850fps. I still shoot more Scenars than 140 Bergers, due to accuracy. With Lapua brass I can still run 45.1gr and better accuracy.
 
#21
Op had the very same problem,
with a dpms just like yours,
traded off, but found the new owner running the120 gr to 129 gr bullets an shooting great.
wished I had it back now .
my 260 apache built bolt rifle runs outstanding
but now have learned need a gaser to play Woody's match(just did not have hindsight)
 
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