How hard are you pushing your 260

[summitsitter]

I've run the ladder test and came up with my high and low node with H4350 and 140Amaxs. Low node is 40.8grs at 2600fps and high node is 43.4grs at 2950 fps. To me 2600fps is too slow to optimize the BC of the 140s. I think the 43.4grs in right on the edge of being to hot but man it shoots great. 97 degrees today and I blew a primer, although there is not real pressure signs. Ocassional extractor mark on head. I've shot 43.2 and it is a noticable difference. My question is, is anybody else running there's this hard? I have this posted in some other forums to try and get everyones general opinon.

 

[HPMike800]

I've shot a fair bit of 260Rem. In my experience anything around 2850 is high pressure, even in long barrels. Both my barrels were most consistent for 20 shots around 2780-2800. IMHO if you want to go fast with a 260, drop down to 123's

 

[summitsitter]

Well that part of the problem. I don't care about going that fast but 2600 is alot slow to me and the accuracy is to good at 2950. Nothing in between.

Guess I'll try the ladder again for the 3rd time and see if I can find something inbetween 2600 and 2900fps.
As you can see in the target even 43 and 43.2 show increased group size and this isn't just for this target.

 

[summitsitter]

Besides the one blow primer all the other brass I've shot looks fine.

 

[Hondo64d]

You ain't gettin 2950 with 140s from a .260 w/o high pressure... Period.

John

 

[Minesweeper3433]

you can see primer cratering and some of the brass looks like it got a little smooshed around the lettering in the pic you posted

 

[Heavies]

I think that even though your groups are small at the 43.4 charge, you are getting too much vertical. This will be exaggerated at long range. I'd drop the charge down, look for something below 43 grains, mess with seating depth to get the groups you want. 42.2??

 

[2644ever]

Summitsitter, your H4350 load develops in excess of 58,500 psi according to QLoad...
You might be better off with 45.5 grains of H4831 SC at 2850 fps and 52,000 psi OR 43.0 Re 19 at 2830 fps and 53,000 psi.
Anyway, you really should back off a little bit with that H4350 charge. I can't help thinking of that guy:

 

[Rock Knocker]

You need some R19. If that doesnt give you what your looking for try the H4831.

The way that hot load is going your brass is going to make it maybe 3 firings, wont have to worry about anealing though

 

[Jaxdilation]

I have a GAP rifle with Rem action 26" 1/8 barrel and I'm shooting 142gr SMKs

I did pressure testing about 6 weeks ago with virgin Lapua and Fed Primers
I didn't see pressure signs until 43 gr H4350 - that was just a touch over 2800fp

I have heard that 4831 seems to give higher velocity, like RockKocker said.

 

[summitsitter]

Thanks guys. I don't want yall to think I'm one of those guys that likes to push the envelope. I just loaded my ladder up to 43.8 grs. to see where I would start to get pressure signs at just so happened 43.4 shoot great. I loaded up the 10rounds shown and went to do some shooting. I new this was alittle above max, but thought I would try a few and see what happened. I'm going to try some RL17 next as I've heard some good stuff with it. Then on to 4831. Kinda sucks to have a load that shoots great but the load is unshootable...

 

[AusFclass]

are you going to be shooting long range or short range? if you are shooting long range you should try and find a load with low ES/SD (this might be below your 43.4gr load) then with a tuner, seating depth adjustment or fine powder adjustment you can tune your barrel to the node.

i was in a similar boat to you. had excellent results at short range with a load that was too hot. didnt know what to do so backed off in .5gr increments untill i found a load with good ES SD then played .2-.3gr eigther side of that to get the barrel harmonics spot on. i would have been over weight limit with a tuner

short range shooters barrel tune. long range shooters barrel tune AND load tune.

thats my .2 worth

 

[Dug]

To answer the original question, it looks like I'm pushing my 260 as hard as summitsitter. 43.5 of H4350 w/a 142 SMK.
But thats where the simularities end. I get 2850fps instead of 2950 & have a 28" barrel. I've had zero problems with brass loss or primer issues. The pockets are getting loose after 5 reloads but wern't that great when new. The rifle & ammo have been setting in the sun on 90+ degree days & fired many times.
I'm "thinking" about whats different. My Rem brand 260 brass has a larger internal cap than necked up 243 Lapua that I've checked but not used. My OAL is long, 2.940, therefore increasing case cap more.
I have no verticle stringing & the extreme spreads are in the single digits,so really happy with the load. Oh, & another varible, .002" neck tension.

Now, are my ideas valid, or am I too, walking a tight rope?

 

[ttfreestyle]

i am shooting 44.3 H4350 with the 142 smk and cci 200 primers. my ten shot average is 2905 fps. my gun started showing pressure at 44.7 in 95 degree weather but doesnt show any at 44.3. i am using win 7-08 brass sized to 260 rem. from what i have read here seems like i should be getting pressure signs but i dont see any. o well just my experience.

 

[260Remshtr]

I had been shooting 44.0grns of H4350 with a 142SMK with CCI 200 primers and no real pressure signs. I backed the load down to 43.6grns as in a ladder test that showed great grouping 11shots into .25 inch. According to my chronograph I am averaging 2950fps, out of a 30 in. Bartlein barrel. I am using Remington brass and have five to six to eight firings on some pieces. For matches I always start with new brass as that is what I've found to be the most accurate combination for my rifle. The once or twice fired brass I recycle to my father who also shoots a .260rem, or I keep it for "fun days" at the range.

 

[Joeski]

GAP 260 1-8.5 twist 26" Bartlein barrel 142 Sierra Match King I believe it has the 5r rifling too.
I've shot 42.5-44 grs H4350
New Remington Brass
Winchester primers
Seems like I have a Short lead .020 off the lands is less than 2.800 oal
I'v settled on 43grs at about 2850fps

Ladder test at 600 showed no difference in verticle between 43-43.5grs so I'm sticking with the lower charge.

Just my experience
Considering H4831SC for comparison this Eliseo RTS rifle is fairly new with 55 rounds shot on so far.

 

[wnroscoe]

I've had the best results with my 260's with 42 grains of H4350 in Nosler Brass with CCIBR2 Primers and 139 Scenars. When I shot the 130 Bergers I was using the same components but with 43.5 grains of H4350.

Several clients are also using the same load data with 260's I've built.

Velocity is 2,920 fps with the 139's and 2,950+ with the 130 Bergers. So far, the Nosler Brass has been far superior to even the Lapua.